In this video, I'm showing a setup that I use to tight fit a metal shaft into a micro ball bearing using a drill press. The bearings I used in this projects are 3x10x4mm and also 3x8x4mm. I tried the 2.9mm shaft at first but it was too loosed from the inner of the bearings and will create a lot of vibration for the drones. The problem I got with the 3mm shafts is that they are a bit bigger compare to the inner diameter of the bearing. I create in this video a 3D printed setup, combined with some metal parts:
- Steel plate
- 10mm stand off screw spacer
Then I used a drill press to push (force) the shaft through the bearing without damaging it and keep its free rotation characteristics.
This is my general idea how to fit the shaft into the bearings. If you wanted to fit other sizes of bearings with different sizes of shafts and wanted me to design a 3D part for it, just leave a comment with dimensions of the bearing, dimensions of the type of spacer you wanted to use (see the video to understand what I meant here).
Link to the video for instructions: