Am5n knocking and clicking at zenith with 15kg (33lb) scope - need bigger counterweight? - Forums

Bluetooth1989

Topic starter

28 days ago

Short version: My am5n knocks and clicks when tracking from zenith when my 15kg (33lb) scope is on the east side even with 4.2kg (9.25lb) counterweights… is it faulty or do I just need to get a bigger weight?

Long version :

So I just bit the bullet on a second hand edge hd 9.25 scope. I’ve loaded it with some standard accessories etc and it comes in at about 15kg (33lbs). I have spent the past 2 nights playing with autofocus and trying to get my guiding up to scratch as it’s the first time i’m using a OAG.

At the end of the night I decided to try and slew to a target to see how it looked. The target just so happened to be at zenith. So the mount slewed over to the east and then when it stopped it started making a knocking/clicking sound and my 2 second test exposures where trailing. Im guessing the gears were slipping? I only had a 1.5kg (3.3lb) counterweight and it was starting to get windy so I packed it up for the night.

This morning i’ve turned it on and slewed to zenith in the east. It sat there humming but no knocking… I then turned on tracking and the knocking appeared again.

So I grabbed all the counterweights I own which total 4.2kg (9.25lb) with the count weight bar. I tried again and I still get the same knocking.

If I slew to the west and track it is silent…. So I am assuming the mount is struggling to lift the weight of the scope as it tracks to the west.

I’ve tested rough centre balance on a rolling pin and it seems the centre is pretty inline with the axis the counterweight bar is located.

I see alot of people say they use a 5kg (11lb) weight and have no issues. I’ve already had 4.2kg (9.25lb) of weight and it hasn’t worked… However that was spread over 3 different weights and half the counterweight shaft length… as oppose to just one big counterweight right at the end.

Would getting that single weight solve my issue? Or does it sound like my mount may actually be faulty? Those that have this set up and are succesful, have you actually tested it at zenith to the east with tracking turned on? Just incase it turns out that it’s normal and sorts itself out as it tracks further from zenith.

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BlackStarsAstro

28 days ago

Can you provide pic of setup?

Bluetooth1989

Topic starter

28 days ago

20251214_111123.jpg

I am thinking maybe removing the losmandy and putting it back on its original dovetail bar so it lowers it an inch or so.

I have the celestron reducer, celestron oag with 174 mini guide cam and touptek 1.25” filter wheel with the atr585m camera. Also an eaf, wanderer astro wonder box v3 and melee mini pc with a vixen dovetail/handle at the top. It’s all just roughly put together at mo.

I also have a gemini automatic flat panel on the way… And will probably have to get the aluminium dew sheild for it as i cant put the flat panel on with the flexible dew shield i have currently (not using at the mo though)

Chris Henderson

28 days ago

With regard to the knocking sound, I HAVE heard this very briefly recently when slewing my Edge HD 8”. I happened to have not had my usual 5lbs counterweight installed at that moment, although that may have been a coincidence.

With regard to the mount drifting off at the zenith, double check some things. Has guiding seemingly turned itself off? If you look at the tracking indicator in the ASIAir App then I will guess that tracking itself is also off. Indeed, if you try to turn guiding back on then it might complain that the mount is too near the meridian to do so. This is because tracking is turned off X minutes before the meridian flip is executed (the number of minutes is configurable).

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Bluetooth1989

Topic starter

28 days ago

Update. Just swapped out the losmandy I bought for the original that comes with the scope…

20251214_121228.jpg

It still does the same thing.

And cheers chris. I’m unsure if it was a guiding issue as such. Even without guiding and only tracking I could get 10sec subs without trailing. However when at zenith with the mount knocking (you can feel the knocks if you put your hand on any part of the set up) with just 2 second exposures I was getting trails of 10-20x the length of the stars. My guess is the knocking is causing the scope to shift causing the trails.

I’m pretty sure in nina my guiding works right up until the flip (I think with my previous scope set up it would image all the way up until my length of exposure would cross over with the meridian flip) … However the guiding was pretty bad (about 1.5rms or so… but jumping around alot. With my svbony 122 and guide scope I would continually get 0.2-0.3 rms) so I do defo need to play about more on that front… but it feels like a loosing battle at the mo if the mount is struggling with it :(

noon

28 days ago

I had the same issue. I sent it back to ZWO for warranty repair. They tried to fix, sent it back, and when I sent it back again for the same issue they replaced it. New mount has no issues.

