Zwo harmonic mount release

[PaulSthcoast]

Hi everyone

Just found this online.

https://astronomy-imaging-camera.com/product/zwo-am5-harmonic-equatorial-mount

Short YouTube review

https://youtu.be/DFfJ9ZFlBic

For those who may be interested.

Paul.

[gregbradley]

I'll watch that with great interest. I am looking for another mount to mount my AP130 on in the near future. Something light and portable is even better.

The actual PE is conflicting on this site. In one spot it says 0.5 to 0.8 arc secs
which is better than high end mounts currently.

In another talking about PE correction it says +/- 20 arc seconds which is not good at all.


Greg

[AdamJL]

Very interesting indeed! Could be a great travel mount or secondary mount for lighter setups. I looked at the Rainbow Astro but that price is (IMO) OTT for what it is

[PaulSthcoast]

Zwo promtional video


https://fb.watch/a67M_xgMSn/

Music sounds like a mash up of the themes from
The Omen and The Excorsit !!!


Paul.

[Zuts]

Hi

wow, the mount only weighs as much as an AZEQ6 tripod...

very tempted to buy as they are including a carbon fiber tripod for free and shipping is free.

Please convince me it can't be any worse than a HEQ5 Pro and potentially far better...

[Startrek]

My first thoughts on this mount being so light with an incredibly accurate precise drive system, you want to make sure there’s no wind gusts around when imaging unless your using it in an Obs or you have protection against the elements.
I’m old school , I prefer a heavier tripod and mount for stability together with a lower centre of gravity.

I must say this mount looks impressive, time with tell after 6 to 12 months out on the market. If there is an issue with performance, folk will be straight onto the ZWO forum I’m sure.

Thanks for posting

[Zuts]

Hi,

Wind, cloud, dew we just cannot win can we...

I am thinking of downsizing to a Esprit 100 from my Esprit 120. This mount looks like it may be a good match.

[Kuz]

Thanks for posting Paul. I am looking for a third down the track. Might wait a for the second model to come out . So all the.problems have been ironed out. It looks awesome as well.

[Hemi]

This looks very much like the rainbow Astro and hobym mounts. Similar specs but this one is a bit heavier.

I think it would make a good all round travel mount.

[Startrek]

I just read these posts on the ZWO forum regarding the proposed laser for this mount

No reply from ZWO as yet ?

https://bbs.astronomy-imaging-camera.com/d/13695-new-zwo-am5-harmonic-mount-laser-problem

[PaulSthcoast]

Thanks Martin...

Yes...

I was wondering about the green laser as well.

Paul.

[Peter Ward]

Humm...look at ZWO's own data, the PE does seem to be about 30 arc sec. Might be high frequency ripple there too of about 1-2 arc sec....

But, it's Christmas so..." Everything is awesome. Everything is cool when you're part of a (zwo) team " :)

P.S. My decade plus old-school Losmandy Starlapse has +/- 6 arc seconds of PE.....might keep it a bit longer ;)

[Drac0]

Was looking at this earlier today & might make a decent lightweight travel mount, an improvement over something like the EQM-35, without the need for counterweights for lighter rigs.



But looking at the "what's in the box" it seems the counterweights & bar may be an optional extra as they aren't listed, so no go for a heavier rig out of the box. They also recommend under 1000mm focal length. Think I might wait to see how they perform in the wild before considering one of these over a HEQ5 Pro.

[Zuts]

I am a newb and really don't know much about harmonic drives, but don't they all have high PE (without encoders) and can't it be mostly guided out with 0.5 second guiding?

; and isn't that the point, its a 5kg mount costing $1,999. I mean I am 63 and still lug around my AZEQ6 (21kg with tripod), which I am happy with and can get 0.4 RMS (out of the wind), but I am getting on and if i can get decent images out of this, without a permanent setup it would be a game changer for me.

LOL, I may have to sell my Esprit 120 and buy a redcat, to colour coordinate my ZWO camera, guider , focuser and ASIAir Plus :), but it's a good scope so i probably won't. nǐ hǎo, everyone :)

bugger that bortle 9 plus moon skyglow in glebe...

