We initially printed a set of the team 125 2" meccanum and had trouble getting all the Hardware plus we made the decision to not change nozzles during the season as that sometimes went bad (we cross threaded some) and with a .8 that is a tough print plus there was not much to put it together so there was a list made:
1.) Has to work with 1/2hex shaft
2.) Is to be optimized for 3DP so must either be splitable or allow for easy to remove support (based on prusaslicer capabilitys
3.) Should be symmetrical - that means 6 rollers instead of 5 to match up with the hex shaft
4.) Should use easy off the shelf (our shelf) available hardware.
So below is the results - the wheel size was increased from 2 in to 2.5 in to allow for 6 rollers and in case we split it for printing wihout support with enough room for hardware. For hardware we picked M3 bolts both as axles for the rollers and to mount it if we split the hub and M3 lock nuts. and M3 washers. Washers are at both ends of the roller to decrease friction. And the locknuts stay put and allow the axle (bolt) to stay in place without bending the plastic and work like a break.
We tested one and are currently putting the rest together. If you slice it you might want to mirror the Hub so you get a left and a right. Below find both the STL and the IPT (inventor) files. Print 6 rollers per wheel.
Mec25_hub.ipt (6.5 MB) Mec25_hub.stl (839.2 KB) Mec25_roller.ipt (411 KB) Mec25_roller.stl (560.4 KB)Mec25_hub.pdf (1.1 MB)