I have an inexpensive DC motor with a smooth shaft (no hole for a set screw). It's small like the $3.00 toy DC motors you find everywhere. Not only will this motor be rotating a small load (no more then an ounce) about 100RPM, but the motor itself along with the load will also rotate around the Y-axis around 100RPM. My concern is centrifigual forces will add to the calculated load and my concern is about keeping the load from flying off.
The load will be some lightweight carbon fiber (with some electronics mounted on it) and I have read a set screw is one of the more common ways to attach a load to a shaft like this, however is there something that might be more secure? I'm just a hobbyist, so no real way to machine parts. I'd either have to buy something or homebrew it. I don't know the exact shaft size, but I will get the specs on the motor (pulled it out of a toy).
Is there a good source for threaded motor shafts? Everything I find in the low price range is smooth.