Quote:
Originally Posted by Chak
Nice and light; too bad it'll never see the light of day. I'm looking at GrabCAD right now, and I have some questions.
Is it worth it to machine a rim onto the custom wheel if rivets on the tread already hold it on?
How is the bevel gear attached to the wheel?
For the 4 little spacers/bearings on a bolt that help hold the 72t turning gear onto the main plate, do they do anything the delrin groove ball bearing doesn't do? I guess they could just be helpers, but I can imagine that tiny bearing breaking if it has to take the whole weight of the robot.
On a side note, I have no idea why some of your bolts have blue threads.  |
The wheel is 3D printed and pressed onto the bevel gear, although you could probably throw it on a CNC or lathe now that I think about it. It has I think a 0.014" interference fit (similar to colson wheels).
It has a rim, because if you want to get away without one you need a lot more rivets, and you have to put more care in attaching the tread. We found out about that on our 2012 robot after the tread wore out.
The delrin groove bearing takes all the load in normal operation. The only time the small bearings are called upon is when the module lifts off the ground and the module is free-spinning. I might add a bit more vertical clearance to that due to the possibility of odd loading.