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The ZWO AM5 landed!


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Why the AM5?

I've had serious back problems from before the start of this year, so I was looking to downsize my Altair 102ED refractor and iOptron GEM45. These are not overly heavy by most standards, but there was no way I'd be able to shift those lumps about, particularly as I have to build up and strip down my gear for each session. The fickle British forecasts didn't help my state of mind either, and a general malaise had set in.

Someone else now has the benefit of my gear, and as a lighter weight replacement I've gone with the Askar FRA400 coupled with an ASI533 (my first astro camera too, and not really seen first light yet!) and all driven by an ASIAir Plus. Except of course I've had no way to use it without a mount. Until now! At about the time I was downsizing the ZWO AM5 harmonic mount appeared, and seemed an ideal mount for my needs. Not too heavy, no need for counterweights or balancing either, and therefore easier to set up and tear down. I'm not by nature someone keen to be a first adopter, and there were a lot of unknowns, but with the expected lead time and promotion price, it seemed to fit the bill. There was no way I would be prepared to shell out for a Rainbow mount! So, that's where I'm coming from.

Open the Box!

On Friday I got a message to say that the mount would at last be delivered tomorrow, but as it turned out I got a further message yesterday that it would be delivered that day. Well, I was somewhat disappointed to find that only the mount had been delivered, not the tripod :sad2:. Hopefully that will be delivered tomorrow. So today I thought I'd show some photos of the mount itself.

The mount was delivered in the original ZWO outer packaging, well protected by cushions.

Here's the mount in its presentation box.

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Inside there is a nice padded semi-rigid case with optional carrying strap, introductory guide and the all important PE curves for this particular mount.

 

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Opening up the case this is what will confront you.

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That is the mount, hand controller and connecting cable, two Allen keys, and a USB A to B cable. There is room for the counterweight bar, should you have purchased one.

Sadly, that's as far as I can go at the moment, until I receive the tripod.

The PE curve

What we know about harmonic mounts is that the PE curve is not regular, and furthermore, each manufactured harmonic reducer is unique. Hence the provided curve is specific to this mount and identified by the serial number. According to ZWO, manufacturers of harmonic reducers are unable to control the PE within reason, and for industrial uses they can far exceed the accuracy needed for astro imaging. ZWO requires their suppliers to undertake PE testing and they  select only those for which the PE is <±20 arcsec. How many other mount manufacturers provide the PE curve?

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Details of what this means is given here: https://astronomy-imaging-camera.com/tutorials/10-things-you-need-to-know-about-the-custom-am5s-pe-test-report-provided-by-zwo.html

So what does this mean for my mount? For the worst case PE:

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18 arc.sec drift would occur in 0.6°. Since 360° takes 24hr, 0.6° will take 144s, so the PE max drift rate will be 0.125 arc.sec/s. Hence, with 1s guiding, the error should be no more than 0.125 arc.sec. In reality of course, guiding errors will be worsened, but even so, it looks as though performance will be more than adequate for my needs. I'm pleased that it would seem I have a relatively good sample.

When the tripod arrives I shall continue this post.

Ian

 

 

Edited by The Admiral
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3 hours ago, gilesco said:

I know you obfuscated the serial number in the PE Test Report, you might also want to obfuscate the QR code as well if you really want to protect that information.

Ah, true! Thanks for the heads-up. Doh, I forgot about that. I'll do it now :smile:.

Ian

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14 minutes ago, Ouroboros said:

Thanks, Admiral. I’m really quite envious of the adventure you’re about to embark upon. Good luck and I look forward to hearing further updates. 

Thanks for your kind comments. It will certainly be interesting :smile:.

Ian

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These type mounts new to the scene look good and i hope they perform but a couple of things make me cautious so I'd sit back and wait for real life performances.. for something without a worm has quite a bit of periodic error, my brain tells me that most PE comes from the worms.. I have a hunch where it's coming from we will see.. peak to peak seem drastic..

