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Recommendation for auto-focuser for Skywatcher Esprit 80?

Filroden

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Filroden

Filroden

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I'm reaching the stage where I want to automate focusing on my Skywatcher Esprit 80ed. I've recently shifted to LRGB imaging from DSLR and I'd like to fine tune focus between filters, and also as temperature changes. I set up and dismantle my kit every session with the scope being returned to its case for safe keeping, so I'm looking for a recommendation for what kit I would need to automate focusing but also be simple enough to fit.

For information, I use SGPro for capture, and I'd use it to run focusing. Currently I eyeball focus with the Bahtinov mask then fine tune it by monitoring the HFW value until I can get it roughly minimised. However, it's quite difficult as every movement on the focus knob means letting it settle.

Many thanks to anyone that can help!

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Filroden

Filroden

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1 minute ago, Dr_Ju_ju said:

Hi Ken,

If you have a practical bent, it is possible to make your own Arduino\Stepper motor based unit, there are a number on SourceForge i.e. https://sourceforge.net/directory/os:windows/?q=arduino focuser

Usually the most difficult part is mounting the motor on the OTA....

Unfortunately not! I need something to be as simple and easy as possible! I can do IT but nothing mechanical.

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iapa

iapa

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Would the SkyWatcher Auto Focuser do the job? Not int he sort of price range as the Esprit :)

Seems to work for most Skywatchers e.g. Evostar models 90/102/120/150, Startravel models 80/102/120/150, Skyliner models 150/200/250/300 & Explorer models 150/200/250/300.

I have one on a Skywatcher PD-S dual speed focuser, and a Celestron 130 SLT RP focuser.

How to fit a Skywatcher Auto focuser onto a Skywatcher ED80 DS Pro Telescope

 

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Starflyer

Starflyer

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I use the Lakeside motor focuser with my two scopes and SGP, once set up correctly in SGP it performs perfectly every time. I wouldn't recommend removing it after every session so you may need to modify your case to take the scope with the motor attached.

Fitting is simple with the custom bracket supplied to fit your scope.

I was becoming frustrated with losing subs due to poor focus, or having to manually refocus at every filter change, (my Baader filters aren't parfocal in either of my scopes).  With SGP and the Lakeside I refocus automatically every 30 or 60 minutes and it just works, perfect focus 100% of the time.

 

Cheers,

Ian

 

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  • 2 weeks later...
Filroden

Filroden

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It's ordered and in stock. He's just making me the adapter to fit it and I should have it soon :) SGPro looks like it's easy to use for auto-focusing so I can almost fully retreat indoors now once I've set everything up! Just some narrowband filters on the wish list to get.

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Starflyer

Starflyer

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Great news Ken, I'm sure you won't regret it.

SGP auto focusing can be tricky to set up, but once you've nailed it you can forget about it.  Have a good read of the help document and also the threads on focussing on the SGP forum, there's a wealth of information there that fills in the gaps in the manual.  Setting backlash was crucial for me and now I get almost perfect V curves, so read up on backlash.  If you're seeing a zig-zag pattern at the start of the V-curve (ie it goes up first and then down) then that's backlash.

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Filroden

Filroden

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Well, the Lakeside Astro focuser arrived from http://www.iankingimaging.com/ during the week along with the adapter to fit it to the scope. After getting the rights tools, I tried to fit it yesterday. I hit my first snag in the lack of any useful guides on the net. I found a guide for a different focuser but that one was fitted to the side with both the coarse and fine focus knob and I was sure this one fitted on the side with only the course knob. I just couldn't see how to remove it. The other side was easy, with a visible grub screw holding in the fine knob and then removing the rubber grip from the course knob revealed another grub screw to release that one. I couldn't see an equivalent on the other side.

So, after a very quick email exchange with Ian who replied very quickly with the information I needed...the grub screw could be seen by rotating the course knob and looking into the second central hole until the screw was visible (which needed a torch). After that, it took me about 10-15 minutes to get the whole thing fitted. A quick Stanley knife to the padding in my scope case later, and it sits inside its case quite nicely.

IMG_1334.jpg

I then installed the drivers and got it working :) I've just done the initial calibration and it moves just under 9000 steps between almost full in and almost full out and I'm guessing focus will be around step 6000 (it's usually around 4cm into the 6cm travel). And that's about as far as I can go today as the next step (setting up SGPro) requires stars!

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Davey-T

Davey-T

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Well done Ken, I've just fitted one to my WO Star71 and had trouble getting the knob off, undid the said grub screw but it wouldn't budge turned it 180 degrees to check there weren't 2 screws but nothing showing, kept wiggling until it came off and found that there were 2 screws but the second one was at right angles to the first LOL

Instructions could be better and he seems to have given up on the black anodizing of previous ones.

Dave

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Filroden

Filroden

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3 minutes ago, Davey-T said:

Well done Ken, I've just fitted one to my WO Star71 and had trouble getting the knob off, undid the said grub screw but it wouldn't budge turned it 180 degrees to check there weren't 2 screws but nothing showing, kept wiggling until it came off and found that there were 2 screws but the second one was at right angles to the first LOL

Instructions could be better and he seems to have given up on the black anodizing of previous ones.

Dave

I think there are just too many possible scopes to provide details for each of them, hence including a few above just in case anyone else searched. Ian was very helpful with all my questions so it was an easy job in the end. I also thought there was backlash on manual but the motor ramps up in manual, unlike auto mode which is immediate. So just need a clear night to configure SGPro (printing the instructions out too, as there is a lot of steps and I'll miss one if I'm working from screen).

Build quality is good and it fits very snuggly. There's zero play in any element.

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  • 1 year later...
froggy100

froggy100

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HI Ken

I see that you managed to fit a motor to your focuser on the Esprit 80. I would like to do the same and I need to know which size bolt  and length you used to fit the plate to the focuser.

Thank you very much for your help.

Vince

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