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| {{site header}} | | {{Lang|LifeTrac}} |
| <center>
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| LifeTrac, the low cost multipurpose open source tractor.
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| [[Image:lifetrac_loader.jpg|thumb]]
| | <html><iframe src="https://player.vimeo.com/video/49216792" width="500" height="281" frameborder="0" webkitAllowFullScreen mozallowfullscreen allowFullScreen></iframe> <p><a href="http://vimeo.com/49216792">The LifeTrac Story 2012.</a> from <a href="http://vimeo.com/opensourceecology">Open Source Ecology</a> on <a href="http://vimeo.com">Vimeo</a>.</p></html> |
| [[Image:lifetrac_bend.jpg|thumb]]
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| [[Image:Backhoe.jpg]]
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| <ehtml>
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| <br><br>
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| <object width="480" height="385"><param name="movie" value="http://www.youtube.com/p/28958DE807A18811?hl=en" /><embed src="http://www.youtube.com/p/28958DE807A18811?hl=en" type="application/x-shockwave-flash" width="480" height="385"></embed></object>
| | {{Header Parent|ToolParent=LifeTrac|ToolName=LifeTrac III|}} |
| | [[Image:LiftTracWithTracks.jpg|thumb|right|400px|LifeTrac Tractor - Prototype III]] |
| | [[Image:ltonfire.jpg|thumb|Night time photography on LifeTrac IV by Parker 2012]] |
| | =Overview= |
| | [[LifeTrac]] is a low-cost, multipurpose open source tractor. It serves as a workhorse backbone for many of GVCS technologies. Prototype III stage has been completed, and field testing determined the need for Prototype IV prior to product release. |
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| <br>
| | Featuring a modular design and detachable [[PowerCube]] units, it has the ability to rapidly switch between a variety of GVCS machines and/or Commercial [[Of-The-Shelf]] tools via the [[QA Plate]]. The machine is overbuilt with a focus on lifetime design and ease of repair. |
| See corresponding <a href="http://openfarmtech.org/weblog/?p=480"> blog post</a>
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| </ehtml>
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| </center>
| | Four hydraulic motors provide skid steer power to the wheels, and a chain tread system enables navigation of extreme terrain. |
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| =LifeTrac Concept= | | Join discussion at [https://news.ycombinator.com/item?id=28827785 Hacker News] - tractor discussion got the longest thread on Hacker News so far. |
| | ==Details== |
| | Latest version of LifeTrac as of Jan. 2013 is LifeTrac IV - with [[Quick Connect Wheels]] and [[Bent Loader Arms]], where III had straight arms and non-detachable wheel units. |
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| OSTrac is an open source tractor/ loader. It is an articulated tractor that steers by bending in the middle. It also has a flexible coupling between the front and back, so that the wheels stay on the ground at all times.
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| It is based on [http://www.cadplans.com/cadtrac.htm CADTrac, a set of plans that you can buy]:
| | ==Versions== |
| | See [[LifeTrac Genealogy]] |
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| [[Image:CADTrac.jpg]]
| | =Remote Repository= |
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| But it is redesigned thoroughly by enlarging the size and making construction simpler.
| | [https://github.com/Amakaruk/OSELifeTrac Lifetrac Github Repository] |
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| ==Goals== | | =Distributed Collaboration= |
| *Lifetime design
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| *Scalable
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| *Modular
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| *Easy to maintain
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| ==Features==
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| It has a number of features that set it apart from skid loaders and make these vehicles suitable for agriculture. The main features for agriculture are a 3-point hitch, power takeoff, and high-flow hydraulic takeoff. These features make the [[LifeTrac]] capable of using any agricultural implements.
