pic: Base Idea


any one have feed back on this drive base wondering what i did wrong or right or should i be changing things.

direct center wheel drive
35 chain
13f/s and 5f/s

I would use 25 chain
mike d

Looks pretty good.

I’m not sure why so many teams use the 80/20 like this. 80/20 always seemed more useful for attaching things to the sides rather than the ends. But thats just my opinion. Your way would make attaching a manipulator a breeze.

How are you tensioning the chains? Maybe you aren’t tensioning them at all? You can get away without tensioners with #35, if you do have tensioners I’d suggest using #25 for weight.

5fps is way to slow… At least it was for this years game… :frowning: Believe me, that was our low gear and it was useless. I’d suggest 8 fps for the low gear. 8fps was a good speed for our low gear in '07.

38 lbs. seems reasonable, but don’t be suprised if it pushes 45 lbs. Nothing wrong with that, just my estimate.

Are the wheels wooden? How do you attach the treads and what kind do you use? Seems like a clever way to make a wheel.

I like how you CAD’ed the bumper mounts. Good to see you’re paying attention to the details. :]

your only putting two bearings on the axles right? because i see your inner wall is a tube and has a bearing on the inside, and i can’t see the other side. But you only really want 2 bearings fixed for an axle.

you might want to add in the shifting mechanisms (servo or pneumatic) to be sure you have ground clearance / protection for those devices. with the motors mounted up, all of the shifters would be low - possibly below the bottom of the transmissions?

You will want to support your transmissions more than you are, with four contact points instead of just two. Either support the two rear bolt points on the transmission or support the two upper front bolts. There would be flex during an impact that would leave your transmissions misaligned afterwards.

I’m with some of the others; go with #25 chain (4 chains total), especially if the center wheel is dropped. With the center wheel dropped, most the traction comes from the center wheel. Also, is it all to scale? I know we had a similar setup in 2007 and we didn’t have enough room for pneumatic shifters. We had to make an adapter to make it all work. Of course, this was with the AM Gen2 Shifters and no the Supershifter. I’m not familiar with the size of the supershifter, but I do believe it is a bit thinner.

ok this is whats going on:

the wheels are 5in plywood our team has much experience with them and they have never failed us. the treads are contact cemented and then wood screwed in. yes its 35 chain if its going to defense. the tensioner s are sprockets that are in a slot the movement is controlled by 2 vertical screws each. the axles are all supported in only two places. and thanks for bringing up the pneumatics i never actually thought of it not fitting but i believe it will fit. also the am ss are supported with 4 .25" bolts.

Looks good. Here a couple of suggestions:

  1. I would take a look at self aligning bearings. By the looks of it you are just using a standard flange bearing. How are you retain the bearings

2.)You might also consider putting the sprockets on the outside of chassis as it would be easier to work on once you put a mechanism on top.

3.) Consider modifying it so you can easily remove an entire side of the chassis.

4.) You have a large rectangular piece of tubing for the inside mounting rails. That seems a little excessive. You might just consider mounting you entire wheel assembly into a large piece of tubing instead.

Hope this helps

the axles that run thru the bearings are drilled and taped for 10-32s so the bearings will be kept in by washer and bolt. also the sides are easily detachable for servicing sides are held together by standoffs. we run the same type of system on our gear drive base for the sides and it comes apart in a minute with a drill.