DIY dual speed focusser

[nigelbeaumont]

Since I have access to a small machine shop, I'm wondering whether I could convert the focusser on my reflector to dual speed. I assume it's an epicyclic reduction gear using ball bearings instead of planetary gears: does anyone have a diagram of the internals of a dual speed focusser before I start 'exploring' the internals of the one on my other telescope?

[Mukv]

Greetings

I did this for both SW 300PDS and a 90mm refractor

http://stargazerslounge.com/topic/205608-diy-motorised-focuser-for-crayford-type-focuser/

The motor works at 3v but I feed it with 2.4v or 1.2v and it gives duel speed. the motor is from maplins £9.15 ish it works very well on both scopes.

Andy ( Mansfield )

[nigelbeaumont]

Thanks - very interesting, I'm tempted

[Astrobits]

Hello from one Nigel to another

I have sucessfully made my own two speed knobs.

I found a web site from a Chinese source that I cannot immediately locate. It provided enough detail that I could experiment with the design. I still have my drawings that I can send to you just PM me if interested.

Here's one image that I got from the Chinese source;

Nigel

[Astrobits]

O.K. Found that web site:

http://bbs.astron.ac.cn/thread-54988-1-3.html

Nigel

[AndyH]

Superb link Nigel.

 I always wondered how the fine focus worked. I had an idea, but the many detailed drawings make things clear.  Thanks !!

Andy.

[JamesF]

Please post some photos of your progress if you do go ahead

James