Connecting and using the ZWO EAF on the Esprit 120ED
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- Опубликовано: 25 июл 2024
- Hi, I’m Ian and I live in Surrey in the UK.
In this video I explain how I attached and calibrated the ZWO Electronic Automatic Focuser on to my Sky-Watcher Esprit 120ED telescope and then how I used it to image M33, the Triangulum galaxy.
I’d not been sure whether to buy an electronic focuser as I’ve done really well with just a Bahtinov mask until now, but I thought the benefit of re-focusing when I’m asleep would be great!
I looked at a few videos on line and realised there are some scaring approaches out there on how to connect the EAF to the Esprit 120ED.
However, if you buy the Takahashi bracket it is fairly easy to attach with no drilling etc. just using the supplied screws and washers.
In the video you will see all the parts that come with the EAF and how I attached it to the Esprit 120ED. I then go on to show it’s first use, though for some reason my ipad video seemed to stall a few times but you will see the main areas of calibration, such as setting the starting position to zero and then working out how many steps to the maximum position. In my case about 18,000. I have ended up setting my maximum as 17,800. I tend to get focus around 12,300 at the moment.
I then show that you need to set the small and course step levels, which I set at 10 and 1,000 and then run a calibration to estimate the backlash. This is really done by moving the focuser out to a point and then moving it in by the small steps of say 10 and see how many times you need to press the advance button before the focuser actually moves. In my case it was 7 presses or in other words 70 steps. I saw elsewhere that it might be worth making the actual backlash a little higher so I’ve currently set it at 90 and will see how it goes.
Finally, I set the steps for the Auto focusing at 30.
You will see me use this for the first time to focus on M33 and I think I ended up with a reasonable image of the Triangulum galaxy.
The final image is from the 13th January with 30 five minute (300 second) exposures at a gain of 120. 60 flat and Dark flat frames and one master dark frame.
Thanks for everyone who watches and all those who have subscribed to my channel.
Main Equipment:
• Sky-Watcher Esprit 120ED (Super APO Triplet)
• Sky-Watcher Esprit 120ED Field Flattener
All above acquired from FLO
• Sky-watcher EQ6-R-PRO equatorial mount
• ZWO ASI 294MC-Pro single shot colour camera
• ZWO 60mm Finder/Guidescope
• ZWO ASI 120MM Mini
• Baader 610mm Longpass Red Colour Filter
• ASIAir Pro
• ZWO IR/Cut Filter
• PixInsight
• Topaz Denoise
• Photoshop
Music (at the beginning):
Isolated by Kevin MacLeod is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
Source: incompetech.com/music/royalty-...
Artist: incompetech.com/
Music (at the end):
Dream Escape by The Tides
Appreciate the video. Be aware that as of 9/2023 [or maybe earlier] the Takahashi kit does not work as described. First, you have to now assemble the grate [no big deal] but the 35 mm screws are too long now 40 mm so you either have to use a s$itload of washers, cut the screw or buy shorter screws. The install on my Esprit 120 has been pretty tough actually. The spindle holder did not fit well into the focuser so it was tough to get it tightened onto the spindle without it locking up. I know Starizona has a pre-fit holder but it is back-ordered for who knows how long, right? Overall a PIA [and not yet done].
Update: Turns out I had a defective ZWO EAF cylinder. Purchased another EAF and it fit perfectly!
@dadwhitsett it would be great if you can update this comment in the other video related to the same subject. I checked your comment there and I thought I would have issues installing mine, then I checked here and I saw that you had a defective cylinder :-)
Great explanation! I installed my ZWO EAF on my SW120 a few months ago and did exactly this. Works great. There is a lot of misinformation out there, but this is exactly the way to do it!
Thank you so much for this video , I spent my Saturday afternoon watching your tutorial while hooking up my EAF . Thank you again it was so helpful and informative . Your a gentleman. Clear sky's.
Many thanks, hope you get some great ‘Sharp’ images, clear skies Ian
Great video! Thx so much!!
This is absolutely gold - thanks so much Ian. Very clear explanation and demonstration.
Excellent video. Precise and informative. Clear skies!
Excellent - very well done on the backlash explanation. Thank you !
A very clear, methodical explanation. Many thanks!
Hey, Ian, fantastic explanation... thanks for putting this video together!
Hi Ian, thanks to your excellent video I’ll be adding the ZWO EAF to my Esprit 120! Very clear explanation on both the installation and setup/backlash.
Really Good Video Ian, practical, informative and well narrated. I'm about to fit the ZWO EAF to my Esprit ED 80, I didn't know I needed a Takahashi bracket adapter which saved me a lot of grief. Thanks.
Your guiding figures are really good.
Awesome video. I was on the fence about ordering the ZWO EAF for my Esprit 100 due to installation concerns that I had. But, thanks to your video I just ordered one! Clear skies!
Great video, Ian!
