{{BOM}}
- Push the M3x25mm hex head screw{qty:1} into the thumbwheel(fromstep){qty:1, cat:printedpart}.
- Thread the M3 washers{qty:2} onto the screw.
- Place a drop of light oil{qty:1 drop} on the screw thread. You might want to put some kitchen paper or blu roll on your bench to soak up any dribbles of oil.
- Push the M3 nut{qty:1} into the slot in the focusing assembly(fromstep){qty:1, cat:printedpart} (using the nut insertion tool(fromstep){qty:1, cat:printedtool})
- Screw the thumbwheel assembly into the M3 nut in the focusing assembly.
- Next, we will insert the O-ring to complete the mechanism.
- Thread the 30mm diameter, 2mm thickness Viton O ring{qty:1} through the two holes in the foot(fromstep){qty:1, cat:printedpart}, and use the band insertion tool(fromstep){qty:1, cat:printedtool} to stretch the two loops of band as shown in the picture.
- Line the foot up with the hole in the bottom of the focusing assembly, and push on the band insertion tool to click the band into place.
- You should feel two clicks as the two ends of the band hook over the actuator column. It's easier if you use the nut insertion tool to hold the mechanism still as you do this.
- Gently pull the band insertion tool out of the foot.
- The band should pull the foot tight against the focusing assembly as shown.
Well done, you have now assembled the [focusing mechanism]{output, qty:1}.