Bluetooth1989

Topic starter

28 days ago

That doesn’t sound great. I got the mount 13months ago… in australia we are meant to have 2 year warranty but wether that is going to happen or not i’m unsure. I have just sent in a support request with zwo to see what they say.

20251214_143902_2.mp4

Just realised I can upload video but only able to do a small file so have had to make it short and sweet. But it shows the knocking sound I am experiencing.

noon

27 days ago

It may just be the belt skipping teeth under load. ZWO may talk you through an adjustment process. They tried that with me at first.

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BlackStarsAstro

27 days ago

I have the Am5 original. Sounds like you think it may be a balance issue. As a last option, Mount your Mele and power box on the lower dovetail bar. You wont have a lot of space, so make sure you move the mount around to insure clearance. That is how I run my EdgeHd 11 mono setup on my Am5 without issue. 📷 IMG_1178.HEIC

Bluetooth1989

Topic starter

27 days ago

noon · Dec 14, 2025, 09:38 PM
It may just be the belt skipping teeth under load. ZWO may talk you through an adjustment process. They tried that with me at first.

Cheers. I recieved a reply this morning from zwo saying it sounds like a belt slipping and they will send me through the adjustment guide. So hopefully later on i’ll be able to have a crack at that.

Did you manage to see the video I uploaded in the comments? I’m guessing it is public and people can see…. Was that a similar sound to your one?

Bluetooth1989

Topic starter

27 days ago

BlackStarsAstro · Dec 14, 2025, 10:14 PM
I have the Am5 original. Sounds like you think it may be a balance issue. As a last option, Mount your Mele and power box on the lower dovetail bar. You wont have a lot of space, so make sure you move the mount around to insure clearance. That is how I run my EdgeHd 11 mono setup on my Am5 without issue. 📷 IMG_1178.HEIC

Cheers mate. I’m at work at mo and that photo isn’t loading on phone but will look on pc later. I was hoping I wouldn’t have to move the PC etc down there but may have to give it a try… this set up is alot heavier than my previous set ups but it is still well within the limits of the mount.. so only thing I can think is it’s a balance issue taking too much weight away from the centre… but then like yourself you have an 11inch so that is even bigger still and it manages… i’m waiting on zwo to send me through belt adjustment guides so will see how I get on from there

Michael Kalika

18 days ago

BlackStarsAstro · Dec 14, 2025 at 10:14 PM
I have the Am5 original. Sounds like you think it may be a balance issue. As a last option, Mount your Mele and power box on the lower dovetail bar. You wont have a lot of space, so make sure you move the mount around to insure clearance. That is how I run my EdgeHd 11 mono setup on my Am5 without issue. 📷 IMG_1178.HEIC

Very cool! What is the longest good and guided exposure you had with this rig?

Well Written Engaging

noon

18 days ago

Bluetooth1989 · Dec 14, 2025 at 11:04 PM
noon · Dec 14, 2025, 09:38 PM
It may just be the belt skipping teeth under load. ZWO may talk you through an adjustment process. They tried that with me at first.
Cheers. I recieved a reply this morning from zwo saying it sounds like a belt slipping and they will send me through the adjustment guide. So hopefully later on i’ll be able to have a crack at that.
Did you manage to see the video I uploaded in the comments? I’m guessing it is public and people can see…. Was that a similar sound to your one?

The sound was similar but it is hard to tell from such a short video. I went through the adjustment guide and, when that didn’t work, sent it in to ZWO (New Jersey repair center). They replaced the motherboard and send it back. When it kept doing it, I sent it back and they gave me a replacement free of charge under warranty.