[AdamJL]

^ this.
PEC is high, but that's normal for harmonic drives without encoders, and yes, it goes away with short-sub guiding.

[Camelopardalis]

I have no idea what this harmonic stuff means, but if makes for a more portable imaging rig then it could be interesting!

[ChrisV]

Similar $$ and PE to an AZEQ6 - well close anyway, I think.
But only 5kg and no counter weights needed with a moderate size OTA.

Like Zuts - this sounds very appealing to me with my back. And don't have to adjust backlash like a normal worm gear driven mount

[Hans Tucker]

A competitor (similar specs) to the Hobym Crux Mini at a significantly lower price.

https://optcorp.com/collections/equatorial-mounts/products/hobym-crux-mini-computerized-german-equatorial-mount

[BlakPhoenix]

The weight advantage is huge. I own a RST-135E and it's amazing how much more I get out now with the lighter mount. Saying that.... Harmonic drive PE is very different to worm drives. It's always changing based on the weight and angle th mount is at (based on torque on drive in current orientation), so can not use PEC/PPEC like you can with EQ6, etc. This means the true error is MUCH worse than what you may be used to. Not saying it can't be overcome, but don't compare error bars of harmonic drives to more traditional drives.


The biggest thing with these mounts is you need very fast guiding exposures to keep on top of the PE as it can move quite fast at some parts of the sky so you need good SNR for your guide cam so it can keep on top of it.

[AnakChan]

I've got a custom boutique HD mount from SS-One, a Japanese maker. It's a great travel setup where I can mount my FSQ85ED and not use any counterweights.

Would I do another HD mount? I don't think so unless it has encoders like the RainbowAstro's. Strainwave geared drives have a high PE which can be countered by guiding but somehow I feel encoders with HD mounts is more a of a must than a nice-to-have.



That's got to be old stock. Crux stopped making the Mini a few years back now. It's been replaced by the Crux 140 Traveler.

[AdamJL]

Thanks for the info.

I think this shows a good gap in the market, that a product like the SkyWatcher AZ-GTi hints towards.

I'd love something a little heavier/beefier than the AZ-GTI but with the accuracy of say the EQ6-R in a package not much bigger than the AZ-GTI. Of course, I'd be willing to sacrifice mount weight capacity, and maybe image with 6-7kg of equipment.

That would drive a perfect travel and wide-field setup

This AM5 ticks a lot of boxes, but it might be exactly what I'm after, personally. We'll see.

[AdamJL]

Pricing here:
https://www.testar.com.au/collections/new-products/products/zwo-am5-harmonic-equatorial-mount

So yeah, half the price of the Rainbow Astro (less than half compared to the RA Encoder version)... but still, that's a lot of dollaroos. I'll wait to see if SkyWatcher updates the AZ-GTI.

https://www.siderealtrading.com.au/product/rainbow-astro-rst-135e-harmonic-drive-mount-with-high-resolution-encoder/

[Zuts]

Well, I put down a $1,000 deposit with Testar for the AM5. Hopefully by the time they arrive there will be some public PHD logs or guiding reviews and I can make a final decision as to whether I should proceed.

Here's hoping :)

[AdamJL]

Nice! Looking forward to seeing/hearing your review, Zuts if you get it.

[PaulSthcoast]

So,

as luck would have it, tonight looked promising.

I took out my asi air pro and powered it up.

There was a software update....

Nothing unusual about that...it happens.

But then after the update...

THIS was revealed !!!


Paul.

