Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Celestron C8 Telescope 4-1 focuser mod for £1.


coulthamst

Recommended Posts

The local Pound Shop has double -sided 2mm thick adhesive tape rolls for - of course - £1. The stated function is to mount picture mounts to pictures to give  a "3D" effect, and the roll is 3mm wide x 100mm OD, which led me to think that it might serve to create a fast and easy way to create a fine focuser.

The Celestron C8 focuser knob is 22mm OD, and protrudes from the OTA 35mm. I cut a 15mm wide strip of paper long enough to fit once round the knob (to stop the "sticky" contacting the rubber of the knob), stuck it to the first section of the tape, and then tightened this round the knob, leaving a 3mm gap between the tape and the back case of the OTA. i continued carefully wrapping the tape round the knob until I had created a wheel of 90mm ODx13mm wide. AsI had not removed the backing of the tape, there was the option of removing it back from the knob and onto the roll if I didn'tlike the result, and to leave a non sticky surface on the outside of the wheel I had created  ifI did like it.

I now have a very usable fine-control 4-1 drive to my focuser, with sufficient of the original 22mm knob protruding to use as a coarse focuser. My C8 is fitted with a 2" visual back and diagonal, and there is no interference either way between those and the focuser. The 90mm wheel is white, making it more easily findable in the dark. The only minor drawback is that the 90mm wheel has a 2mm step where the final tape cut was made,but in practice I barely notice this, I  even have a 65mm OD (with 32mm centre hole) piece of adhesive tape left - certainly not enough for another "wheel", but for £1 I won't be complaining!

Link to comment
Share on other sites

Archived

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

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • 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.