HARMONIC DRIVE Mounts Showdown! HEM27 vs. AM5

[@flyingmedic]

The reason you are able to work full time from your channel is because you are excellent at your objective. This review was second to none. Thanks again.

[@jonrbryan]

I've had an AM5 for a couple of weeks now, and I'm very pleased with it. The portability is great, and a hand controller would just get in the way. I have an ASIAir Plus, and I don't even plug in the supplied joystick. I started with a Sky-Watcher AZ-GTi a year ago, align with a laptop/ASIAir+, and have never even used a polar scope, so it was a natural transition for me.

[@davidjennings2733]

Great tip on not even plugging in the hand controller, did not even think about that since you are using the ASIAIR to connect anyways. Mine is not unplugged, haha.. Thx again...

[@RichardKinch]

Just astonishing that what used to be clock drives (lesser quality) or worm gears (higher quality) when I started the hobby in the 1960s, has advanced to digital stepper motors and belt drives, and now harmonic drives. All the while the prices have remained relatively constant in real dollars.

[@cmahar3]

It is amazing what we have in amateur astronomy these days when you compare to the past. We're so fortunate.

[@40Sec]

I've only been into the imaging part of astronomy for around eight months now (I have about 11 years of experience with visual, which definitely helps), and it's genuinely incredible what I'm able to access. I don't drive, so everything has to go in a hiking backpack, but I'm able to manage a HEM15 (once it comes to replace my Skyhunter), a Skywatcher 72ed, an Asiair Plus, battery, and camera, and all the other bits and pieces to create a pretty marvelous little full setup.

[@deep_space_dave]

Awesome review! I own a HEM27EC and as for the polar alignment, I pretty much just hand tightened the lock screws and I don't ever have to touch them again as you can still adjust the ALT/AZ and use the hex key inserted into the knobs for more more torque. It doesn't move through the night either. As for guiding, I had issues at first but after I figure out how to reset the iPolar and have the mount auto-calibrate the RA axis (EC mount) I am getting usually around .5 arc second average. The DEC axis is the typical iOptron backlash free worm drive but I don't know why it is called that because I always have backlash even on my CEM26 so you just have to use the guiding assistant to figure out the backlash or just dither in RA. I so far am up to 30lbs on the mount and found out the hard way that I needed a counterweight. The strain wave is powerful but if you park and you have over 29lbs the RA starts to back drive not good! I also was starting to have tracking problems. Added the 5kg counterweight and no more back driving, tracking issues, or odd popping noises 😳Thanks again for the through review! Clear Skies and Happy New Year!

[@alandyer910]

Another excellent and thorough review. Thanks for doing all the work needed to put three mounts to the test as equally as possible. Well done!

[@NebulaPhotos]

Thank you Alan!

[@starwatcher]

As far as I know your review is the only side by side comparison. Very helpful.

[@AntonioPena1]

Nico, thanks for taking your time for evaluating these mounts, I’m planing to get one, waited in pre-order more than 8 months for AM5 and cancelled because is not serious, I still planning to buy one, thanks for honest review, will be nice to see a test without guiding to see tolerance.

[@12zaf1]

Very nice. I always appreciate field testing of gears and not just reading specs. Good job

[@DSOImager]

Great comparison review. I have to say that I loved seeing a little rust on the EQ6... such character :) These harmonic drive mounts look interesting.. especially for the portability. I think for a semi permanent location like my backyard.. I'd prefer to have the heavier EQ6 though. CS!

[@rodrigogutierrez2882]

Wonderful review. Thanks Nico. I am getting the same performance with the EQ6R and the AM5. I would just say that the AM5, handling a small telescope, as a RedCat, gives incredible results. Consistent total error below 0.45.

[@StargazerFS128]

You really know how to review stuff, amazing job covering all the features!

[@Youthinkyoudobutyoudont]

Im new into astro photography and put myself on a 4 month wait to buy anything before i pulled the trigger on anything you and @astrobiscuit have helped me huge amount, getting into the game.

[@felipemacauliffe1528]

Thanks for your great presentation. Absolutely brilliant and clarifying. I love my AM5. All the best, clear skies and shine on from Chile, Cluster One Observatory.

[@WilliFromEarth]

By far the best review I have seen for these mounts !!!!!!!! Thank you !!!

[@fredmercury1314]

13:58 My Pegasus power box came with both 5x2.1 and 5x2.5 cables. Which was a nice surprise. I really like that all the cables on the HEM27 go into the back, out of the way. Also, my hand controller came with a button battery installed (maybe the supplier added it?). I have my NUC mounted on the tripod behind the mount connections, using a 3D printed bracket, the power box is next to it, on another 3D printed bracket, which feeds the mount and the NUC, plus the two heaters, using a 12v 10a power supply. The mount feeds power to my IMX 571 via it's 12v 3a output on the DEC axis, plus the ZWO focuser is powered and controlled via the mount USB2 connection on the DEC axis. I then run the guide cam USB2, IMX571 USB3, and the two heater cables, down to the NUC and the power box, in one nice tidy group, bound together with some 3D printed cable tidies. The focuser USB2 comes out of the back of the mount and straight into the NUC. I could run the guide cam and focuser through the IMX571, which has a USB2 hub, but that would only eliminate one USB cable and would potentially slow down my USB3 data speed. I could get a USB2 hub and run them both through the USB2 on the DEC but... meh... why bother? If the mount had USB3 I could run everything together through the mount and eliminate two of the cables. But it was not to be.

[@NebulaPhotos]

Nice setup! And great that Pegasus is now supplying both cable types. I admittedly haven’t bought any new power boxes in several years. Interesting that the button battery was supplied as iOptron makes it clear they won’t supply due to some shipping issue.

[@fredmercury1314]

@@NebulaPhotos I'm in the UK, so I don't know if that factors in, re. the battery?

[@yellowlynx]

Love the comprehensive review. iOptron made good mounts, but the sheer number of knobs and tools needed to fiddle around during polar alignment makes using it a bit of a hassle. My thought is that, unless you are used to iOptron mounts, with the Allen wrench that can drop accidentally, get a plastic mat or even a thin plastic table cloth that is white and stick it beneath the tripod legs and spread it flat - so that if the wrench slipped from your hands it won't be lost in the grass or dirt in the dark. Regarding the EQ6-R mount AC plug, the same kind of 12mm aviation plug is used in AZEQ5, I made one from 12mm aviation plugs I ordered so that it can use 12V DC output from my power box instead of dangling with a power brick or using a cigarettes' light plug.

[@VRzichtbaar]

Again a very thorough comparison. And what a work you have put into it. Experience really shows compared to how I struggle to get everything right for just one setup. LOL. Thanks for sharing and showing how it needs to be done.

[@greatpix]

I was a member of PPA many years ago when I had my photography business. I knew some of my friends who were members and had cause to use their insurance, and it saved them $$$$$.

[@NebulaPhotos]

That’s great to hear Robert. I haven’t put in a claim yet, so happy to hear some positive feedback on it.

[@greatpix]

@@NebulaPhotos There are also business oriented legal matters they can help with like copyright, information on starting a business and other help. At club meetings of local photography clubs (like PPOC) they had speakers although sometimes those could be rather dry, but sometimes very informative. It was a long time ago but you might look into whether forming a local club would offer any benefits over solo. I 'think' there were advantages to group membership in a club, but don't quote me. The last time I was a pro photographer was over 20 years ago.

[@Mike_Gibbs971]

Great review and happy to see one comparning three mounts, with different payloads. I've had my AM5 for a few months now and love it. I was a Celestron AVX user, and looking at getting the EQ6R when the AM5 was released. I'm getting older (a bit!) and I have to move my equipment in and out of the house a lot, so was willing to take the risk of the AM5 preorder. So glad I did! Thanks again for the review :)

[@amature_skywatcher]

Thank you Nico like always the details in the video are above and beyond. Thanks for your efforts. Clear Skies. This video helped me in deciding my next upgrade!

[@rickspeedygonzales]

Great review. I'm an EQ6R guy myself, and my back has had enough.... :) AM5 looks good, thanks again for the valuable info

[@XShadowAngel]

I sold my EQ6R-Pro a few months after getting an AM-5. The AM5 does everything the EQ6R did at a fraction of the weight and size.

[@michaellewis7768]

Good review/overview. Thanks! I have the HEM27 and I’ve grown to really like it. At first I was also put off by needing the little allen key wrench for alt/az adjustments, but I’ve gotten used to it. It is a pain when you drop it though. I was also surprised by the inability to bypass the hand controller. Honestly, you pretty much called out all of my annoyances with the mount when I first got it. What I do like is the pass through cabling, and compact size. I also own a RST-135 which like the AM5 has cables and power plug into the declination, and I really don’t like having my power plugged into a moving part with an unsecured plug. I also like that I can throw any of my small to midsized telescopes on it without worrying about dealing with a counterweight.

