A wheeled version of the Universal Track Unit, where wheels can be added on top of the tracks simply via a recessed accessible shaft

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2017 version of the self-contained Universal Wheel Unit - wheel-based only, works and has been interchanged between LifeTrac v16, LifeTrac VII, and LifeTrac VI - as well as the Microtrac proofs of concept MicroTrac Prototype 1, MicroTrac Prototype 2. Universal wheel unit was not used in production on the MicroTrac because of its size and thus requirement for the non-symmetric track design. Production Microtrac version (in house use) of MicroTrac v17.10 utilized dedicated smaller motors with sprocket mounted directly to them, without the frame superstructure.
Universal Wheel Unit was also used in the Trencher 2013_Prototype
In 2023, LifeTrac VI is in use. It appears that the key came loose and Universal Wheel Unit would need to be disassembled to replace the key. This may be done in the future, but right now (2024) the tractor is operating with 2 wheel drive with the rear drive disconnected. Fix job is estimated to be 4 hours - removal of Universal Wheel Unit, wheel, shaft removal, replacement of key - then reassembly. Lessons - this type of deep repair must be streamlined. Further modularity is required, so from 2024 onwards we are looking at one single motor size, chain geardown to with 120 Chain, with replaceability of motor in 5 minutes and replaceability of geardown in 5 minutes with quick release sprockets and couplers. LifeTrac v16 has demonstrated 3500 lb torque drive system with clamp couplers - though the couplers are quite lengthy at about 12".

Universal Wheel Unit