Open Source Ecology - User contributions [en]

HydraFabber

2013-06-08T23:52:10Z

Leo.dearden: /* Quick Route to Functional Prototype */

Note: document all progress here, and start [[Leo Log]]. See [[Marcin Log]] as an example.

HydraFabber - after [[HydraRaptor]] - is a portable, multi-headed CNC fabrication machine that can do 3D printing, circuit milling, and laser cutting. It is intended to be a portable machine that can be brought to [[OSE Design Sprint]]s for prototyping. During the sprints, we design machines in Sketchup, and then prototype them by printing out modular parts with a 3D printer and laser cutter. The laser cutter cuts out flat sheets that are folded to make 3D beams and other parts, and these beams form 3D frames and other 3D parts. Then the circuit mill functionality can be used to prototype circuit boards, such as controllers for automated machines.

=Specifications=

==Functional Spec==

* 200x200x120mm mininimum build volume
* Quick change heads with accurate repeatable alignment
* Complete system includes robust carry case
* At most 10 minutes for a competent user to set up or prepare for travel

* Printer
** One material at a time
** heated bed to at least 140C
** reliable extruder
** hot end to at least 245C
** Glass print surface for flatness
*** Optional tape over glass for ABS adhesion
** Fan to cool print
** at least 60mm/s practical print speed (more is better)

* Laser
** 1.5W laser cutter diode

* Circuit mill
** depth of cut control relative to surface of PCB
** easy tool change
** effective quick change PCB holddown

* Folds up into a portable suitcase so it can be brought to design sprints and other events

===Functional Spec Questions===
'''General Comment: study of open source industry standards is our best bet. It appears the 3D printer part is all go. Shapeoko has sold 1500 of their routers - so let's assume they work well enough. Search for laser diode paper cutters on the web. Combine RepRap, Shapeoko - and come up with a design. I could foresee that the Router Module is just 2 reinforcement plates for the sides of the machine to provide rigidity. Perhaps use Shapeoko as base, add a 3D printer head or laser diode head to convert to the other 2 functions? Then we have structure all worked out. Does Shapeoko appear to get us the right accuracy?'''

* Is 1.5w optimum? '''See discussion at [[SLS_Wax_Printer]]. Requirement is anything that cuts paper.'''
* What wavelength? '''That which cuts paper, may have to work with black paper'''
* What laser radiation safety measures (1.5w is plenty to blind)? '''Good question. Let's research industry standards'''
* Fixed laser + moving optics or moving laser? '''Replacement for extruder head on the triple machine'''
* What feed rates would be ideal? '''Need to look at specs of laser diode or other projects'''
* How accurate do we need to be for circuit milling?'''Same performance as Shapeoko'''
* What is our target track pitch? '''What is this'''
** Are we aiming for through hole or SMT? If SMT, then how small (just SOICs or QFNs and BGAs)? '''Same as Shapeoko'''
* Is a dremmel type spindle good enough? '''Appears so'''
** Noise? '''What kind of noise?'''
** Speed (RPM)? '''That of dremel tool'''
** Accuracy (TIR)?
** Mass - is it too heavy?
** Size - is it too big? '''No.'''
* Are there any reasonable off the shelf alternatives to the dremmel? '''Don't know. First prototype with dremel appears sound. Based on Shapeoko.'''
* How hard/expensive would it be to make a good small open source spindle? '''I wouldn't worry about it in the first iteration.'''
* What feed rates would be ideal? '''See Shapeoko'''
* What cutting forces are we going to get? '''I would say 2 lbs of force'''
* How do we hold down the PCB? '''Paper Clamps in first version?'''
* Will the dust from the PCB milling interfere with the 3D printing? '''We will have to get data on that.'''

=Process=

== Quick Route to Functional Prototype ==

Almost any RepRap will fulfil the printer part of the functional spec. The need for quick-change heads without recalibration requires a new head mount that will position the head very repeatably each time it's mounted. A kinematic mount is under development for this purpose.

https://github.com/leodearden/kinematic-mount

[[File:2013-06-09-kinematic-mount-scad-03.jpeg]]
[[File:2013-06-09-kinematic-mount-scad-04.jpeg]]
[[File:2013-06-09-kinematic-mount-scad-05.jpeg]]

The more rigid RepRap the better. A Mendel90, MendelMax, ORD Bot, or TAZ would be particularly suitable.

== Complete design process ==

Start with Window 7, presentation page 2 - concept design.

#Do [[Systems Engineering Breakdown Diagram]]

* Software
** CAD
** CAM/slicing
** Device control
** firmware
* Control Electronics
** Embedded microcontroller
** I/O
*** motor drivers
*** high current digital drivers (fans, heaters, etc)
*** digital inputs (eg: limit switches)
*** analog inputs (eg: thermistors)
* 3 axis positioning robot
** X
** Y
** Z
** Quick change head mount
*** mechanical
*** electrical/electronic
**** ID for head available to controller
** Quick change bed (reversible?)
** fold down mechanism
* heads
** print
** laser
** mill
* beds
** print
** laser
** mill

Diagram to follow.

#Potentially do an interface design that shows how modules fit together
#Then embed the original i3 RepRap STL via an [[STL Viewer]] in the wiki

=Printer Reliability=
*Leo's RepRap Kit had at best 4/5 print success on 8 hour overnight prints. Drift in mechanical calibration, failure of print adhesion, nozzle blockage, filament feed slip, and filament spool tangles are the main cause of failures in long prints.
*For short prints, once print parameters are established for a particular object for a particular printer with a particular material. Once you are dialed in, ~1% failure rate for prints of 1 hour. This is for unambitious - ie, safe zone - prints. Wall thickness safe, fairly thick layers, not too fast, etc.

=Links=
*[[Leo Dearden]]
*Opencreators Korean printer - [http://cafe.naver.com/makerfac]
*[[Suitcase 3D Printer]]
*[[Lulzbot]]
*[[RepRap Kit]]
*[RepRap Prusa i3|http://reprap.org/wiki/Prusa_i3]

File:2013-06-09-kinematic-mount-scad-05.jpeg

2013-06-08T23:51:38Z

Leo.dearden:

File:2013-06-09-kinematic-mount-scad-04.jpeg

2013-06-08T23:51:25Z

Leo.dearden:

File:2013-06-09-kinematic-mount-scad-03.jpeg

2013-06-08T23:50:16Z

Leo.dearden:

HydraFabber

2013-06-08T23:48:42Z

Leo.dearden: /* Process */

Note: document all progress here, and start [[Leo Log]]. See [[Marcin Log]] as an example.

HydraFabber - after [[HydraRaptor]] - is a portable, multi-headed CNC fabrication machine that can do 3D printing, circuit milling, and laser cutting. It is intended to be a portable machine that can be brought to [[OSE Design Sprint]]s for prototyping. During the sprints, we design machines in Sketchup, and then prototype them by printing out modular parts with a 3D printer and laser cutter. The laser cutter cuts out flat sheets that are folded to make 3D beams and other parts, and these beams form 3D frames and other 3D parts. Then the circuit mill functionality can be used to prototype circuit boards, such as controllers for automated machines.

=Specifications=

==Functional Spec==

* 200x200x120mm mininimum build volume
* Quick change heads with accurate repeatable alignment
* Complete system includes robust carry case
* At most 10 minutes for a competent user to set up or prepare for travel

* Printer
** One material at a time
** heated bed to at least 140C
** reliable extruder
** hot end to at least 245C
** Glass print surface for flatness
*** Optional tape over glass for ABS adhesion
** Fan to cool print
** at least 60mm/s practical print speed (more is better)

* Laser
** 1.5W laser cutter diode

* Circuit mill
** depth of cut control relative to surface of PCB
** easy tool change
** effective quick change PCB holddown

* Folds up into a portable suitcase so it can be brought to design sprints and other events

===Functional Spec Questions===
'''General Comment: study of open source industry standards is our best bet. It appears the 3D printer part is all go. Shapeoko has sold 1500 of their routers - so let's assume they work well enough. Search for laser diode paper cutters on the web. Combine RepRap, Shapeoko - and come up with a design. I could foresee that the Router Module is just 2 reinforcement plates for the sides of the machine to provide rigidity. Perhaps use Shapeoko as base, add a 3D printer head or laser diode head to convert to the other 2 functions? Then we have structure all worked out. Does Shapeoko appear to get us the right accuracy?'''

* Is 1.5w optimum? '''See discussion at [[SLS_Wax_Printer]]. Requirement is anything that cuts paper.'''
* What wavelength? '''That which cuts paper, may have to work with black paper'''
* What laser radiation safety measures (1.5w is plenty to blind)? '''Good question. Let's research industry standards'''
* Fixed laser + moving optics or moving laser? '''Replacement for extruder head on the triple machine'''
* What feed rates would be ideal? '''Need to look at specs of laser diode or other projects'''
* How accurate do we need to be for circuit milling?'''Same performance as Shapeoko'''
* What is our target track pitch? '''What is this'''
** Are we aiming for through hole or SMT? If SMT, then how small (just SOICs or QFNs and BGAs)? '''Same as Shapeoko'''
* Is a dremmel type spindle good enough? '''Appears so'''
** Noise? '''What kind of noise?'''
** Speed (RPM)? '''That of dremel tool'''
** Accuracy (TIR)?
** Mass - is it too heavy?
** Size - is it too big? '''No.'''
* Are there any reasonable off the shelf alternatives to the dremmel? '''Don't know. First prototype with dremel appears sound. Based on Shapeoko.'''
* How hard/expensive would it be to make a good small open source spindle? '''I wouldn't worry about it in the first iteration.'''
* What feed rates would be ideal? '''See Shapeoko'''
* What cutting forces are we going to get? '''I would say 2 lbs of force'''
* How do we hold down the PCB? '''Paper Clamps in first version?'''
* Will the dust from the PCB milling interfere with the 3D printing? '''We will have to get data on that.'''

=Process=

== Quick Route to Functional Prototype ==

Almost any RepRap will fulfil the printer part of the functional spec. The need for quick-change heads without recalibration requires a new head mount that will position the head very repeatably each time it's mounted. A kinematic mount is under development for this purpose.

https://github.com/leodearden/kinematic-mount

The more rigid RepRap the better. A Mendel90, MendelMax, ORD Bot, or TAZ would be particularly suitable.

