External focuser for EdgeHD 8

[souls33k3r]

Hi All, 

I think I mignt have to end up buying an external focuser for my EdgeHD 8" scope and because I'm not too well versed in this subject matter, I'd like your kind help in suggesting something which will fit my purpose. 

Allow me to explain my setup, I have EdgeHD which has a stock focuser and I've had a terrible experience using the motorised stepper focuser on it so was suggested to leave the stock focus knob and buy an external focuser which does make sense for my application. My scope is currently in such formation

EdgeHD 8 - 0.7x Reducer - Spacer/Adapter to attach to an OAG - TOAG - Spacer/T2 to attach to FW - ZWO FW - Asi1600 camera 

I would like to keep all the components so the external focuser needs to come somewhere in between. Can you kindly suggest any that does not break the bank? I already have a Lakeside focuser so will look in to attaching that.

Options I have seen so far are:

1) Moonlite CHL 2.5" focuser for which I've seen the price hike (£130 in the last few days) so that's out of the question. 

2) Primaluce lab Essato 2" which again is stupidly expensive and I already have Lakeside so now what? 

3) Baader SteelTrack Diamond SC for SCT Telescopes

4) Revelation 2" SCT Crayford - 1:11 Dual Speed Focuser 

Any others? Any experiences with any of the above? Whatever choice I would like to have like I said will need to incorporate all of my gear above. 

Thank you. 

[MarkAR]

Is it the Celestron Motor focussed you've had problems with? What were they?

[souls33k3r]

Just now, MarkAR said:

Is it the Celestron Motor focussed you've had problems with? What were they?

No sorry mate, its the lakeside focuser. 

[MarkAR]

The Celestron will fit.

https://www.firstlightoptics.com/focuser-controllers/celestron-focus-motor-for-sct-and-edgehd.html

 

[MarkAR]

Just realised you're looking to change the actual focus mechanism not a stepper controller.

[garryblueboy]

The CHL focuser has been £550 for some time the CL is about £130 cheaper 

[souls33k3r]

2 minutes ago, garryblueboy said:

The CHL focuser has been £550 for some time the CL is about £130 cheaper 

Really? I'm sure just under a month ago I saw it at £420

[garryblueboy]

Unless it was on an offer you get loads of extras with it above the standard one it’s a quality focuser still cheaper than a feather touch the next best is the Baader steel track there really nice 

[johninderby]

The Baader Steeltrack is a good option. in the same class as the Moonlite but will handle more weight and is more durable. One of these days Moonlite will do something about using only an anodised surface of the drawtube instead of something like Baader’s diamond coated surface that simply doesn’t wear. 

https://www.firstlightoptics.com/baader-diamond-steeltrack-focusers/baader-steeltrack-diamond-sc-for-sct-telescopes.html

[souls33k3r]

No it wasn't, it was on that price for at least 6months if not more. I'm sure they're all nice mate. It's just that because I'm a total noob at this external focuser business so wanted some assistance in knowing and understand if all of my above gear will be able to get incorporated in the imaging train. The EdgeHD 8" backfocus after the Reducer is 105mm.

Also if I have missed any other focusers, would be super helpful. 

[souls33k3r]

1 minute ago, johninderby said:

The Baader Steeltrack is a good option. in the same class as the Moonlite but will handle more weight and is more durable. One of these days Moonlite will do something about using only an anodised surface of the drawtube instead of something like Baader’s diamond coated surface that simply doesn’t wear. 

https://www.firstlightoptics.com/baader-diamond-steeltrack-focusers/baader-steeltrack-diamond-sc-for-sct-telescopes.html

Baader one seems to be looking like a contender but will it all take the first post gear that I mentioned? That's the question really.

