1-16th scale radio-controlled Allis-Chalmers HD-41 and Fiat-Allis 41B.

The 1-16th scale radio-controlled Allis-Chalmers HD-41 and Fiat-Allis -41B are finished. The HD-41 is fitted with a Full-U tilt and multi-shank and the 41B is fitted with a severe service straight tilt and single shank. The drawings for these tractors were made by scaling photos and manufacturers spec sheet drawings. The frames were prototyped in ply and fitted with the rolling gear and drive motors to test the fit, drawings then modified as required and then the parts were laser cut in mild steel plate. The sub-assemblies were mig-welded using 0.6mm mig wire, the blades were rolled from the drawings using an adjustable slip roller to obtain the three radii required for the dig, lift and dump radius and corner sheets of each blade. Other parts such as the fuel and hyd tanks and hoods were shaped using a small sheet bender. Apart from the GET, the two model tractors are largely the same, some basic cosmetic changes are evident by the air intakes depending on which turbochargers, air filters and exhaust systems were used on the 1:1’s. You can see the 41B intakes are offset on this model since it was modeled of a particular 1:1 machine. They are each powered by a pair of 12v Ford F350 window winder motors geared down by 4:1using #25 roller chain and sprockets. The tracks are made using #35 K1 industrial attachment chain and sprockets with the grousers bolted on. The sprockets are keyed to ½ inch diameter steel drive shafts. I turned up the idlers and rollers on the lathe to fit the #35 track chain. The whole drive arrangement is very strong. The motors are controlled by PWM motor controllers powered by a 12v lead-acid motorcycle battery. They weigh approx 44lbs each and traction break on concrete is at 29lbs on the drawbar tested with a simple fish scale. The blade, tilt and ripper actuators were made on the lathe and mill. I had the paint mixed for the colors by a pro paint shop and sent the drawings for the transfers out to an outside supplier. The 41’s, like the T-800 and D575A-2, were welded up in a workshop with parts supplied by industrial suppliers. If we calc out the weight of the models at 44lbs in three-dimensions, compared to the 1:1 we are a little on the heavy side. The models are accurately 27 inches long. Since these photos were taken, I have fitted tilt cylinders as seen in the photo. Both models have been tested and work well. The action photos were taken during the first finished field tests We are currently working on line of sight programmable radio control units. These radio controlled models serve as the test units for this program. I will put some operational videos taken at the closed coal mine when we complete them. When the videos are completed they will be available on the Global General Robotics channel here: https://www.youtube.com/channel/UCGzwwUsynsd0iHu6VIUAeJA