[pmrid]

I asked Testar a few questions about these mounts - mainly prompted by a very good review on YouTube, and received the answers quoted below. Very helpful people there:

1. The quoted 0.5 to 0.8 arc seconds figure is the typical guided tracking accuracy.
2. There is no ( power failure) brake on the DEC axis (like there is on RA.) According to ZWO this is not necessary, but I have reached out to them for more information.
3. The mount is suitable for long exposures, depending on your focal length, guiding configuration, seeing and environmental conditions, etc. Generally I wouldn’t go longer than 10 minute exposures with mounts in this class. If you need greater accuracy, there is always Avalon or 10 Micron (although of course these are a step up in price).
4. The 900mm figure is based on ZWO’s recommendation to keep your pixel scale above 1 arcsecond/pixel, given the common pixel size of around 4um. Lower than that, and you may hit the limits of the guided tracking performance.

I’m a bit puzzled by item 4. I fail to make the leap from the pixel scale of the imaging camera and guiding performance. Still, I admit to spending a lot of time head-scratching these days.


I’m still chewing this over.

[ChrisV]

That guiding accuracy doesn't sound great for the price? No better than my old modded CGEM.
The 900mm'ish focal length makes sense with a standard camera given that guiding accuracy. Its near the arcsec pixel size

Nonetheless, be interesting to see how it performs

[AnakChan]

Yep, personally I wouldn't get a HD mount (unless it has encoders) for a long FL scope. As such putting the FSQ85ED on my HD mount (where with my camera, it's 1.7"/px - so guiding RMS of 0.5-0.8 is within limits).

[Zuts]

I have done nearly all of my imaging on either a TV85 or more recently an Esprit 120. This is more or less my desired image scale and since i don't have a permanent setup really value portability, so the recommended FL is fine for me.

I may even try and trade the Esprit 120 for an Esprit 100 to enhance portability.

If I can get a consistent 0.5 rms then I will be satisfied.

I also have a Edge 9.25 which I use for planetary and here guiding is not an issue, so the mount should be fine for that as well.

I hope :)

[AdamJL]

Anyone got one of these yet? I'm hoping mine comes in the next couple of weeks. Hoping to hear from people with real world experience. I have heard that the performance is very good, at least for AP.
For visual, apparently anything more than 1 star alignment doesn't work.

[TeamG]

Be keen to hear more real world users of this mount. The weight is so appealing.

[AdamJL]

That it is, Glenn. These strain wave gear mounts sure are shaking up the industry.

[AstroJunk]

An AM5 is high on my list for a number of reasons but mainly the amazingly compact size for its weight capability as a travel grab and go (and I am unashamedly beholden to the programming skills of ZWO and their eco-system, so I know it will perform).

A couple of thoughts based on limited knowledge, so feel free to debate:

Harmonic drives have no backlash, and I mean NO backlash, it's why they are used in robotics. Even the best tuned belt driven mount i've seen has a few arc seconds of give which can cause issues on blustery nights. I'd love to see the imaging/guiding results on far less than perfect nights in the field with this mount.

The ZWO uses stepper motors rather than servos like others. Stepper motors lock without power - it's actually quite hard but not impossible to move them. The break on power failure for the RA drive suggests that 13+ kg without counterweights is sufficient to overcome the natural resistance to movement!

Looking forward to some real world reviews!

[Crater101]

Given the issues I had with my copy of the recent Star Adventurer GTi, I'm also interested in some real world reviews of this.



I don't have a lot of knowledge in relation to the "strain wave" system though. Anybody care to recommend a good article / video on this?

[AstroJunk]

https://www.youtube.com/watch?v=7QidXf9pFYo&ab_channel=JetpackAcademy

This worked for me!

[Crater101]

Thank you kind Sir. Much appreciated. I'll let you know if I can find more.

[Bassnut]

This is very interesting, a rare look into actual user feedback.Pretty damning in IMO. On Testars web site "very low periodic errors (within ±20 arc-seconds) make the AM5 an excellent mount for astrophotography". thats a bit of a stretch :eyepop:. A very specific use case, the need for very fast guiding exposures. If this had output encoders, and ZWO could actually get these encoders to work reliably with guiding to get PE (or it seems just high non PE errors) down this would become a killer mount.

[AdamJL]

The high PE is not really an issue. On Cloudy nights, most users are getting between 0.4-0.6RMS for guiding and good star shapes. There's not much else that matters really. There are occasional spikes, but really the mount seems to be performing very well from what everyone has experienced so far.

My one will be here end of September unfortunately. Still a long wait to get my hands on one.

[gregbradley]

Yes I would PE can be jagged and hard to correct or it can be smooth and easy to correct.

If fast guiding is working well then perhaps the PE is smooth. Just a guess.

Greg.

[gbeal]

Had mine a while now, and absolutely love it. So much that my humongous CEM70 is packed away possibly to sell.
Being able to pick it up and move about the property fully loaded is a boon.
Very happy.

[The_bluester]

That is actually not quite the case. Most stepper motors will have an amount of "Detent" torque, which is the amount of torque required to move then when they are unpowered, it is generally not a huge figure. If you take a typical small stepper you will rotate it pretty easily by hand with "Cogging" felt at each point the motor would stop. When they are powered but not being stepped they then produce "Holding" torque, proportional to the current supplied.

This page has a good write up.

https://www.motioncontroltips.com/faq-whats-the-difference-between-detent-torque-and-holding-torque/

[Bassnut]

OK, well going by that extra feedback (i havent looked that hard for it really) it sounds promising :thumbsup:. I have a small dome im thinking of putting a 12" SCT in at some stage (for DS lucky imaging, very short exposures). An EQ mount for it wouldnt fit, but I think a HD would, so this all becomes doable.

[JohnH]

Take a look at the iOptron HEM27EC. The HD systems can have high and fast moving PE (hopefully it is smooth though), the EC system should tame this and the ability to guide out the residual errors l means this could be the ideal portable AP mount. It is on my wish list...but I want to see some real world results before I take the plunge...I have a CEM40EC at the moment and it performs admirably but is just heavy/bulky enough to dissuade me from travel on days when the conditions are 50/50.

[AdamJL]

Got my AM5 today. What a well built unit. Will setup and play around with it tonight (indoors of course....)

[AstroJunk]

I had the pleasure of being at the powering-on of a friends AM5 today and it was a very fine moment. The solidity of that thing is quite amazing and it was so quiet as it threw the Edge 8 around with absolute ease. Want, want, want!

Every bit of this mount oozes class, even the cracking carry case it comes in. ZWO really have been upping their game over the years and this mount shows just how far they have come. BTW the carbon fibre tripod is a bit of alright too!

Looking forward to see how well it performs under a pristine sky.

[beren]

Received a AM5 mount Thursday and got a chance to do a little visual last night. So far impressed with it , light and compact but solid. Mount seems easily capable with smaller refractors and 8” SCT”s, the tripod probably is a little short for taller people for visual. For larger scopes I’d feel more comfortable with the expected counterweight system Zwo will be releasing installed and a tripod with a wider footprint ( the William Optics Mortar tri-pier would be a option)

[AdamJL]

Nice pic, beren

I've been so happy with the limited use of my AM5, that I'm almost certainly* going to replace my EQ6-R with the Pegasus mount next year (it can do 20kg without a counterweight).

*I'm not 100% locked in on that idea just yet, as I'll want to do some more comprehensive tests, but for now I'm very happy with the purchase and need to be convinced not to do it

And yes, the carry case is excellent and I love love love the artwork on it (and the mount).

[Bassnut]

mmm had a look at the Pegasus NYX-101 Harmonic Gear Mount and although it looks very interesting, the PE in the sample at the bottom of the add ( and this is a promotional pic....), shows RMS PE of RA 3.74 and DEC 4.91. Its not flash. Not saying this is a show stopper, but does require home work to see if this is best case. The graph doesnt look that bad actually, it looks like the spikes upped the RMS, mmm, those spikes...

