Open Source Ecology - User contributions [en]

Collaborative Engineering

2012-06-05T21:50:05Z

Logari81: /* FreeCAD + WebGL*/

{{CADTemplate}}

= Overview =
An online collaborative engineering system provides a means for project managers to create requirements and assign tasks, for engineers to create, version and collaborate on parts and assemblies, and for fabricators to choose a project they want to build and track their progress from acquiring raw materials to completing build steps. By using an integrated system there is a constant feedback loop between all three major roles:

# Project managers can track the progress, resolve blockers and maintain momentum of engineers by following Agile/SCRUM methodologies. Once a component is released they can observe and generate reports on blockers, inefficiencies and other issues that fabricators are having building and using components.
# Engineers have clear, concise tasks achievable within short iteration cycles. A CAD repository and versioning system allows several engineers to work on related components at the same time and resolve commit conflicts if they arise.
# Builders have a convenient organizational tool to keep track of their own fabrication process, ask questions and share lessons in the dedicated component builder forum. All data from fabricators feeds back into the project to help focus direction and prioritize stories and tasks for the next iteration.

== Agile Hardware Success Story ==
[http://www.wikispeed.com WIKISPEED] uses Agile/SCRUM methodologies to achieve unprecedented efficiency and build process optimizations:
* TED Talk: http://www.youtube.com/watch?v=x8jdx-lf2Dw
* Much longer (1h) detailed presentation: http://www.wikispeed.com/p/agile,-lean,-and-scrum

= Roles =

* Project Owner/Customer - Creates a project, defines high level requirements, is invested in the success of the project, follows progress via Dashboard.
* Project Manager/Scrum Master - Collaborates with engineers to create stories, tasks and organize them into iterations. Schedules and participates in SCRUM sessions, planning, reviews and retrospective meetings.
* Engineer/Prototyper - Creates CAD models, physical prototypes and other artifacts fulfilling project requirements and specification.
* Observers/Subject Experts - Provide review, technical advice and comments on the ongoing design.
* Builder - Instantiates a finished design project into an fabrication project.

= Basic Functionality =

# Create Account
# Login / Logout
# Search and view projects, builds and users.
## When listing the designs show how many ongoing/complete builds there are for that design.
# Subscribe to project, build and user activity RSS feeds.

= Dashboard =

# View progress of projects and builds you are part of or are watching.
# View daily logs of users, projects or builds you are watching.
# View tasks you are currently working on accros all projects.
# Provide reports on where builders seem to be stuck the most (acquiring part, completing step) or which steps take the longest time or have the most discussion activity.

= Design =

== Project ==

#'''Attributes'''
#* Name
#* Slug (used in human readable URL)
#* Description
#* Organization (default: OSE)
#* Visibility
#* URL if project has a dedicated website.
#'''Collaborators'''
#* Engineers
#* Project Managers
#* Customer/Owner
#* Subject Experts
# Each collaborator can enter a short daily log/SCRUM statement.

== Agile Process ==

The Agile process consists of creating stories that describe a problem that needs to be solved, adding tasks necessary to solve the problem, adding tests detailing how to verify that the problem is indeed solved and then creating iterations and moving stories into iterations based on priorities.

See:
* http://en.wikipedia.org/wiki/Agile_software_development
* http://en.wikipedia.org/wiki/Scrum_(development)

Similar Software:
* http://www.scrumy.com
* http://www.rallydev.com
* http://www.atlassian.com/software/greenhopper
* http://www.pivotaltracker.com
* http://www.scrumninja.com
* http://www.versionone.com

=== Story ===

# '''Attributes'''
#* Name
#* Description
#* IsBlocked
#* Status: Defined, In-Progress, Completed
#* Priority
#* Iteration/Backlog
#* Single Thread Discussion
#* File Attachments (photos, sketches, etc)
#* Owner
#* Subject Expert
# New stories automatically go into the Backlog.
# Stories can be moved into different iterations.

=== Story: Task ===

# '''Attributes'''
#* Name
#* Description
#* IsBlocked
#* Status: Defined, In-Progress, Completed
#* Assignee
# Tasks are added to stories.

=== Story: Test ===

# '''Attributes'''
#* Name
#* Description
#* Status (None or Pass/Fail from the most recent Run)
# Tests are added to stories.

=== Story: Test : Run ===

# '''Attributes'''
#* Timestamp
#* Pass/Fail
#* Notes
# Test Runs are added to tests.

=== Iteration ===

# '''Attributes'''
#* Name
#* Start Date
#* End Date
#* IsActive
# '''Backlog'''
#* A default iteration that cannot be deleted and is also not scheduled. This is where all new stories go unless explicitly assigned to a different iteration.

== Artifacts ==

# '''Create Part''' - Create a blank part or duplicate an existing part.
#* Bill of Materials
#* Build Instructions
#* Manuals
#* Revision History
# '''Create Assembly''' - Create a blank assembly or duplicate an existing assembly.
#* Add parts from this project or another project.
# '''Forum'''
#* Forums are threaded and work similar to current Vanilla OSE forum.
#* Two project level micro-forums automatically created:
#*# Design and prototyping forum
#*# Fabrication forum available from within eventual build projects
# '''Wiki'''
#* Ability to select a wiki page as the default project home page.
#* Wiki syntax for referencing:
#** Other projects and wiki pages in other projects.
#** Listing dependencies.
#** Still image of specific component specifying image size, camera location and angle.
#** Any other metadata from a component file.
#** Status widget showing:
#*** Burn down chart.
#*** Currently active tasks.
#*** Last X number of daily logs.
#*** Status of ongoing builds.
# '''Release'''
## Mark project/component available to fabricators, this means people can create builds.

= Build =

# Find a Design project and start a build from it.
# Keep track of required parts.
# Mark steps complete as build progresses.
# Add comments, photos and suggestions to the design and steps.
# Enter daily log/SCRUM.

= FreeCAD =

To provide a truely collaborative environment it's important to tightly integrate with desktop CAD software. Tentatively the chosen software is [[FreeCAD]]. The following integration would be considered:

* Checking in/out parts and assemblies from online repository.
* Displaying list of active tasks and allow basic modification of them such as marking Complete or Blocked.
* Chat feature with logs being accessible inside the project.
* Concurrently view/editing the same part by multiple engineers at the same time. This would facilitate the pair-engineering part of Agile development.
** The plugin would stream live modifications and view angle of the part to the central server which would forward the change modifications to any other clients editing/viewing the same part. - This is a whole problem domain on its own and will likely take a lot of work to get right, but we can start simple and provide robustness over time.
** By merging changes in realtime and piecemeal we eliminate the need to manually merge/resolve conflicts of parts as is done traditionally with source code repositories.
** Problem with this approach is that you have to be online in order to edit a part. One solution to this is that if you need to work on the part offline you can lock it and this would prevent anyone else from making changes.
** Streaming operations piecemeal also would provide unlimited undo and detailed history of changes. Additionally it will be possible to keep track of who made which changes.

There is currently a project by FreeCAD developers to provide parts/assemblies functionality. Much of the integration described in this document will depend on the completion of this work. Details and status: http://sourceforge.net/apps/mediawiki/free-cad/index.php?title=Assembly_project

== WebGL ==

A relevant discusion and a WebGL based prototype can be found here:
[https://sourceforge.net/apps/phpbb/free-cad/viewtopic.php?f=10&t=2397]

[[Category:CAD]]
[[Category:Digital Fabrication]]

Category:Torch Table

2012-06-05T07:16:41Z

Logari81:

=Introduction=

This page keeps track of all the pages related to the open source CNC torch table, and serves as an annotated bibliography for all the torch table pages.

'''The current design can be found here [[CNC_Torch_Table]] and currently work is being done here: [[Open_Source_Torch_Table_Prototype_II]]'''

[[Category: RepLab Tools]]

CNC Torch Table

2012-06-05T07:13:34Z

Logari81:

{{GVCS Header}}
{{Category=Torch Table}}

==Overview==
[[Image:TorchTable.png|thumb|400px|Torch Table]]

[[Image:CNC Torch Tablepic.jpg|thumb|right|400px]]

The CNC Torch Table is a table capable of cutting designs out of metal with a 2-axis torch controlled by computer.

The CNC Torch Table provides a quicker solution for cutting sheet metal, especially into intricate patterns that are difficult to cut by hand.