| | [[Distributed Collaboration]] is a way to manage the digital files that describe the machine in such a way that people all over the world can work together through the internet. The process is made up of three steps: definitions, projects and reports. |
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| LifeTrac is also designed with a winch, and is designed to be equipped with well-drilling equipment with 10-foot drilling pipe sections. | | [[LifeTrac III Definitions]] |
| | The definitions are any files that specify what the pieces of the machine are. An experience fabricator would be able to make all the pieces from just these files. |
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| As such, the design is one of highest utility and versatility, combining the power of skid loaders with agricultural tractors and construction tractors. A Compressed Earth Block press [[CEB Press]] is designed for use as an implement with [[LifeTrac]], and a backhoe as well.
| | [[LifeTrac III Projects]] |
| | The project(s) is a database that turns the definitions into steps which, if all accomplished, will result in a finished machine. At the moment, we're just using an existing project management program. |
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| The unique feature is the modularity and design for dis-assembly. Priority one is lifetime design, where any problem can be troubleshooted and fixed readily. Bye-bye to $1-2,000 transmission jobs at the shop. No transmission is required - it's built-in to the hydraulic drive. | | [[LifeTrac III Reports]] |
| | The report(s) is a polished document that compiles all the definitions and project steps together in a way that is easy to follow. Additionally, the report includes background, context and any other piece of information that is relevant to the machine but is not strictly related to making it. |
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| Components are designed to be standard steel as much as possible. The goal is to have the user-owner fully capable of maintenance. By design, no issue in LifeTrac should be more expensive than $250 to fix. Standard steel components (sheet, tubing, shaft, etc.) is used, with no forming or machining outside of minor welding and lathing, for repair and construction of [[OSTrac]].
| | =Product Evolution= |
| | Use the Product Evolution tree below to learn about the different versions of the LifeTrac and how far they got in product development (shown in italics). Follow the arrows to see where branching occurs. The dashed outlined represents the most complete documented version to date and tested at FeF. |
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| ==General design goals==
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| *Skid loader concept
| | {| style="text-align:center;" |
| *Articulated steering
| | ! Major Design <br> Style |
| *4 wheel drive
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| *2 wheel drive for doubled speed
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| *Front-end loader
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| *Backhoe attachment available
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| *Well-drilling attachment available
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| *CEB attachment available
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| *Hybrid between a skid loader, agricultural tractor, and construction tractor
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| ==Specifications== | | |- |
| | | '''Articulated <br>Design''' |
| | | [[File:LifeTrac.jpg|100px|link=LifeTrac I]] |
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| | | [[File:Arrow_right.jpg]] |
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| | | [[File:LifeTrac4_(v5)_snip2.PNG|100px|link=LifeTrac 5]] |
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| | | [[File:Arrow_right.jpg]] |
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| | | [[File:Lifetrac6.jpg|100px|link=LifeTrac_6]] |
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| | |- |
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| | |'''[[LifeTrac I]]''' <br> ''Prototype 1'' |
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| | |'''[[LifeTrac 5]]''' |
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| | | '''[[LifeTrac_6|LifeTrac 6]]''' |
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| | | [[File:Arrow_down.jpg]] |
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| | | [[File:Arrow_up.jpg]] |
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| *5-10 mph in 4 wheel drive
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| *29 gpm auxiliary hydraulics, 3 channels
| | | '''Skid Steer <br>Design''' |
| *Weight: 3000 lb
| | | [[File:LTIICompleted.jpg|100px|link=LifeTrac_II]] |
| *Modular: 2 OSTracs may be mounted together for double traction power
| | | [[File:Arrow_right.jpg]] |
| *3500 lb winch
| | | style="border:3px dashed green"|[[File:LiftTracWithTracks.jpg|100px|link=LifeTrac III]] |
| *55 hp Deutz diesel engine
| | | [[File:Arrow_right.jpg]] |
| *Four 32 cubic inch hydraulic motors
| | | [[File:LifeTracIII_bent_arms.PNG|100px|link=LifeTrac_IV]] |
| *3-point hitch
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| *Power take off, hydraulic - 0-700 rpm
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| ==Maintenance==
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| *Yearly maintenance costs designed to be no more than $100 with heavy duty usage
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| :What are the key points in a maintenance check?
| | | '''[[LifeTrac_II| LifeTrac II]]''' <br> ''Prototype 1'' |
| :What are the skill sets required to perform a systems check accurately?