== Complete design process ==

Start with Window 7, presentation page 2 - concept design.

#Do [[Systems Engineering Breakdown Diagram]]

* Software
** CAD
** CAM/slicing
** Device control
** firmware
* Control Electronics
** Embedded microcontroller
** I/O
*** motor drivers
*** high current digital drivers (fans, heaters, etc)
*** digital inputs (eg: limit switches)
*** analog inputs (eg: thermistors)
* 3 axis positioning robot
** X
** Y
** Z
** Quick change head mount
*** mechanical
*** electrical/electronic
**** ID for head available to controller
** Quick change bed (reversible?)
** fold down mechanism
* heads
** print
** laser
** mill
* beds
** print
** laser
** mill

Diagram to follow.

#Potentially do an interface design that shows how modules fit together
#Then embed the original i3 RepRap STL via an [[STL Viewer]] in the wiki

=Printer Reliability=
*Leo's RepRap Kit had at best 4/5 print success on 8 hour overnight prints. Drift in mechanical calibration, failure of print adhesion, nozzle blockage, filament feed slip, and filament spool tangles are the main cause of failures in long prints.
*For short prints, once print parameters are established for a particular object for a particular printer with a particular material. Once you are dialed in, ~1% failure rate for prints of 1 hour. This is for unambitious - ie, safe zone - prints. Wall thickness safe, fairly thick layers, not too fast, etc.

=Links=
*[[Leo Dearden]]
*Opencreators Korean printer - [http://cafe.naver.com/makerfac]
*[[Suitcase 3D Printer]]
*[[Lulzbot]]
*[[RepRap Kit]]
*[RepRap Prusa i3|http://reprap.org/wiki/Prusa_i3]

HydraFabber

2013-05-11T22:36:23Z

Leo.dearden: /* Process */

HydraFabber

2013-05-11T22:27:48Z

Leo.dearden: /* Links */

HydraFabber

2013-05-11T22:26:26Z

Leo.dearden:

HydraFabber

2013-05-11T18:50:49Z

Leo.dearden: /* Notes */

HydraFabber

2013-05-11T18:50:21Z

Leo.dearden: /* Notes */

HydraFabber

2013-05-11T18:47:07Z

Leo.dearden: /* Links */

Quick Connect Wheels

2011-12-09T11:47:16Z

Leo.dearden: /* What is the impact of reducing bearing loads on lifetime of bearings? */

=Introduction=

LifeTrac wheel couplers suffered catastrophic failure when used with tracks.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//i4GjoFQ3zsg" frameborder="0" allowfullscreen></iframe></html>

.

The key on the motor shaft sheared. We put on thicker couplers, and LifeTrac currently works - but we will not take it through destructive testing prior to testing splined motors. NOTE: Discussion at [[31.88 Cubic Inch Motors]] shows hints that pressure setting was too high, and could have been the reason for failure.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//BKoBcslT_Vo" frameborder="0" allowfullscreen></iframe>
</html>

.

It is suspected that the 4-wheel drive, when coupled by wheel tracks, makes the motors fight each other.

=What we want=

[[Requirements for LifeTrac Wheel Motors and Couplings]]

=Possible solution: Removing Tracks, Adding Quick Connect Wheels=

To remedy the failing coupler, we will remove the tracks as the first step, and run the motors in series to simplify control valve requirements. That means that a 3000 PSI pump can deliver a max of 1500 PSI to each motor. This puts a low limit on the pressure, while delivering 6525 in lb for each motor - which makes this still higher torque than the 5000 cu in former [[31.88 cu in motors]] used on LifeTrac I-III.

The rough concept of a quick connect wheel is this:

[[Image:quickconnectwheel.jpg|400px]]

==Implementation==

To design the quick connect wheel, complete [[LifeTrac Frame]] geometry must be considered.

See pictures of wheeel:

<gallery>
Image:ltframe1.jpg
Image:ltframe2.jpg
Image:ltframe3.jpg
Image:ltframe4.jpg
</gallery>

and the real object:

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//hICQOCHkDsk" frameborder="0" allowfullscreen></iframe></html>

.

==Concept Quick Release Wheel==

Design Rationale:
*Triple mechanism of holding using peg, a cam lock, and a bolt:

Download [[File:wheelmount.dxf]]

See it:

[[Image:wheelmount.jpg|400]]

Model:

[[Image:wheelmodel1.jpg]]

Download pngs of above and STEP file - [[File:wheelmodel.zip]]

Relation to frame:

[[Image:wheelmodel2.jpg]]

Download the relation to frame, STEP and X_T files - [[File:wheelmodel2.zip]]

==Reducing loads on the shafts and bearings==

In order to reduce the bending load of the shaft the following design could be implemented:

[[Image:Wheelmodel_3.png]]

The idea is moving the main bearing as close to the wheel center as possible. This will reduce the bending moment on the shaft close to zero and reduce the loads on the bearings. The roller element bearing close to the motor could actually be replaced now by a much smaller one.

In this design the 4"x4" transverse tube takes over the whole bending moment for transferring the forces from the wheel to the frame. There are different possibilities for anchoring this tube to the frame. One should only keep in mind that the loads will push the external frame tube upwards and pull the internal one downwards.

You can download the CAD model of this first rough design in the following file

Download FreeCAD model: [[File:Wheelmodel_3.FCStd]]

===Discussion===
====What is the critical clamp-down/disconnect mechanism?====
====What is the impact of reducing bearing loads on lifetime of bearings?====

Lifetime is very load sensitive (more than cube of load):

*Doubling load reduces life to one tenth. Reducing load by one half increases life by ten,
*Doubling speed reduces life by one half. Reducing speed by one half doubles life.

See [http://www.google.co.uk/url?sa=t&rct=j&q=bearing%20lifetime%20calculation&source=web&cd=2&ved=0CCYQFjAB&url=http%3A%2F%2Fwww.machinediagnostics.com%2Fpdf%2FBearings%2C%2520Gears%2520and%2520Lubrication%2FCalculate%2520Bearing%2520Life%2520(Timken).pdf&ei=9PLhTp3SCcTFtAbxo82RBA&usg=AFQjCNFyQjCQSBaG_XQ_T66lTmoVqWMmdg&sig2=O5puzfjyDgrVAp2SRQkExQ].

====Are there similar industry standard designs?====

=Solution Pathways for Addressing Failing Motor Couplers=
==Solution Pathway 1==

Concept:
*Use a motor with more torque
*Direct coupling to wheel eliminates bearings, shafts, and collars
*Retain tracks
*Use one motor per side to eliminate motors 'fighting each other'

Possible solution: [[15,000 Inch Pound Motor]]
[[Image:15kmotor.jpg|400px]]

=Solution Pathway 2=
*Use 2 motors per side, and same drive train as in [[LifeTrac Wheel Assembly Video]], but with splined shaft motors
*Do motors 'fight each other' in this case?
*The new splined motors are [https://www.surpluscenter.com/item.asp?item=9-9327&catname=hydraulic these from Surpluscenter]:

[[Image:splinedmotors.jpg|thumb|Splined shaft wheel motors from Surpluscenter]]

[[Image:3188.jpg|thumb|31.88 cubic inch wheel motors from Surpluscenter]]

=Pathway 3=
*Reduce pressure on hydraulic motors?
*1160 PSI only is max on [[31.88 Cubic Inch Motors]]. Is this sufficient to drive the tractor?

=Peer Review=

This page should be peer reviewed by hydraulics specialists, such as at hydraulics forums.
[[Category:LifeTrac Field Testing]]

Quick Connect Wheels

2011-12-09T11:46:38Z

Leo.dearden: /* What is the impact of reducing bearing loads on lifetime of bearings? */

=Introduction=

LifeTrac wheel couplers suffered catastrophic failure when used with tracks.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//i4GjoFQ3zsg" frameborder="0" allowfullscreen></iframe></html>

.

The key on the motor shaft sheared. We put on thicker couplers, and LifeTrac currently works - but we will not take it through destructive testing prior to testing splined motors. NOTE: Discussion at [[31.88 Cubic Inch Motors]] shows hints that pressure setting was too high, and could have been the reason for failure.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//BKoBcslT_Vo" frameborder="0" allowfullscreen></iframe>
</html>

.

It is suspected that the 4-wheel drive, when coupled by wheel tracks, makes the motors fight each other.

=What we want=

[[Requirements for LifeTrac Wheel Motors and Couplings]]

=Possible solution: Removing Tracks, Adding Quick Connect Wheels=

To remedy the failing coupler, we will remove the tracks as the first step, and run the motors in series to simplify control valve requirements. That means that a 3000 PSI pump can deliver a max of 1500 PSI to each motor. This puts a low limit on the pressure, while delivering 6525 in lb for each motor - which makes this still higher torque than the 5000 cu in former [[31.88 cu in motors]] used on LifeTrac I-III.

The rough concept of a quick connect wheel is this:

[[Image:quickconnectwheel.jpg|400px]]

==Implementation==

To design the quick connect wheel, complete [[LifeTrac Frame]] geometry must be considered.

See pictures of wheeel:

<gallery>
Image:ltframe1.jpg
Image:ltframe2.jpg
Image:ltframe3.jpg
Image:ltframe4.jpg
</gallery>

and the real object:

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//hICQOCHkDsk" frameborder="0" allowfullscreen></iframe></html>

.

==Concept Quick Release Wheel==

Design Rationale:
*Triple mechanism of holding using peg, a cam lock, and a bolt:

Download [[File:wheelmount.dxf]]

See it:

[[Image:wheelmount.jpg|400]]

Model:

[[Image:wheelmodel1.jpg]]

Download pngs of above and STEP file - [[File:wheelmodel.zip]]

Relation to frame:

[[Image:wheelmodel2.jpg]]

Download the relation to frame, STEP and X_T files - [[File:wheelmodel2.zip]]

==Reducing loads on the shafts and bearings==

In order to reduce the bending load of the shaft the following design could be implemented:

[[Image:Wheelmodel_3.png]]

The idea is moving the main bearing as close to the wheel center as possible. This will reduce the bending moment on the shaft close to zero and reduce the loads on the bearings. The roller element bearing close to the motor could actually be replaced now by a much smaller one.

