ZWO EAF on Skywatcher ED 80 Pro

[Tom33]

I have been imaging for a year now with my trusty Skywatcher ED 80 pro and have been very pleased with the results. I have been focusing by hand using a Bhatinov Mask but would like to move to EAF. The focuser on the scope is not great, it sometimes slips but I have managed to get enough tension into it to keep my camera gear in place so my question is this ….. will the EAF work ok on the original focuser or would it be better to upgrade the focuser as well as fitting me EAF. Any comments / suggestions would be appreciated.

[iapa]

there is this video for installing Skywatcher's focus motor on the Evostar.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj6pqHrpuv3AhWTM8AKHetlCicQwqsBegQIBhAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DgpIteLt3xcw&usg=AOvVaw03vFuRrt-qvyLs-iYp8NLt

If you are looking at ZWO's focussed, FLO sell a bracket for the Esprit ED80, not sure if fits the Evostar.
 

[Adreneline]

2 hours ago, Tom33 said:

would it be better to upgrade the focuser as well as fitting me EAF.

I use an EAF on all three of my OTAs (RedCat, 6"RC and Samyang 135mm) - they are perfect for my needs allowing fine focus control and repeatability.

I used to own an ED80 and used it with a SW dc motor focus unit, initially with the stock focuser. The problem was the drawer tube kept slipping so I could not go back to a focus position with any degree of repeatability. In the end I swapped the stock focus unit for a Baader Diamond SteelTrack (BDS) and never looked back. There are times I wish I'd never sold the ED80 - with hindsight it was a great scope.

Good luck.

P.S. The EAF comes with an 'L' shaped bracket and a variety of couplers and will definitely fit on a BDS but it does leave the EAF sticking way out at the side of the OTA which made it really difficult to balance when used on my CEM25 mount.

 

I have the BDS+EAF on my 6" RC but chose not to use the direct shaft coupler - I prefer a piggy-back belt drive arrangement.

The BDS focus unit has a HTD compatible belt pulley built in! Very handy

HTH

[StevieDvd]

It depends on what you want to do focus wise.

There are 2 main types, a DC motor and Stepper motor:

• The dc motor is generally used with a hand control to ease manual focusing.
• A stepper based system, such as the ZWO EAF/Pegasus/DeepskyDad units can be used for the same purpose but are also used to do proper auto focusing (Software controlled) for astro-photography.

I have seen the DC being touted for auto focusing but not very often supported for that purpose in astro software.

Either a DC or stepper system needs the focuser to work properly and won't solve slipping on the older SW focusers. A stepper will help if the focuser is a rack & pinion, but you may need a hand controller or version with a clutch to use the focuser manually.

Personally I would update the focuser for a rack & pinion first.

[Clarkey]

2 hours ago, StevieDvd said:

Personally I would update the focuser for a rack & pinion first

I am also an advocate of the Baader Steeltrack even though it is not a R&P focuser. I have camera and filter wheel hanging off mine but it does not slip. R&P is certainly a good choice but can still have backlash. The ST's do not suffer from this.

[Tom33]

Thanks to everyone for the very helpful comments

 

 

[Philter]

On 19/05/2022 at 11:35, Adreneline said:

I use an EAF on all three of my OTAs (RedCat, 6"RC and Samyang 135mm) - they are perfect for my needs allowing fine focus control and repeatability.

I used to own an ED80 and used it with a SW dc motor focus unit, initially with the stock focuser. The problem was the drawer tube kept slipping so I could not go back to a focus position with any degree of repeatability. In the end I swapped the stock focus unit for a Baader Diamond SteelTrack (BDS) and never looked back. There are times I wish I'd never sold the ED80 - with hindsight it was a great scope.

Good luck.

P.S. The EAF comes with an 'L' shaped bracket and a variety of couplers and will definitely fit on a BDS but it does leave the EAF sticking way out at the side of the OTA which made it really difficult to balance when used on my CEM25 mount.

 

 

I have the BDS+EAF on my 6" RC but chose not to use the direct shaft coupler - I prefer a piggy-back belt drive arrangement.

