My astronomy project:
Design of a 3D-printed filter wheel

Content:

1. CAD design of a filter wheel
2. Chassi
3. Stepper motor
4. Gears
5. Shaft and Roller bearings
6. Home position sensor
7. Lid
8. Off-Axis guider
9. To be continued

Note:
I take no responsibility or liability for what are written here, you use the information on your own risk!

5: Shaft and roller bearings

The filter wheel must be attached to a shaft, stable, not wobble and be centered. Roller bearings is the solution to this.

Shaft and roller bearings:

I found these two roller bearings in my desk, maybe something I can use for the filter wheel. The dimension are: 16 x 8 x 5 mm, little bit special with its1 mm flange, they use them in 3D-printers. If I want two of them I have to increase the total thickness of the filter wheel from 13 mm to 17 mm, but I think I have to do that anyway.

With the thin roller bearings I have chosen I can have bigger diameter on the wheel's shaft, now 8 mm. The shaft connect to the lid and enforce the construction. To fit these roller bearings, 16 mm outer diameter, I have to move the filter holes outwards by 3 mm and then increase the chassi's diameter too.

3D-print:

After cleaning the surfaces from plastic debris I pressed in the roller bearings. They fit perfect directly. When I rotate the wheel I can't see any tendency to wobbling.

I needed a little bit extra force to get the roller bearings all the way in.