EQ8-R Pro - problem with worm drive Generic equipment discussions · Marc · ... · 22 · 1790 · 0

Lasastard 3.10
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Hi,

I just got a brand new EQ8-R Pro - unfortunately, the mount is not working out of the box. Specifically, after loading the scope etc and starting the star alignment, the RA axis (I think) made a terrible grinding/screetch noise, not always, but in certain positions or after a short time of operation (< 1min). Tried to optimize balance etc (only got 10kg on it anyway), but it seems there is something wrong with the gears. 

Here is a small video of what it looks like after my first short test run (which I aborted due to the issues mentioned above): https://youtu.be/Ss9ZTA28Rzk

The vendor told me this is due to the gear/worm being too tight and that I should losen it a bit. 

Problem is, I am not an engineer (or handy with tools in any way...). And the only instruction manual available is from the Dec axis of the original EQ8. 

My question thus... is this (gearing too tight)what's happening here, or should I better return the mount? And if this is fixable by clusmy me, are there any more detailed instructions available so I don't have to go in blind?

Cheers,
Marc
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stevendevet 6.77
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If it's brand new, I'm guessing its still covered under warranty and such.
As long as it is, I'd let the vendor deal with it. quite frankly: "it's not your problem, it's theirs (or skywatchers)". 
I'd be pretty pissed if I'd pay such an amount and the mount I get isn't perfect out of the box. So I'd want a fix or preferably; a new one. (just to make sure that this isn't a deeper issue than a tune of the gears)



I did try and find some instruction manuals, but.. I can't seem to find any.

I did find an entire breakdown video, where they tear down an entire mount to parts.
Perhaps it's somewhat useful, but no idea: EQ8 breakdown

Screwing up something with gears and such, might mean you lose your warranty.  So not worth the risk on such an expensive mount.
But even if I knew what I was doing, I'd still want it to be perfect out of the box. You also have no idea if this now damaged the motors ever so slightly, and they fail further down the line because of the issue you're having now.
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AstroAdventures 0.00
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It should be perfect from the box. Just contact the vendor and get it changed.
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andreatax 7.22
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I suspect there is more to it that an overtightened worm. It can probably be fixed but I doubt you can having no previous experience. As other said, that is a faulty unit and they should fix it, end of story.
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Lasastard 3.10
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Thanks for the feedback! The mount will be returned later this week; it's just not worth the hassle to me. And you are right, who really knows what might be wrong with the unit - what looks like a small issue could lead down a very expensive and time consuming rabbit hole.
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daserpey 0.00
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Hello Marc,
Where did you buy the mount?
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DuglasEstrada 0.00
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Hello everyone, I received my new Eq8-r a few days ago, I just installed it in my observatory and found out that it has the same problem, same ugly noise in RA motor, Marc did you fix it, got a replacement?, what shoul I do? please help!!! Thank you everyone.

Douglas.
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AstroDarkSky 2.41
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While it is the vendor(manufacturer)'s problem to properly adjust the tightness of the worm, manufacturers state that things shift temp wise from when it ships and arrives. To an extent, I get that, but it should never be that far out of spec to be totally unusable to that extreme. Seems it was never in spec to begin with. Right call to ship back, but a lot of people on other non-Astrobin forums instantly say to send it back to make it the vendor's problem (which I agree), but can you state if they pre-paid for the shipping to return it back and fix?

That part is frequently left out of the equation and even if under brand new warranty, I think the community would like to see if return shipping costs were covered by them. That is a very heavy mount and I would be surprised if you didn't have to spend >$200 shipping to fix a problem that shouldn't have occurred in the first place.
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rudolfge 0.00
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Hi there,

Remote diagnosis is difficult. I had a similar problem with a new EQ8.
If it isn't due to gear/worm play, it could be due to a weak power supply unit, as it was in my case.
Since I've been using the mount with a 15A power supply (13,8 Volt), the rattling and blocking of the RA motor was over.

Gerd
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Soupernova 2.11
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Have used mine for a good 6 months pretty heavy and no issues thus far.  Eq8-Rh bought middle of 2021. Probably a good call just to send it back as it was new.  It's in my backyard so if I can help anyone with diagnosis just let me know.
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martindufour 1.91
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·  4 likes
Hi Marc and Duglas, l got the same problem as you describe, it's easy to fix.   You have to release a little bit the DEC Worm.

your salesman is telling you the truth: The vendor told me this is due to the gear/worm being too tight and that I should losen it a bit

If you need help, we could make a video call with messenger, I could show how to do it. It takes less than 30 minutes


CS  Martin
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Lasastard 3.10
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Thanks for the offer, Martin! 

