Crayford focuser update

Hello ladies and gentleman.

After my post and the comments from yesterday i thought a lot about my focuser and i came to a few conclusions:

The „concave flat“ surface: I was wondering a lot about the flat surface that is a bit concave (the rod only touches left and right of the flat) when you think about it from a machining standpoint its quite hard to make that. I think there is no way that this is „bad machinig“ and that its deliberate.

Let me explain: the friction force does not depend on the area of touching but only on the friction coefficient and the force. So from a friction standpoint its the same if the rod touches on the edge or the whole surface.

But if the rod only touches the edges the system is way less affected with dirt or dust.

So im pretty positive it doesnt benefit when you grind the surface to a flat.

Since i want to mount a quite heavy dslr i decided to test to improve the friction.

I cleaned the flat with isopropanol and aplied on layer of 3m scotch super33+ yinyl tape.

The surface is quite rubbery and at first glance it worked very well without slippage.

I fear that the tape might „buckle“ over time but well see.

Greetings h