[@yellowlynx]

get a plastic mat or even a thin plastic table cloth that is white and stick it beneath the tripod legs and spread it flat - so that if the wrench slipped from your hands it won't be lost in the grass or dirt in the dark - I have a mat on my roof top such that any tools dropped will land and not bounce around and I could see it in the dark

[@hael8680]

​@@yellowlynx that mat would be an additional annoyance when the ground is covered with snow. That little Allen key has been a show stopper for all ioptron mounts for me.

[@tomaskonkol8894]

Nothing what neck strap for glasses can solve.

[@lukomatico]

What a wonderful video mate, your methodology and presentation are a real inspiration! 😀 I've seen all of these mounts individually in person, yet nothing can prepare you for the side-by-side view, haha! It's near unfathomable that these all have the same payload capacity! I was impressed with all three, but the am5 stood out most to me in this group comparison, I'd like one of those some day. Thank you for your work in putting this together Nico, amazing work as always!

[@dominickzaucha]

Great job being first to put together such a great review. Really helped me make a decision here

[@alexalmeida8627]

You read my mind! I was looking for a video like this just a few days back. Thanks a lot. I am considering to buy a harmonic mount because I am planning a trip to Atacama and I don't want to bring my heave EQ6-R. One thing that I was looking into you video but there was no comment about it is the compatibility of the AM5 with NINA. I don't want to use ASIAIR and I heard that the AM5 cannot handle two different "external" softwares at the same time, like NINA and PHD2. Amazing video, thanks again!

[@NebulaPhotos]

They must have fixed that. I had no problem connecting the ASCOM driver to several external software at once on windows. I was connected to Cartes du Ciel, PHD2, and SGP all at once and could control the mount from any of them. I have no doubt it will work with NINA

[@Neanderthal75]

Just for the record, the EQ 6R was about $1500 pre-covid times. I wonder if these mounts would cost the same if we wouldn't have this crazy inflation.

[@BennyColyn]

I looked it up, the cumulative rate of inflation in the USA between 2018 (year I bought my mount) and Jan 2023 is about 19.1%. So a $1,500.00 mount ought to end up around 1750, not 2000. Def more than just inflation it seems.

[@WilliFromEarth]

In Germany at TS: - EQ6R with steel tripod - €1685 - AM5 with carbon fiber tripod - € 2’664 - HEM27 with carbon fiber tripod - € 2’464

[@radioparisment628]

In France, inflation is the cost of quantitative easing. I suppose that in the States, the problem is the same.

[@progshark]

Thanks for the comprehensive comparison. I am actually looking for a second mount to optimize my sparse clear sky hours. I have been leaning to the EQ6-R, which was my original choice before I purchased a GEM45G, but opted for the shortest back order time. If I had to pick a winner from the video, it is clearly...flying unicorn tie-dye!

[@leoncorns1450]

Thank you Nico. Your comparison videos are really scientific. I guess the only difference is in the long-term wear of the gears, where the harmonic drive might perform better.

[@michaeledmonds3027]

Superb piece of work.... You're one of the best astro folks on KZbin. Thanks for a great job.

[@KopLamp]

Ok... well thanks Nico ;) I have an AM5 review video in the works, but you now made me realize I am nowhere near finished with that video. Hahaha. I'll do mine in Dutch primarily, but your video made it clear I have skipped a few very important things to share.

[@lorenzt1099]

The fact that the HEM27 requires an allen key for mechanical adjustments just frustrates me. It reminds me of when Celestron came out with the CGX and decided to engineer the mount around the use of an allen key. It just feels like a downgrade from previous workhorse mounts like the CGEM and AVX. Appreciate how in depth this review was, fantastic video as always!

[@lavers_1]

it's not that big of a deal, once it's set it will go all night. It's eerily precise

[@melgross]

The HEM27 lock screws can be replaced with adjustable handles. They come in many screw sizes in both metric and inch. Also different screw lengths. McMastercarr sells these as do other companies. They tend to cost anywhere from about $5 for the smaller ones to about $9 for the bigger ones. I use these in most machinery I build, and often replace locking screws on commercial machinery with them as well. This is a very interesting review. Even though I’ve been interested in astronomy since high school, living in NYC doesn’t give one the best (best, ha!) viewing conditions, so I’ve never gotten involved.