===Current Work being done here: [[Open Source Torch Table Prototype II]]===

{{Video}}

==Description==

<html><object width="400" height="233"><param name="allowfullscreen" value="true" /><param name="allowscriptaccess" value="always" /><param name="movie" value="http://vimeo.com/moogaloop.swf?clip_id=23785186&server=vimeo.com&show_title=0&show_byline=0&show_portrait=0&color=00adef&fullscreen=1&autoplay=0&loop=0" /><embed src="http://vimeo.com/moogaloop.swf?clip_id=23785186&server=vimeo.com&show_title=0&show_byline=0&show_portrait=0&color=00adef&fullscreen=1&autoplay=0&loop=0" type="application/x-shockwave-flash" allowfullscreen="true" allowscriptaccess="always" width="400" height="233"></embed></object>
</html>

==Product Ecology==
[[Image:2b-Genfabecology.png|600px|thumb|General Fabrication [[Product Ecology]]]]

'''Made with'''
*{{Induction Furnace}} - Steel
*{{Multimachine}} - Precision Guides, bearings

'''Creates'''
*{{Lifetrac}} - Plates, holes
*{{CEB}} - Holes
*[[QA Plates]]

See [[Product Ecologies]] for more information.

==Components==

*[[Motors]]
*[[XYZ Table]]
*Frame
*[[Torch]]

==Specifications==

==Status==
'''Prototype I'''
Currently being used in experimental production runs. Tighter integration of [[Digital Fabrication]] is being researched as is the software toolchain (which is a current bottleneck).

'''Prototype II'''

*First step: perfection of mechanical design for replicability to 1/32" over 4x8' area
*Need open source controller, end stops, and z height automation/detection.
*We could use existing structure, with modifications. Right now we use gear rack. We can simplify the carriage structure.
*If we want to go all out - we could use full gas flow control - but that is probably beyond the scope of the present program - as it would require expensive parts until we can manufacture them ourselves.
*Open source [[stepper motors]] would be a good addition - if we could find somebody to design/fab them - that would be great.
*Computer vision for fully automated cutting would be the last step.
*Next steps: stiffening frame design to accommodate router heads
*Interview with owner of Ben's excellent DIY table setup in Smithville, TX:
<html>
<iframe width="640" height="360" src="https://www.youtube.com/embed//uebW4jhIiro?rel=0&hd=1" frameborder="0" allowfullscreen></iframe>
</html>
*[http://www.candcnc.com/ CandCNC setup used by Ben (dragon-cut 620 AIO); $1478]

==Suggested steps from [[Luke Iseman]]==
video of ben's setup:http://opensourceecology.org/wiki/CNC_Torch_Table
photos of OSE's current table, including measurements:
http://opensourceecology.org/wiki/Torch_Table_Build
DIY standalone sensor ideas:
http://opensourceecology.org/wiki/Sensing_Distance_from_Work_Piece .
note particularly the circuit i found for an independent z-axis
control
CNC circuit mills: http://opensourceecology.org/wiki/CNC_Circuit_Mill
. comparison of existing kits, and updated parts list on mantis 9 (
http://opensourceecology.org/wiki/Mantis_9 )

recommended next steps:
1. get the candcnc.com 's dragon-cut 620-4 and implement on the
current table. utilize your same bearing setup for the z-axis.
2. build the mantis 9 , but use the snaplock electronics.

=See Also=
*[[Torch Table Build Prototype 1 Completion]]
*[[Torch Table Specifications]]
*[[Open_Source_Torch_Table_Prototype_II]]

*[http://openfarmtech.org/weblog/?p=1424 Blog Post]
*[http://en.wikipedia.org/wiki/Cnc Wikipedia: CNC]
*[[Torch]]

{{GVCS Footer}}

Category:Torch Table

2012-06-05T07:09:59Z

Logari81: /* Introduction */

=Introduction=

This page keeps track of all the pages related to the open source CNC torch table, and serves as an annotated bibliography for all the torch table pages.

Currently work being done here: [[Open_Source_Torch_Table_Prototype_II]]

[[Category: RepLab Tools]]

Open Source Torch Table Prototype II

2012-06-05T07:03:08Z

Logari81: There are two categories: "Torch Table" and "CNC Torch Table", I am dropping the second one

=Introduction=

See table that we are pursuing from Ben, Texas, USA. An [[OSE Specifications]] compliant design with hundreds of hours of use, and capable of CNC router duty.