In this design the 4"x4" transverse tube takes over the whole bending moment for transferring the forces from the wheel to the frame. There are different possibilities for anchoring this tube to the frame. One should only keep in mind that the loads will push the external frame tube upwards and pull the internal one downwards.

You can download the CAD model of this first rough design in the following file

Download FreeCAD model: [[File:Wheelmodel_3.FCStd]]

===Discussion===
====What is the critical clamp-down/disconnect mechanism?====
====What is the impact of reducing bearing loads on lifetime of bearings?====

Lifetime is very load sensitive (more than cube of load):

*Doubling load reduces life to one tenth. Reducing load by one half increases life by ten,
*Doubling speed reduces life by one half. Reducing speed by one half doubles life.

See [[bearing life white paper|http://www.google.co.uk/url?sa=t&rct=j&q=bearing%20lifetime%20calculation&source=web&cd=2&ved=0CCYQFjAB&url=http%3A%2F%2Fwww.machinediagnostics.com%2Fpdf%2FBearings%2C%2520Gears%2520and%2520Lubrication%2FCalculate%2520Bearing%2520Life%2520(Timken).pdf&ei=9PLhTp3SCcTFtAbxo82RBA&usg=AFQjCNFyQjCQSBaG_XQ_T66lTmoVqWMmdg&sig2=O5puzfjyDgrVAp2SRQkExQ]].

====Are there similar industry standard designs?====

=Solution Pathways for Addressing Failing Motor Couplers=
==Solution Pathway 1==

Concept:
*Use a motor with more torque
*Direct coupling to wheel eliminates bearings, shafts, and collars
*Retain tracks
*Use one motor per side to eliminate motors 'fighting each other'

Possible solution: [[15,000 Inch Pound Motor]]
[[Image:15kmotor.jpg|400px]]

=Solution Pathway 2=
*Use 2 motors per side, and same drive train as in [[LifeTrac Wheel Assembly Video]], but with splined shaft motors
*Do motors 'fight each other' in this case?
*The new splined motors are [https://www.surpluscenter.com/item.asp?item=9-9327&catname=hydraulic these from Surpluscenter]:

[[Image:splinedmotors.jpg|thumb|Splined shaft wheel motors from Surpluscenter]]

[[Image:3188.jpg|thumb|31.88 cubic inch wheel motors from Surpluscenter]]

=Pathway 3=
*Reduce pressure on hydraulic motors?
*1160 PSI only is max on [[31.88 Cubic Inch Motors]]. Is this sufficient to drive the tractor?

=Peer Review=

This page should be peer reviewed by hydraulics specialists, such as at hydraulics forums.
[[Category:LifeTrac Field Testing]]

Quick Connect Wheels

2011-12-09T11:46:09Z

Leo.dearden: /* Discussion */

=Introduction=

LifeTrac wheel couplers suffered catastrophic failure when used with tracks.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//i4GjoFQ3zsg" frameborder="0" allowfullscreen></iframe></html>

.

The key on the motor shaft sheared. We put on thicker couplers, and LifeTrac currently works - but we will not take it through destructive testing prior to testing splined motors. NOTE: Discussion at [[31.88 Cubic Inch Motors]] shows hints that pressure setting was too high, and could have been the reason for failure.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//BKoBcslT_Vo" frameborder="0" allowfullscreen></iframe>
</html>

.

It is suspected that the 4-wheel drive, when coupled by wheel tracks, makes the motors fight each other.

=What we want=

[[Requirements for LifeTrac Wheel Motors and Couplings]]

=Possible solution: Removing Tracks, Adding Quick Connect Wheels=

To remedy the failing coupler, we will remove the tracks as the first step, and run the motors in series to simplify control valve requirements. That means that a 3000 PSI pump can deliver a max of 1500 PSI to each motor. This puts a low limit on the pressure, while delivering 6525 in lb for each motor - which makes this still higher torque than the 5000 cu in former [[31.88 cu in motors]] used on LifeTrac I-III.

The rough concept of a quick connect wheel is this:

[[Image:quickconnectwheel.jpg|400px]]

==Implementation==

To design the quick connect wheel, complete [[LifeTrac Frame]] geometry must be considered.

See pictures of wheeel:

<gallery>
Image:ltframe1.jpg
Image:ltframe2.jpg
Image:ltframe3.jpg
Image:ltframe4.jpg
</gallery>

and the real object:

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//hICQOCHkDsk" frameborder="0" allowfullscreen></iframe></html>

.

==Concept Quick Release Wheel==

Design Rationale:
*Triple mechanism of holding using peg, a cam lock, and a bolt:

Download [[File:wheelmount.dxf]]

See it:

[[Image:wheelmount.jpg|400]]

Model:

[[Image:wheelmodel1.jpg]]

Download pngs of above and STEP file - [[File:wheelmodel.zip]]

Relation to frame:

[[Image:wheelmodel2.jpg]]

Download the relation to frame, STEP and X_T files - [[File:wheelmodel2.zip]]

==Reducing loads on the shafts and bearings==

In order to reduce the bending load of the shaft the following design could be implemented:

[[Image:Wheelmodel_3.png]]

The idea is moving the main bearing as close to the wheel center as possible. This will reduce the bending moment on the shaft close to zero and reduce the loads on the bearings. The roller element bearing close to the motor could actually be replaced now by a much smaller one.

In this design the 4"x4" transverse tube takes over the whole bending moment for transferring the forces from the wheel to the frame. There are different possibilities for anchoring this tube to the frame. One should only keep in mind that the loads will push the external frame tube upwards and pull the internal one downwards.

You can download the CAD model of this first rough design in the following file

Download FreeCAD model: [[File:Wheelmodel_3.FCStd]]

===Discussion===
====What is the critical clamp-down/disconnect mechanism?====
====What is the impact of reducing bearing loads on lifetime of bearings?====

Lifetime is very load sensitive (more than cube of load):

*Doubling load reduces life to one tenth. Reducing load by one half increases life by ten,
*Doubling speed reduces life by one half. Reducing speed by one half doubles life.

See [bearing life white paper|http://www.google.co.uk/url?sa=t&rct=j&q=bearing%20lifetime%20calculation&source=web&cd=2&ved=0CCYQFjAB&url=http%3A%2F%2Fwww.machinediagnostics.com%2Fpdf%2FBearings%2C%2520Gears%2520and%2520Lubrication%2FCalculate%2520Bearing%2520Life%2520(Timken).pdf&ei=9PLhTp3SCcTFtAbxo82RBA&usg=AFQjCNFyQjCQSBaG_XQ_T66lTmoVqWMmdg&sig2=O5puzfjyDgrVAp2SRQkExQ].

====Are there similar industry standard designs?====

=Solution Pathways for Addressing Failing Motor Couplers=
==Solution Pathway 1==

Concept:
*Use a motor with more torque
*Direct coupling to wheel eliminates bearings, shafts, and collars
*Retain tracks
*Use one motor per side to eliminate motors 'fighting each other'

Possible solution: [[15,000 Inch Pound Motor]]
[[Image:15kmotor.jpg|400px]]

=Solution Pathway 2=
*Use 2 motors per side, and same drive train as in [[LifeTrac Wheel Assembly Video]], but with splined shaft motors
*Do motors 'fight each other' in this case?
*The new splined motors are [https://www.surpluscenter.com/item.asp?item=9-9327&catname=hydraulic these from Surpluscenter]:

[[Image:splinedmotors.jpg|thumb|Splined shaft wheel motors from Surpluscenter]]

[[Image:3188.jpg|thumb|31.88 cubic inch wheel motors from Surpluscenter]]

=Pathway 3=
*Reduce pressure on hydraulic motors?
*1160 PSI only is max on [[31.88 Cubic Inch Motors]]. Is this sufficient to drive the tractor?

=Peer Review=

This page should be peer reviewed by hydraulics specialists, such as at hydraulics forums.
[[Category:LifeTrac Field Testing]]

Requirements for LifeTrac Wheel Motors and Couplings

2011-12-09T11:27:40Z

Leo.dearden:

Status: provisional/incomplete. See discussion for required actions.

Please maintain the distinction between requirements - things to achieve - which should be on this page, and designs or design specs - things to have or ways to achieve or do things - which should be elsewhere. Link them in if relevant.

==Notes for Designers==

Please model your design as fully as is feasible. The best design will have the best evidence that it meets all the requirements and has the best trade-offs in all areas.

Please share any solution models (eg: FEAs) you use including original files and summary reports in standard formats.

Please share general modelling of the problem domain - loads, statistical models, etc, so that the entire community can refine its understanding of the problem.

If you think any part of the spec is unreasonable, unclear, or missing or incomplete, please tell us. Help us to refine it.

If you can't model, or can't meet any part of the spec, please say so, and please share your designs anyway. Anything is better than nothing, and other people may be able to build on your work.

==Functional Requirements==

===Drive===

At least two wheels must be driven by hydraulic motors. At least four wheels must be mounted. All wheel drive is highly desirable. Suggested motor for AWD is XXXX(link).

===Construction/Fabrication===

The mount - motor - coupler assembly must be fabricated simply, using only a minimum of special purpose components. In addition to the hydraulic motors, bearings, standard fasteners (nuts, bolts, etc), XXXX, sheet plate tube and bar steel are allowable. Cutting (Flame, Plasma, abrasive), drilling, punching, XXXX, and welding (Oxy Torch) are allowable.

Other components and processes will be considered, but are discouraged.

Bolt together assembly should be used where possible to facilitate repair and component upgrade or reuse.

===Quick change mounts===

Bolt or other temporary fixing must be used for attachment to the LifeTrac frame.

Quick change mounting between the motor-coupler assembly and the frame is highly desirable, to reduce MTTR and allow easy modular repairs with few tools.

==Quantitative/Non-Functional==

===Solution must be robust===

All aspects of the LifeTrac must be long lasting and reliable under intended, and reasonably anticipated but unintended, uses.

====Typical Load====

Torque: Motors will often be operated at maximum rated torque. Design for a duty cycle of 50%, with one reversal every 3s.