[@gazza9839]

Nice idea, do you have a link for one that will fit the HEM 27 ?

[@melgross]

@@gazza9839 I don’t know the sizes of the ones on the 27. If you look at their manual, hopefully they’ll have a parts list which will tell you the size screw and the length. Otherwise you’ll have to remove it and measure it. McMastercarr, which you can find by typing it in Google has many sizes and types. I wish I could be more specific, but I can’t.

[@mvdeehan]

Great review! Fyi the batteries in the GoToNova are not installed as the company were heavily fined by US customs according to their support team.

[@radioparisment628]

And Nico drew his weapon : the 130PHQ ! A dream scope. It seems that payload isn't a problem. I'm reassured : my 160 mm scope in the procces of being manufactured will be fine ( 14Kg with collars and dovetail ). Thank you Nico for this very informative video.

[@ChoosyMothersVideos]

This was really REALLY well-done! Very thorough and easy to understand. Thank you and I’ll be joining your Patreon!

[@skye7690]

This video is perfect! Exactly what i was looking for, this new mount tech is great!!

[@michaeledmonds3027]

Thanks again Nico....I now own an AM5 with ZWO's "free carbon tripod" sale.

[@CuivTheLazyGeek]

Excellent in-depth comparison, Nico, thank you very much! A bit disappointed that the HEM27 isn't cheaper than the others (that would have been the point of using strain wave gears for only one axis...), but glad to see that mounts are working great! I assume you used multi-star guiding in PHD2 right?

[@NebulaPhotos]

Thanks Cuiv! Yes, to multi-star guiding.

[@the_astro_guyy]

In India it is cheaper than all other strain wave mounts because of one axis strain wave setup

[@gazza9839]

HEM 27 £1845 AM5 £2,363 in the UK !

[@hael8680]

Great video!!! Thank you!! I am surprised you didn't run all 6 tests on the same night !?!? 😲🤣 I am sure you could have managed 6 mount assemble and dissemble no problem 😉 I'll remember this video when I am annoyed by dissembling my mount after my session.💪

[@NebulaPhotos]

Ha 😂

[@jesusalbertoponcedeleon7124]

Thanks, your videos and tutorials are the best in my opinion due to the easy and detailed way that you explain things. Thanks

[@OscarShu]

thanks for the comparison, it would be an interesting to see if the two Harmonic drive mounts tested with a C8 next

[@Astronurd]

I’ll stick to the EQ6R pro as that extra weight is great if there’s any wind about

[@celestromel]

Thanks heaps for the very practical revelations. A great comparison very informative for panning future upgrades.

[@alimaleki217]

Nico, another superb review/comparison; thanks!

[@lgf30022]

Hi Nico! Very good review, much needed for my planning. Have a Happy Holiday and Happy New Year!

[@davidsierra8520]

Great review! Thanks for spending the time to make such a thorough review. Now I have more EQ to drool over. :)

[@user-rn6ni8mr2q]

This is the best review of these mounts I've seen! Thanks! One thing I'm still curious about is what they looked like when cabled up. Cable management is a pain with my current set up (HEQ5).

[@yellowlynx]

One part I would like Nico consider to test is to keep the OTA setup weight within both HEM27A/AM5 maximum payload without counterweight and use a long OTA to compare with the short StellaVue OTA test. The second set of tests changed more than two variables (OTA weight, FL, camera and the counter weight)

[@rawhead909]

I've found Alt-Az mode is great for planetary imaging, too. You don't have to worry about meridian flip, and for low-altitude planets, you can more or less keep the ADC angle constant. In Eq mode, you have to constantly rotate the ADC so that's it's horizontal vis-à-vis the horizon. The former advantage would've come in really handy to those farther east of me the other day when Mars was occulted by the moon. While I wouldn't have had a big issue here in New Mexico since the main event occurred well after meridian, for those on the east coast, the crucial main even occurred right around meridian. Obviously mounts can go past meridian, but it would've been hairy. AM5 would've worked perfectly in Alt-Az mode :)

[@MrGp3po]

ADC?

[@rawhead909]

@@MrGp3po Atmospheric Dispersion Corrector; helps keep the R G and B aligned when shooting large objects, e.g., planets, near the horizon. One difficulty of using an ADC is that the orientation of the instrument needs to be kept stationary with respect to the horizon, so if you are using an equatorial mount, which rotates the orientation of your scope with respect to the horizon, you have to constantly adjust the ADC's orientation. In Alt-Az mode, the scope never rotates (which is precisely why the *field* rotates, something you that becomes problematic when doing long exposures on deep space objects) so you don't have to constantly adjust the orientation of the ADC. This is why Alt-Az mode is good for visual observations as well, especially when you are using a diagonal.

[@richards3192]

You have to love the EQ 6R Pro. Looks like it's made out of cast offs from a cheap washing machine conglomerate operating out of a junk yard in Shenzen, with parts from a neighbouring breakers yard. One point about port positions: Ports should not be facing upwards (take note ZWO) because they will catch any condensation, rain or dew, and short out your connections. Water can also get inside the mount through the ports

[@WVAA304]

Love the curtain reveal! I wish I could've seen more of the rho complex. Great video tho!

[@mreddick786]

Couldn't have come at a better time

[@Gordonlanguam]

Thank for this video. I was thinking about upgrading merely because of the size and portability

[@blakebrothers]

Thanks so much for the review - very helpful!

[@astromatz]

Great in depth review! Wishing you all the best for the next year and good luck to you in your new full time job :-) Clear Skies!

[@miguellarosa]

The HEM27 has conventional stepper Belt Drive on DEC axis. Where the HEM5 has Harmonic on Both axis. Slow Dec time recovery. Thanks Nico

[@deep_space_dave]

Yep backlash on a backlash free axis. Ask me how I know LOL. The hybrid still works pretty well if you load it up tough as Nico found out.

[@miguellarosa]

@@deep_space_dave I chose iOptron because of Hand Controller. Their HAE series is Full Harmonic and Alt-Azimuth. Does anyone know how much better an Encoded version of an iOptron would Be. Any thoughts Nico?

[@cmahar3]

Wow. Excellent review. Thanks very much.

[@scalemodelenthusiast1633]

It baffles me that to this day not one manufacturer has motorized the polar alignment process. It would be so cheap and easy to add a couple stepper motors.

[@ScottyBishop]

I bought the HEM27A and the carbon fiber tripod to go with a petzval type scope for a checked bag airplane friendly travel kit. That thing is amazingly lightweight.

[@bad_metaphor]

Good review. I realize it would be a logistical nightmare, but it would be nice if you could image from all three mounts at the same time to eliminate the varying seeing conditions.

[@rawhead909]

Also, you are able to adjust the volume of the sound that AM5 makes; when set to lowest, it becomes quite silent.

[@DataSmithy]

That's cool. I just learned about harmon drives last year, on a couple of other maker and robot oriented channels.

[@massimo541]

Excellent review as always. I think that many, me first and foremost, are also interested in knowing the settings you would give on Asiair plus for harmonic frames: exposure time (apart from 0.5 sec for the iOptron), calibration step, Max Dec and Max RA duration, RA and Dec Aggr with both scopes you used for the test and viewing conditions during your test. Thank you very much

[@RobertKarlBerta]

I have two Astro Physics mounts in observatory....900 and 1100 that run either a 6" APO or 11" SCT with Hyperstar. For remote imaging that is a lot of gear and weight to deal with. I recently desided to get a AM5 ZWO mount and their ASI AIR plus which will be used with a couple of refractors but not the 6"....generally 80 or 85mm APOs. If you go with the AM5 you have to use their cameras, and their autofocuser and motorized filter wheel or they won't interface with the ASI AIR plus. I don't mine that as since they developed the system they should be able to gain some financial pay back. The ASI AIR does work with many other mounts though incluiding Celestron and my AP mounts. Other than the weight the main reason to go with the AM5 is the ASI AIR plus.....it indeed takes imaging to the next level. That one box and your cell phone or tablet replace ALL your software, stacing, focusing, autoguiding, etc. are all do ne from those two pieces of equipment. The ASI air now does polar alignment by looking anywhere in the sky and doing a plate solve. An on screen view in the app shows exactly how far you are off and lets you adjust both axis easily until perfectly aligned. Main con is that they recommend to stick to a maximum focal length of around 900mm. My small refractors are fine as is a Hyperstar equiped SCT. The other huge advantage of these harmonic drives is the ease of setup. I have the mount, cameras, autoguide scope and its camera and all wiring in one assembly. The tripod is the only other piece of equipment other than a power source (I use a wheel chair battery). I can take the battery, mount, and out of my car and have it running in about 2 minutes. The ASI AIR plus has wireless operation so I can have the scope out on my patio and operate it from my nice warm kitchen (here in Michigan Winters that is nice) Finally you can also use Sky Safari to control the mount and switch to the ASI AIR app for image capture, autoguiding, stacking, etc. Although the ASI AIR plus app has its own planetarium program. There is a 10# counterweight and a short 9" counter weight bar that is used when you get over 28# load and want to carry up to 44#. I don't believe the weight is needed for balancing of the mount so much as keeping the losd from getting off to one side during tracking and toppling the whole thing over. I use a different tripod than the one WZO sells for the mount since I had it already and it is a bit heavier duty tripod. the mount uses a standard 3/8" screw common to most camera tripods.

[@brownj2]

Outstanding review. This is comprehensive and useful information. Well done!

[@mistaskate8715]

Awesome as always!

[@danielm4703]

Hi Nico, the other reason to use a counterweight (at least with the RST-135) is to ensure the altitude stays fixed in place with heavier OTAs. I have had it slip with an Epsilon 130D, and there are even reports of it slipping with much lighter OTAs, like an FSQ85.

[@MatheusSantanaMS]

Really? But one the advantages from this mount is use OTA without counterweight. Is there any way to lock better the altitude?

[@danielm4703]

@@MatheusSantanaMS I believe someone had success with longer locking screws. There is a thread about it on CloudyNights.

[@artiraina5857]

Hi Nico first of all happy new year to you And i am a big fan of you and your videos about astrophotography i just love them.I was wondering if you could make a video about astrophotography without a motorized or tracking mount,but with a manual eq mount with a 6inch newt on it. This will help beginner astronomers like me a lot..🙂

[@artiraina5857]

I would be better if you use a mobile phone camera with a mobilephone adaptor on it with the setup i mentioned above in main comment. It would be soo helpful for the whole amateur astronomy community.

[@NebulaPhotos]

I have something planned coming that should be similar enough to what you are asking for that you will be pleased. :)

[@artiraina5857]

Ohh... well that's great. I will be waiting for that🙃

[@khoardTubeYou]

Purchase a set of "uxcell 3mm Ball End Hex Key T-Handle Wrench Spanner, Metric S2 Steel 2 Pcs" off Amazong for the HEM27. There is a 3mm hex head inside both Azimuth knobs for polar alignment. you can insert these wrenches inside the knobs and have much finer control.

[@dmccallie]

Excellent review. Thank you.

[@markbourque9590]

I would think mounting the AM5 on a Tripier with adapter would be the best of both worlds for stability, clearance, portability and weight.😀

[@bronco_fv]

From what I understood the strainwaves are limited by torque rather than mass. So in this respect, putting an EdgeHD 925 (as opposed to the Askar) would probably give you worse figures because although they have the same mass, the arm differs considerably.

[@rvoykin]

I got the AM5 and didn’t think it would “win” but glad to see it did really well. I’ve had solid results thus far at 540mm with the 2600mc and able to do 10 minute exposures pretty reliably. I’ve tried it under bortle 7 and bortle 2 and definitely getting better guiding under bortle 2 usually .45-.6 and .7-.9 under City conditions. Since I use the ASIAIR and mostly ZWO products I love her seamlessly. It all works together and the form factor of everything being red doesn’t hurt. ;)

[@Stefan-Astro-Art]

The good thing about this mount you take it easy on vacation with asiair and a tablet. I like the EQ6-R pro but that's to heavy for take on vacation. So in the future I think to buy this mount for when i go on vacation. Last February I got my 2nd scope the edge Hd8. But I miss the clear sky in the Netherlands now

[@siegfriednoet]

Great thorough review and comparison video Nico, I would be curious how those lightweight mounts would perform with a little wind. Although ZWO says that 900mm is the maximum for the AM5, but you had a good result with the 1000mm Also curious how those harmonic drive mounts would perform after a few years of use, because they always have to pull/push the complete weight because they are not balanced, what do you think ?

[@NebulaPhotos]

Hi Siegfried, I've been told the strain wave gearing is designed to handle that kind of weight imbalance and still last for many years, but I guess time will tell. I think ZWO was giving a rule of thumb rather than a strict maximum focal length. Good point on the wind. With a long or large telescope, you always want to image when there is little wind or have wind protection. That goes double when it comes to these harmonic drive mounts since they aren't providing a super heavy base as your typical EQ mounts do.

[@terrizittritsch745]

Excellent review of mounts and performance.

[@amp2amp800]

Really nice Nico, thanks! Thats great. Exactly what I was looking for. After doing my back in (again!) two weeks ago, I'm thinking again of retiring my venerable EQ6 in favour of an AM5. Glad to see confirmation that they can all take my EON 130APO and are all comparable options. I would love to know if tools are needed to attach the harmonic mounts to their tripod with/without pillar? I have a bit of a hand disfunction (so basically setup and tear down has to be something I can still manage one handed - including dismantling to pack into their box at the end of the night).

[@NebulaPhotos]

I would suggest the ZWO AM5 in that case. Whether you use it just on the tripod or with the pier, it uses an adapter plate that can be left on and makes attaching it easy with no tools (just plastic knobs). The iOptron attaches to the tripod with those little hex screws that also function as alt-az locks and are secured with a small hex key.

[@amp2amp800]

@@NebulaPhotos Thanks very much for answering. I just bit the bullet and ordered an AM5 with extension pillar and counterweight. I hope that the tripod comes with a carry bag, but I can work something out there if needs be. Old faithful EQ6 is now on the market 😢.

[@RahilSethi]

For Alt adjustment, I find SkyWatcher EQM35 adjustment screw way better than EQ6R Pro.

[@stevehowell5410]

You mention a couple of times the problems of working in the dark. That may apply to visual astronomers who have to aclimatise their eyes, but for imaging that's not necessary. I have my garden floodlit if setting up after sunset, and switch off for imaging.

[@williamcavender7166]

I look foward to a full evaluation of the Ioptron HAE29 which uses the harmonic drive for both RA and DEC.

[@kurt6840]

Very nice review.

[@anata5127]

PHD2 setting on Eq6-r is not optimal. Periodic waves are seen clearly. These waves can be eliminated by setting guiding algorithm. Then, guiding accuracy will be 0.5-0.6” rms.

[@bunlessness]

thank you so much! this is valuable

[@2badger2]

I always wonder if there is a technical reason why the companies don't use fine threaded bolts for the polar alignment adjustment.

[@MrDirtyRod]

Great review

[@psuaero100]

Great comparison of "old" tech and new! I really appreciate the graphs (as an engineer) and calling out the pros/cons of each mount. I personally have an Orion EQ-G (HEQ5) and have been thinking hard about replacing it with a AM5 soon. The one thing I didn't really see addressed was balancing of the scope/mount. The EQ6R is a no brainer... what about the balancing of the other two? The HEM has at least one clutch so I guess DEC balancing is pretty standard but how do you balance your scope on a strain wave setup?

[@NebulaPhotos]

Sorry I didn't mention this. Other than the Dec axis on the HEM27, you don't balance a mount with strain wave gearing. In fact, I've heard they even need some imbalance to work properly. Even with a large payload (44 pounds), ZWO doesn't suggest putting any more than 11 pounds on the counterweight bar.

[@JosephConroy]

Thanks!

[@jacquigreenland4768]

just FYI you can definitely use an iPolar with EKOS on a raspberry pi using the V4L driver and the polar alignment assitant - we did it for quite some time but it's a pig as it shows a lot of noise when aligning and it's far easier to just use your guidescope instead.

[@NebulaPhotos]

Thanks, good to know 👍

[@GaryMCurran]

Nico, a few questions for you. With the typical EQ Mount, we're told that the payload, for AP, shouldn't exceed 50-60% of the rated payload, so for the EQ6-R, with a 44 pound payload, that should be 22-26 pounds total. Do the Strain Wave mounts have that same limitation? Next, Cody over on Astroblender (IIRC) was saying that he found better results with the AM5 using an older Celestron AVX mount. You also did mention the baseplate extender adapters. Would you recommend that over the carbon fiber tripod? Finally, what do you think of the Askar telescopes? TIA

[@NebulaPhotos]

Hi Gary, I would say the 50% thing is a rule of thumb that is useful for beginners, but don't take it too seriously. Personally, I wouldn't call it a limitation, just advice to make imaging easier. I have used my EQ6-R extensively at around 35 pounds of payload, and am confident even when I do have issues, they are not issues with the mount. At the end of this video, I used all three mounts with a 34-lb. payload at 0.78"/px and found they all performed adequately. Of course, there is some sample variation in mounts, so I'm not guaranteeing these results. AVX tripod vs. Carbon fiber tripod. Depends on what you are were putting on top. If keeping it under 20 lbs. I think the Carbon fiber tripod should work fine. If really pushing the limits, a beefier tripod like the AVX one is the way to go. I have lots of reviews of Askar telescopes on my channel. I am a big fan of their PHQ line of scopes, and have reviewed the 80mm and the 130mm in the past few months.

