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Open Source Tractor – LifeTrac 6 Challenge


Open Source Ecology challenges you to refine the design of an open source tractor.

We are building a modular tractor. The technical requirements are shown at LifeTrac 6 GrabCAD Challenge on our wiki.

This includes:
(1) stock materials to use
(2) design requirements
(3) The main point to achieve is sound design of the loader arms, with proper height reach, using simple building materials and components.

Overall, goal is to develop a 'Lifesize Erector Set'. We are an open source project, so the tractor will be dedicated under a CC-BY-SA license.

Full story about LifeTrac 6


The specifications, requirements and technical details will be updated by August 26 based on your questions and feedback so there is enough time for everyone to ask questions, talk with OSE and GrabCAD and make sure GrabCADrs know what to work on and what OSE expects.


  • The design should be built from existing design - see the design files in Sketchup. All files can be downloaded from LifeTrac 6 wiki

  • Use stock tubing, plate and pivot plate for all major structures:
    - Use 4" x 4" x 1/4" square tubing - all tubing is 1/4"
    - Use Stock Plate and Pivot Plate - all plate is 1/2"
    - Use 8" x 16" bonding plates
    - Use 3" shaft for pivots

  • There are specialized components that fill in the rest of the design - such as hydraulic cylinders, some weldments, etc.

  • Wherever maximum structure is needed, use XYZ corners.

  • Use stock bonding plates for joining 2 (adjacent) parallel square tubes - whether adjacent or not (can allow 8" space between parallel tubes).

  • Minimum height cab that allows operator to fit & see & be protected.

  • Must use given PowerCube dimensions or take Power Cube File:
    - Power Cube dimensions are determined by fitting all components from PC6 - into the square tubing frame.

  • Works with 1 structural Power Cube, or more Power Cubes can be added by using 4 bolts to attach towards the rear. Allow use of a single or more power cubes.

  • 1" holes in tubing can be used as mounts for 1" pins.

  • Cab is 3' wide outer distance.

  • Tractor is minimum width that allows modular wheel mount fit.

  • Tractor has a safety cab, entry though front.

  • Rear of tractor with ground hug pivot has lowest center of gravity as possible.

  • 2500 PSI system pressure.

  • Allowance for larger power cubes in the future.

  • 3" pins (and cylinder pins) have a head on one side and safety pin (drilled through) on the other.

  • Roll bar function is included. A closed driver cab with XYZ corners serve this purpose.

  • Seat belts are used.

  • Start key activated within cab.

  • Use a wheel locking for the drive control - cylinder valve.

  • Loader: 7' reach upon, appr. 60 degree dump of bucket - measured at bottom tip of bucket. This helps to dump moist soil, such as into a CEB hopper with grate where lower lip is 6' and grate slopes up.

  • When loader is in lowermost position, the bottom of the loader foot is on the ground level in the plane of the bottom of the wheels - when tilting bucket down, allows digging.

  • Curling the wrist pivot up in the lowermost arm position allows you to drive the tractor without digging.

  • The loader forearm bar needs to be flush with the front of the tractor cab in the lowermost loader position.

  • Allowance for loader cross-bar for stabilization somewhere on loader.

  • Articulations: get about 30 degree turning angle in both directions.

  • Ground-hugging pivot allows all 4 wheels to stay on the ground at all times.

  • Ground-hugging pivot allows for 10+ degree twist of tractor rear (about 16" over an 8 foot wheelbase).

  • Pivot steering and forward motion need to occur at the same time.

  • Submitting CAD format Sketchup format is preferred – so that the full designs are accessible to anyone in the world - or it could be exported into STEP format so we can import into Sketchup.

  • Full details, files and requirements on LifeTrac 6 wiki

Download specification


  • The competition is open to everyone. Multiple entries are acceptable. Team entries are welcome - prize will be transferred to team leader.

  • Tag your entry with “lifetrac6” when uploading to GrabCAD. If you submit through the "Submit entry" button, this should be added automatically. Only entries with valid tag will participate. Only entries uploaded to GrabCAD through the "Submit entry" button on this Challenge page will be considered an entry.

  • The winning designs become the intellectual property (IP) of the Challenge sponsor.

  • By entering this competition, you 1. Warrant that the work is your original work. 2. To the best of your knowledge, it is not, and has not been in production or otherwise previously published or exhibited. 3. Neither the work nor its use infringes the intellectual property rights (whether a patent, utility model, functional design right, aesthetic design right, trade mark, copyright or any other intellectual property right) of any other person.
    If you think an entry may infringe on existing copyrighted materials, please email challenges@grabcad.com.

  • Applicants are not entitled to any compensation or reimbursement for any costs. The applicant’s participation shall not constitute employment, assignment or offer of employment or assignment.

  • Winning designs will be chosen based on the rules and requirements. This Challenge starts on August 26, 2013 and ends on September 22, 2013 (11:59pm UTC). Winners will be announced by October 22, 2013.

  • The sum of the Awards is the total gross amount of the reward. The awarded participant is solely liable for the payment of all taxes, duties and other similar measures if imposed on the reward pursuant to the legislation of the country of his/her residence, domicile, citizenship, workplace, or any other criterion of similar nature.

  • We will release the finalists before the final announcement to give the Community an opportunity to "vote" for their favorites in the comments. The jury will take these into consideration when picking the final winner. This new addition is based on feedback from you!

  • Criteria upon which the entries will be judges: design.


Prizes for top 5 places

1st Place

Tractor will be named after the winner. The official name of tractor will be LifeTrac 6 - ________ Edition. The name of winner will be published on our blog – with any prototype 6 machine carrying that name. Plus, free admission to the September 28, 2013 build of the OSE Microhouse to see tractor in action.

2nd Place

Free admission to the September 28, 2013 build of the OSE Microhouse to see tractor in action + GrabCAD shirt and mug.

3rd Place

Free admission to visit Factor e Farm, the headquarters of Open Source Ecology + GrabCAD shirt and mug.

4th-5th Place

GrabCAD shirt and mug.

About the jury?

The jury is comprised of experts from Open Source Ecology and GrabCAD teams.

About Open Source Ecology

Open Source Ecology is a non-profit organization. The mission of Open Source Ecology (OSE) is to create the open source economy. An open source economy is an efficient economy which increases innovation by open collaboration.


We have updated our terms in order to better protect your hard work and keep our challenges running smoothly! To submit your challenge entry, please read and accept the new Challenge Terms and Conditions.

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