Weight supported by the four wheels will be XXXXkg total, including LifeTrac, X powercubes (at the back), and XXXXkg on the loader.

Vibration: When driven on rough ground, additional cyclic loads of 0.8G @ 15Hz will be applied.

====Impact Load====

Should survive driving over a sharp a drop of 15

Quick Connect Wheels

2011-12-09T11:25:31Z

Leo.dearden: /* What we want */

=Introduction=

LifeTrac wheel couplers suffered catastrophic failure when used with tracks.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//i4GjoFQ3zsg" frameborder="0" allowfullscreen></iframe></html>

.

The key on the motor shaft sheared. We put on thicker couplers, and LifeTrac currently works - but we will not take it through destructive testing prior to testing splined motors. NOTE: Discussion at [[31.88 Cubic Inch Motors]] shows hints that pressure setting was too high, and could have been the reason for failure.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//BKoBcslT_Vo" frameborder="0" allowfullscreen></iframe>
</html>

.

It is suspected that the 4-wheel drive, when coupled by wheel tracks, makes the motors fight each other.

=What we want=

[[Requirements for LifeTrac Wheel Motors and Couplings]]

=Possible solution: Removing Tracks, Adding Quick Connect Wheels=

To remedy the failing coupler, we will remove the tracks as the first step, and run the motors in series to simplify control valve requirements. That means that a 3000 PSI pump can deliver a max of 1500 PSI to each motor. This puts a low limit on the pressure, while delivering 6525 in lb for each motor - which makes this still higher torque than the 5000 cu in former [[31.88 cu in motors]] used on LifeTrac I-III.

The rough concept of a quick connect wheel is this:

[[Image:quickconnectwheel.jpg|400px]]

==Implementation==

To design the quick connect wheel, complete [[LifeTrac Frame]] geometry must be considered.

See pictures of wheeel:

<gallery>
Image:ltframe1.jpg
Image:ltframe2.jpg
Image:ltframe3.jpg
Image:ltframe4.jpg
</gallery>

and the real object:

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//hICQOCHkDsk" frameborder="0" allowfullscreen></iframe></html>

.

==Concept Quick Release Wheel==

Design Rationale:
*Triple mechanism of holding using peg, a cam lock, and a bolt:

Download [[File:wheelmount.dxf]]

See it:

[[Image:wheelmount.jpg|400]]

Model:

[[Image:wheelmodel1.jpg]]

Download pngs of above and STEP file - [[File:wheelmodel.zip]]

Relation to frame:

[[Image:wheelmodel2.jpg]]

Download the relation to frame, STEP and X_T files - [[File:wheelmodel2.zip]]

==Reducing loads on the shafts and bearings==

In order to reduce the bending load of the shaft the following design could be implemented:

[[Image:Wheelmodel_3.png]]

The idea is moving the main bearing as close to the wheel center as possible. This will reduce the bending moment on the shaft close to zero and reduce the loads on the bearings. The roller element bearing close to the motor could actually be replaced now by a much smaller one.

In this design the 4"x4" transverse tube takes over the whole bending moment for transferring the forces from the wheel to the frame. There are different possibilities for anchoring this tube to the frame. One should only keep in mind that the loads will push the external frame tube upwards and pull the internal one downwards.

You can download the CAD model of this first rough design in the following file

Download FreeCAD model: [[File:Wheelmodel_3.FCStd]]

===Discussion===
*What is the critical clamp-down/disconnect mechanism?
*What is the impact of reducing bearing loads on lifetime of bearings?
*Are there similar industry standard designs?

=Solution Pathways for Addressing Failing Motor Couplers=
==Solution Pathway 1==

Concept:
*Use a motor with more torque
*Direct coupling to wheel eliminates bearings, shafts, and collars
*Retain tracks
*Use one motor per side to eliminate motors 'fighting each other'

Possible solution: [[15,000 Inch Pound Motor]]
[[Image:15kmotor.jpg|400px]]

=Solution Pathway 2=
*Use 2 motors per side, and same drive train as in [[LifeTrac Wheel Assembly Video]], but with splined shaft motors
*Do motors 'fight each other' in this case?
*The new splined motors are [https://www.surpluscenter.com/item.asp?item=9-9327&catname=hydraulic these from Surpluscenter]:

[[Image:splinedmotors.jpg|thumb|Splined shaft wheel motors from Surpluscenter]]

[[Image:3188.jpg|thumb|31.88 cubic inch wheel motors from Surpluscenter]]

=Pathway 3=
*Reduce pressure on hydraulic motors?
*1160 PSI only is max on [[31.88 Cubic Inch Motors]]. Is this sufficient to drive the tractor?

=Peer Review=

This page should be peer reviewed by hydraulics specialists, such as at hydraulics forums.
[[Category:LifeTrac Field Testing]]

Talk:Functional Spec for LifeTrac Wheel Motors and Couplings

2011-12-09T11:24:47Z

Leo.dearden: moved Talk:Functional Spec for LifeTrac Wheel Motors and Couplings to Talk:Requirements for LifeTrac Wheel Motors and Couplings

#REDIRECT [[Talk:Requirements for LifeTrac Wheel Motors and Couplings]]

Talk:Requirements for LifeTrac Wheel Motors and Couplings

2011-12-09T11:24:47Z

Leo.dearden: moved Talk:Functional Spec for LifeTrac Wheel Motors and Couplings to Talk:Requirements for LifeTrac Wheel Motors and Couplings

I've framed the requirements as best I can.

Required actions:

*fill in the XXXs
*peer review (optional, but suggested)
*pass it to GrabCAD, to amend the competition.

Functional Spec for LifeTrac Wheel Motors and Couplings

2011-12-09T11:24:46Z

Leo.dearden: moved Functional Spec for LifeTrac Wheel Motors and Couplings to Requirements for LifeTrac Wheel Motors and Couplings

#REDIRECT [[Requirements for LifeTrac Wheel Motors and Couplings]]

Requirements for LifeTrac Wheel Motors and Couplings

2011-12-09T11:24:46Z

Leo.dearden: moved Functional Spec for LifeTrac Wheel Motors and Couplings to Requirements for LifeTrac Wheel Motors and Couplings

Status: provisional/incomplete. See discussion for required actions.

==Notes for Designers==

Please model your design as fully as is feasible. The best design will have the best evidence that it meets all the requirements and has the best trade-offs in all areas.

Please share any solution models (eg: FEAs) you use including original files and summary reports in standard formats.

Please share general modelling of the problem domain - loads, statistical models, etc, so that the entire community can refine its understanding of the problem.

If you think any part of the spec is unreasonable, unclear, or missing or incomplete, please tell us. Help us to refine it.

If you can't model, or can't meet any part of the spec, please say so, and please share your designs anyway. Anything is better than nothing, and other people may be able to build on your work.

==Functional Requirements==

===Drive===

At least two wheels must be driven by hydraulic motors. At least four wheels must be mounted. All wheel drive is highly desirable. Suggested motor for AWD is XXXX(link).

===Construction/Fabrication===

The mount - motor - coupler assembly must be fabricated simply, using only a minimum of special purpose components. In addition to the hydraulic motors, bearings, standard fasteners (nuts, bolts, etc), XXXX, sheet plate tube and bar steel are allowable. Cutting (Flame, Plasma, abrasive), drilling, punching, XXXX, and welding (Oxy Torch) are allowable.

Other components and processes will be considered, but are discouraged.

Bolt together assembly should be used where possible to facilitate repair and component upgrade or reuse.

===Quick change mounts===

Bolt or other temporary fixing must be used for attachment to the LifeTrac frame.

Quick change mounting between the motor-coupler assembly and the frame is highly desirable, to reduce MTTR and allow easy modular repairs with few tools.

==Quantitative/Non-Functional==

===Solution must be robust===

All aspects of the LifeTrac must be long lasting and reliable under intended, and reasonably anticipated but unintended, uses.

====Typical Load====

Torque: Motors will often be operated at maximum rated torque. Design for a duty cycle of 50%, with one reversal every 3s.

Weight supported by the four wheels will be XXXXkg total, including LifeTrac, X powercubes (at the back), and XXXXkg on the loader.

Vibration: When driven on rough ground, additional cyclic loads of 0.8G @ 15Hz will be applied.

====Impact Load====

Should survive driving over a sharp a drop of 15

Talk:Requirements for LifeTrac Wheel Motors and Couplings

2011-12-09T11:23:35Z

Leo.dearden: Created page with "I've framed the requirements as best I can. Required actions: *fill in the XXXs *peer review (optional, but suggested) *pass it to GrabCAD, to amend the competition."

I've framed the requirements as best I can.

Required actions:

*fill in the XXXs
*peer review (optional, but suggested)
*pass it to GrabCAD, to amend the competition.

Requirements for LifeTrac Wheel Motors and Couplings

2011-12-09T11:20:50Z

Leo.dearden: Created

Quick Connect Wheels

2011-12-09T11:19:08Z

Leo.dearden: Added link to functional spec

=Introduction=

LifeTrac wheel couplers suffered catastrophic failure when used with tracks.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//i4GjoFQ3zsg" frameborder="0" allowfullscreen></iframe></html>

.

The key on the motor shaft sheared. We put on thicker couplers, and LifeTrac currently works - but we will not take it through destructive testing prior to testing splined motors. NOTE: Discussion at [[31.88 Cubic Inch Motors]] shows hints that pressure setting was too high, and could have been the reason for failure.

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//BKoBcslT_Vo" frameborder="0" allowfullscreen></iframe>
</html>

.

It is suspected that the 4-wheel drive, when coupled by wheel tracks, makes the motors fight each other.

=What we want=

[[Functional Spec for LifeTrac Wheel Motors and Couplings]]

=Possible solution: Removing Tracks, Adding Quick Connect Wheels=

To remedy the failing coupler, we will remove the tracks as the first step, and run the motors in series to simplify control valve requirements. That means that a 3000 PSI pump can deliver a max of 1500 PSI to each motor. This puts a low limit on the pressure, while delivering 6525 in lb for each motor - which makes this still higher torque than the 5000 cu in former [[31.88 cu in motors]] used on LifeTrac I-III.

