I had the problem that I couldn't focus, no matter which eyepiece I used - there was always 1 - 2 cm missing.
I then made a longer drawtube, but the longer version caused too much wobble.
So I extended the base by 3 centimeters and now I can focus on all objects with this focuser.
The author remixed this model.
Adds some extra height (30 mm) to the base.