pic: 6WD Sheetmetal Chassis

[apalrd]

For gearboxes, we actually used AM shifters with a final drive chain to a live axle. The gearboxes used 0.090" aluminum plates, and there were four slots in the frame where the gearboxes would bolt, and we could slide the entire gearbox up/down up to 3/4" or so to tension the final drive chain. The encoder was integrated into the AM shifter output. We really liked this design, and would do something similar again. The ability to change the final drive ratio was very nice, we changed it three times during the season.


On sheet metal alloy, we've had no trouble bending 6061 0.050" and 0.063" in our shop on a manual finger brake, but 5052 is easier to bend, especially thicker sheets. Using 6061 allows us to use thinner sheets.

[BrendanB]

Originally Posted by apalrd

For gearboxes, we actually used AM shifters with a final drive chain to a live axle. The gearboxes used 0.090" aluminum plates, and there were four slots in the frame where the gearboxes would bolt, and we could slide the entire gearbox up/down up to 3/4" or so to tension the final drive chain. The encoder was integrated into the AM shifter output. We really liked this design, and would do something similar again. The ability to change the final drive ratio was very nice, we changed it three times during the season.


On sheet metal alloy, we've had no trouble bending 6061 0.050" and 0.063" in our shop on a manual finger brake, but 5052 is easier to bend, especially thicker sheets. Using 6061 allows us to use thinner sheets.

Sounds like a very nice setup! Do you have any pictures to share?

[apalrd]

I don't have any pictures of the gearboxes. I'll see if I can take some soon.

[apalrd]

I took some pictures. Here are two.



The case bolts go all the way through both gearbox plates, the spacers, and the frame. There is a nut on the outer gearbox plate, then some washers, the frame panel, more washers and another nut. The frame panels have slots to move the gearbox up/down to adjust the chain tension of the final drive chain. The final drive ratio is 12:22, the final drive sprocket is an AM 22T with AM 500 hex hub. The CAD model will be released in the next week or so.