The rough concept of a quick connect wheel is this:

[[Image:quickconnectwheel.jpg|400px]]

==Implementation==

To design the quick connect wheel, complete [[LifeTrac Frame]] geometry must be considered.

See pictures of wheeel:

<gallery>
Image:ltframe1.jpg
Image:ltframe2.jpg
Image:ltframe3.jpg
Image:ltframe4.jpg
</gallery>

and the real object:

<html><iframe width="300" height="233" src="https://www.youtube.com/embed//hICQOCHkDsk" frameborder="0" allowfullscreen></iframe></html>

.

==Concept Quick Release Wheel==

Design Rationale:
*Triple mechanism of holding using peg, a cam lock, and a bolt:

Download [[File:wheelmount.dxf]]

See it:

[[Image:wheelmount.jpg|400]]

Model:

[[Image:wheelmodel1.jpg]]

Download pngs of above and STEP file - [[File:wheelmodel.zip]]

Relation to frame:

[[Image:wheelmodel2.jpg]]

Download the relation to frame, STEP and X_T files - [[File:wheelmodel2.zip]]

==Reducing loads on the shafts and bearings==

In order to reduce the bending load of the shaft the following design could be implemented:

[[Image:Wheelmodel_3.png]]

The idea is moving the main bearing as close to the wheel center as possible. This will reduce the bending moment on the shaft close to zero and reduce the loads on the bearings. The roller element bearing close to the motor could actually be replaced now by a much smaller one.

In this design the 4"x4" transverse tube takes over the whole bending moment for transferring the forces from the wheel to the frame. There are different possibilities for anchoring this tube to the frame. One should only keep in mind that the loads will push the external frame tube upwards and pull the internal one downwards.

You can download the CAD model of this first rough design in the following file

Download FreeCAD model: [[File:Wheelmodel_3.FCStd]]

===Discussion===
*What is the critical clamp-down/disconnect mechanism?
*What is the impact of reducing bearing loads on lifetime of bearings?
*Are there similar industry standard designs?

=Solution Pathways for Addressing Failing Motor Couplers=
==Solution Pathway 1==

Concept:
*Use a motor with more torque
*Direct coupling to wheel eliminates bearings, shafts, and collars
*Retain tracks
*Use one motor per side to eliminate motors 'fighting each other'

Possible solution: [[15,000 Inch Pound Motor]]
[[Image:15kmotor.jpg|400px]]

=Solution Pathway 2=
*Use 2 motors per side, and same drive train as in [[LifeTrac Wheel Assembly Video]], but with splined shaft motors
*Do motors 'fight each other' in this case?
*The new splined motors are [https://www.surpluscenter.com/item.asp?item=9-9327&catname=hydraulic these from Surpluscenter]:

[[Image:splinedmotors.jpg|thumb|Splined shaft wheel motors from Surpluscenter]]

[[Image:3188.jpg|thumb|31.88 cubic inch wheel motors from Surpluscenter]]

=Pathway 3=
*Reduce pressure on hydraulic motors?
*1160 PSI only is max on [[31.88 Cubic Inch Motors]]. Is this sufficient to drive the tractor?

=Peer Review=

This page should be peer reviewed by hydraulics specialists, such as at hydraulics forums.
[[Category:LifeTrac Field Testing]]

User:Leo.dearden

2011-07-06T19:12:07Z

Leo.dearden: /* WHO are you? */

[[Image:myfotofile.jpg|thumb| myname]]

==Team Culturing Information==

==='''WHO''' am I?===

====Name====
Leo Dearden

====Location====
Hampshire, South England (United Kingdom)

====Contact Details====
* email: leo@leodearden.org
* telephone: +44 7796 177180 (Please restrict calls to 1100-2030 London time)
* skype: leo.dearden

''Picture & Introductory Video to follow.''

====Resume/CV====
I've always been a Maker.

I have a Computer Science MA Cantab. from Cambridge University (UK). I have more than 10 years of full time software development experience, mostly with a mixture of C & C++ on Linux and various embedded systems. I have also some experience with Java, Verilog RTL/HDL for FPGAs, TCL, Perl, Python, Ruby, ML, Prolog, and some assembly languages. I studied Materials Science as a minor part of my degree.

I'm comfortable designing moderately complex digital, analog, and/or power electronics, though I don't have any formal training. I have built a couple of PA audio amplifiers and the CNC control electronics for my router (though I did use power amp and servo control modules to handle the really hard bits). I use mixed signal osciloscopes for hardware and low level software debugging and optimisation.

I'm something of a self trained Engineer. I have a theoretical appreciation of many issues of mechanical design, and I'm starting to apply that to making CNC machinery, starting with the [[http://RepRap.org|RepRap]] 3D printer. I'm the founder of [[http://RepRapKit.com|RepRapKit]], which I'm operating fully open source, with the intention of freeing myself from the time-for-money wage slavery and spreading abundance enhancing technology as widely as possible.

I run a CNC router, interfaced to a PC via GeckoDrive based electronics of my own design, and controlled with EMC2.

I have good fabrication skills with wood, plastics, electronics, composites, and light metals. I don't weld yet, but intend to learn soon.

==='''WHY''' am I motivated to support/develop this work?===
I'm an enthusiastic proponent of open source everything. Open source is a fundamental cooperative organisational pattern, one of the crucial tools that will allow us to build post-scarcity.

OSE is one of the most exciting projects in existence. It addresses our fundamental human needs in a ways that are resilient (and sustainable), efficient, and freedom promoting. It offers solutions to a swathe of problems that, if unsolved, would lead to massive suffering, even up to the destruction of life on earth.

By providing a promise of 'everybody wins' abundance through cooperation, development of the GVCS (and the projects that follow it) demonstrates by example the overwhelming benefits of cooperation. The GVCS will provide the currently fragile Developed World with desperately needed resilience, and unlimited opportunity for anyone who will just grasp it. It will also provide the impoverished of the world a clear and ever easier pathway to abundance.

I am bootstrapping my own prosperity, to enable me to give a major part of my efforts to creating post-scarcity. For the moment I am fully occupied with that effort (which has GVCS beneficial side effects), and as soon as my efforts pay off sufficiently I will become a very active supporter of OSE. I have my own pathway to freedom/prosperity, and I'm happy that I'm progressing along it fast.

So far, the OSE related projects have had little commercial success. I'm sure that this will change with only a little time, and I urge everyone to recognise the benefits of such success - it will provide us with resources that we can re-invest to accelerate the exponential growth of the project. Though we oppose scarcity (especially artificial scarcity), in the near future we can most easily obtain the resources we need to live and to progress by creating enormous value and trading it skilfully and generously. As various participants and component projects work towards that goal, we'll start to see opportunities for cooperation in the commercial and productive spheres, and well as in technical development. I strongly advocate that we take and expand those opportunities as fast as we can.

==='''WHAT''' are your skills?===

*'''List all of your skills in these areas: Communications - Organizational - Computer Support - Finances - Design - Natural Building - Electronics - Automation - Metallurgy - Engineering - Fabrication - Agriculture - Energy - Architecture - Video/Graphics/Art - PR/Marketing - Education - Construction - Industry - CNC - Chemistry - Product Design - Other'''

*''How have you already contributed to the project?''

===HOW can you help?===

*''How are you interested in contributing to the work of GVCS development?''

I am very interested in contributing to the development of the GVCS. I have already made some small contributions, in the form of advice to Marcin on the subject of the Li

*''Can you volunteer to work with us, and if so, how many hours per week?''

*''Are you interested in working with us for pay? If so, what services can you offer, and what is your hourly or per-project rate?''

*''Are you interested in a [[Dedicated Project Visit]]?

*''Are you interested in purchasing equipment from us to help bootstrap development?''

*''Are you interested in bidding for consulting/design/prototyping work?''

*''Are you a [[True Fans|True Fan]]? If not, why not?''

*''Would you like to see yourself working with us on a full-time basis?''

*''Are you interested in being part of the world's first, open source, resilient community? The GVCS is the preparatory step for the OSE Village Experiment – a 2 year, immersion experiment (2013-2014) for testing whether a real, thriving, modern-day prototype community of 200 people can be built on 200 acres using local resources and open access to information? We are looking for approximately 200 people to fill a diverse array of roles, according to the Social Contract that is being developed. This may be the boldest social experiment on earth - a pioneering community whose goal is to extend the index of possibilities regarding harmonious existence of humans, ecology, and technology.''

[[Category: Team Culturing]]

User:Leo.dearden

2011-07-06T19:10:46Z

Leo.dearden: /* WHY are you motivated to support/develop this work? */

[[Image:myfotofile.jpg|thumb| myname]]

==Team Culturing Information==

==='''WHO''' are you?===

====Name====
Leo Dearden

====Location====
Hampshire, South England (United Kingdom)

====Contact Details====
* email: leo@leodearden.org
* telephone: +44 7796 177180 (Please restrict calls to 1100-2030 London time)
* skype: leo.dearden

''Picture & Introductory Video to follow.''

====Resume/CV====
I've always been a Maker.

I have a Computer Science MA Cantab. from Cambridge University (UK). I have more than 10 years of full time software development experience, mostly with a mixture of C & C++ on Linux and various embedded systems. I have also some experience with Java, Verilog RTL/HDL for FPGAs, TCL, Perl, Python, Ruby, ML, Prolog, and some assembly languages. I studied Materials Science as a minor part of my degree.

I'm comfortable designing moderately complex digital, analog, and/or power electronics, though I don't have any formal training. I have built a couple of PA audio amplifiers and the CNC control electronics for my router (though I did use power amp and servo control modules to handle the really hard bits). I use mixed signal osciloscopes for hardware and low level software debugging and optimisation.

I'm something of a self trained Engineer. I have a theoretical appreciation of many issues of mechanical design, and I'm starting to apply that to making CNC machinery, starting with the [[http://RepRap.org|RepRap]] 3D printer. I'm the founder of [[http://RepRapKit.com|RepRapKit]], which I'm operating fully open source, with the intention of freeing myself from the time-for-money wage slavery and spreading abundance enhancing technology as widely as possible.

