Zwo eaf

[Hemi]

in case anyone is interested, I got an email from ZWO informing me that a bracket for SCT's is coming out this month.

Hemi

[The_bluester (Paul)]

That would be a handy thing, I have a Celestron focus motor on my C925 but they did not include a temperature sensor in those and temperature changes are the most critical thing to refocus for with that scope, The ZWO documentation does not say it (Or did not when I bought mine for my ED72) but they do have one.

[Hemi]

I thinks it’s one of the most cost effective solutions out there, and cloudy reviews are positive in the main, indicating high quality. I built an arduino focuser but got stuck at the housing/attaching stage. I’m looking forward to electronic focus. I’m going to opt for the kit with hand controller and temp sensor.

[Imme (Jon)]

They’re a good bit of kit, gives me great focus every time.

FYI - you probably don’t need the additional temp sensor unless you have a specific use for it. The inbuilt temp sensors works fine in my opinion and is sensitive enough to identify even a small temp change

[Hemi]

That’s a good heads up imme, thanks. Do you use the hand controller?

[Imme (Jon)]

No, I’m 100% computer controlled so have no need for a hand controller.

If you’re imaging with it I’m not sure why you would want a hand controller unless doing video feed

[Hemi]

im still predominantly into eyeball Mark 1 (EM1) astro.

[Hemi]

I missed this!

https://www.youtube.com/watch?v=51uvMbKUs0s

[Hemi]

The bracket for feather touch for sct has been released.

H

[The_bluester (Paul)]

If I knew that one was coming I would have kept the FT focuser I used to have on my SCT. I reckon the EAF is better than the Celestron focus motor, it has a temperature sensor built in for one thing.


I might have to try to make a mandrel that clamps over the brass focus tube/nut of the stock focuser, ending with a small shaft to suit one of the EAF couplers and a bracket to mount the motor.

[Hemi]

Ordered one, and an EAF 😀
Will be my first electronic motor focuser.

Hemi

[Imme (Jon)]

I don't think you'll be disappointed. Great bit of kit.....takes focusing away as one of the things you need to worry about

[Hemi]

So I’ve been in Tassy for a couple of weeks (holiday, first time there), and on my return had a nice shiny new EAF focuser with SCT bracket.

Very easy to install, but scant documentation re the sct bracket.
Easy to setup software wise (ascom and sharpcap)

I’m a complete electronic focuser newbie, of course I ran out of focus travel! So I dismounted the eaf, wound it in a bit with the hand controller, then remounted it!

At initial installation I wound the mirror right back and then attached the focuser.

Is there a correct way of doing this? Should I have wound the focuser out to its end point?
What happens when you put a reducer or Barlow into the equation, is there usually enough focus travel?

Currently just doing this with the hand controller for visual....I’m smitten, no shake, and so precise!

Hemi

[The_bluester (Paul)]

I have mine on a refractor with a rack and pinion focuser so it wont slip like a Crayford would so it is similar to the SCT focuser. I made sure that "IN" on the focus motor was "IN" for focuser movement, set the focuser physically at approx 2mm from fully racked in and set that point as zero on the focus motor, then set the maximum step count to a figure which stops the motor approx 10mm before the focuser is fully racked out (I don't need to go anywhere near that far out to get focus) That way the focus motor will stop in either direction before the physical stop of the focuser itself.

If I put one on my SCT I would do something similar, work out which direction is "IN" on the focus motor then run the focus knob right to that end of its travel and then come back a couple of turns before attaching and zeroing the EAF. Then work out how many steps gets to the other end of the physical focuser travel and set the maximum steps to keep it a couple of turns away from that point, so the focus motor will never drive the mirror to one of the hard stops.

The Celestron focus motor does that as part of its setup routine, it finds the two ends and sets it's internal limits to suit and you should only need to redo that if you do something that moves the focuser without moving the focus motor.

[Hemi]

Thanks Paul,

Is setting a zero point and step size etc done in Ascom setup or within the imaging software?

Hemi

[The_bluester (Paul)]

It is done via the ASCOM driver usually, but depending on what capture software you are using you can probably call the setup windown from within it.