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EAF on a C11

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#1 kevinbreen

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Posted 12 April 2024 - 01:50 PM

My Moonlite Focuser is kaput and I'm looking for other options for when it's planetary time again later in the year.
My seal, Evan, is the standard C11. Has anyone here tried a ZWO EAF on a C11 using this gizmo?

https://www.astronom...11-and-c14.html

And if so, what's your appraisal?

The EAF will shift the primary mirror though which isn't ideal for me as there's quite a bit of image shift when the primary is moved. I have avoided that problem since 2019 when I started using the Moonlite, but as of today I've had it with that bloody thing, having taken it apart countless times as well as replacing bearings a few times.

Another option of course is a JMI motofocus, one of which I had on my trusty old 8SE a few years back.

Any opinions or advice, folks?

Thanks

#2 hyiger

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Posted 12 April 2024 - 02:36 PM

My Moonlite Focuser is kaput and I'm looking for other options for when it's planetary time again later in the year.
My seal, Evan, is the standard C11. Has anyone here tried a ZWO EAF on a C11 using this gizmo?

https://www.astronom...11-and-c14.html

And if so, what's your appraisal?
 

I use the EAF on my C11 with the same bracket you linked. It works fine. Yes, mirror flop will always be an issue on a scope where you can't (or don't) lock the mirrors. This is true even with a Crayford which is why I think they only get in the way on a non-Edge SCT.  I'm just super fastidious about focusing which makes up for the mirror flop. When the C11 is setup for imaging, I pretty much have to allow for frequent refocussing which is not hard to do with autofocus routines. 


Edited by hyiger, 12 April 2024 - 03:06 PM.


#3 pyrasanth

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Posted 12 April 2024 - 03:04 PM

If you have the option of removing the secondary mirror then you can use the Optec SMFS available for the C11 & C14. This focuses by moving the secondary mirror in 200nm steps and you lock the primary mirror. I implemented this solution many years ago for the C14 and have never focused ever again by moving the primary. It is a robust & reliable solution.



#4 Chris MN

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Posted 12 April 2024 - 03:32 PM

If you have the option of removing the secondary mirror then you can use the Optec SMFS available for the C11 & C14. This focuses by moving the secondary mirror in 200nm steps and you lock the primary mirror. I implemented this solution many years ago for the C14 and have never focused ever again by moving the primary. It is a robust & reliable solution.

+1 on that!  I have one on my C11 and can't go back to any other type of focuser.  Also, collimation holds no matter where the scope is pointing.  VERY precise focusing.  Plus there is never any load on the focuser itself.  I have used JMI and Optec's TCF-S (another great focuser) but the SMFS is by far the best.  Not cheap though.

 

 

Chris



#5 RedLionNJ

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Posted 15 April 2024 - 09:58 AM

Guys, I (and I'm sure Kevin) appreciate the suggestions, but I think we're straying from the situation he has.

 

He has an EAF and is looking for an adequate Crayford focuser to attach it to. He's not interested in solutions which involve moving the primary during fine-focusing. My MO is to achieve reasonable focus with the stock focus knob turned in a CCW direction and then close in on best focus with a motorised Crayford. Many of us do that and that's the method Kevin employed with a motorised Moonlite focuser until it became inoperable over the weekend. Moonlites are too expensive as a replacement right now and are out of the question. Instead, he's looking for a reasonably decent Crayford that he can attach the EAF to. It need only be a single speed Crayford and nothing fancy. His intention is to use this setup later on in the year for planetary work and also use it with NINA for autofocusing with NINA for DSO work.

 

Can anyone recommend a cheap and adequate Crayford for his scope to which I can attach an EAF?

 

I would say a used JMI, but I'm not sure the EAF can be attached to those.



#6 kevinbreen

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Posted 15 April 2024 - 10:06 AM

Guys, I (and I'm sure Kevin) appreciate the suggestions, but I think we're straying from the situation he has.

He has an EAF and is looking for an adequate Crayford focuser to attach it to. He's not interested in solutions which involve moving the primary during fine-focusing. My MO is to achieve reasonable focus with the stock focus knob turned in a CCW direction and then close in on best focus with a motorised Crayford. Many of us do that and that's the method Kevin employed with a motorised Moonlite focuser until it became inoperable over the weekend. Moonlites are too expensive as a replacement right now and are out of the question. Instead, he's looking for a reasonably decent Crayford that he can attach the EAF to. It need only be a single speed Crayford and nothing fancy. His intention is to use this setup later on in the year for planetary work and also use it with NINA for autofocusing with NINA for DSO work.

Can anyone recommend a cheap and adequate Crayford for his scope to which I can attach an EAF?

I would say a used JMI, but I'm not sure the EAF can be attached to those.


Thanks Grant. You've hit the nail on the head there. Hmmmm, what model exactly is your JMI?

#7 Borodog

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Posted 15 April 2024 - 10:30 AM

Kevin,

 

I use my EAF on my GSO dual speed crayford on my 11" EdgeHD, using a bracket from Buckeye Stargazer. 

 

gallery_346195_18030_266356.jpg



#8 DeepSky Di

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Posted 15 April 2024 - 03:32 PM

I was also going to recommend looking at the GSO. Agena stock 4 versions and the 4th one is compatible with the EAF out of the box while some of the others will work with adapters.

 

https://agenaastro.c...dual-speed.html

 

Then you also have to choose a base plate and 11" is not one of the options. Read the product description completely.

 

I got mine before I completely understood the divide between planetary and DSO for reflectors. This focuser has no threaded fitting for the optical train, instead it has a 2" compression fitting for a planetary camera nosepiece or for an eyepiece. I have not dared fit my DSO optical train onto it. The other issue is whether it works with the Celestron reducer for Edge HD8. I have heard you have to choose between reducer or Crayford. 

 

For now, as I use my Edge 8 for DSO, I stayed with the reducer, and the EAF mounted on the focus knob. I haven't had issues with image shift. When I get back to planetary, I'll try the Crayford.




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