Nice video. I have had the pro and eaf for a year and works amazingly well.
Thanks so much for this tutorial, it was so helpful and clear what to do. Easily the best on RUclips!
Thanks for the video. Well explained. I think I am going to get a Takahashi bracket for my SW100. At the moment I have it secured with just one screw and the bracket that came with the ZWO EAF.
Excellent install video. The ZWO EAF works great.
Logan, many thanks, yes it’s a great addition to the set up, kind regards Ian
Excellent video Ian, just subbed to your channel, you explained that much better than my ‘quick version’ on my channel Lol. Found you in the comments in Ollie’s Astro, he’s just joined the 120 club! Great scope, had mine for about 8-9 months. Great image of M33!
Clear skies!
Simon, many thanks for watching, subscribing and enjoying the video, kind regards Ian
Good video. I like the EAF.. just ordered a 2nd one. CS!
Thanks Ian .. nice job.
When I went to install the plate on my 100ED and I loosened the 2 screws the entire focuser came loose…seems the other 2 screws were never tightened…not the first QC issue I’ve seen with SW products 😠 Also imo the kit should have more then 2 screws holding the plate on.
Great install video ty
Turns out the other 2 screws we’re supposed to be loose as the actual focuser sits off off the telescope by about a millimeter to allow for clearance on the gears. You need to adjust all 4 screws down equally to make sure the focuser sits level to the telescope…my mistake
Very nice Ian thanks! I'll be doing this next week with my FF80 when it arrives. I have to say (without wanting to denegrating your good result) that final M33 image closeup doesn't appear to be any more in focus than my own M33 taken with a similar (EON 130 APO) telescope and a Bahtinov mask. The autofocus seems to take a lot of time too (and 'waiting' time always drags slower than 'busy' time). Living in a city flat, I have to stand guard over the rig when it is operating, so I use live mode EAA to amuse me while I'm capturing lights. I only use 'plan' to remember and manage my calibration routine and run that at the start of the session. But it seems the EAF refocus triggers are only available in plan mode. I can't help feeling I let myself fall victim to the hype and bought me a solution to a problem I don't have, together with some features I cant use! You would think I'd have learned at my age 🤣. Still I'm sure to enjoy building the new rig and playing with the toy!
Lovely image Ian, I bought a esprit 120 in Australia about 7 months ago and sky watcher have now added 2 threaded holes in the centre of the focuser so it now accepts the standard bracket that comes in the eaf box. I bought the tak bracket when I bought the scope, because even the vendor didn’t know of the change. Also the backlash setting in the air is only used in manual focus. AF compensates for this by final movement in one direction. Great informative video and my reason to make this comment, people should check their focuser first before wasting their money on the tak bracket. Clear sky’s
Martin, thanks for watching and for highlighting, clear skies Ian
I wish I had read your comment before. I've just finished installing mine and obviously I bought the tak bracket too.... such a shame that vendors don't know about it, because it's not really needed anymore
@@JonathanKvoth one positive you have an amazing piece of glass, enjoy!
@@martinalcock680wow, also just ordered the Tak bracket yesterday but wish I saw this comment first! I suppose I can return it now :)
@@martinalcock680 wait, which bracket to use then? The one with the long channel through the middle? Would it risk coming off then?
Hi Ian - great video, really useful and clear!
I have a question - I have the Esprit 100, but I believe the focuser is the same as the 120 anyway - when I attach the coupler WITHOUT THE EAF to the focuser shaft, I can no longer move the focuser manually from the fine-focus side. If I loosen the grub screw then the coupler rotates and the focuser moves normally. I would have expected the focuser to still move with the coupler attached, and moving the focus knob on the fine-focus side would simply rotate the coupler?
I installed the coupler in exactly the same way as your video, so not sure if I am missing something here...
Thanks, Darren
Hi Darren, thanks for watching. Interesting, I must admit I didn’t test if the focuser would rotate once the coupler was on as I knew that once attached to the EAF you can no longer use the manual focuser, even the normal or fine tune elements as the focuser is locked into the EAF and moving the manual focuser would risk damaging the EAF motor. Clear skies Ian
It was a good demo but I agree with some of the earlier comments - I'd be inclined to install the bracket onto the EAF first.
An EAF by its very nature has to perform some delicate tasks and having the EAF hanging on the spindle - as well as any downward pressure put on it by your hands - may not be good for it.
You only need to calibrate in 1 direction in terms of backlash?
Great demonstration! I have a question though regarding the EAF. The EAF shaft has a "flat side" also. Thus, it needs to be screwed onto the flat side of the EAF too? So, if one has a flat side to the telescope focuser shaft and the EAF shaft has a flat side, then you only use one of the screws on each side of the coupling even though the coupling has two screws on each side? Otherwise, if you use both the screws on the coupling, one screw will not be hitting the "flat side" of the shaft. Thanks!
