5 replies to this topic

[theeyeofthemind]

I feel like this is a common topic and problem with focuser provided with the SW 72ED, but my focuser has completely gave out. I am using the scope for imaging paired with a ZWO ASI 2600MC x Orion FF x spacers for weight context. It started with grinding and now it has no bite at all even after adjusting. To sum it all up I'm ditching the stock focuser and am ISO of a GSO Crayford, I want to make sure I make the right purchase here. A lot of what I am seeing is for the 80ED and am unclear whether it will work with my scope. Thoughts? Questions? Hit me with it all before I make this purchase. 

[Oldfracguy]

I installed one of those small GSO 86.4mm Dual-Speed Crayford Focusers on two scopes I used to have, but those both had 90 mm (3.5") ID tubes:

 

 

 

I'm not sure if these will fit the smallest SW Evostar, the 72ED model.  Here is a table of compatability for different scopes and the appropriate size GSO focuser:

 

https://agenaastro.c...patibility.html

 

The SW 72ED Evostar is not listed.

 

On the bright side, the stock Dual-Speed Crayford Focusers on the Sky-Watcher Evostars can be adjusted to operate better than many do as they come from the vendor.  Here is a guideline to follow:

 

https://teleskop-aus...ent_SW120ED.pdf

Edited by Oldfracguy, 11 September 2024 - 06:02 PM.

[theeyeofthemind]

Thank you for getting back to me! I will purchase one of these and pray it works, I've looked at the capability charts and to be honest I'm still a bit confused. I've talked to SW and they didn't have much information about if the GSO would work. I've also reached out to High Point and they also didn't have much knowledge on the subject. I'm going to have to reach out to GSO and see if they can provide a bit more insight. I also tried to adjust the stock focuser but after taking it apart pieces of what I think what the bearings fell out but I could be wrong. I heard a rattling when packing the scope for a bit of time, now I know what was rattling.  

[Oldfracguy]

I don't think you will get any response from GSO directly, but it might be worth a try.  I think you would be better sending an email to Agena Astro, or just giving them a phone call.  I'm pretty sure somebody else has wondered about replacement focusers for the 72ED Evostar, since Agena has sold a bunch of those over the years. 

 

The most important thing you will need to know is the Inside Diameter of the tube on your 72ED Evostar.

Edited by Oldfracguy, 17 September 2024 - 09:10 PM.

[ares53405]

According to the Sky-Watcher USA website, the Evostar 72ED Apo Refractor has an outside tube diameter of 3.5” (88.9mm).

https://www.skywatch...-apo-refractor 

Look under Specifications and then General Info. That’s a standard tube size and the 86.4mm focuser usually fits that size tube.  I hope this info is of some help to you.   

- Mark

[Agena AstroProducts]

>>I will purchase one of these and pray it works,

 

Please do not do that! We've provided very detailed focuser measurements to check compatibility before purchase. Buying without checking and returning only increases both our costs and frustration.

 

It is generally very easy to measure the tube ID. We do not have any compatibility feedback for the SW72ED so we welcome any accurate measurements you might be able to provide that might help us both. Please feel free to contact us via our website once you have this measurement.

 

Sincerely,

Tom

AgenaAstro.com

Edited by Agena AstroProducts, 17 September 2024 - 06:37 PM.