I run a CNC router, interfaced to a PC via GeckoDrive based electronics of my own design, and controlled with EMC2.

I have good fabrication skills with wood, plastics, electronics, composites, and light metals. I don't weld yet, but intend to learn soon.

==='''WHY''' am I motivated to support/develop this work?===
I'm an enthusiastic proponent of open source everything. Open source is a fundamental cooperative organisational pattern, one of the crucial tools that will allow us to build post-scarcity.

OSE is one of the most exciting projects in existence. It addresses our fundamental human needs in a ways that are resilient (and sustainable), efficient, and freedom promoting. It offers solutions to a swathe of problems that, if unsolved, would lead to massive suffering, even up to the destruction of life on earth.

By providing a promise of 'everybody wins' abundance through cooperation, development of the GVCS (and the projects that follow it) demonstrates by example the overwhelming benefits of cooperation. The GVCS will provide the currently fragile Developed World with desperately needed resilience, and unlimited opportunity for anyone who will just grasp it. It will also provide the impoverished of the world a clear and ever easier pathway to abundance.

I am bootstrapping my own prosperity, to enable me to give a major part of my efforts to creating post-scarcity. For the moment I am fully occupied with that effort (which has GVCS beneficial side effects), and as soon as my efforts pay off sufficiently I will become a very active supporter of OSE. I have my own pathway to freedom/prosperity, and I'm happy that I'm progressing along it fast.

So far, the OSE related projects have had little commercial success. I'm sure that this will change with only a little time, and I urge everyone to recognise the benefits of such success - it will provide us with resources that we can re-invest to accelerate the exponential growth of the project. Though we oppose scarcity (especially artificial scarcity), in the near future we can most easily obtain the resources we need to live and to progress by creating enormous value and trading it skilfully and generously. As various participants and component projects work towards that goal, we'll start to see opportunities for cooperation in the commercial and productive spheres, and well as in technical development. I strongly advocate that we take and expand those opportunities as fast as we can.

==='''WHAT''' are your skills?===

*'''List all of your skills in these areas: Communications - Organizational - Computer Support - Finances - Design - Natural Building - Electronics - Automation - Metallurgy - Engineering - Fabrication - Agriculture - Energy - Architecture - Video/Graphics/Art - PR/Marketing - Education - Construction - Industry - CNC - Chemistry - Product Design - Other'''

*''How have you already contributed to the project?''

===HOW can you help?===

*''How are you interested in contributing to the work of GVCS development?''

I am very interested in contributing to the development of the GVCS. I have already made some small contributions, in the form of advice to Marcin on the subject of the Li

*''Can you volunteer to work with us, and if so, how many hours per week?''

*''Are you interested in working with us for pay? If so, what services can you offer, and what is your hourly or per-project rate?''

*''Are you interested in a [[Dedicated Project Visit]]?

*''Are you interested in purchasing equipment from us to help bootstrap development?''

*''Are you interested in bidding for consulting/design/prototyping work?''

*''Are you a [[True Fans|True Fan]]? If not, why not?''

*''Would you like to see yourself working with us on a full-time basis?''

*''Are you interested in being part of the world's first, open source, resilient community? The GVCS is the preparatory step for the OSE Village Experiment – a 2 year, immersion experiment (2013-2014) for testing whether a real, thriving, modern-day prototype community of 200 people can be built on 200 acres using local resources and open access to information? We are looking for approximately 200 people to fill a diverse array of roles, according to the Social Contract that is being developed. This may be the boldest social experiment on earth - a pioneering community whose goal is to extend the index of possibilities regarding harmonious existence of humans, ecology, and technology.''

[[Category: Team Culturing]]

User:Leo.dearden

2011-07-06T18:38:28Z

Leo.dearden: /* Resume/CV */

[[Image:myfotofile.jpg|thumb| myname]]

==Team Culturing Information==

==='''WHO''' are you?===

====Name====
Leo Dearden

====Location====
Hampshire, South England (United Kingdom)

====Contact Details====
* email: leo@leodearden.org
* telephone: +44 7796 177180 (Please restrict calls to 1100-2030 London time)
* skype: leo.dearden

''Picture & Introductory Video to follow.''

====Resume/CV====
I've always been a Maker.

I have a Computer Science MA Cantab. from Cambridge University (UK). I have more than 10 years of full time software development experience, mostly with a mixture of C & C++ on Linux and various embedded systems. I have also some experience with Java, Verilog RTL/HDL for FPGAs, TCL, Perl, Python, Ruby, ML, Prolog, and some assembly languages. I studied Materials Science as a minor part of my degree.

I'm comfortable designing moderately complex digital, analog, and/or power electronics, though I don't have any formal training. I have built a couple of PA audio amplifiers and the CNC control electronics for my router (though I did use power amp and servo control modules to handle the really hard bits). I use mixed signal osciloscopes for hardware and low level software debugging and optimisation.

I'm something of a self trained Engineer. I have a theoretical appreciation of many issues of mechanical design, and I'm starting to apply that to making CNC machinery, starting with the [[http://RepRap.org|RepRap]] 3D printer. I'm the founder of [[http://RepRapKit.com|RepRapKit]], which I'm operating fully open source, with the intention of freeing myself from the time-for-money wage slavery and spreading abundance enhancing technology as widely as possible.

I run a CNC router, interfaced to a PC via GeckoDrive based electronics of my own design, and controlled with EMC2.

I have good fabrication skills with wood, plastics, electronics, composites, and light metals. I don't weld yet, but intend to learn soon.

==='''WHY''' are you motivated to support/develop this work?===
*''Do you endorse open source culture?''

*''Why are you interested in collaborating with us?''

*''How do you think that the GVCS can address pressing world issues?''

*''What should happen so that you become more involved with the project?''

*''What is missing in the project?''

*''What are your suggestions for improvement of the project?''

==='''WHAT''' are your skills?===

*'''List all of your skills in these areas: Communications - Organizational - Computer Support - Finances - Design - Natural Building - Electronics - Automation - Metallurgy - Engineering - Fabrication - Agriculture - Energy - Architecture - Video/Graphics/Art - PR/Marketing - Education - Construction - Industry - CNC - Chemistry - Product Design - Other'''

*''How have you already contributed to the project?''

===HOW can you help?===

*''How are you interested in contributing to the work of GVCS development?''

I am very interested in contributing to the development of the GVCS. I have already made some small contributions, in the form of advice to Marcin on the subject of the Li

*''Can you volunteer to work with us, and if so, how many hours per week?''

*''Are you interested in working with us for pay? If so, what services can you offer, and what is your hourly or per-project rate?''

*''Are you interested in a [[Dedicated Project Visit]]?

*''Are you interested in purchasing equipment from us to help bootstrap development?''

*''Are you interested in bidding for consulting/design/prototyping work?''

*''Are you a [[True Fans|True Fan]]? If not, why not?''

*''Would you like to see yourself working with us on a full-time basis?''

*''Are you interested in being part of the world's first, open source, resilient community? The GVCS is the preparatory step for the OSE Village Experiment – a 2 year, immersion experiment (2013-2014) for testing whether a real, thriving, modern-day prototype community of 200 people can be built on 200 acres using local resources and open access to information? We are looking for approximately 200 people to fill a diverse array of roles, according to the Social Contract that is being developed. This may be the boldest social experiment on earth - a pioneering community whose goal is to extend the index of possibilities regarding harmonious existence of humans, ecology, and technology.''

[[Category: Team Culturing]]

User:Leo.dearden

2011-07-06T18:19:05Z

Leo.dearden:

[[Image:myfotofile.jpg|thumb| myname]]

==Team Culturing Information==

==='''WHO''' are you?===

====Name====
Leo Dearden

====Location====
Hampshire, South England (United Kingdom)

====Contact Details====
* email: leo@leodearden.org
* telephone: +44 7796 177180 (Please restrict calls to 1100-2030 London time)
* skype: leo.dearden

''Picture & Introductory Video to follow.''

====Resume/CV====
I've always been a Maker.

I have a Computer Science MA Cantab. from Cambridge University (UK). I have more than 10 years of full time software development experience, mostly with a mixture of C & C++ on Linux and various embedded systems. I have also some experience with Java, Verilog RTL/HDL for FPGAs, TCL, Perl, Python, Ruby, ML, Prolog, and some assembly languages. I studied Materials Science as a minor part of my degree.

I'm comfortable designing moderately complex digital, analog, and/or power electronics, though I don't have any formal training. I have built a couple of PA audio amplifiers and the CNC control electronics for my router (though I did use power amp and servo control modules to handle the really hard bits). I use mixed signal osciloscopes for hardware and low level software debugging and optimisation.

I'm something of a self trained Engineer. I have a theoretical appreciation of many issues of mechanical design, and I'm starting to apply that to making CNC machinery, starting with the [[RepRap|http://RepRap.org]] 3D printer. I'm the founder of [[RepRapKit|http://RepRapKit.com]], which I'm operating fully open source, with the intention of freeing myself from the time-for-money wage slavery and spreading abundance enhancing technology as widely as possible.

I run a CNC router, interfaced to a PC via GeckoDrive based electronics of my own design, and controlled with EMC2.

I have good fabrication skills with wood, plastics, electronics, composites, and light metals. I don't weld yet, but intend to learn soon.

==='''WHY''' are you motivated to support/develop this work?===
*''Do you endorse open source culture?''

*''Why are you interested in collaborating with us?''

*''How do you think that the GVCS can address pressing world issues?''

*''What should happen so that you become more involved with the project?''

*''What is missing in the project?''

*''What are your suggestions for improvement of the project?''

==='''WHAT''' are your skills?===

*'''List all of your skills in these areas: Communications - Organizational - Computer Support - Finances - Design - Natural Building - Electronics - Automation - Metallurgy - Engineering - Fabrication - Agriculture - Energy - Architecture - Video/Graphics/Art - PR/Marketing - Education - Construction - Industry - CNC - Chemistry - Product Design - Other'''

*''How have you already contributed to the project?''

===HOW can you help?===

*''How are you interested in contributing to the work of GVCS development?''

I am very interested in contributing to the development of the GVCS. I have already made some small contributions, in the form of advice to Marcin on the subject of the Li

*''Can you volunteer to work with us, and if so, how many hours per week?''

