SCT Focuser options - query

Hi all,

I am looking at upgrading my focuser options for the C11, particularly for Lunar and Planetary imaging.

As you know, using the Focus knob on the back of the C11 introduces shake to the telescope and needs to dampen down before attempting another fine focus attempt.

With this in mind, I am looking at options to motorise the focus procedure and have been looking at the following options.

A Motor focus controller for the C11
www.scopecity.com/detail.cfm?ProductID=2716

Or upgrading the SCT with a Crayford style Focuser such as the William Optics Linear-Power Focuser for SCT Telescopes

www.williamoptics.com/accessories/SCT_LinearPower_feature.php

And then look at the possibility of motorising that, using something similar to the Orion Accufocus www.telescope-service.com/OrionUSA/acces...ries.html#Motorfokus .

Any advice and opinions are welcome.

Many thanks

Steve

Steve,

If your interested in a money saving DIY option you might consider this project which I wrote up some time ago. If your not that good with a soldering iron you may be interested in a new project which I hope to publish this week which uses premade boards which can be gotten easily (and cheaply) off ebay thus negaing the need for soldering or any electronics knowledge at all. I have written fully functional ascom drivers for both projects.

Cheers Dave,

Thats an excellent project indeed, I look forward to seeing your new project.

I might give it a go!

Best regards

Steve

Steve - you should seriously consider locking down the primary - that, and the poor mechanical quality of the Celestron SCT focus design, will still haunt you with an electronic focuser.

There are a number of methods:
1. Use the shipping bolts that came with OTA (I'm not sure how good they are)
2. Use a locking collar (requires you to butcher the tube and open it up completely)
3. Use a flop-stopper system (pm me if interested)
4. Buy a Richey Chretian (preferably 32")

If you do that and then install an electronic fcouser that simply moves your imager, you'll get no image shift and you'll get very little mirror flop when slewing.

Consider it but feel free not to go down that route. Just thought I'd point it out as a more "robust" option for now and the future.

Cheers
Dave

Thanks Dave,

The 32 inch Richey Chretian, might be just outside my budget at the moment : blink:

However, the flop-stopper system, you have suggested is of interest. PM sent

Many thanks

Steve

My C11 has quite a bit of mirror flop in that if I slew it more than about 20-30 degrees I have to refocus it. The focuser shift is not that bad though (better than my 8" Meade).
Having live view on the camera makes this fairly quick and easy to adjust for.
Without live view I would be looking to fix the mirror down also.