*Need open source controller, end stops, and z height automation/detection.
*Open source [[stepper motors]] would be a good addition - if we could find somebody to design/fab them - that would be great.
*Computer vision for fully automated cutting would be the last step.
*Next steps: stiffening frame design to accommodate router heads
*Interview with owner of Ben's excellent DIY table setup in Smithville, TX:
<html>
<iframe width="640" height="360" src="https://www.youtube.com/embed//uebW4jhIiro?rel=0&hd=1" frameborder="0" allowfullscreen></iframe>
</html>
*[http://www.candcnc.com/ CandCNC setup used by Ben (dragon-cut 620 AIO); $1478]

=Videos=
This is Ben's table, and our gantry has several improvements:

<html><iframe width="420" height="315" src="https://www.youtube.com/embed//yTzDtb3oKX4" frameborder="0" allowfullscreen></iframe></html>

More videos of FeF Torch Table parts being prepared by Ben are found on James' YouTube:

http://www.youtube.com/TehSlade

=Strategy=

Design and parts are at Factor e Farm. [[Darren Vandervort]] is doing the [[Open Source Stepper Motor Controller]] design and fabrication. [[Yoonseo Kang]] is doing the USB-Arduino toolchain integration. [[Chris DeAngelis]] is doing 3D CAD. 2D component drawings already exist. [[Jose Bravo]] will be doing the table fabrication.

=CAD=

===Sketchup===
[http://dl.dropbox.com/u/20960013/OSE/OpenSourceEcologyTorchTable.skp sketchup file]<br/>
[http://dl.dropbox.com/u/20960013/OSE/IsometricScreenshot.PNG Overall Screenshot]<br/>
[http://dl.dropbox.com/u/20960013/OSE/Detail1.PNG Detail 1] the new tensioning system which is designed to push or pull he flatbars equally, creating a desired curvature which will increase stability.<br/>
[http://dl.dropbox.com/u/20960013/OSE/Detail2.PNG Detail 2] the adjustable table feet, these will minimize destruction to the workshop floor by distributing the load.<br/>
[http://dl.dropbox.com/u/20960013/OSE/Detail3.PNG Detail 3] a tilted side view of the flat bars angle irons, 3/16 wall square tubes and the long axis tracks.<br/>
[http://dl.dropbox.com/u/20960013/OSE/Detail4.PNG Detail 4] is a view of the underside of the table, rectangular tubes have been replaced with 3/16 wall 2 inch square tube in an effort to streamline production and bolster integrity through consistency<br/>
[http://dl.dropbox.com/u/20960013/OSE/Detail5.PNG Detail 5] shows where an example plate of steel would sit, if it were to be cut. This image illustrates the potential of the Z axis, and how low it will be able to cut.<br/><br/>
Todo: Exploded parts diagram, parts list (frame only) [[User:Chris DeAngelis|Chris DeAngelis]] 01:16, 5 June 2012 (CEST)
===DXF===
Torch table frame:

[[File:cncttp2struc.zip]]

X, Y, and Z gantry parts:

[[File:cncttp2gantryparts.zip]]

[[Category:Torch Table]]

Category:Torch Table

2012-06-05T06:57:56Z

Logari81:

=Introduction=

This page keeps track of all the pages related to the open source CNC torch table, and serves as an annotated bibliography for all the torch table pages.

Currently work is done here: [[Open_Source_Torch_Table_Prototype_II]]

[[Category: RepLab Tools]]

Quick Connect Wheels

2011-12-10T19:59:58Z

Logari81: /* Reducing loads on the shafts and bearings */

See Design Challenge - http://grabcad.com/challenges/lifetrac-quick-connect-wheels

=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 load on the roller element bearing close to the wheel will approximately be halved and 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 - sorry, this won't work, still need bearings and shaft
*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;
*Use tracks
*Use [[Cushion Valve]] to prevent localized pressure spikes
*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=
*Use 2 motors per side, and same drive train as in [[LifeTrac Wheel Assembly Video]], but with [[Splined Shaft Motors]]
*Use no tracks, but [[50/50 Flow Divider]]
*Use double relief valve ([[Cushion Valve]]) to prevent localized pressure spikes
*Do motors 'fight each other' in this case? They may, but they won't break due to double relief valve.
*The new splined motors are [https://www.surpluscenter.com/item.asp?item=9-9327&catname=hydraulic these from Surpluscenter]:
=Pathway 4=
*Same as Pathway 3 but with [[https://www.surpluscenter.com/item.asp?item=9-8092&catname=hydraulic]]

=Pathway 5=
*Same as Pathway 4 but with [https://www.surpluscenter.com/item.asp?item=9-7703&catname=hydraulic] for traction of 4200 lb, comparable to a F250 pickup truck, matching maximum available traction from 16" truck tires

=Peer Review=

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

Quick Connect Wheels

2011-12-06T09:51:15Z

Logari81:

=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.

=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 [[File:Wheelmodel_3.FCStd]]

=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]]

File:Wheelmodel 3.FCStd

2011-12-06T09:47:07Z

Logari81:

File:Wheelmodel 3.png

2011-12-06T09:44:19Z

Logari81: