Skywatcher 150 SinDar dual-speed focusing knob

1.To prevent slippage of the sun gear (12 teeth) central shaft, a hexagonal prism is used for the central shaft. As standard parts are unavailable, a 2.5mm Allen wrench needs to be manually cut to a length of 27-30mm

The image shows a 28mm length of a 2.5mm Allen wrench inserted into the sun gear

2.Thread the pre-drilled holes and insert M3*6 set screws for later use

Thread the pre-drilled lateral holes using an M3 tap (excluding the lateral holes on the cylindrical surface of the table)

Thread the area within the red box using an M4 tap

Actual effect of inserting M3*6 set screws after threading

3.The planetary gear (18 teeth) central shaft uses an M2*22 cylindrical pin

4.Planetary gear assembly

5.Lubrication with petroleum jelly or glycerin is recommended for the gearbox, ensuring smooth operation

6.Actual installation result

7.All necessary hardware is shown below