Mounting Mecanum Wheels

I recently acquired some 8 inch mecanum wheels. I was going to try to mount them on a robot but learned I had no idea how. Is there a certain part I need to mount them to a standard drive shaft? I have most standard parts to work with.

8 Inch?!?!? Do you mean the VEX 4inch Mecanum Wheels?

VEX only has 4" mec wheels, so either that’s a typo or the wheels you have are not VEX wheels. If they are not VEX wheels, but you want to use them with the VEX system, you can drill out the hole in them (if needed), so a drive shaft fits through them, and then fasten the shaft so it won’t spin by screwing on lock bars, gears, sprockets, or anything with a square hole.

They might be talking about VEXpro Mecanum wheels. which come in 4", 6", and 8".

Take a look at this page for examples of how to use VersaHubs to mount VEXpro wheels:

Here’s one specific example:

Yeah, those look right, I will take a look.

Do I need a separate part other than the wheel for that system?

Do those adapters work with a standard vex drive shaft? I can’t tell from the description.
Also which one works with the 8" wheel?

The VEX Pro system uses a different shaft system than the VEX EDR shafts, so you may have to improvise a bit. The VersaHub system seems to have the mounting holes 1.875" apart (the bolt circle size), and for example the VEX EDR 60 tooth gear has the outer holes 2" apart. So you should be able to file the holes on the gear (or a sprocket) a little bit towards the inside, and then screw one onto each side of the wheel. As the gears have the square hole in the middle that fits VEX EDR shafts, you can then connect the wheel to other VEX EDR components.