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| | | '''[[LifeTrac III| LifeTrac III]]''' <br> ''Documentation'' |
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| | | '''[[LifeTrac IV| LifeTrac IV]]''' <br> ''Retrofit'' |
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| ==Evolution== | | |- |
| *Flash-steam bladeless turbine drive being explored
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| *Flash-steam electric hybrid drive being developed
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| | | [[File:Arrow_down.jpg]] |
| | |- |
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| | | [[File:LifeCat 1.0.png|100px|link=LifeCat 1.0]] |
| | |- |
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| | |'''[[LifeCat 1.0| LifeCat 1.0]]''' <br> ''R&D'' |
| | |} |
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| =Versatility= | | =Safety Concerns= |
| | No structural engineering analysis has been performed on the LifeTrac III or IV. If you choose to replicate this product you are doing so at your own risk and with this understanding. We will be performing analysis soon and will post those results as we get them. |
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| For us at [http://openfarmtech.org/weblog/ Factor e Farm], LifeTrac will be the backbone of our agricultural, agroforestry, and land stewardship operations. It will also be used in construction, power generation, and possibly other workshop tools. Interestingly, hybrid hydraulic drive also applies to cars - here's an example [http://www.fordmuscle.com/blog/ford-to-build-60-mpg-f150/112114]. The identical hydraulic design, minus agricultural implement features - can be used with a car - simply by using faster, lower-torque wheel motors.
| | There is also [https://groups.google.com/group/ose-europe/browse_thread/thread/3d0fcd5477ea94a4 an email] to OSE Europe mailing list describing some concerns about LifeTrac safety of use, and points out possible issues with: Frame, Steering, Brakes and Roll-Over Protection. |
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| The basic drive is all hydraulic, and all implements are run hydraulically as well. Three hydraulic motors - PTO motor, high torque motor, and winch motor are used for accessory power applications. These can drive the following devices which we are also building contemporaneously:
| | =Product Ecology= |
| | {{Product Ecology |
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| *Tilt-blade sawmill
| | |From= |
| *Rototiller
| | *{{Power Cube}} |
| *Post-hole digger/tree planter
| | *{{Hydraulic Motor}} |
| *Mixer | | *{{Induction Furnace}} Steel |
| *Winch | |
| *Well-drilling rig (future work) | |
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| Other implements that we are preparing are:
| | |Uses= |
| *[[CEB Press]] | | *{{Power Cube}} |
| *Backhoe
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| *Trencher
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| The unique feature is that the motors can be mounted on the front-end laoder quick-connect plate - which serves, in effect, as an implement attachment mechanism that is much more versatile than a tractor 3 point hitch. All implements may be mounted on the quick-connect
| | |Creates= |
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| As of 5.24.08, the current working program surrounding LifeTrac is:
| | |Enables= |
| [[Image:LifeTrac program.jpg]]
| | *{{CEB Press}} |
| | *{{Rototiller}} |
| | *{{Backhoe}} |
| | *{{Universal Rotor}} |
| | *{{Well Driller}} |
| | *{{Trencher}} |
| | *{{Baler}} |
| | *{{Seeder}} |
| | *{{Spader}} |
| | *{{Rototiller}} |
| | *{{Hay Rake}} |
| | *{{Hay Cutter}} |
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| =Articulated Tractor Design=
| | }} |
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| After examining the function of skid-steering, we decided to add articulated steering with a 2-degree of freedom flexible coupler. The tractor can both bend and rotate around the middle joint. This allows the tractor to minimize impact on the ground when turning. It also allows all 4 wheels to remain on the ground in uneven terrain - where otherwise it is likely that 1 wheel is off the ground often in uneven terrain.
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| [[Initial LifeTrac design]] is updated here:
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| ==Basic Frame== | | =Videos= |
| | {{Video:Tractor}} |
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| Here is the basic frame concept, made of 4x4x1/4" tubing.
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| [[Image:LifeTrac 2.jpg]] | | [[Category: Farm equipment]] |
| | [[Category: Earth moving]] |
| | [[Category:GVCS]] |
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| Here is the frame in practice, starting to be bolted together:
| | {{GVCS Footer}} |
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| [[Image:frame start.jpg]]
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| You can see our [http://openfarmtech.org/weblog/?p=201 blog] for additional information.
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| ===Other 2D Drawings===
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| See [[LifeTrac 2D Drawings]] for other views.
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| ==Engine, Wheel, Hydraulics Addition==
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| [[Image:lifetrac_bend.jpg]]
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| ===Engine===
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| Power plant selection will depend on intended fuel source.
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| A number of different fuel sources, which could be produced at a local scale, could be utilised.
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| ====Pure plant oils====
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| Oil plants can be grown and using simple technologies the oil extracted and used directly as fuel. A compression ignition (diesel) engine of suitable design is required to allow reliable operation with PPOs.
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| ====Biodiesel====
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| Biodiesel is a fuel made from plant oils. It involves chemically modifying the oil as to give it properties more closely resembling diesel fuel.
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| ====Biogas====
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| Biogas can be produced from biomass. It can be used to fuel spark ignition engines or used as the main fuel source for compression ignition engines which use a small charge of oil to begin each combustion event.
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| [http://en.wikipedia.org/wiki/Jean_Pain System for biogas and heat production from woody biomas]
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| ====Ethanol====
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| Ethanol is produced through fermentation of sugar and then strength is increased through distillation.
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| [http://wiki.obed.org.uk/index.php?title=Theory OBED Open Biofuel Engine Development wiki page detailing biofuels]
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| ==Loader Addition==
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| [[Image:lifetrac_loader.jpg]]
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| =Hydraulics Design=
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| ==Design Rationale==
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| Several aspects must be considered:
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| *Wheel Motor Control
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| *Turning Cylinder
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| *Loader
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| *Auxiliary Hydraulics
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| ===Wheel Motor Control===
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| A 50/50 flow divider is recommended to make sure that if the front wheels come off the ground with the loader, the back wheels still have adequate flow. Without using a divider, the wheels that come off the ground will spin fast and back wheels will stop - because hydraulic fluid takes the path of least resistance.
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| One way to address this is with a 50/50 rotary flow divider. Expensive option - such as this 21 gpm divider from Surpluscenter - [[http://surpluscenter.com/item.asp?UID=2008101313500912&item=9-5120-21&catname=hydraulic]]
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| What are alternative routes? What about a simple ''adjustable flow control valve''?
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| Would a 50/50 flow divider work - [[http://surpluscenter.com/item.asp?UID=2008101313500912&catname=hydraulic&qty=1&item=9-1048-c]]
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| ==Schematic==
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| Here is a schematic for the hydraulic power system:
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| [[Image:LifeTrac hydraulics.jpg]]
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| ==Hydraulics Part Sourcing==
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| Here are some of the part numbers from [http://surpluscenter.com Surplus Center]:
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| [[Image:LifeTrac hydraulics parts.jpg]]
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| Detail of hydraulic pump from Northerntool - [http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200329724_200329724] - and calculations -
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| ===Hydraulic Pump===
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| [[Image:hydgearpump.jpg]]
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| ===Hydraulic Motors===
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| These are used on each of the wheels and on the rototiller:
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| [[Image:wheelmotors.jpg]]
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| ===Calculations===
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| *1800 RPM gives 26 gpm, so 2000 rpm engine speed of the Deutz 55 hp diesel yields 29 gpm, at a max of 3300 PSI.
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| **From Surpluscenter tech support, [http://surpluscenter.com/techhelp.asp?UID=2009012117064247&catname=hydraulic] - we have:
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| [[Image:hydraulicscalculations.jpg]]
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| **Calculating engine power requirements for the above pump, we have PSI*GPM/1714=3300*29/1714 = 56 hp - or we won't get absolutely high 3600 PSI, '''but only 3300 PSI''', which is still sufficient for any applications.
