This is our teams first year, and as the title states, sorry in advance for posting a simple problem. Short of legos, no one on our team has ever built, designed, or had any experience with a “high tech” robot.
My question is, what is the preferable way to attach axles to the frame? It seems like such a hassle compared to the rest of the robot, but again, we lack experience.
The wheels we will probably use are the traction wheels on ifirobotics. They have bearings in their hub and the sprocket is attatched to the wheel, so I assume that the axle will not have to rotate at all? If not, should we use a clamp to attach it to the frame? Where would I obtain one? Should I make it? Can it attach firmly to C-channel? Am I even on the right track with any of these questions?
Welcome to FIRST! What an adventure you have before you…
Anyhow: You are correct, the axle does not rotate, it stays still and the outer part of the bearing rotates with the wheel. There are a zillion ways to attach an axle to a frame, but you should support the axle at both ends. The axle should be just a few inches long, not going from one side of the robot to the other.
You drive the wheel with a chain in the sprocket, the drive power might come from the CIM motor transmission with two (smaller) CIMs in it. (Note that this is but one way of doing it. There are almost as many motor/gearbox/drive configurations as there are teams)
I recommend going to the Robot Gallery and look at pictures. Also go to team websites. And, try to find a mentor who has some experience with this kind of stuff - like another nearby team!
And please, please - ASK QUESTIONS, we’re ALL happy to help. Just remember to searchhere before asking, your question will already be answered 99% of the time, and be sure to read the manual too, everything you really NEED to know is in there, somewhere.
Good Luck, and feel free to write me at any time, with any questions.
The suggested method of using a 3/8" bolt and attaching it to the frame (using additional nuts to prevent the wheel from sliding) will work quite well. The use of nylock nuts or loctite is also recommended. Just make sure that you can easily access the bolts if you need to replace a bent one (and bring spares to competition).
As Don said, there are many ways of attaching a shaft. Just make sure that you never cantelever your wheel at the end of a shaft if, and that every shaft is supported in at least two places. Don’t forget that just because the axle doesn’t need to rotate doesn’t mean that it has to be be prevented from rotating.