The incredible screw drive tractor is back. We’ve covered the previous test ride, which ended with a bearing pillow block ripping in half, but since then, again, a lot of repair work has been done. [REDNIC79] reinforced the load-bearing parts and put on a fresh pair of “tires”. The result is still as unbelievable as the previous versions, but it now propels itself forward at a blazing 3 mph (this time without tearing itself apart).
[REDNIC79] walks us through all the details of the improvements he made since the first version. After the last failure, he figured, that a larger screw pod diameter would give the vehicle a better floatation while smaller thread profile would prevent the screws from digging too deep into the ground, thus reducing the force required to move the vehicle forward.
[REDNIC79] found four identical 100 pounds, 16 inch diameter propane tanks to build the new pods from. The tanks were a bit too short for the tractor, so he cut open two of the tanks and used them to extend the other two before welding a double thread screw onto each. He also tapered the front ends of the tanks to make the ride even smoother. After mounting the new pods to the speedster, a pair of custom steel chain guards were added to prevent rocks from getting into the chain. And then, it was time for another test ride. Enjoy the video:
Continue reading “Screw Drive Tractor Is About To Conquer Canada”
[REDNIC79] lives somewhere in Canada where key terrain features include mud and snow. Half pontoon boat, half auger, screw-propelled vehicles excel in this kind of terrain as long as you’re okay with going really slow.
In his 11-and-counting part video series, [REDNIC79] goes through the conversion of a lawn tractor into a slow, theoretically unstoppable, Canadian screw-propelled tractor. He welds a frame, plonks some beefy chains on it, and throws a few hefty looking bearing mounts on there to boot. Then he makes some screws out of gas tanks; which was an enormous amount of work.
It was time to fire up the tractor. On the first muddy incline encountered, the tractor ceased to move. The culprit? A cracked transmission housing. Ouch. The end of the shaft holding the chain for the right screw was unsupported. When the shaft turned, it imparted its rotational force, but there was also an unconsidered down force on the end of the shaft, which resulted in a moment the bell housing wasn’t designed for.
Undeterred, [REDNIC79] welded the housing back together and threw a bearing on the end of the offending shaft to balance the moments. He fired it up, engaged the transmission, and the right screw bearing pillow block completely shattered. Ouch again. We can safely begin to assume that screw-propelled vehicles see a lot of forces.
[REDNIC79] hasn’t shelved the project yet. His next plan is to beef up the supports and build a much larger set of screws with smaller blades out of some propane tanks. This should reduce the force the power house needs to put out. Video of the first fail after the break. Continue reading “Screw Drive Tractor Hasn’t Conquered Canada Yet”