Most ioptron mounts come with PE curves

Edited by newbie alert
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3 minutes ago, newbie alert said:

Most ioptron mounts come with PE curves

My comment was really directed towards manufacturers in respect of their harmonic mounts, where we know that the PE curve can be quite hairy. I agree that it is good to wait for real life test reports and reviews, but I my case that would have been a luxury. I'll have to take what comes, but I believe that the harmonic mounts have a place, with known limitations, and for me, it should meet what I need. As for ZWO, I do feel that they are going into this venture with their eyes wide open and they're keen to get it right. They may not totally succeed, but good enough for what I want. They have got a small bunch of amateur astronomers to put these mounts through their paces during the development phase, so they are listening to needs of the community. I can't ask for any more than that at this stage.

Ian

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27 minutes ago, newbie alert said:

These type mounts new to the scene look good and i hope they perform but a couple of things make me cautious so I'd sit back and wait for real life performances.. for something without a worm has quite a bit of periodic error, my brain tells me that most PE comes from the worms.. I have a hunch where it's coming from we will see.. peak to peak seem drastic..

Most ioptron mounts come with PE curves

The calculation of the max-PE of 0.125 arc.sec/s seems a sane calculation. It looks like the min-PE will be around 0.04 arc.sec/s and average of 0.08 arc.sec/s. Combining this with the reported zero-backlash means guiding should be able to compensate pretty well, although with bad seeing I suspect people might start ditching their OAGs and start looking for wider aperture guide scopes and more expensive and sensitive guide cameras - as they look to be able to do sub-second guiding to further minimise the error.

I guide my CGX, typically with 1-2s guiding exposures through my OAG. 1s is probably the lowest I can go with the guiding at the moment, and this is with the new moon, my neighbours and my wife turning their house lights off etc... In truth I think best case current error in my exposures is around 0.6 arc.sec/s and at worst quite possibly as high as 1.2 arc.sec/s - but that's why we take multiple exposures and discard the worst ones.

For long exposures, guiding is going to be a must with this mount I'm sure. But the pro's of being lightweight and compact compared to the heaviness of my CGX probably makes it a mount that will be on my future wish list.

As you say, let's wait and see what the early adopters report with it.

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The calculation is based on a unachievable data.. Zwo are one of many pushing the harmonic drives, it's very early to have any sort of idea of the performance likely.... Thorough testing could thou, but as per normal it's pushed out far too soon.. seen a couple of u tube testers one has failed to respond to questions asked because he has no idea what to look for other than will it run on a ASI air.. The peak to peak data is the main one for me and one that most don't look for, seems far too large for me at the moment.. my own data is only deleted when cloud ruins the guiding

 

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1 hour ago, gilesco said:

The calculation of the max-PE of 0.125 arc.sec/s seems a sane calculation. It looks like the min-PE will be around 0.04 arc.sec/s and average of 0.08 arc.sec/s. Combining this with the reported zero-backlash means guiding should be able to compensate pretty well, although with bad seeing I suspect people might start ditching their OAGs and start looking for wider aperture guide scopes and more expensive and sensitive guide cameras - as they look to be able to do sub-second guiding to further minimise the error.

It does seem that the early testers guide at 0.5s, though I'm not clear why 1 second guiding shouldn't give satisfactory results. Time will tell. At these sub-second guide exposures concern has been expressed that it'll guide on the seeing rather than the star, so it'll be interesting to check how much multi-star guiding can ameliorate this. Another option would be to use an IR filter on the guide camera. Note that I'm no expert in guiding, having done Alt-Az imaging for a number of years before recently switching EQ, so this is as much a learning experience for me.

Ian

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Today, with the mount on the tripod, I used both the handset and the ASI Mount software to control the mount. This was through the wi-fi hotspot created by the hand controller. All appeared to work fine, within the limits of what I was able to test.

I then took the assembly outside and mounted my intended scope for testing with the ASIAR. I'm pleased to report that the mount is sufficiently light, when mounted to the tripod, for me to carry both ready assembled. That's 5.5kg for the mount and 2.3kg for the tripod. For most this would be a very easy carry. Incidentally, there is now an 'official' manual for the mount (https://astronomy-imaging-camera.com/manuals/AM5_user_manual_V1.0.pdf). The rubber feet of the tripod can be unscrewed and replaced with the supplied spikes.

