LifeTrac

LifeTrac Concept

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.

It is based on CADTrac, a set of plans that you can buy:

But it is redesigned thoroughly by enlarging the size and making construction simpler. The goal is to make it:

• Lifetime design
• Scaleability
• Modularity
• Easy maintenance

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.

LifeTrac is also designed with a winch, and is designed to be equipped with well-drilling equipment with 10-foot drilling pipe sections.

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 Eearth Block press is designed for use as an implement with LifeTrac, and a backhoe as well.

The unique feature is the modularity and design for disassembly. 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.

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.

General design goals:

• Skid loader concept
• Articulated steering
• 4 wheel drive
• 2 wheel drive for doubled speed
• Front-end loader
• Backhoe attachment available
• Well-drilling attachment available
• CEB attachment available
• Hybrid between a skid loader, agricultural tractor, and construction tractor

Specifications:

• 4.5 mph in 4 wheel drive
• 9 mph in 2 wheel drive
• 40 gpm auxiliary hydraulics, 2 channels
• Weight: 3000 lb
• Modular: 2 OSTracs may be mounted together for double traction power
• 3500 lb winch
• 60 hp 4.2 l GM engine (weak point)
• Four 32 cubic inch hydraulic motors
• 3-point hitch
• Power take off, hydraulic - 0-600 rpm

Maintenance:

• Yearly maintenance costs designed to be no more than $100 with heavy duty usage

Evolution:

• Flash-steam bladeless turbine drive being explored
• Flash-steam electric hybrid drive being developed

Articulated Tractor Design

After examining skid-steering as in the Initial Conceptual Drawings below, 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.

Initial Conceptual Drawings

OSTrac Frame

OSTrac Wheel Mounting

OSTrac Hydraulic System