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Bluetooth1989

Topic starter

18 days ago

noon · Dec 23, 2025, 09:30 PM
Bluetooth1989 · Dec 14, 2025 at 11:04 PM
noon · Dec 14, 2025, 09:38 PM
It may just be the belt skipping teeth under load. ZWO may talk you through an adjustment process. They tried that with me at first.
Cheers. I recieved a reply this morning from zwo saying it sounds like a belt slipping and they will send me through the adjustment guide. So hopefully later on i’ll be able to have a crack at that.
Did you manage to see the video I uploaded in the comments? I’m guessing it is public and people can see…. Was that a similar sound to your one?
The sound was similar but it is hard to tell from such a short video. I went through the adjustment guide and, when that didn’t work, sent it in to ZWO (New Jersey repair center). They replaced the motherboard and send it back. When it kept doing it, I sent it back and they gave me a replacement free of charge under warranty.

Cheers for the info. Sounds similar process to me now, belt adjustment didn’t work etc… so was told raise an RMA… so I did… then they replied saying as i’m under warranty I need to deal with the seller for after sales issues. I’ve messaged the seller and they have told me to send it back to them and they will try and replicate the issue and repair it if they find out its faulty. Hopefully they can replicate the issue… it’s clearly not right and i’m 5kg under the weight limit they state it has. I do have another am5n but i’m too scared to try that one incase the weight has broken this one… i’m hoping I don’t have to upgrade to a cem70 but i’m having less faith in this mount at that weight capacity the more I look into it

noon

18 days ago

Just between you and me (and everyone else here), I’ve had this problem with both the AM3 and the AM5N… both loads were barely in the “recommend counterweight” range and I was using a counterweight both were fairly balanced fore-aft on the Dec axis… I balanced the Losmandy plate on a dowel and marked the balance point with tape, which I aligned with the center axis of the saddle.

Both had issues with clicking and skipping, giving me unusable images and both ended up being replaced under warranty but it was a pain to go through all the steps.

I think if you oversize the mount, don’t try to push it, and NEED the portability of the small size/weight then they can be great mounts. They work until they don’t, and then there is nothing much you can do except hope they are under warranty.

I hope the technology continues to advance and they get more consistent. Plenty of people seem to use them consistently with no issues so I think I just had some poor luck. The new ones work perfectly but if I end up replacing it down the road it will probably be with a GM811 or CEM40…old tried and true workhorses that are easier to repair down the road, even if they are a little heavier.

In the meantime I’ll continue to use these and enjoy them.

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Bluetooth1989

Topic starter

18 days ago

noon · Dec 24, 2025, 12:10 AM
Just between you and me (and everyone else here), I’ve had this problem with both the AM3 and the AM5N… both loads were barely in the “recommend counterweight” range and I was using a counterweight both were fairly balanced fore-aft on the Dec axis… I balanced the Losmandy plate on a dowel and marked the balance point with tape, which I aligned with the center axis of the saddle.
Both had issues with clicking and skipping, giving me unusable images and both ended up being replaced under warranty but it was a pain to go through all the steps.
I think if you oversize the mount, don’t try to push it, and NEED the portability of the small size/weight then they can be great mounts. They work until they don’t, and then there is nothing much you can do except hope they are under warranty.
I hope the technology continues to advance and they get more consistent. Plenty of people seem to use them consistently with no issues so I think I just had some poor luck. The new ones work perfectly but if I end up replacing it down the road it will probably be with a GM811 or CEM40…old tried and true workhorses that are easier to repair down the road, even if they are a little heavier.
In the meantime I’ll continue to use these and enjoy them.

Ye I think you’re speaking truth here. With my svbony sv550 122mm on the same mount it’s been amazing. I regularly guide that at 0.2-0.5rms and can spend the whole night not chucking any images. That makes it even more annoying because I think for that set up I recieved a really good mount from the factory but there’s obviously some under lying issue that wasn’t noticeable on that set up.

I have to break down and set up every night so the mount portability has been ideal for me… But I think i’ve probably reached the realistic limit of the mount now i’ve upped my set up a bit. Maybe the am7 will be the answers we need but who knows when that’s coming out.

Garcimor

15 days ago

noon · Dec 14, 2025 at 06:10 AM
I had the same issue. I sent it back to ZWO for warranty repair. They tried to fix, sent it back, and when I sent it back again for the same issue they replaced it. New mount has no issues.

Same here. My mount was changed after they tried to fix it.