Hi Heidi, thanks for watching. Yes I seem to use one screw on the focuser end and two on the EAF end. I’ve had no problems so it seems to work okay, I presume the screw on the flat surface is the dominant one and hence no issue from the other one, but presume you could just use one on each end on the flat surface. Clear skies Ian
@@astrotimetraveller4622 Thanks so much!
You can replace the stock coupling with a disk type to improve the backlash.
Searched but cannot find “disk type” is there a link handy? Please
Thanks for the video Ian, I have exactly the same setup as you but I’m struggling to get the eaf to find focus.
Are you using the esprit 120 with the field flattener? When your scope is in focus where on the focus tube is it? Mine falls at about 81 with max extension at 85 which seems to cause problems for the eaf.
Cheers.
Pete, thanks for watching, I had a similar problem initially but it cleared after the first night. It is in focus around mid to high 7, so near the end but not right at it. You can edit where it thinks it is, which can help. Mine works, so yours should too, if anything else comes to mind I’ll let you know. Clear skies Ian
Hi Ian! Great tutorial.
I´m thinking to buy the ZWO EAF, but I´m worried about how to adapt the Esprit case to keep the tube with the focuser. Did you have to modify your box?
Thanks for the video.
Juan, I haven’t tried to adapt the case. I can keep my Esprit in a cupboard with the EAF attached so haven’t tried to see if will fit back in it’s case. I will look at this now you have posed this question. Clear skies, Kind regards Ian
@@astrotimetraveller4622 thanks!
Hi Ian, great video just one question when you set your max steps and back lash in the ASIAIR then come out of that window does it not save them settings, when I’ve tried this and come back into the settings window the max steps are back at 60,000
Cheers
Tony
Hi Tony, thanks for watching and your comments. I think it is a quirk of the ASIair, when you put a new value or rename something, say in the planning mode or here with the value of steps you have to hit the return key to make it stay. If you just move on it won’t have ‘saved’ what you wanted. I think you see this but very quickly in the video when I set the maximum steps. Hope that helps, clear skies, Ian
Thanks Ian I’ll give that a try, by the way love that scope of yours 👍
Hi! One question: Why do not attach the EAF to focuser precision knob? It's supposed to be more precise on that knob than on the one you're using because the demultiplication gearing inside. Am I wrong?
Hi Antonio, thanks for watching. I think all that I read about the installation was that you have to attach it to the normal focuser and not the fine tune one, as I believe it will not actually fit that focuser. Clear skies Ian
Unfortunately I've got one of the early ones with the Helinear focuser. It has a tension adjustment knob, not a flip-lever. The coarse knob doesn't come off!!
After setting the zero then getting the figure for the maximum the tube will go out ,the maximum figure goes back to 60000 as in the video.Does that mean I have to reset the maximum figure every time I use the aef?
wouldn't you want to attach the EAF to the fine focusser?
I have tried this method for backlash.The problem is when I press the remote the small wheel moves straight away.Am I just lucky that the backlash is 0 or am I doing something wrong?
Hi John, thanks for watching, do you have the steps on the lowest level so you are only turning by say 10 steps? If so then suggest you test it in the field. You may find you need to adjust the backlash further once in use. Clear skies Ian
Hi, maybe this is a silly question : is it still possible to focus manually even if the EAF is installed ? Does the EAF need to be powered off to focus manually ?
Hi, thanks for watching. Because the EAF is screwed to the focus tube you can not focus manually by trying to rotate one of the focus knobs, you would potentially damage the EAF motor. However, with the ASIair, and I assume other programmes, you can move the EAF by very small steps then take an image, check star size, or I guess even put on a Bahtinov mask, to get sharp focus by moving the focuser with the EAF. Hope that helps, kind regards Ian
ZWO sell a hand control unit that you plug into the EAF, it’s quite cheap too.
@@BTurner. Oh I see, well, this looks quite redundant, why would anybody use that remote hand controller since the EAF is already remotely controlled ? Weird...
I thought of some kind of manual switch to disengage the motor gears so we can MANUALLY ( with the real hand) control the focus (which would probably require a calibration once gears are re-engaged, a bit annoying...)
Same goes for good motorised mounts : there's no way you could rotate the axes manually and accurately, there're times when you don't need the mount to be motorised for occasional and visual sessions, the use of a simple manual knob would be enough...
@@gloubiboulgazeblob I use the hand controller for when I’m using my telescope for observing, which I do occasionally.
@@BTurner. Ok, but how is it powered ? A battery in the hand controller ?
First.... Nice Vid!
AEF, will not allow my scope to fit in its case, without cutting the foam, the result of cutting the foam, would result in not enough foam left to protect the scope at that point. NOT 1 video on the ASI EAF shows how to set the focuser to min for storage. Might be great for an observatory rig, but a pain for those who have to set up every night, if the EAF has to be removed from the focuser to enable fitment to the case