I've been more than happy with the quality of finish of both the mount and the tripod. Both operate smoothly and feel of high quality. Not dissimilar to the iOptron GEM45 I had before.

Now for some pretty pictures :rolleyes:.

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To my mind that's a decently robust dovetail clamp for both Vixen- and Losmandy-style dovetails, with decent sized knobs that don't hurt the fingers when tightening.

 

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I think this area is a bit vulnerable on account of the long azimuth adjustment bolts, which presumably has come about because early testers found that the original knobs were too small and the only way to accommodate larger ones would have been to extend the bolts. I can see these getting bent inadvertently.

The elevation adjustment is smooth and easy, though this is with a lightly loaded mount. On the plus side, the barbell arrangement would give a decent amount of leverage.

Now loaded with an ASKAR FRS400, ASI533MC, William Optics 50/200mm guide scope with an ASI120MM, and the ASIAIR Plus. That's 4.6kg, so the load on the mount is only ~1/3 the maximum unbalanced load for the mount.

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As an early adopter I got to choose whether I wanted the front faceplate to be blank or be embossed with the "bunch of galaxy balloons" emblem. I chose blank.

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I power the mount and ASIAIR separately. As ever the power blocks never have long enough output leads, so they're conveniently sitting in the weight bag. I used the USB connection from the ASIAIR to the mount, not the wi-fi link. I used the ASIAIR via my Android tablet to control both the direction and speed of my mount by means of the direction 'buttons', to assess whether or not a mount/tripod collision was possible. I concluded it was! As a first step I shall need to increase the distance between the tube mounting rings and the dovetail, which is something I'd have to do anyway if I ever mounted an EAF. I used the 'send to home' function too. I'm pleased to report all worked without a hitch.

Note that today there has been some feedback on the ZWO Mount Facebook site that says if the mount is switched off without it being at the home position, then the next time power is re-applied, it assumes that the position it is then at, is the home position. So it is important that the mount be returned to the home position prior to shutdown. I guess that there could be an update in the pipeline for this.

Until I can get a chance to do some imaging, which I assume won't be for a while yet, I'm unable to report beyond these rather simplistic checks. But overall, I'm happy with my mount.

Ian

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Edited by The Admiral
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3 hours ago, knobby said:

I noticed on Cloudy nights that ZWO have been releasing these to Aliexpress before fulfilling pre-orders ... tut tut 😞

 

I have read that of some rancour expressed on the ZWO Facebook site, but this may have been at a time when ZWO were unable to ship through the ports and had decided to distribute 'off-list', within China. Also, I get the impression that America is less well served than we are, but may be wrong on that front.

Ian

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54 minutes ago, The Admiral said:

I have read that of some rancour expressed on the ZWO Facebook site, but this may have been at a time when ZWO were unable to ship through the ports and had decided to distribute 'off-list', within China. Also, I get the impression that America is less well served than we are, but may be wrong on that front.

Ian

And my oh my, don't they like to moan over there 🙂

 

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1 hour ago, The Admiral said:

I have read that of some rancour expressed on the ZWO Facebook site, but this may have been at a time when ZWO were unable to ship through the ports and had decided to distribute 'off-list', within China. Also, I get the impression that America is less well served than we are, but may be wrong on that front.

Ian

Yeah, also bear in mind that shipping mounts by boat from China to Europe / USA can take 6-8 weeks + customs clearance time, so they may have temporarily cleared the back orders and then sold further mounts in China (which being domestic over land they can fulfil orders in 1-2 days).

I take what I read on Cloudy Nights with a pinch of salt, the USA media is constantly feeding anti-China rhetoric much more than we are. But in short, there are lots of people who have opinions who, unfortunately, have little idea of the logistics of international order fulfilment.

Edited by gilesco
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