The good thing about the moonlite is that the 0.7x EdgeHD reducer fits within its flange which gives you more of the back focus ( or at least that's how I've interpreted it) 

[johninderby]

FeatherTouch would be first choice but serious money now. Moonlite and Baader are budget focusers in comparison. 🙀🙀🙀

[garryblueboy]

For imaging I’d go for either the Moonlite or the Baader the revaluation is ok for visual I’ve owned all three 

[SyedT]

I have 2 Esattos for my Edge HD 8 and FSQ85 and can't fault them in any way; autofocusing is now a breeze with zero slippage and accurate results. The only issue is that the focuser is 67 mm in length, and so that leaves you with only 38 mm to play with if you're using the reducer. I find that with an OAG I'm well over the spacing, so I'm imaging at F10 at the moment (which I'm actually liking!); I spoke to Primaluce Lab about it, and they said that another customer had a similar issue but managed with the reducer and is getting good results despite the spacing being off by approx. 25 mm. I don't know how much I trust that to be honest, so I'll attempt to use the OAG with the spacing as it is, and then use a guidescope if that doesn't work out. My gear at the moment: Atik 490EX + Atik EFW2 + Atik OAG + M54-M54 male-male adapter + F54-F56 adapter. The F56 adapter screws directly into the Esatto's drawtube, so at the moment the whole imaging train is screwed in (with the exception of the dovetail connection between the 490EX and EFW2 which is easy to adjust) with minimal potential for tilt.

The Esatto is £510, the scope-side adapter is £30 and the camera side adapter is £80, so a total of £620 from FLO. My issue with focusers where the motor is attached to the focuser shaft is that there's a very real potential for slippage, and this can come into play any time and ruin a perfectly good imaging session. I've had this issue with the Moonlite and Feathertouch focusers, which is when I gave up and bought the Esatto. No issues since! PM me if you need any more details.

Edited April 7, 2020 by SyedT

[garryblueboy]

2 minutes ago, souls33k3r said:

Baader one seems to be looking like a contender but will it all take the first post gear that I mentioned?

That’s why I’d go for the Moonlite 

[johninderby]

Worth looking on the Baader site for tech info.

https://www.baader-planetarium.com/en/downloads/dl/file/id/175/product/2856/instruction_manual_for_all_baader_diamond_steeltrack_bds.pdf

https://www.baader-planetarium.com/en/downloads/dl/file/id/29/product/2856/bds_sc_dimensions_technical_drawing.pdf

 

[Davey-T]

The Essato looks like a knock off of the Meade microfocuser that I use and it works fine with loadsa stuff hanging off it.

You can always sell the Lakeside.

Dave

[souls33k3r]

53 minutes ago, johninderby said:

FeatherTouch would be first choice but serious money now. Moonlite and Baader are budget focusers in comparison. 🙀🙀🙀

Yeah I'm really swaying towards baader but need to be sure of the available back focus on this bad boy. Got any experience with either of these specifically Moonlite with EdgeHD 8 or Baader Steeltrack on its own? 

53 minutes ago, garryblueboy said:

For imaging I’d go for either the Moonlite or the Baader the revaluation is ok for visual I’ve owned all three 

Top man. You got any experience with the Baader by any chance mate? 

54 minutes ago, SyedT said:

I have 2 Esattos for my Edge HD 8 and FSQ85 and can't fault them in any way; autofocusing is now a breeze with zero slippage and accurate results. The only issue is that the focuser is 67 mm in length, and so that leaves you with only 38 mm to play with if you're using the reducer. I find that with an OAG I'm well over the spacing, so I'm imaging at F10 at the moment (which I'm actually liking!); I spoke to Primaluce Lab about it, and they said that another customer had a similar issue but managed with the reducer and is getting good results despite the spacing being off by approx. 25 mm. I don't know how much I trust that to be honest, so I'll attempt to use the OAG with the spacing as it is, and then use a guidescope if that doesn't work out. My gear at the moment: Atik 490EX + Atik EFW2 + Atik OAG + M54-M54 male-male adapter + F54-F56 adapter. The F56 adapter screws directly into the Esatto's drawtube, so at the moment the whole imaging train is screwed in (with the exception of the dovetail connection between the 490EX and EFW2 which is easy to adjust) with minimal potential for tilt.

The Esatto is £510, the scope-side adapter is £30 and the camera side adapter is £80, so a total of £620 from FLO. My issue with focusers where the motor is attached to the focuser shaft is that there's a very real potential for slippage, and this can come into play any time and ruin a perfectly good imaging session. I've had this issue with the Moonlite and Feathertouch focusers, which is when I gave up and bought the Esatto. No issues since! PM me if you need any more details.

