We don’t have extra wheel bearings so we want to attach a wheel directly to the axle.
For FTC there were kind of like axle hubs we could screw into the wheel and onto the axle, and we were thinking of a similar approach where we’d put a bolt through some hub and through the lag bolt we’re using for the axle.
Is there something like this axle hub?
What type of wheels are you using?
If they are the kit wheels, you can use this hub made by Andymark. But you can only use this application if you have a keyed shaft. (i.e. direct drive)
Well the question is, what do you plan to do with a wheel that does not have bearings? Unless you don’t plan on it turning often, and you are not concerned with efficiency, I suggest getting more bearings. Andy Mark has quite a few hubs that will interface directly with their wheels.
In my humble opinion you really should buy more bearings, at the very least you should machine Delrin. Press fit it into where the bearing would fit in the wheel, with a .375 id.
Use a hub to connect it to a keyed shaft. Drive the shaft with a sprocket. Mount the shaft so it spins in bearings.
One way is called a live shaft. The other is a dead shaft. Both are perfectly viable options depending on the specific application.
Our team tends to use dead shafts for our wheels, visible in this photo:
But our shooter prototypes use live shafts:
Here is an evaluation of the pluses and minuses in one specific application: