With circular slots you need 1 jig per shaft size. Without the drill bushing you have to print one upper half for each hole. I rate the drill bushing above the V-slot. Bit of a wash perhaps because both were sugested by the same person.

Glue works well for small applications, though do you have any trouble with glue piling up on one side, causing eccentricity?

I would try a flex coupler first, I think the torque is low enough they will hold. There are also flex couplers that use a red or orange plastic "spider", those can handle a bit more torque. Otherwise I would use a set screw to connect to the shaft. I would not try to drill into it, it's a hard shaft, a small drill, and clamping a motor accurately is hard.

@@antalz Thanks for the fast reply. The motor will be loaded at around 100-110w, so I hope the flex couple works

I think printing a removable slot could work, but you need some kind of method to drill bushing still points straight down. Probably some kind of tapered fitting would work out. That's also the main thing I'm not sure about in the linked video. He appears to eyeball the angle of the drill chuck in the vise, so I'm not sure the hole is properly concentric, in other words does it point straight down? I'm also not sure he can reliably place his jig length-wise along the shaft, for my jig you can index the ends of the shaft against the ends of the jig.

That's a great idea! The drill bushings are quite annoying to get indeed. A lot of places that do sell them also charge high shipping rates, which is rather annoying.