ZWO EAV for SCT Nexstar SE8

[StarChildDazee]

Hi Everyone, I trying to search if there is available an adapter for the ZWO EAV Electronic Automatic Focuser to fit my Celestron Nexstar SE8?
Couldn't see any on the ZWO web page.
I cant justify $400 for a Celestron auto focuser, so looking for an alternative.
Any suggestions please??

[Ukastronomer]

Looks simple on any scope

https://youtu.be/KcXf-xHYtBw


????????? $400 unless your exchange rate is massive it is under £190 here

https://www.tringastro.co.uk/celestron--focus-motor-for-sct-and--edgehd-telescopes-16109-p.asp?gclid=Cj0KCQjw0IDtBRC6ARIsAIA 5gWvrXG716D7t_GMcCA1rIo5Z3YoulItPX2 _tIm8S1b_WlWAoj75KRckaAr-_EALw_wcB

[Hemi]

Hi DF,

The ZWO forums seem to indicate that an SCT bracket is on the way shortly.
There is also a thread somewhere on cloudy, suggesting that the Pegasus focus cube 2 sct mounting kit works with the eaf.
The current recommendation from zwo is to use an external focuser, on an sct. Like a baader steeltrak or SW sct Crawford. The eaf should mount to that with the included hardware.....this does defeat the cost implication though, but does provide other benefits (reduced mirror flop etc).

Cheers

Hemi

[truss]

The AUD to GBP exchange rate is abysmal at the moment.

I'm looking at an EAV for my rig, the Celestron one looks the goods.

[StarChildDazee]

Hi Ukastronomer, 190 pounds equals aud$360 then you need to add postage which puts the cost well over the aud$400 to buy here in OZ.
I hopefully an able to get one now for aud$300 shortly.
Even going with an aftermarket auto focuser will eventually cost over aud $400.
This now confirms that all things Astro will eventually cost you an Arm and a Leg. Ho Hum and that's the way it is, I guess......

[The_bluester]

The issue with using an external focuser with an SCT is that if you are using a reducer/corrector the sensor spacing is quite critical, the only focuser I know of that permits a reducer to be installed in the focuser drawtube is the 2.5” Moonlite one, so you can get your corrector spacing right and have it move with the focuser.

I have a Celestron one on my SCT and have wondered about removing it and fitting a ZWO one on an adapter bracket (I have one of them on my little refractor) The ZWO has an inbuilt temperature sensor where the Celestron does not and it is useful information to have, and I think the step size of the ZWO is smaller and it certainly has less backlash.

[StarChildDazee]

Hi bluester, is the sensor spacing you mention, is the increment stops that the auto focuser uses to gain proper focus and obviously a more finer stop or smaller space between stops is required when employing the focal reducer/corrector??
I'm relative new to most things astro so just trying to get my head around all this tech jargon!!!

Dazee

[StarChildDazee]

It does Truss, i hope to have gotten a great deal at $100 below retail here in OZ.
Prices suck here compared to O/S A/A's (Over Seas Amateur Astronomers)

[The_bluester]

To take my SCT as an example, the commonly given distance that you are supposed to have between the reducer that can be fitted to the rear cell of the telescope and the sensor of the camera is 104mm (I have found it to be different)

If you have that spacing different to the required figure then in the case of my scope, the correction of elongated stars in the corners, and the reduction in focal length of the scope as a system changes.

If you are stacking multiple images and provided any change in star shapes is not severe it probably does not matter too much, particularly with some of the modern software, but it is generally better to maintain the spacing between your camera and reducer and move the image train elsewhere to focus. As the telescope cools an SCT can change focus significantly, but I don't know if it is enough to cause too much drama, but if I was to fit an external focuser to mine I would plump for the bigger moonlite and an adapter to fit it to my scope.

I doubt if I will do that, what I am doing with my SCT photographically is pushing it's limits fairly hard. No sense in pouring cash into something with optical limits that I have reached, and which cant be cured by any amount of money.

[StarChildDazee]

All sorted now. I bit the bullet bought the new Celestron AEF.
Not cheap but as its designed for the Celestron Scopes I decided to KISS (keep it simple stupid).

Thanks for all the input you guys. Appreciated...:)