*''Are you interested in working with us for pay? If so, what services can you offer, and what is your hourly or per-project rate?''

*''Are you interested in a [[Dedicated Project Visit]]?

*''Are you interested in purchasing equipment from us to help bootstrap development?''

*''Are you interested in bidding for consulting/design/prototyping work?''

*''Are you a [[True Fans|True Fan]]? If not, why not?''

*''Would you like to see yourself working with us on a full-time basis?''

*''Are you interested in being part of the world's first, open source, resilient community? The GVCS is the preparatory step for the OSE Village Experiment – a 2 year, immersion experiment (2013-2014) for testing whether a real, thriving, modern-day prototype community of 200 people can be built on 200 acres using local resources and open access to information? We are looking for approximately 200 people to fill a diverse array of roles, according to the Social Contract that is being developed. This may be the boldest social experiment on earth - a pioneering community whose goal is to extend the index of possibilities regarding harmonious existence of humans, ecology, and technology.''

[[Category: Team Culturing]]

User:Leo.dearden

2011-07-06T18:12:40Z

Leo.dearden: Created page with " myname ==Team Culturing Information== ==='''WHO''' are you?=== ====Name==== Leo Dearden ====Location==== Hampshire, South England (United King..."

Leo Dearden

2011-07-06T17:30:02Z

Leo.dearden: moved Leo Dearden to Leo.dearden: This is a page about me. I makes sense for it to be my Wiki user page.

#REDIRECT [[Leo.dearden]]

Leo.dearden

2011-07-06T17:30:02Z

Leo.dearden: moved Leo Dearden to Leo.dearden: This is a page about me. I makes sense for it to be my Wiki user page.

== Leo Dearden ==

I'm committed to the RepLab project.

=== Tools of interest ===

RepRap.
* support material
* for electronics
** Pick n place
** conductive material deposition
* for mold making
* for ceramics

CNC Machine Tools. Lathe, Router, Mill.
* air bearings based on graphite blocks for linear slides and spindles
* casting whole machines from epoxy/granite/carbon fiber composites
* using laser interferometers during fabrication and operation to tool up to extreme accuracy from inaccurate components and with inaccurate tools.
* fabricating low cost high performance linear motors for extremely high motion performance low to moderate load tools
* carbon fibre composite air bearing screws for high load high performance tools

Software tools
* Electronics place and route for RepRap
* Unsupervised CAM (subtractive cutting path generation)

Curing oven for composites
Vacuum mixing and casting systems for composites
Vacuum pumps
Air Compressors

=== Personal Participation ===

I will work on (in order, subject to revision)
* CNC router bootstap:
** improved spindle mounting
** 4th axis.
** Later, vacuum clamping and precision kinematic clamping.
* RepStrap (based on CNC router cartesian bot)
** single plastic extruder head
** second hot extruder head
** paste head
** low melt alloy and copper composites for extrusion
** printing circuits
** pick and place.
* Powerful and high precision machine tools as detailed above.

I'll offer advice and comment wherever it's welcome.

=== Resources ===

I have a fairly extensive personal workshop (http://fabricationsofthemind.blogspot.com/2008/10/in-praise-of-good-workshop.html).

I'm peripherally involved with the RepRap project, and will get more deeply involved as I work on my RepStrap. I'm a well liked friend of the explosively growing Noisebridge San Francisco hackerspace. I currently work for Google. I may be able to harness or evoke contributions from any of these, and I will listen for opportunities to do so.

=== Funding Model ===

I've funded my work so far from my income. In the next three years I intend to bootstrap through having more free time to taking paid work based on RepLab technology to develop and deploy machines. The things I learn in that work will be contributed open source and the money from it will support me and my work. If possible, I will replicate this model, supporting others in doing the same.

=== Time Budget ===

I'm working very full time at the moment. I can currently contribute a very little. I'll have a little more time in the spring 2010, and hope to secure one day a week to work on open source circuit printing, as part of my paid job, later 2010. Beyond that, more and more time as I can arrange it.

=== RepLab Tool List Opinions ===

Build/Defer is ever only a personal opinion. FWIW, I'm open to persuasion, and more importantly, whoever wants to Build anything, can of course get on with it. :-)

1. Laser cutter - large DIY community exists for C02 lasers

Very handy. It's basically a new tool head for a plasma table or similar. Defer.

2. ShopBot - RepTab is the Factor e Farm version

RepTab looks like a good plasma table. I'm not sure how well it will handle cutting loads. Perhaps it will require modification to do that, but some sort of gantry router will work well and should definitely be in the toolkit. Build soon.

3. Precise router for milling circuits

Precise router, for many things. If we can make it stiff and coolant proof enough, it becomes a Mill, too. If it's heat and RF resistant enough it's a plasma table. If it's fast enough it's a laser cutter, or a RepStrap. Build soon.

2 and 3 can have a lot in common. 3 is just smaller and more precise. Common designs could be mostly parametrised to provide both.

4. Plasma cutter - power circuit is main point to opensource

Yes. The head is also non-trivial, IMHO. I suggest: Defer.

5. Welder - power circuit is main point to opensource

Yes. Likewise, Defer.

6. Oscilloscope - can a computer oscilloscope cover most needs?

Yes it can. It can be just as good as (or better than) a standalone one. There are projects out there to make these already. Obtain, commercial or open source.

7. Rep(st)Rap

Build or Obtain a kit then Build our version as discussed in other posts.

8. Mill

Build

9. Drill

Hand drill, drillstand: Obtain. Pillar drill can be built as part of the Mill.

10. Lathe

Build.

11. Induction furnace - power electronics are main point to opensource

Defer.

12. Ciruit fab - automated process including pick-and-place

Build.

13. Aluminum extrusion

14. Metal casting - of ingot from induction furnace, and other molds
15. Hot rolling
16. Cold rolling
17. Forging
18. Metal shear and hole punch for up to 1" steel
19. Wire drawing

Defer all.

The heavy industrial infrastructure will be easier once we have the machine tools working. We'll also have a better idea of what we want and need.

=== Beyond RepLab ===

Air compressor

Vacuum Pump
* 0.1 mbar, >10cfm for degassing and lamination.
* 0.1 bar, >100cfm for vac clamping.
** i hear a shop vac + light duty pump and check valve works great

1 phase -> 3 phase converter.

Shaker, for casting

[[Category:RepLab Developers]]

Open Source Stepper Motor Controller

2010-11-05T00:21:37Z

Leo.dearden: /* Block Diagram and Modules */

=Introduction=

Stepper motors are the simplest drive for moderate precision motion control applications (such as CNC plasma cutting). They provide the best price:performace for low to moderate mechanical power (<200W) at low to moderate RPM (<500 RPM). There is no open source stepper driver, AFAIK. This project will fill that need.

=Concept=

The output of this project will be a family of general purpose electronic drivers for a variety of electromechanical actuators. The first of them will be a stepper motor driver. With the appropriate alternative firmware (embedded software) the same hardware might be used as a servo driver for a brush-DC servo. With a modified output stage we could drive brushless DC or AC servos, or linear motors.

=Design Rationale=

Adaptability is good. Software is usually easier than hardware. Microprocessors are cheap. Simple circuits are better than complicated ones (other things being equal).

We keep the circuit simple and general, and we implement the control algorithm in software. We can tweak it most easily that way, and even replace it with something totally different.

This design should give good performance, excellent versatility, good replicability, and moderate cost.

=Block Diagram and Modules=

Major functional units:
* Computational logic. An Arduino could be used in the initial prototype, for speed of development. Later versions would want a cost reduced and/or higher performance microprocessor, or an FPGA for minimum latency and maximum bandwidth. The logic must be shielded from electromagnetic interference by the other parts of the system, especially the output drive (and the plasma cutter, if there is one). Independent power and small signal power supplies, and careful grounding, are likely to be needed.
* Fast A/D converters. Allows the logic to monitor the current flowing through the load.
* High power robust drive circuit. N-channel power MOSFETs in an H bridge, with appropriate protection. Select MOSFETs with plenty of current and voltage headroom, and favour ones with built in clamp diodes. A stepper motor is a heavily inductive load, so it can generate voltages substantially outside the supply rails.

[[File:Stepper-drive-block-diagram.jpg]]

[[File:Stepper-drive-H-bridge.jpg]]

An H-bridge allows the voltage to be applied to the load (to motor winding) in either direction.

[[File:Stepper-drive-schematic-symbols.jpg]]

[[File:Stepper-drive-normal-operation.jpg]]

Top row: active current path. Bottom row: Corresponding Current (I) and Voltage (V) graphed against time.

From left to right: Positive applied voltage, rapidly increasing current; No voltage (except due to the resistance of the wires, gradually decreasing current; Negative applied voltage, rapidly falling current.

[[File:Stepper-drive-failure-modes.jpg]]

Shoot-through occurs when both transistors on one side of the H are turned on at the same time. It shorts the rails together and blows the transistors in a few us.

The overvoltage shown occurs when all the transistors are turned off simultaneously while current is flowing. Stopping the current near instantly creates a huge voltage spike. The same effect can occur if a motor lead comes loose while the driver is operating.

[[File:Stepper-drive-waveforms.jpg]]

Contrast stepping with microstepping. The microstepping gives less vibration and smoother movement, and makes it possible to stop between the steps.

[[File:Stepper-drive-MOSFET-timing.jpg]]

MOSFETS take some time to turn on and off. We need to take account of this for optimum performance (or even for to avoid the above failure modes?). See the MOSFET data sheet for exact timings.

=== Method of operation: ===

*Position instructions come to the drive from EMC. These could be step and direction pulses or some more structured data.
*The drive determines target current for each winding.
*The drive uses software [http://en.wikipedia.org/wiki/PID_controller PID] compensation to achieve and maintain those drive currents.
** sensor: voltage induced across sense resistor by the drive current.
** actuator: [http://en.wikipedia.org/wiki/Pulse-width_modulation PWM] of applied voltage between the three normal operation modes.
*The drive determines new target current for next (micro-)step.