[Londoner]

Took delivery of my AM5 mount last week and last night I used it to look at Saturn, which was close to zenith. I normally mount my AAP on the scope. Whilst awaiting for an adapter from Bintel, I chose to temporarily use the adapter on the mount for my ASI Air Plus. Big mistake :sadeyes:

Whilst in the middle of focussing I crushed the USB cables going into the AAP and the mount was unable to be parked back to the home position.
I had to dismantle the entire OTA and mount from the tripod in order to retrieve the AAP. I then used the hand controller to park the mount back to home.
Fortunately, no damage done to any of the equipment but a warning not to use the mounting bracket on the mount. It will be removed today.


Mick

[AdamJL]

agree with that 100%. Nearly destroyed my AA+ on the first run with this machine, because of the cables. The torque on these strain-wave mounts is incredibly high. You don't want to get your fingers caught in there either.

Now I mount the AA+ on the top of my scope.

[joshman]

I too recieved my AM5 last week. As previously stated, it feels like a very premium and well built bit of kit. The CF tripod is alot sturdier than i was expecting, which was a nice surprise.

I've managed first light with it for a few hours on Friday night before the clouds rolled in, and was pleasantly surprised at its performance in slinging around the 4" refractor. The strain-wave drives are quiet, quick, and smooth. I think i'll need to work out a way to weigh down the entire setup, as i'm still a bit uncomfortable with how top heavy the setup is, and how off centre that weight can be when pointing straight up

Guiding was as good as could be expected given the conditions (even better than I expected, TBH).

I had second light on Saturday night, but the sky conditions were atrocious and my guiding RMS barely reached 1 arc-second.

All in all, I'm very impressed and looking forward to a future of better imaging.

[pmrid]

I am thinking about an AM5 and wondering how tricky it might be to mount on my existing obs pier. ATM it hold a EQ6R Pro which you all probably know has a recessed centre hole and a removable azimuth adjustment pillar in the front.

Any ideas any of you fortunate owners?

[AdamJL]

Hi Peter.
I’m asking Joshua Bunn to build me an adapter. I’m a bit behind on some measurements he’s after but I can share it all’s when we’ve worked out what it’s going to look like

[pmrid]

Thanks mate!

[Zuts]

I ordered one of these

https://www.teleskop-express.de/shop/product_info.php/info/p11431_Artesky-3-8--Photo-Adapter-for-EQ6-and-CGEM-Tripods.html

They are also available from ALIExpress https://m.aliexpress.com/item/32984166214.html?spm=a2g0n.order_de tail.0.0.74b9f19cEUUB1I

Pros

Seems to hold the mount securely to the tripod
works with azeq6 pier extension
can stay attached to either the mount or the tripod

Cons

Even though it has a slot for the pin the pin still needs to be removed so you can rotate the adaptor to screw it on tightly. Of course you no longer need the pin for adjustment.

The base of the adaptor is higher than the recessed lip of the azeq6 tripod, see photo, so there is less area connecting adaptor to tripod. Still seems a solid enough connection, but have not used it much yet with my c9.25.

NOTE, be sure to order the one with the m12 tripod connector thread. I made a mistake and ordered the m8 one for the eq5 and had to drill and tap out the thread to m12 to fit the azeq6.

NOTE, I ordered from ALIExpress because cost and shipping (AUD 71 plus AUD 16 shipping) was much cheaper than from Telescop Express ( EUR 75 plus EUR 38 shipping).

NOTE, Image shows it connected to the azeq6 pier extension.

NOTE, YMMV as I have not used it extensively, but on the face of it, it does connect the two.

Cheers
Paul

.

[AdamJL]

Okay thanks to Josh for letting me share screenshots of what he's been designing.

This is the EQ6 adapter (I presume no one will want to see the EQ8 Tri-pier adapter so I'll leave that out).

First image shows the adapter from the bottom. This part sits in the EQ6 Tripod. There are two additional holes which I thought could be used to anchor the adapter in place with the azimuth holes on the tripod. This will prevent any rotation of the adapter

Second image shows the adapter at the top. It has the central column for the locking screw plus 3 additional screws to again prevent rotation.

What do you all think? At first blush the only thing I might ask to be changed it to align the three holes on the top plate so that the forward weight will sit over one of the legs.