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| ==Hydraulics Implementation Steps==
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| The first step of hydraulics implementation is the wheel drive circuit. This includes the hydraulic pump coupled to the engine, the hydraulic reservoir, wheel motors, control valve, cushion valve, hoses, and hydraulic return line filter. Before the main control valve is activated for driving the wheels, we test the pump by observing proper hydraulic fluid circulation back to the hydraulic reservoir. As a safety measure, the wheels are lifted off the ground, to oberve correct direction of motion of each wheel.
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| Wheel circuit:
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| [[Image:wheel drive circuit.jpg]]
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| Test procedure:
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| #Connect hydraulic pump, main wheel control valve, cushion valve, return filter, hydraulic reservoir.
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| #Turn on engine, observe flow through tank
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| #Connect wheel motors
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| #Disengage motors from wheels or lift wheels off ground, and test wheel motors
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| ##Observe correct forward and reverse motion
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| #Connect steering cylinder, priority flow divider, and steering cylinder valve
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| #Drive the tractor on even ground and test steering
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| ===Cushion Valve Plumbing===
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| From part [http://surpluscenter.com 9-4019-B] documentation:
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| [[Image:cushionplumbing.jpg]]
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| ===PTO Motor Connection===
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| [[Image:ptoplumbing.jpg]]
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| ===Post to [http://forums.hydraulicspneumatics.com/groupee hydraulics-pneumatics forum]===
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| http://forums.hydraulicspneumatics.com/eve/forums/a/tpc/f/8641063911/m/5881043582
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| Posted 24 May 2008 08:37 PM
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| Hello,
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| I am looking for suggestions on the design of the hydraulic system for an articulated tractor/loader that I am building.
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| Please view the hydraulics design. This includes a 55 hp diesel engine, and a series circuit. The circuit includes: (1), 4 reversible wheel motors for the drive; (2), double-acting turning cylinders for articulated steering; (3) front-end loader circuit; (4) 3 pairs of hydraulic take-offs with 12 gpm quick connects. See:
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| http://openfarmtech.org/index.php?title=LifeTrac#Hydraulics_Design
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| Please let me know if the design looks sound. In particular:
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| 1. Is this a sufficient pressure release for protecting the wheel motors:
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| http://www.surpluscenter.com/item.asp?UID=2008052417204...35&catname=hydraulic
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| 2. Is it better to do an adjustable priority valve: http://www.surpluscenter.com/item.asp?UID=2008052417204...50&catname=hydraulic
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| or a fixed flow control valve:
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| http://www.surpluscenter.com/item.asp?UID=2008052417204...-5&catname=hydraulic
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| for the first divider in the circuit?
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| 3. If I have a 24 gpm flow requirement for a load at the hydraulic takeoffs, is it ok to utilize two takeoffs to feed into one load? I am looking to run a 24 gpm reversible motor, with 12 gpm per takeoff channel.
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| 4. Is the 0-25 gpm flow control valve:
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| http://www.surpluscenter.com/item.asp?UID=2008052417204...75&catname=hydraulic
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| suitable for controlling the amount of flow to the hydraulic takeoffs?
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| Marcin
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| ----
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| REPLY:
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| Margin;
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| This forum is mainly frequented by persons in the Industrial Hydraulic & Pneumatic field.
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| Try your request at one of these sites:
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| http://www.offroadfabnet.com/
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| http://www.machinebuilders.net/forum
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| http://www.hydraulicinnovations.com/forum
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| Bud Trinkel
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| FP Consultant Retired
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| ===Post to [http://www.hydraulicinnovations.com/forum/showthread.php?p=2932#post2932 Hydraulic Innovations]===
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| This is my hydraulic circuit for a hydraulic, 4-wheel, articulated tractor:
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| http://openfarmtech.org/index.php?title=Image:LifeTrac_hydraulics.jpg
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| Is the priority flow divider and flow control valve, plus pressure relief valve for the wheels, sufficient to regulate the flow/prevent overpressure?
