Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Crayford focuser- gear ratio modification


Recommended Posts

Folks just a short note to share a modification which some of you may find useful.

The standard Crayford has fairly poor focus accuracy as we all know.

But rather than chuck it and buy the twin speed version at about 150 quid... try this first.

Simply double the gearing ratio by reducing the dimaeter of the spindle.

I used a 2.5mm screwdriver and a ball of tape to give me a handle.

The original spindle is abour 5mm

So in stead of 3 full turns to rack end-to-end, you get amnost 6 full turns of the spindle.

here is a fairly crude yet very effective implementation using a precision scredriver.

 

this has greatly improved my focus accuracy!

...and as a bonus it can how hold my DSLR without applying the focus lock!

 

Hope you like it and give it a go!

 

Cheers

 

Ray

 

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.