[Joshua Bunn]

Hey Adam,
I thought I aligned the 3 top holes so the AM5 when mounted, it's south facing part was over the correct part on the skywatcher tripod, if this is not the case, I will deffinetly change that :)

Cheers, Josh.

[AdamJL]

Hi Josh!

You're probably right. I haven't looked at it in depth yet, it was just a first impression. I'll check it out in detail today and measure everything up.

Cheers

[Joshua Bunn]

No worries Mate!

[AdamJL]

Well it can drive 17kg pretty well!

I'm still iffy on the tripod, which is being stabilised here with a 5kg counterweight in the underside pouch, but otherwise, this is a great mount!

[Crater101]

Adam, it looks like you have a pier / extension as well. Not to derail the thread, but has raising the centre of gravity made a significant difference to the rig? Nice setup, by the way.

[AdamJL]

Hi Warren

Yes I've got both pier extension types, but I feel this one is more solid than the columned version. It's also mandatory on a long OTA setup like mine. For my ASKAR FRA400, the pier isn't so necessary but I'll just use the columned version there.

For the centre of gravity, well not really. Without the counterweight bar extension then yes it's not great when slewing about. There's a lot of weight here. Balancing in Dec I'm sure would help but it's very difficult to do that here (I'd likely pre-balance on a table or something then transfer that to the mount).

Once the counterweight bar and a secondary counterweight was added in the pouch underneath, the setup became very stable. That said, it has yet to be tested it in the field. As soon as these clouds go away (2023?!) maybe I can give it a go.



Cheers :)
I'll be doing cable-management soon. I am just slew testing this afternoon.

[Crater101]

Thank you young man. You've answered a couple of "I wonder..." questions for me. I'd be interested to hear of how it goes in the field. All the best, and yes, some cloud-free evenings would be a welcome change!

[nikanj]

Been watching this one. AstroWithRoro did a good video on it. It's a bit pricey though, the iOptron HEM27 looks like a very similar product for consierably less. I guess it'll all come down to PE performance.

[AdamJL]

The HEM27 does look good and I like the weight, but I'm not convinced of the Dec gearing. And I've seen people with a few issues over on CN.

[AdamJL]

Btw. I had my first session with this mount the other night. It's fantastic. Here's 4 hours or so of Ha on the Tarantula, with a very light edit. Guiding was anywhere from 0.4-0.7RMS.
It did spike to 3.5 or thereabouts but that's because it was on a wooden deck and someone was walking around it :D

[pmrid]

I’d be keen to see a feature comparison between the AM5, the iOptron HEM27 and the HEM27EC. The latter is quite a bit dearer so I’d want to be clear about the differences.

Of particular interest to me would be compatibility with ASiair.

[JohnH]

The main difference here is the encoders....so that is why the cost is higher than the non-EC version but that only makes it about the same as the AM5.


Encoders are good for two scenarios - unguided AP are shortish focal lengths and when guiding with an OAG (typical for longer FL setups). Without EC you will need to use guide exposures in the range of 0.5s to keep the PE under control which will make it tricky to find a suitable guidestar with an OAG and may also cause issues if the seeing is not good.


I am very interested in this mount but am in wait an see mode as there is not much real world usage out there yet and my preference is not to go for vsn 1.0 of anything. I also note iOptron are now taking pre-orders for the HEM44 which might also be of interest...



On a side note : does anyone know anything about the BH-17H or 20H mounts?

[JohnH]

Not really, PE is a bit of a furphy when it comes to HD mounts imho. None of the manufacturers make these gears - all are 3rd party and thus are similar in performance. PE of an HD mount is not repeatable like a worm driven mount, it varies with loading, orientation etc. I the HEM27 is lighter and probably better for portable use. AM5 is 5kg and costs $4399, HEM27 is 3.7kg and costs $2999, carrying capacity is the same...

[AdamJL]

Not entirely accurate. You're comparing a SKU with a tripod (ZWO) to one without (iOptron).
AM5 is $3699 without the tripod.