The vendor just pointed me to an older instruction for the previous generation EQ8. But I wasn't comfortable tinkering with anything at this price point, truth  be told. So I ended up returning the mount for a refund. 

The vendor arranged for a pick up, at no extra cost, and I had my money back within 2 weeks after that. Bit of a shame, but considering that one of the features I was keen on - the USB hub - isn't really working as advertised anyway, I guess it was for the best.
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DuglasEstrada 0.00
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Hi Martin, thanks for the info, have you posted a video on how to fix it somewhere so we can watch it? Thanks in advance. 
Duglas.
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martindufour 1.91
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Hi Duglas, i don't have video but a could explain it to you using messenger (video call).   I will show to you what you have to do on a video call.
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sachi_mr 0.00
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Hi Martin,

Lately I am having the same issue with eq8-rh and it happens every time the mount slews . Could you please help me with the steps to fix it .


Thank you, 
Sachin
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DarkSky7 3.61
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That's a new rubbing sound I have not heard before.  Usually when the steppers stall it has a different sound on my EQ6R.  But hopefully just readjusting the worm mesh will help.  It certainly should not do that out of the box, but do understand that this is going to be a lifelong adjustment for these mounts.  Temperature will play a large roll in gear mesh and backlash, so learning how to adjust it will be a real positive for you!  It is not as difficult as it seems, but yeah-it is always scary to start playing with a new mount, for sure!  These ring gears are not really precision in that they are slightly elliptical so they will have high spots and low spots on the full cycle.  You sort of have to adjust where you get the best feel and no screeching or binding!  Best of luck!
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ludot62 0.00
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·  1 like
Martin Dufour:
Hi Marc and Duglas, l got the same problem as you describe, it's easy to fix.   You have to release a little bit the DEC Worm.

your salesman is telling you the truth: The vendor told me this is due to the gear/worm being too tight and that I should losen it a bit

If you need help, we could make a video call with messenger, I could show how to do it. It takes less than 30 minutes


CS  Martin

Hello Martin,
I have the same problem (EQ8 R Pro, new from April 2022), but only when my mount is outside (and load, of course), it's very strange to understand. The noise was gone for 4 months, and it just came back. It's as if the cold or the humidity outside brought an additional constraint to a specific place.

I'm sure it's not the powersupply (I have tested 4 different alimentation 12V 15A). The motherboard has been change also.

When I turned tha RA axe with my hand, there is a very small hard point to pass (and this is where the engine blocks).

Could you explain the setting you did the resolve the problem please ?

Thanks a lot,
Best Regards,
Ludovic
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Soothsayerman 2.11
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·  1 like
I would contact Skywatcher directly immediately if the vendor has not solved your problem.
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DarkSky7 3.61
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Also, try to loosen your Ra thrust bearing. My eq6R thrust bearing was pretty tight from factory. Being able to adjust out has made a lot of difference in balance and guiding.
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martindufour 1.91
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Could you explain the setting you did the resolve the problem please ?


Yes, i will take time to do it shortly ...
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martindufour 1.91
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@Ludovic TERNISIEN

Here is a little video I just made, it's in French but I think you'll understand. Basically, unscrew the housing of the mount and unscrew the left and right screws, then unscrew the middle screw by +- 1/8 max and then tighten the left and right screws. Do a full test before putting the plastic case back in case you need to give back a little more space with the center screw.

EQ8WORMGEAR.mp4
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WhooptieDo 8.77
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I'm a little late to this one, but that video sounds more to me like the worm/spur isn't even engaged, or is coming out of engagement.  Maybe the bolts were loose from the factory and it slipped.   While the mount clutch is locked, try to wiggle it about the RA axis.  Do you feel any play?   I suspect you will feel it.

Regardless though, worm adjustment is something that you can do on your own, don't fear.   Skywatcher will give you permission to adjust it and still maintain warranty.   They do ask that you contact them prior to adjustment though, and they will give you instructions.   If it's not something your comfortable with, send it back.     Better safe than sorry.            I've found with my EQ6, depending on temperatures I have to adjust mine for the season, so it might be worth it for you to get comfortable with a fairly simple procedure.
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ludot62 0.00
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Martin Dufour:
@Ludovic TERNISIEN

Here is a little video I just made, it's in French but I think you'll understand. Basically, unscrew the housing of the mount and unscrew the left and right screws, then unscrew the middle screw by +- 1/8 max and then tighten the left and right screws. Do a full test before putting the plastic case back in case you need to give back a little more space with the center screw.

EQ8WORMGEAR.mp4

Ok thanks, no problem for the french, I'm French ;).  The seller just told me the same thing, but simply to loosen the 2 outer screws (do not touch the middle screw). I do it and I wait the next cold weather to test it ;) Many Thanks
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