=References=
*[http://en.wikipedia.org/wiki/Stepper_motor Stepper Motor in Wikipedia]
=Development Team=

[[Leo.dearden]] - Ideas. I'm to busy to do very much at the moment, but I'll do what I can.

[[Category:RepLab]][[Category:Automation]]

File:Stepper-drive-MOSFET-timing.jpg

2010-11-04T23:55:36Z

Leo.dearden:

File:Stepper-drive-waveforms.jpg

2010-11-04T23:55:24Z

Leo.dearden:

File:Stepper-drive-failure-modes.jpg

2010-11-04T23:53:37Z

Leo.dearden:

File:Stepper-drive-normal-operation.jpg

2010-11-04T23:53:26Z

Leo.dearden:

File:Stepper-drive-schematic-symbols.jpg

2010-11-04T23:52:15Z

Leo.dearden:

File:Stepper-drive-H-bridge.jpg

2010-11-04T23:51:07Z

Leo.dearden:

File:Stepper-drive-block-diagram.jpg

2010-11-04T23:49:05Z

Leo.dearden:

Open Source Stepper Motor Controller

2010-11-04T23:41:26Z

Leo.dearden: /* Block Diagram and Modules */

Open Source Stepper Motor Controller

2010-11-04T23:25:52Z

Leo.dearden: /* Block Diagram and Modules */

Open Source Stepper Motor Controller

2010-11-04T23:25:22Z

Leo.dearden: /* Design Rationale */

Open Source Stepper Motor Controller

2010-11-04T23:24:35Z

Leo.dearden: /* Design Rationale */

Open Source Stepper Motor Controller

2010-11-04T23:23:53Z

Leo.dearden: /* Design Rationale */

Open Source Stepper Motor Controller

2010-11-04T23:10:24Z

Leo.dearden: /* Concept */

Open Source Stepper Motor Controller

2010-11-04T23:09:54Z

Leo.dearden: /* Concept */

Open Source Stepper Motor Controller

2010-11-04T23:01:22Z

Leo.dearden: /* Introduction */

Open Source Stepper Motor Controller

2010-11-04T22:56:38Z

Leo.dearden: /* Development Team */

=Introduction=
=Concept=
=Design Rationale=
=Block Diagram and Modules=
=References=
*[http://en.wikipedia.org/wiki/Stepper_motor Stepper Motor in Wikipedia]
=Development Team=

[[Leo.dearden]] - Ideas. I'm to busy to do very much at the moment, but I'll do what I can.

[[Category:RepLab]][[Category:Automation]]

Leo.dearden

2009-11-25T21:13:21Z

Leo.dearden:

== Leo Dearden ==

I'm committed to the RepLab project.

=== Tools of interest ===

RepRap.
* support material
* for electronics
** Pick n place
** conductive material deposition
* for mold making
* for ceramics

CNC Machine Tools. Lathe, Router, Mill.
* air bearings based on graphite blocks for linear slides and spindles
* casting whole machines from epoxy/granite/carbon fiber composites
* using laser interferometers during fabrication and operation to tool up to extreme accuracy from inaccurate components and with inaccurate tools.
* fabricating low cost high performance linear motors for extremely high motion performance low to moderate load tools
* carbon fibre composite air bearing screws for high load high performance tools

Software tools
* Electronics place and route for RepRap
* Unsupervised CAM (subtractive cutting path generation)

Curing oven for composites
Vacuum mixing and casting systems for composites
Vacuum pumps
Air Compressors

=== Personal Participation ===

I will work on (in order, subject to revision)
* CNC router bootstap:
** improved spindle mounting
** 4th axis.
** Later, vacuum clamping and precision kinematic clamping.
* RepStrap (based on CNC router cartesian bot)
** single plastic extruder head
** second hot extruder head
** paste head
** low melt alloy and copper composites for extrusion
** printing circuits
** pick and place.
* Powerful and high precision machine tools as detailed above.

I'll offer advice and comment wherever it's welcome.

=== Resources ===

I have a fairly extensive personal workshop (http://fabricationsofthemind.blogspot.com/2008/10/in-praise-of-good-workshop.html).

I'm peripherally involved with the RepRap project, and will get more deeply involved as I work on my RepStrap. I'm a well liked friend of the explosively growing Noisebridge San Francisco hackerspace. I currently work for Google. I may be able to harness or evoke contributions from any of these, and I will listen for opportunities to do so.

=== Funding Model ===

I've funded my work so far from my income. In the next three years I intend to bootstrap through having more free time to taking paid work based on RepLab technology to develop and deploy machines. The things I learn in that work will be contributed open source and the money from it will support me and my work. If possible, I will replicate this model, supporting others in doing the same.

=== Time Budget ===

I'm working very full time at the moment. I can currently contribute a very little. I'll have a little more time in the spring 2010, and hope to secure one day a week to work on open source circuit printing, as part of my paid job, later 2010. Beyond that, more and more time as I can arrange it.

=== RepLab Tool List Opinions ===

Build/Defer is ever only a personal opinion. FWIW, I'm open to persuasion, and more importantly, whoever wants to Build anything, can of course get on with it. :-)

1. Laser cutter - large DIY community exists for C02 lasers

Very handy. It's basically a new tool head for a plasma table or similar. Defer.

2. ShopBot - RepTab is the Factor e Farm version

RepTab looks like a good plasma table. I'm not sure how well it will handle cutting loads. Perhaps it will require modification to do that, but some sort of gantry router will work well and should definitely be in the toolkit. Build soon.

3. Precise router for milling circuits

Precise router, for many things. If we can make it stiff and coolant proof enough, it becomes a Mill, too. If it's heat and RF resistant enough it's a plasma table. If it's fast enough it's a laser cutter, or a RepStrap. Build soon.

2 and 3 can have a lot in common. 3 is just smaller and more precise. Common designs could be mostly parametrised to provide both.

4. Plasma cutter - power circuit is main point to opensource

Yes. The head is also non-trivial, IMHO. I suggest: Defer.

5. Welder - power circuit is main point to opensource

Yes. Likewise, Defer.

6. Oscilloscope - can a computer oscilloscope cover most needs?

Yes it can. It can be just as good as (or better than) a standalone one. There are projects out there to make these already. Obtain, commercial or open source.

7. Rep(st)Rap

Build or Obtain a kit then Build our version as discussed in other posts.

8. Mill

Build

9. Drill

Hand drill, drillstand: Obtain. Pillar drill can be built as part of the Mill.

10. Lathe

Build.

11. Induction furnace - power electronics are main point to opensource

Defer.

12. Ciruit fab - automated process including pick-and-place

Build.

13. Aluminum extrusion

14. Metal casting - of ingot from induction furnace, and other molds
15. Hot rolling
16. Cold rolling
17. Forging
18. Metal shear and hole punch for up to 1" steel
19. Wire drawing

Defer all.

The heavy industrial infrastructure will be easier once we have the machine tools working. We'll also have a better idea of what we want and need.

=== Beyond RepLab ===

Air compressor

Vacuum Pump
* 0.1 mbar, >10cfm for degassing and lamination.
* 0.1 bar, >100cfm for vac clamping.

1 phase -> 3 phase converter.

Shaker, for casting

[[Category:RepLab Developers]]

Talk:Lathe Build

2009-11-22T20:49:00Z

Leo.dearden: Blanked the page

Lathe Build

2009-11-22T20:46:50Z

Leo.dearden:

=Auger=

Ben,

So here's my plan right now. Use a hydrauilic fixture with 20 hp that can be fixed to a table readily. This is what I have already on [[LifeTrac]] - a stiff auger mechanism:

[[Image:multiauger.jpg|thumb]]

=Bill of Materials=

Here is the bill of materials:

[[File:augerbom.jpg|thumb|left|Bill of Materials]]

=Lathe=

Is it possible to convert the auger to a lathe? Sure. Take a chuck from [http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310096648710&rvr_id=&crlp=1_263602_263622&UA=L*F%3F&GUID=1357ab741250a0265337bec7ff94d6a7&itemid=310096648710&ff4=263602_263622 here].

[[Image:chuckselfcent.png|thumb|left]]

Add a [http://www.use-enco.com/CGI/INSRIT?PMAKA=201-2826&PMPXNO=951820&PARTPG=INLMK3cross slide from Enco]. See [http://www.cartertools.com/newjose3.html review]

[[Image:crossslide.jpg|thumb|left]]

== Spec ==

What are the needs?
*Length, diameter of object?
*Tolerances, including surface finish?
*Manual or CNC?
*Material to be turned?
*etc
*RPM range?

== Danger ==

20HP at low rpm involves HUGE forces. This is going to be seriously dangerous because many of the possible failures would be catastrophic and faster than a human operator can react. Much smaller lathes cause fatal accidents from time to time. Breakage of the tool support or failure of the workholding would quite likely lead to big bits of metal flying about. Extreme caution is justified.

The proposed XY table is not intended to support anywhere near the max load that the hydraulics can apply. Most cast iron will fail fast (shatter).

A much smaller version may be a rewarding use of time to prove the design at reduced scale, cost, risk of failure, and danger of fatal or crippling injury.

== Materials, Rigidity ==

Pro lathes are usually made of the fewest thickest possible pieces of cast iron, for rigidity and damping. If mild steel box and sheet, bolted or welded, was good enough then there would probably be examples out there (If it's easy and cheaper and the Chinese won't do it then it probably doesn't work). There are substantial risks that the lathe will work poorly or not at all unless it is small and made of very thick stock. If any machine tool is insufficiently rigid then the cutting edge chatters on the work piece, giving a bad finish, rapid heating of the tool, and rapid tool failure. Also, cutting forces cause the machine to elastically distort, quickly introducing very large errors.

Without defining the spec, it is difficult to design. Materials for machine tool frames include
*Aluminium alloy, on small cheap low precision or soft material tools
*Cast Iron, on most machines. Well proven.
*Synthetic or real Granite, on super precision moderate mechanical load machinery

Synthetic granite is made from ~80% granite powder with an epoxy binder, and has ~9x better damping than cast iron but much lower tensile strength. (I'd like to experiment with machine tools made from a synthetic granite modified with chopped strand carbon fibre, but that's an unproven material. [[User:Leo.dearden|Leo.dearden]])

[[Category:Lathe]]