 

The BDS focus unit has a HTD compatible belt pulley built in! Very handy

HTH

Sorry for bumping this but I've just ordered a ZWO EAF to be fitted on a BDS like in the first picture and I have a couple of questions. Am I right in thinking that the slot on the mounting bracket is too small for M6 screws and will need will need to be widened in some way? Also, can you remember how long the screws were that you used to fit the EAF to the focuser? Thanks!

[Adreneline]

16 minutes ago, Philter said:

Sorry for bumping this but I've just ordered a ZWO EAF to be fitted on a BDS like in the first picture and I have a couple of questions. Am I right in thinking that the slot on the mounting bracket is too small for M6 screws and will need will need to be widened in some way? Also, can you remember how long the screws were that you used to fit the EAF to the focuser? Thanks!

Yes, I had to widen the slots by drilling through and a bit of filing as well . I don't recall the size but it was either M5 or M6 - whatever the BDS takes.

I can't remember the length and I won't be able to check until the weekend I'm afraid. I recall they were short as the BDS threaded holes are only shallow.

I have to say I was surprised that ZWO designed a bracket that would not fit one of the most popular third party focusers on the market, especially as their website says it will fit all popular models.

I think my biggest frustration with AP is that nothing is cross compatible - every manufacturer seems to have different ideas on holes spacing, thread types, slot widths - drives me mad! I'm just glad I own a pillar drill 👍

Adrian

 

[Philter]

Thanks for the quick reply.

Don't worry about checking the lengths if you have to take things apart. I'm sure I'll be able to figure it out when it turns up. 😄

I am a bit weary about having to permanently modify the bracket just to fit the EAF if I'm honest as once it's done I can't really return it if I'm not happy! I prefer things to fit right out of the box, haha. I wouldn't have minded if I could buy a separate bracket designed for the BDS.

[iapa]

I bought the bracket set for the ED80 for £30.  Just replace the slotted racket, fitted perfectly.

No mechanical skils whatsoever.

[Adreneline]

3 hours ago, Philter said:

I am a bit weary about having to permanently modify the bracket just to fit the EAF if I'm honest as once it's done I can't really return it if I'm not happy!

I am very happy with the performance of my EAF units, so much so I have three; other than the bracket design I can't fault them.

[StevieDvd]

5 hours ago, Philter said:

Thanks for the quick reply.

Don't worry about checking the lengths if you have to take things apart. I'm sure I'll be able to figure it out when it turns up. 😄

I am a bit weary about having to permanently modify the bracket just to fit the EAF if I'm honest as once it's done I can't really return it if I'm not happy! I prefer things to fit right out of the box, haha. I wouldn't have minded if I could buy a separate bracket designed for the BDS.

I hope I'm already stating what you already know but the EAF does not come as standard with a belt and pulley, as in the posted BDS picture.  Before I sold an ED80 with the BDS focuser it was fitted with a lakeside focuser (and before that a SW DC focuser using a kit from Teleskop Service which included a bracket, screws & the pulley/belt).

Having recently fitted a 5v EAF to my Evolux ED62 I know the adpaters can be tricky. I was lucky that the optional Esprit adapter had the right spacing to fit, I guess there would be no universal fit bracket.

[Philter]

18 hours ago, Adreneline said:

I am very happy with the performance of my EAF units, so much so I have three; other than the bracket design I can't fault them.

That's good to hear. Hopefully everything will be ok with it so I don't have to return it!

16 hours ago, StevieDvd said:

I hope I'm already stating what you already know but the EAF does not come as standard with a belt and pulley, as in the posted BDS picture.  Before I sold an ED80 with the BDS focuser it was fitted with a lakeside focuser (and before that a SW DC focuser using a kit from Teleskop Service which included a bracket, screws & the pulley/belt).

Having recently fitted a 5v EAF to my Evolux ED62 I know the adpaters can be tricky. I was lucky that the optional Esprit adapter had the right spacing to fit, I guess there would be no universal fit bracket.

Oh yeah, I know the belt setup is not standard for the EAF but I appreciate you flagging it! I'm going to be connecting the EAF directly to the focuser in place of one of the adjustment knobs using the connectors provided.

Edited September 2, 2022 by Philter