[@GaryMCurran]

@@NebulaPhotos Thanks for the replies. I'm not ready quite yet to purchase, but when I do, I'll be sure to use this information. Thank you for taking the time to answer.

[@JemCruz]

Looks like harmonics can be placed to replace traditional goto mounts. They're light, and can carry huge payload. Imagine they release a smaller harmonic that can match a HEQ5 Pro, but the mount is lighter. They can pretty much replace small mounts like SA2i all the way up to HEQ5 Pro. Except in pricing though, because they will be more expensive lol.

[@socialwebwiki]

Man I love your shirt!!!

[@lastnovicewins]

Thank you for this review. It helped me.

[@marcinradziejewski6086]

Jeez, I've been thinking about getting that eq6-r pro ,but it seems to be huge. I totally understand the payload capacity and all other stuff but still .

[@theastronomydude2175]

This was a nice look at these three mounts. I own the AM5. I find that you have a subtle preference to the EQ6R, mainly in the way you talk about it. The EQ6R is a fine mount, but the newer strained wave systems are really putting a hurting on the older EQ designs, so you might want to get used to the new kid on the block.

[@tarang221]

AM5 can guide at 1500mm focal length? I am curious to know 🤔

[@clungebucket23]

The trouble with the Ioptron altaz locking bolts is that tightening them throws out your PA.. The 'knack' is to tighten each one slightly in turn, back and forth pushing it back to centre each time until it feels solid... Another one of ioptrons many foibles

[@x123wsaq]

I have the Ioptron GEM 27 which has exactly the same setup. The trick is to never tighten the bolts down hard. Just snug. That gives ease of movement but more than tight enough to be steady. I've used the mount like that for over a year with loads up to 20lbs. Never been an issue. Set it and forget it.

[@PeterClarke55]

I just use an allen key to move the back alignment bolt, better sensitivity and accuracy.

[@scottrk4930]

Very excellent Video . Thanks Nico !/SRK

[@aztronomy7457]

I would go with the AM5 for no other reason that it's 100% compatible with the ASI Air. The ASI air has compatibility issues with my HEQ-5 Pro.

[@nikanj]

Oh nice. I've been keeping an eye on the HEM 27. It looks like a great deal for a harmonic drive mount if it performs.

[@praahas]

Same here! There is so little about the HEM27 on the internet! About three videos on KZbin and a few posts on Cloudy Nights.. waiting to see this comparison... also waiting to see HEM27 vs HAE29

[@Psychlist1972]

The iOptron polar alignment locking etc. is just like all their other mounts from the CEM40 down. Given that, the azimuth knobs and screws are best replaced with longer ones with larger knobs. I did that with my CEM26 and CEM40. The iOptron CEM70 and CEM120 are where they really start improving on that. The CEM120 is SO much more usable as a result. The CEM26 also requires the hand controller to be plugged in because that's where the mount computer actually is. Bummer they took their cues from the low end rather than their better mounts. The ZWO isn't perfect either. I keep reading reports about things like it not having any limit stops, and how it wasn't until just recently that the mount could be used by both PHD2 and an imaging app like NINA. Clearly ZWO prioritized ASIAir support first, ASCOM second. FWIW, if there's any computer involved, I wouldn't bother with iPolar. Better off to use a multi-point alignment that doesn't require a view of Polaris. ASIAir has it, as do apps like NINA. Great video.

[@NebulaPhotos]

It seems any early issues with the ASCOM driver have been fixed. I had no issues with it connected to PHD2, Cartes Du Ciel, and SGP all at once.

[@Psychlist1972]

@@NebulaPhotos Yep. As mentioned, fixed recently :)

[@MrWacha]

I've watched this review last year out of curiosity but came back to it just no as only now I'm in a position to purchase a new mount. The issue not mentioned here is DEC axis balancing still required for all HEM-type mounts (it's a traditional GEM axis after all). This could've influenced slower DEC recovery with lighter load while heavier load might have had a chance to be better balanced, bringing HEM closer to AM5. Just a thought. Great review otherwise!