Too kind @SyedT. Really do appreciate your input and the detailed explanation. Obviously if you're rating the Essato high enough then it must be good but the most important thing you mentioned was the available BF which is 38mm. I've just calculated and without any spacers im at 38mm. Bummer! I've noticed tbsi trend with Primaluce Lab is that anything you buy for the gear is always an add-on and they charge you for it. Not cool!

You mentioned you had issues with Moonlite focuser, was this the CHL version that takes in the 0.7x Reducer? If so, I'd love to hear about that. Here or pm, I'll leave that to you buddy

57 minutes ago, johninderby said:

Worth looking on the Baader site for tech info.

https://www.baader-planetarium.com/en/downloads/dl/file/id/175/product/2856/instruction_manual_for_all_baader_diamond_steeltrack_bds.pdf

https://www.baader-planetarium.com/en/downloads/dl/file/id/29/product/2856/bds_sc_dimensions_technical_drawing.pdf

 

I sure will matey, cheers for that. Moonlite is a serious second contender if Baader one doesn't pan right. I guess three things I'm trying to find out is that how much space will this Baader take so that I can calculate the availabile backfocus, secondly if anyone has any experience using Baader Steeltrack and how good are they? And lastly if there are any other options out there in terms of the focuser which I haven't though of?

23 minutes ago, Davey-T said:

The Essato looks like a knock off of the Meade microfocuser that I use and it works fine with loadsa stuff hanging off it.

You can always sell the Lakeside.

Dave

From what I've read, the meade microfocuser is not compatible with EdgeHD 8" scope unless I've read it wrong mate. 

[Davey-T]

1 minute ago, souls33k3r said:

From what I've read, the meade microfocuser is not compatible with EdgeHD 8" scope unless I've read it wrong mate. 

No doubt it's compatible, was just pointing out the similarity with the Essato.

Dave

[garryblueboy]

1 minute ago, souls33k3r said:

1 hour ago, garryblueboy said:

 

Top man. You got any experience with the Baader by any chance mate? 

The Baader is excellent and so is the motor focus you would need few adapters but if you want straight out of the box it’s Moonlite is the way as your flatter screws into the focuser it’s self also it looks cool on an Edge here is one I had on a C14 Edge 

[souls33k3r]

27 minutes ago, Davey-T said:

No doubt it's compatible, was just pointing out the similarity with the Essato.

Dave

Ah gotcha you're quite right, it does indeed look like it. 

23 minutes ago, garryblueboy said:

The Baader is excellent and so is the motor focus you would need few adapters but if you want straight out of the box it’s Moonlite is the way as your flatter screws into the focuser it’s self also it looks cool on an Edge here is one I had on a C14 Edge 

Wowzer! Look at that beast. I assuming this setup is for visual? Now assuming baader is great and will work, question is what adapters do I need and if that would take a massive chunk away from the available back focus. 

[johninderby]

I have owned Baader Sterltrack for a newt, SCT and a refractor and also use one on my Classical Cassegrain but that is a refractor focuser with a lot longer travel than an SCT focuser and a fixed primary mirror.

Check the max load ratings of the Baader and Moonlite and you will be surprised at the difference.

[souls33k3r]

Top man mate. Much appreciated. If I've interpreted the Baader technical drawings correctly, when the focuser is all the way in, it's 93mm. The back focus available to me after the reducer is 105mm so that's only 12mm to play with in which I'll need my camera, oag, and main camera 🙄 am I reading this correctly? 

[garryblueboy]

You would need to use the info John gave link to and work what you need and you need to work out your distance etc you don’t get a lot of focus travel using the SCT version Focusers as really they are for fine tuning you use the normal focuser for rough focus and fine tune with the SCT at back  

[johninderby]

Yes you need to sit down with the Baader drawings and see if it all adds up. 

One reason I went with the Classical Cassegrain instead on an SCT is having a proper focuser instead of a moving primary. The Edge HD is a very nice scope though. 👍🏻

Edited April 7, 2020 by johninderby