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| I am using:
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| 1. Pressure release for wheel motors:
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| http://www.surpluscenter.com/item.asp?UID=2008052417204...35&catname=hydraulic
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| 2. If I have a 24 gpm flow requirement for a load at the hydraulic takeoffs, is it ok to utilize two takeoffs to feed into one load? I am looking to run a 24 gpm reversible motor, with 12 gpm coming from each takeoff channel.
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| Marcin
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| =Quick Attach Plate=
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| ==Proposed Version==
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| The Quick Attach Plate converts the loader arms to a quick release mechanism for attachments.
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| [[Image:quick_attach.jpg]]
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| [[Image:latch_detail.jpg]]
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| ==Implemented Version==
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| Here is an easier version, with pins replacing turnable latches. This is the first implementation:
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| [[Image:quick_quick_attach.jpg]]
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| =Rototiller=
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| Initial rototiller design:
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| [[Image:quick_quick_rototiller.jpg]]
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| =Tooth Bar=
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| [[Image:toothbar.jpg]]
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| [[Image:tooth.jpg]]
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| [[Image:toothmaking.jpg]]
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| [[Image:finishedbucket.jpg]]
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| =Backhoe=
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| [[Image:Backhoe.jpg]]
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| =Bill of Materials=
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| *Wheels
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| **Shaft collars, 1-7/8", double split - 4 of them - [http://surpluscenter.com/item.asp?UID=2008101413105967&catname=&item=1-2768-193] - $6.75 each
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| *Tires
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| **Tire chain quick links, 18 per wheel - 1/4" - [http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92412] - 60 cents each
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| *Wheel control
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| **50/50 divider to allow equal flow to front and back wheels when front wheels come off the ground while doing earth digging with loader - [http://surpluscenter.com/item.asp?UID=2008101413105967&catname=hydraulic&qty=1&item=9-1048-c] - $88
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| =Bill of Materials for Industrial Counterparts=
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| *One tire and rim - a flat proof one - costs $500 for skid loaders - [http://www.radmeister.com/m-14765-743ds.aspx]. Compare to $5 used truck tires with $35 for open source chains - under $50 for a tire. The latter affords the same traction, at 10-100 times less cost, depending if you count the chains or not.
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| **Which is more cost effective over a lifetime?
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| **I've heard that you can fill a tire with insulation foam - as a dirt-cheap alternative to professional puncture-proofing gels. Has anyone done this?
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| I tried this with a small garden cart. My experience was that because insulation foams are non-elastic, once they are compressed, they stay compressed. This would cause a flat spot on your tire each time you hit a rock.
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| =Attachments on Other Machines=
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| *Dingo attachments - [http://www.toro.com/professional/sws/loaderattach/photogallery_attachments.html]
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| =Cost Comparisons to Industrial Counterparts=
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| [[Image:lifetraccomparison.jpg]]
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| *NOTE: Industrial prices are taken largely from Northern Tool catologue - [http://www.northerntool.com/] - your local, global supply chain.
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| *Commercial hydraulic rotary well drilling rig quote - [http://www.hydra-jett.com/1573687.html]
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| =Outstanding Tech Questions=
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| In terms of biofuels conversion, horses may be far more efficient than tractors. In no-till or low-till permaculture farming with local fuel production, tractors might not make sense at all.
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| http://www.lowtechmagazine.com/2008/04/horses-agricult.html
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| ==Response==
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| One would have to do more careful, side-by-side analysis on the above. A horse, whether used or not, eats the equivalent biofuel crop for 1 gallon of liquid fuel every day. A tractor, on the other hand, eats zero gallons of fuel in the same time period.
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| See [[LifeTrac Red Pages]]
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| [[Category:Hydraulics]] [[Category:LifeTrac]]
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| [[Category:Global_Village_Construction_Set]]
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| [[Category:OSA]]
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