You missed the Pegasus Astro NYX 101 😏. Not sure why Pegasus Astro is not as popular they are a great company and their customer service is amazing. Based in Greece
I worked in production environments including production automation and robotics for years (since 1985 or so). I have used many brands of cnc's including Karaki, Servo, Mazak, and others. Used controllers like Yasnak, Faunic, and others. I wrote program code in 8 or 9 different industrial code languages depending on the brand and application. Stepper motors worked well for some applications however, servo drives with precision encoders were considered most accurate. The machines I've operated were generally rated at +/- .0002" and ran anywhere from $80K US upwards to $1M US. (so, I am never too shocked at the prices of these precision strain wave gear mounts). Some of the setup I did were with a 51x microscope, and I could visualize movements of 50 millionths/inch or .00005". Gotta love that precision. I have two AM5s and an AM3. I use these for my smaller refractors (Askar 65, FRA 500, and a Redcat 51). I don't like to put my Askar 151 or Celestron EDGE 11 HD on those mounts although I've been told I could possibly on the AM5s. So, I'm looking for a high-end strain wave gear mount that will accommodate those weights and I might invest in an EDGE 14 HD this year, so I want a mount with that in mind. As usual, your videos help me to find options and make informed choices for this. Thank you much for this one, very helpful and full of great information. ~~~CS~~~
That's such cool experience you have! Such crazy precision! I see your point on the AM5. I think right now the Warpastron WD20 would work for you, but it requires an additional small counterweight for the EdgeHD. Or the iOptron HAE69, but I haven't tested that one!
Nema 35 type 14 is what most people would call a Nema14 & Nema42 type 17 is a Nema17. The 35 & 42 refer to the mm between the fixing holes. The type 14 Gearbox just says "it fits on a Nema14" etc. The bigger the Nema motor the bigger the gearbox and hence the stronger.
ah thanks, that clarifies SO MUCH for me, thanks! Also Cuiv - where the gearbox is identified as a type17-100 strainwave gearbox, that last number will be the gearbox reduction ratio, common ratios are 50(:1), 80, and 100
It's also worth noting that the numbers (14, 17, 23, whatever) have only a casual relationship to the power of the motor itself. They are really only letting you know the geometry of the flange on the front of the motor, and very little about the motor itself aside from a vague idea of the diameter of the rotor/magnets. It's not uncommon for a long nema 17 to have more torque than a pancake 23.
A bit different. Nema 17 is Nema drive with 1.7 inch side size and Nema 14 has 1.4 inch side size. 35/42 are the same size in millimeters. For Nema 17 distance between fixing holes is 31mm
This helps a lot, I'm planning to DIY one of these and it's incredible how cheap and off the shelf the components are. These products are still VERY overpriced.
It's the UMi! My experience with those guys has been great. My concern with the mount has always been that it's very niche, so I'm glad to see it get more exposure.
Great to see an UMi on your channel! I've had my UMI17 for 9 months now and it is fantastic. Can't wait to see the review for the Lite. Keep up the good work Cuiv!
I am considering buying one of these mounts for travel when my wife and I go camping to save weight and especially space. Thanks for explaining the details. They will certainly be helpful when the time comes to make a decision and plunk down the (not Small) pile of cash for one. Keep the great videos coming - we certainly appreciate the effort it takes to produce them - Great job!
I have a Pegasus Astro NYX-101 and I've been quite happy with it. It has two NEMA 17 stepper motors. And Pegasus Astro customer service is top notch. That's why I purchased the NYX-101. Because of their excellent customer service. They replaced one of the original Flatmaster panels with a brand new one without me even having to ask for it. And the new one was so much better than the first one. They new how dissatisfied I was with the original Flatmaster as I had nothing but problems and then when it went belly up, I asked them about fixing it. And they offered to do so, but I was so unhappy with the original Flatmaster, I felt it wasn't worth getting fixed. And it was then when they offered to send me a brand new Type 2. And I've been a Pegasus Astro superfan ever since. ;0)
Excellent details about these mounts! There was so much I didn't really know until now. Thank you! I am looking to purchase one of these later this year and since the AM5, there are so many new options. You explanation of using the torque values to determine the maximum size of what scope goes on which mount was very insightful and helpful. Keep the reviews coming, please. You are a huge help to all of us who have no way to buy them all and pick the best one 🙂
Thanks for the very clear explanation of the math behind these great mounts! I’ve only had the opportunity to run my UMi17 lite two times since I got it, but I’m consistently seeing pinpoint stars on 5 minute subs (Redcat 51/QHY533m/fw/oag 3.9 kg) can’t wait to see how you like it!
This is such a great video mate. There is so much talk online with people mounting gear on top of their scopes and having issues without considering torque impact. Love your videos so much
Good explanation. You covered a lot of important topics especially the importance of keeping the center of gravity of the OTA within the specified max distance from the RA axis.
Cuiv, I have followed your videos on all things astronomy for some time and want to thank you for such in depth information and especially your infectious enthusiasm! I love being a fellow nerd! I have one comment and one question to add to this topic. The comment is to provide some clarity on Warpastron’s meaning of the term Direct Drive. This simply refers to the input shaft of the servo motor being connected directly to strain wave gear, rather than having a belt or other reduction gear between the motor and the strain wave gear. The advantage is the excellent responsiveness you see in your WD-20, as the direct connection eliminates other possible sources of backlash. The disadvantage is that the design prevents through the mount cable management, as the center of the SW gear is filled with the motor’s input shaft. For my money, I would take accuracy over more streamlined cable management everyday. The question I have is have you decided to keep the WD-20? This is somewhat implied in the video. If so, has it continued to perform consistently as you mentioned in your review and what sort of rms values are you getting? Thanks again! Fellow geek, Klaus
Hello Klaus, thanks so much for this, this makes a lot of sense, and that's actually super cool! It explains some of the great experience I have with the WD20... And yep, i finally decided to just bite the bullet and it's now my main mount. It's been absolutely perfect:) I get 0.4-0.6" with my dual barrel frankenscope!
Thank you Cuiv! After seeing what might be possible from your balcony in Tokyo I decided to take the plunge and purchased an AM3 for my first attempt at astrophotography. I live in a suburb of Toronto and have a small 60mm f/5 refractor (Gear60) using some Player One Neptune cameras I purchased last year to image the Moon and Sun to learn very basic stuff. I used information from your videos to set up MeLE minicomputer, N.I.N.A., and advanced sequencing from Patriot Astro to allow me to image some galaxies from my backyard. I would have never even thought it would be possible given I am in a Bortle 8/9 region. I sit in my kitchen and control the scope remotely. I was able to capture M51 for about 212 minutes of integration time. All I need to do is figure out how to process the image. That is probably my main hurdle right now. Without N.I.N.A. advanced sequencing I would not be able to recover from periods of clouds, select multiple targets, and auto focus if the HFR increases. Thank you all who have encouraged me to start this hobby. Thank you Cuiv!
Yay! I have an AM5 and an EQ6 and an AM3. I have had my EQ6 for 20 years. The AM5 isn't as good as it was when I bought it 18 months ago (~0.8"). Now the guiding randomly goes AWOL (>>1"RMS and diverging) seemingly more and more frequently - although it pulls it back in in a way that makes me suspect other causes such as snags and slips. I'm running without a CW (just in spec. with a 12.5kg OTA).The AM3 is (still) very much the best (with a lighter payload permanently attached) It holds 0.6" reliably. The EQ6 always provided steady
Your AM5 belts need tensioning! There are threads on how to do that on Cloudynights! It's a simple fix that would restore your AM5 back to its former glory :)
Great information Cuiv. I was told at NEAF that the Skywatcher SWG mounts also have a clutch system so you can adjust your telescope in the saddle for better balance. I am not sure if it’s in both axis or just one but that is something that I have not seen in other SWG mounts. Great I for as always Cuiv. Best regards Mon Ami Luis from NY
Thank you, your always producing great videos, not sure why others don’t follow your lead. I’ve dropped so many of the other guys because they go months between videos, you and Dark Ranger are by far the best in the business.
Great video explaining what SWG mounts are and how they work. Looking forward to you test of the UMi17 Lite. I am still waiting for delivery of my regular UMi17 which was shipped about 20 days ago. In about 8 - 20 day it should arrive at my door step. Right on time for the really short nights....
If you look up who NEMA is, their website says “… an ANSI-accredited Standards Developing Organization…”. If you look up ANSI, you will see that they are the American National Standards Institute. So, it makes sense that their measurements would be primarily in inches, not millimeters. However, they do a lot of business with international companies, so it would also make sense for them to have equivalent measurements in millimeters. As shown in one of the graphics by Cuiv (@7:57), there is a page that clearly demonstrates 1.4 inches is 35mm (well, actually about 1.378 inches), 1.7 inches is 42mm (well, actually 1.654 inches), and so on. Hence why the same motors might be known by different NEMA numbers, or where there might be a “type” listed for a given motor designation. In short, they’re giving you both types of measurements - Imperial and Metric.
With regards to stepper or servo motors, the term “direct drive” usually means that the driveshaft from the motor does not go through any other gearing or belt system before being attached to whatever the external load is. Someone else might take a direct drive motor and attach it to a gearing or belt system (maybe to reduce the speed and increase the torque), but the manufacturer hasn’t done that. Compare LP record turntables - the really old ones were usually belt drive from a motor, but the newer ones are direct drive where the shaft of the motor directly drives the platter going around.
Great explanation about these mounts Cuiv although I can't see me being able to afford one any time soon lol. I remember commenting before about the servo motors but at the time I did not realise the ones in your mount were brushless so a huge improvement to what my mount had as they have brushes & were know to wear out, the ONSTEP kit I fitted came with NEMA 17's & they are easily capable of slewing the RASA 11so Chad who builds these kits really did his homework.
@@CuivTheLazyGeek That's a much better price I'd be interested to see how it performs, although I noted that owners of these in the comments are very happy with them.
Nice work as always Cuiv! Would just like to mention though that it would be nice to see some coverage comparing these newer mounts to the older RST-135 if you ever have a chance to look into it! It looks like it has a servo motor but no encoders (for the cheap model) so I don’t know why mine guides so well 🤔
Hi Cuiv - The new Sky-Watcher stain waves do come with a power-down lock. So, if the power goes out on the mount, it will lock in place. Kevin Lagore did an entire review of the Sky-Watcher web cast last Friday. So no worries there.
Another timely video for my setup. Thank you, Cuiv! I got the PegasusAstro Nyx-101 as my first mount, and it's been fantastic. Now that I'm stepping up to a 10" Newtonian, though, I've been wondering how to figure out if I need a counter weight, etc.
That's awesome to hear! I think the Quattro 250P for instance would still be well below the 20kg limit (which unlike traditional mounts, doesn't need to be cut by a third for "true" capacity)
The load capacity on the Nyx-101 is a sweet spot. It costs more than worm gear mounts that are on the bottom half of its range, but it costs about the same or less than worm gear mounts that normally take heavier scopes. With counterweights, the Nyx-101 can handle an EdgeHD 11, which is my dream scope. So I went for the Nyx as the best balance of portability and load capacity.
Definitely my next mount is UMi. I checked their mounts and they have several models that have bigger payloads. And the price is reasonable. They also have a great community.
I will be getting a SWG mount later this year but not to replace my EQ6-R Pro, which I will be permanently installing outside, but as an as well as mount to be used either in my back yarrd or taking to a dark sky site. Currently, with the price differential here in the UK, if you intend to set up a mount permanently I don't see the advantage in an SWG, but if you need to set up and take down every time then an SWG mount definitely has the edge. I'm sure the prices will tumble over the coming years and these mounts will completely dominate the market. Anyway Cuiv, thank you for another entertaining snd informative video.
I gotta say, even as a permanent mount, I've found SWG mounts to just *work* without needing babysitting like my EQ6R did back in the day. It's very pleasant! I think for you some of the cheaper mounts would be imported ones like the UMi 17 Lite (better specs than AM3 but cheaper for some reason), a lot of people seem to love to UMi mounts!
Thanks for all these details. I'd like to hear more about the usually larger periodic error and the influence of shorter or longer periods. I also wonder about the importance of the reduction rate which is very low for the AM5 but doesn't seem to have an impact on the popularity of this mount. Enough for Part 2? 😉
Bonsoir Cuiv As far as I am concerned, I use the NYX-101 which carries my RC250 which weights about 20kg fully loaded (cams, Mele,...) with CW, and carried my Sharpstar 200 f3.2 (unfortunately, stolen in a Parisian parkin, 12kg, w/o CW. Nico made a great review of this mount along with AM5 and AM3. Interestingly, Pegasus (a European company, yeah!), just released a lighter version (5kg), with load capacity 14kgs (w/o CW).
In practice even though a stepper motor should move a specific amount, it does not mean it actually does move that amount (wind, out of balance, overweight, resistance in system, gear backlash, etc.). Hence an encoder / closed loop is used on higher end scopes.
So glad you did this I’ve been trying to explain to so many about weight and counterweight with large center mass scopes. Now they will believe me. Lol.
Personally after trialing the AM5 i find it might be useful to remind people who use OAGs that strain wave mounts are really tricky. The constant motion means guiding images need to be good enough at 0.5-1s refresh vs the more necessary 2s for many of us with OAGs. OK OAGs imply a big scope (8”SCT and upwards) but we all wish to benefit from lighter weight mounts!!
After a seeing a UMi Cloudy Nights post I checked out and then bought the UMi17 lite. I use mainly shorter FL scopes on HEQ5 and AzEQ5 mounts which never gave me guiding as good as the Lite first night out (0.3” to 0.5”). Then the UMi17R was released with DC drive on RA promising even better performance - so I bought that too (special introductory deal)! I’ll keep one of the SW mounts for now but these are a no-brainer for me.
My ES EXOS2 PMC8 mount uses NEMA 14's and has plenty of torque to handle a 10+ Kg astrophotography setup with a counterweight. Being a worm drive mount, balancing of the mass is essential as worm drives can't handle the lateral torque imposed by a significant offset weight. NEMA 17 should be more than adequate for a Harmonic drive. FWIW, I would still use a counterweight on a harmonic drive to reduce the load on the gears and increase their longevity.
Hi Cuiv, Very interesting. Do you know what is also what is the required electrical power to guide an unbalanced scope depending on the torque/strain wave gear type/... ? How much current your type 20 gear needs while guiding?
As far as I can tell, direct drive means there are no reduction gears between the motor and RA and Dec. axsis. ( Worm gear, worm wheel.) Like a Tesla I'm assuming. Each wheel has a motor attached directly to it.
Another interesting video Cuiv. I am going with a full ZWO system and was considering the AM-3. I think it will be capable of carrying both the Akar 80phq and the Celestron 8 Edge HD. Any thoughts?
Askar 80, no problem, Celestron 8 EdgeHD should be fine as well, although I'm not sure about how well guiding will work - if you use it for astrophoto make sure to use an OAG like the Celestron OAG!
I recently purchased the am5 mount, very happy with it. I only have a 65mm scope on it. I would like to buy a bigger refractor, just wondering what 100mm refractor I could get away with for this mount without counterweights. Rig is paired with zwo 2600mc pro and small guide scope and guide camera.
Thank you for yor videos, Fantastics all of them. I´m learning a lot. Several questions in the same comments: what do you think of warp astron wd17????, Is it compatible with ASIAIR?. Regards from Spain
Thanks for the video explaining strainvawe mounts . I just wonder how is their tracking performance? What RMS value they provide in good seeing with a good guider system?
With a good guider system, 0.5"-0.6" seems to be quite common - it's also what I get. You do need to have relatively high frequency guiding (1s) and multi-star guiding enabled. So overall, excellent results
Excellent video once again Cuiv. What about the performance of these mounts in Alt-Az mode? I am really looking forward to purchasing one to use it for EAA. To just turn it on, plate solve and start imaging :)
Thanks for this very informative video, but what I would like to know is how big is the periodic error in arcseconds of each of this mounts. ZWO AM5 has 15 or 20 arcseconds error, what about the other mounts?
It really depends on the sample of the mount as well, so it's hard to tell. I've provided charts for some other mounts I've tested (WD20, UMi 17 Lite, EM31Pro) but they're only one sample each
Cuiv, do you know if there is any difference between the encoders on your WA mount and the Rainbow Astro 135E? Thanks for the great content, and look forward to further evaluation of the WA20. I am hoping this pushes ZWO to come out with a higher capacity mount themselves, as I enjoy the ZWO equipment---easy to use!
The WD mount encoders are absolutely necessary for positioning the mount, but aren't as high resolution as the 135E encoders - which are not necessary to positioning the mount, but can be used to track accurately without needing guiding.... If the PA is perfect and the atmospheric model is good and the sky model is good etc.
Au final, tant que ça marche, c'est bien... Mais c'est vrai qu'on aimerait voir un peu plus de détails sans avoir à ouvrir la monture pour regarder dedans :p
It would be interesting for you to get your hands on a Rainbow Astro RST-135, since they were early adopters of making a strain wave mount, to compare to today's new offerings. The current offering is $3,895 US as compared to ZWO AM5 at $2,000 is there anything now that would justify the $1.895 difference or has Rainbow started trading on its name instead of innovation, design, and precision? The shocker is the $5,495 price tag for the encoder model version with a ± 2.5arcsec PE.
I think those early pioneers have been left in the dust, just like Nissan was left in the dust with electric vehicles... The iOptron HAE69EC also has high precision encoders, holds 31kg, has +-0.15" PE according to the latest video by Dark Sky Greek... And is the same price. A UMi 17 Lite has the same specs as the default RST135... Yet is three times cheaper...
Hi Cuiv! Great video as always, thanks for the explanation about these drives, it's very informative. Quick question though, I'm a bit confused. I thought one of the advantages of these strain wave mounts were that I didn't need to bother too much balancing my scope, but looking at the image from ZWO I should actually center my scope with the center of mass so the tip of the scope is 20cm away from the axis? Am I doing things wrong? I have an Askar 120apo with reducer, oag and EFW, does this mean I'm setting my scope completely off balance and sacrificing tracking performance? So far the setup works great and I don't need CW but does this mean I could improve the performance by being more careful about balancing? Anyways, thanks a lot!
Hello! No you're right, you don't need to balance your scope, you're good as is! The 20cm to the axis is about how far the bulk of the scope is from the RA axis, think of it as a 20cm vector to the RA ax
@@CuivTheLazyGeek Phew ok great, thanks for the clarification, I thought I was screwing up something! Thanks a lot for the quick reply, I just came back from a quick solar astrophoto session ;)
@@CuivTheLazyGeek I know... I guess I am looking at mounts in the 31kg range but there is only one. Is there a technical challenge or just a lack of demand.
Super informative, Cuiv! Thanks so much. Just a question about the AM5 mount. I noticed in the specs that in RA it has a Type 42/Type 17 stepper motor and in DEC a Type 35/Type 17 stepper motor. At about 8:30 in the video you mentioned that the max torque for a type 17 motor would be about 28-30 N-m, but the ZWO specs (on their product page) still lists it as 16N-m, i.e., the same as the AM3. I ask because on one of my AM5 mounts I have a Stellarvue SVX90T with high-riser supports so this puts the CG much higher (about 32cm) than 20cm from the RA axis. I'm trying to figure out the maximum payload w/o counterweights for this setup, and how much of a counterweight I'd need to offset this. Thanks again!! Terrific information here.
Probably a typo on their site! I think it should have been 26 N.m, to match their 13kg payload without counterweight AC. If the CW is 20cm away from the RA axis and is 5kg, that should bring the total to 18kg, although they allow placing that CW up to 25cm away from the axis, for an additional 1.5kg, so 19.5kg!
How are strain wave mounts for guiding a 8" or greater SCT that is equipped with an OAG and a guide camera like an ASI174mm mini? My understanding the PE is close to 20" with the strain wave mounts.. With sub 1" image scale on these OTAs can you get sub 1" total rms and quick response to RA/DEC spikes when using PHD2 in NINA or ASIAir? The current reviews I've seen on strain wave mount have been with refractors and guide scopes under 1000mm FL. I'm interested in upgrading to one of these types of mounts from my AVX and would love to ditch the counterweights but if a traditional GEM is better for higher focal lengths guiding then guiding performance is more important. I've read anecdotal evidence that SCT owners are using these types of mounts successfully. Thanks for videos
I routinely get 0.5-0.6" with my dual barrel frankenscope with a very quick guiding response on my WD20, I think it would be very appropriate for an 8 inch SCT. And if you're using an AVX, literally any of these mounts would be a huge step up imo!
Brother, You have no idea how many of your videos I have saved in order to rewatch later when I have/get different gear. This video is among them. Quick question though. I am using a redact 51 based system at the moment and am saving to upgrade my SWSA 2i to a full goto mount. As I use an ASI Air for now I am thinking AM3. The RC51 etc.. is a small set up and would work on the AM3 but I'm wondering if the extra few hundred dollars is worth waiting a bit longer to get the AM5 just for future upgrading? In your opinion. As a bit of background (in case this changes your answer) I do intend to have two set ups at some point. The larger set up will likely be a RASA based system and other than swapping cameras or other accessories the mounts won't be interchangeable. it's the "other accessories" bit that makes me think it might be worth waiting a bit longer to get an AM5. Thanks for sharing your journey. J
Aha, that is a difficult question! Note that the ASIAir can work really well with other mounts like the UMi ones. The UMi 17 and 17 Lite are known to be compatible, and are considerably cheaper (the 17 Lite has better specs than the AM3, but costs $250 less). The UMi 17 and upcoming 17R are true replacements for the AM5, but cheaper (in particular the 17R looks like a great deal, similar to the WarpAstron WD17). Well I'm saying basically: don't limit yourself to ZWO just because you have an ASIAir :)
What strikes me with these mounts is that the connections are either on the front (AM3, AM5, SW Wave 100i) and on some at the back (HAE 29, SW Wave 150i). Which option is best? I'm considering buying such a mount, but I find a few things unclear; the software to control the SW Wave mounts (worse experiences with Sky Watcher pro app), the prices via a Dutch dealer and whether these mounts can also be used from areas without internet/wifi network
The best would be to have power at the base of the mount (so not on a moving part) and be able to have the USB control port on the DEC saddle so the PC or ASIAir mounted on top would never move in relation to the USB port. But overall right now the port positions work decently overall. All those mounts can be used from an area without connectivity. The drivers are different. The lesser known brands like WarpAstron or UMi use OnStep (which is very good, I wish every maker used it), ZWO and iOptron have their proprietary drivers but they work from PC or ASIAir. I don't know what the SW Wave mounts will use, but I assume it will be the usual SW stuff. Hopefully the mount can be directly controlled via EQMOD.
I still use it, but now I'm on NINA again because of my dual barrel frankenscope that requires synchronized dithering, which I believe the SM doesn't support... I'd recommend waiting as the Touptek Astro station is around the corner and it would be good to see how it performs!
Very interesting. So if I put strain wave gears on a properly balanced fork mount then I have essentially zero weight on the gears since there is no offset on either axis!?
I am looking to upgrade from myEQ6 R Pro to a more wind stable mount for my Skywatcher 8” Quattro and 10” Quattro. Weight is not an issue since I use a trolley and don’t travel. With the lighter weight of strain-wave mounts I see no advantage in my situation and am planning to upgrade with a conventional heavy mount like the CQ350. Any thoughts on that plan given my wind sensitive location. Thanks, R Smith
Hello Cuiv. Nice video! Can you tell us more about the method you used for calculating maximum suported weight of the telescope by using the torque values? Is possible you overlooked something? I ask because looking at the AM5 Mount specs shows the same amount of output Torque 16N m as on the Am3 mount, but the AM5 does suports much more weight comapred witht he Am3
They definitely have a typo there - I think they copy pasted from the AM3 without thinking. Reverse engineering from 13kg, it would mean expecting 26NM, and then a 5kg CW at 25cm would add 6.5kg capacity to 19.5kg (which they are free to round up to 20 :) )
@@CuivTheLazyGeek thank you for the answer. I was also thinking that they might have entered the wrong torque there, which is also weird to have this mistakes on the official specs. Recently got the Am5 mount and was thinking to calculate what would be the largest weight of a 10 inch telescop that i could use on the mount but the 16nm of torque just did not made sense if i used this calculation formula
Lazy Geek? I'm lazier. I just watch your videos & let you do all the work. Thank you for being less lazy than me! Calculator? That's for gas mileage right? 🙃
13kg w/o counterweight is kind of minimum standard for this type of mount. I'm looking for the bigger payload mount, the mount's weight isn't issue because I'm planning it to the permanent observation. BTW, my original Umi 17 is absolute excellence, but unfortunately it took me no any interested in the new servo Umi 17R
How to calculate the mount capacity in the AltAz mode? There are virtually zero torques about both Az and Alt axes, assuming that the scope is balanced about the Alt axis.
Good question! I don't have an answer per se, but that would then per up to the forces on the top of the tripod/base of the mount. My guess is that as long as the tripod doesn't tip over, you'd be good :) but it's just a guess!
Servo motors have another significant drawback, along with their advantages, of course - they do not like forced stops when turned on. For example, a telescope meets a column or tripod, the current in their winding increases sharply and, as a rule, this leads to their burnout. Perhaps the manufacturers foresaw this point and installed some kind of protection in such a case, but when choosing between a servo drive and a stepper motor, I vote for the servo drive.
Hello Hello, I am not sure if you have reviewed the hem27 of iOptron. One thing that is plenty bad and difficult, is the iteration process to stars to align. Even after having perfectly centered the ipolar the hem does never reach alignment. I send hours every night and it does not work!! I can align in other mounts in just minutes and this "marvel" ends up in a waste of time. I have seen other review videos on the hem27, and interestingly enough no one mentions, or shows how to align with the "iteration" process. It just does not work! what is your experience on this matter?
i always worry about tripod stability wihen there are no counterweights as the weight is to the front and side. is the tripod any different and this is not really a concern?
It's a good point, and yes you do need a good tripod - and ideally with one leg pointing to the Celestial Pole, so that tipping worries are alleviated!
My understanding is that a strain wave mount is simply an equatorial mount, no better or worse than a comparably well-constructed German equatorial mount. The only real advantage over a GEM is that for lighter loads the mount doesn't need counterweights, making it lighter and more portable than a GEM. But for larger payloads you still need weights (either counterweights or weights to hold the tripod in place) in order to prevent the rig from toppling over once the payload is off center or a strong wind comes along. I don't understand the hype about strain wave mounts. They are superior for one particular niche (portable, small-payload rigs), but they're not going to revolutionize the hobby.
I take it you haven't used a SWG mount yet? If you had you wouldn't think that :) now that I've experienced these mounts (especially the WD20), I'll take a SWG mount over a GEM every time (except maybe an Astrophysics or 10Micron mounts :)) - they just perform more reliably in my experience, with very consistent guiding, no weird nights where the mount performs mysteriously, etc. Give me the choice between an HEQ5 and UMi 17 Lite (same price, same payload) - UMi 17 Lite for sure!
@@CuivTheLazyGeek Have you actually run a controlled test? Two comparably priced mounts (which should account for build quality) with the same payloads? Or are you remembering problems with GEMs of a different quality with heavier payloads? I smell a lot of confirmation bias in what you're saying. (I'm not saying SW mounts aren't good, just that for other than portability with small payloads they're not superior to GEMs.)
Yes! I've run CEM60 vs AM5 (cheaper) and WD20 (similar price) which I've run in parallel for a while. Since I came in as a skeptic of SWG mounts due to a prior bad experience as an early adopter of the Crux 140Tv SWG mount, I would have expected the confirmation bias to lean towards the CEM60 but it didn't.
I’m guessing the real payload for astrophotography is somewhere in the middle of the maximum payload instead of near 100% of the recommended payload (similar to the advice for traditional worm geared German equatorial mounts.
Actually no! I've found that the mount doesn't really care! You might go from 0.5" at the bottom of the range to something like 0.7" at the top in terms of guiding. When I switched from single barrel to double barrel scope on my WD20... Nothing at all change. Exactly the same performance. It's really impressive!
Thank you! Oh the Seestar would trounce the DIY Smart Scope. It's just better AND cheaper... but you don't get the satisfaction of building it yourself
I honestly think it's getting better and better - the cheaper ones are getting towards $1,000, while being easier to use and guide. Give me the choice between a UMi 17 Lite and an HEQ5 (roughly same price), I'll go for the UMi every time
@@CuivTheLazyGeek unfortunately UMI 17 is unavailable in australia unless it's a private import, it becomes very expensive as the heQ5 is cheaper due to numbers available here
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You missed the Pegasus Astro NYX 101 😏. Not sure why Pegasus Astro is not as popular they are a great company and their customer service is amazing. Based in Greece
I worked in production environments including production automation and robotics for years (since 1985 or so). I have used many brands of cnc's including Karaki, Servo, Mazak, and others. Used controllers like Yasnak, Faunic, and others. I wrote program code in 8 or 9 different industrial code languages depending on the brand and application. Stepper motors worked well for some applications however, servo drives with precision encoders were considered most accurate. The machines I've operated were generally rated at +/- .0002" and ran anywhere from $80K US upwards to $1M US. (so, I am never too shocked at the prices of these precision strain wave gear mounts). Some of the setup I did were with a 51x microscope, and I could visualize movements of 50 millionths/inch or .00005". Gotta love that precision.
I have two AM5s and an AM3. I use these for my smaller refractors (Askar 65, FRA 500, and a Redcat 51). I don't like to put my Askar 151 or Celestron EDGE 11 HD on those mounts although I've been told I could possibly on the AM5s.
So, I'm looking for a high-end strain wave gear mount that will accommodate those weights and I might invest in an EDGE 14 HD this year, so I want a mount with that in mind.
As usual, your videos help me to find options and make informed choices for this. Thank you much for this one, very helpful and full of great information. ~~~CS~~~
That's such cool experience you have! Such crazy precision!
I see your point on the AM5. I think right now the Warpastron WD20 would work for you, but it requires an additional small counterweight for the EdgeHD. Or the iOptron HAE69, but I haven't tested that one!
@@CuivTheLazyGeek I am super curious about the HAE69EC on paper it is an excellent design. It is still not clear for me how good those mounts are
Finally, UMi users were teling them to send you one for a while. A happy UMi 17 user here :)
Seems there's a large UMi fan club! I'm waiting for good weather to test it!
Nema 35 type 14 is what most people would call a Nema14 & Nema42 type 17 is a Nema17. The 35 & 42 refer to the mm between the fixing holes. The type 14 Gearbox just says "it fits on a Nema14" etc. The bigger the Nema motor the bigger the gearbox and hence the stronger.
ah thanks, that clarifies SO MUCH for me, thanks! Also Cuiv - where the gearbox is identified as a type17-100 strainwave gearbox, that last number will be the gearbox reduction ratio, common ratios are 50(:1), 80, and 100
It's also worth noting that the numbers (14, 17, 23, whatever) have only a casual relationship to the power of the motor itself. They are really only letting you know the geometry of the flange on the front of the motor, and very little about the motor itself aside from a vague idea of the diameter of the rotor/magnets. It's not uncommon for a long nema 17 to have more torque than a pancake 23.
A bit different. Nema 17 is Nema drive with 1.7 inch side size and Nema 14 has 1.4 inch side size. 35/42 are the same size in millimeters.
For Nema 17 distance between fixing holes is 31mm
This helps a lot, I'm planning to DIY one of these and it's incredible how cheap and off the shelf the components are. These products are still VERY overpriced.
It's the UMi! My experience with those guys has been great. My concern with the mount has always been that it's very niche, so I'm glad to see it get more exposure.
So many people seem to love UMi :)
Great to see an UMi on your channel! I've had my UMI17 for 9 months now and it is fantastic. Can't wait to see the review for the Lite. Keep up the good work Cuiv!
Thank Timothy! I've yet to test it, the weather hasn't been cooperative!
I am considering buying one of these mounts for travel when my wife and I go camping to save weight and especially space. Thanks for explaining the details. They will certainly be helpful when the time comes to make a decision and plunk down the (not Small) pile of cash for one. Keep the great videos coming - we certainly appreciate the effort it takes to produce them - Great job!
checkout the link for the UMi mounts in the description. It's probably not as much $$ as you might think.
I'll soon be testing the UMi 17 Lite, it's one of the cheapest SWG mounts around, same level as the HEQ5!
Ayy! Love to see an UMi, I love my original UMi 17. Glad you are visiting strain wave more.
Review coming as soon as the weather allows!
I have a Pegasus Astro NYX-101 and I've been quite happy with it. It has two NEMA 17 stepper motors. And Pegasus Astro customer service is top notch. That's why I purchased the NYX-101. Because of their excellent customer service. They replaced one of the original Flatmaster panels with a brand new one without me even having to ask for it. And the new one was so much better than the first one. They new how dissatisfied I was with the original Flatmaster as I had nothing but problems and then when it went belly up, I asked them about fixing it. And they offered to do so, but I was so unhappy with the original Flatmaster, I felt it wasn't worth getting fixed. And it was then when they offered to send me a brand new Type 2. And I've been a Pegasus Astro superfan ever since. ;0)
I cannot fault Pegasus for their customer service they are really great to deal with
Awesome! I just got the UMi-17 Lite and have been waiting for some clear skies. Can't wait to see a review on it!
I've been waiting for clear skies as well :(
Excellent details about these mounts! There was so much I didn't really know until now. Thank you! I am looking to purchase one of these later this year and since the AM5, there are so many new options. You explanation of using the torque values to determine the maximum size of what scope goes on which mount was very insightful and helpful. Keep the reviews coming, please. You are a huge help to all of us who have no way to buy them all and pick the best one 🙂
Glad this was helpful, and I'm so hyped to see the market getting more and more crowded, it's good for us beginners!
Thanks for the very clear explanation of the math behind these great mounts! I’ve only had the opportunity to run my UMi17 lite two times since I got it, but I’m consistently seeing pinpoint stars on 5 minute subs (Redcat 51/QHY533m/fw/oag 3.9 kg) can’t wait to see how you like it!
Glad it was helpful! Can't wait for the weather to clear so that I can test the mount :)
This is such a great video mate. There is so much talk online with people mounting gear on top of their scopes and having issues without considering torque impact. Love your videos so much
Glad it was helpful!
Nice job in explaining the technology for many of us in the market for a very portable mount.
Glad this is helpful!
Good explanation. You covered a lot of important topics especially the importance of keeping the center of gravity of the OTA within the specified max distance from the RA axis.
Glad it was helpful!
Cuiv, I have followed your videos on all things astronomy for some time and want to thank you for such in depth information and especially your infectious enthusiasm! I love being a fellow nerd! I have one comment and one question to add to this topic.
The comment is to provide some clarity on Warpastron’s meaning of the term Direct Drive. This simply refers to the input shaft of the servo motor being connected directly to strain wave gear, rather than having a belt or other reduction gear between the motor and the strain wave gear. The advantage is the excellent responsiveness you see in your WD-20, as the direct connection eliminates other possible sources of backlash. The disadvantage is that the design prevents through the mount cable management, as the center of the SW gear is filled with the motor’s input shaft. For my money, I would take accuracy over more streamlined cable management everyday.
The question I have is have you decided to keep the WD-20? This is somewhat implied in the video. If so, has it continued to perform consistently as you mentioned in your review and what sort of rms values are you getting?
Thanks again!
Fellow geek, Klaus
Hello Klaus, thanks so much for this, this makes a lot of sense, and that's actually super cool! It explains some of the great experience I have with the WD20... And yep, i finally decided to just bite the bullet and it's now my main mount. It's been absolutely perfect:) I get 0.4-0.6" with my dual barrel frankenscope!
Thank you Cuiv! After seeing what might be possible from your balcony in Tokyo I decided to take the plunge and purchased an AM3 for my first attempt at astrophotography. I live in a suburb of Toronto and have a small 60mm f/5 refractor (Gear60) using some Player One Neptune cameras I purchased last year to image the Moon and Sun to learn very basic stuff. I used information from your videos to set up MeLE minicomputer, N.I.N.A., and advanced sequencing from Patriot Astro to allow me to image some galaxies from my backyard. I would have never even thought it would be possible given I am in a Bortle 8/9 region. I sit in my kitchen and control the scope remotely. I was able to capture M51 for about 212 minutes of integration time. All I need to do is figure out how to process the image. That is probably my main hurdle right now. Without N.I.N.A. advanced sequencing I would not be able to recover from periods of clouds, select multiple targets, and auto focus if the HFR increases. Thank you all who have encouraged me to start this hobby. Thank you Cuiv!
I've been considering one of these types of mounts to replace my large equitorial mount. Thanks for the detailed review 👍
My pleasure, and I think you won't be disappointed, those mounts are amazing in general :)
Great explanation! Thanks!
I vouch for these mounts took my imaging to the next level
They're just so reliable in my experience! (Besides a bad sample I got years ago as an early adopter)
Great video (AGAIN) Cuiv 😊 I've learnt a fair bit here!
Planning on buying the WarpAstron WD-17
Yay! I have an AM5 and an EQ6 and an AM3. I have had my EQ6 for 20 years. The AM5 isn't as good as it was when I bought it 18 months ago (~0.8"). Now the guiding randomly goes AWOL (>>1"RMS and diverging) seemingly more and more frequently - although it pulls it back in in a way that makes me suspect other causes such as snags and slips. I'm running without a CW (just in spec. with a 12.5kg OTA).The AM3 is (still) very much the best (with a lighter payload permanently attached) It holds 0.6" reliably. The EQ6 always provided steady
Your AM5 belts need tensioning! There are threads on how to do that on Cloudynights! It's a simple fix that would restore your AM5 back to its former glory :)
And yes on the tripod :)
Great information Cuiv. I was told at NEAF that the Skywatcher SWG mounts also have a clutch system so you can adjust your telescope in the saddle for better balance. I am not sure if it’s in both axis or just one but that is something that I have not seen in other SWG mounts. Great I for as always Cuiv. Best regards Mon Ami
Luis from NY
Thanks Luis! Not sure about exactly what they mean by that clutch system... But we'll see once the mounts actually get released!
Thank you, your always producing great videos, not sure why others don’t follow your lead. I’ve dropped so many of the other guys because they go months between videos, you and Dark Ranger are by far the best in the business.
Thank you! I do my best :)
Great video explaining what SWG mounts are and how they work.
Looking forward to you test of the UMi17 Lite. I am still waiting for delivery of my regular UMi17 which was shipped about 20 days ago. In about 8 - 20 day it should arrive at my door step. Right on time for the really short nights....
Hope you get it soon! And yeah short nights are no fun, but they'll get longer soon :)
I got this mount for my grab and go rig months ago. So far the guiding is good, I get the RMS of about 0.4 to 0.7 using 120F4 guide scope with 585MC.
Can't wait to test it!
If you look up who NEMA is, their website says “… an ANSI-accredited Standards Developing Organization…”. If you look up ANSI, you will see that they are the American National Standards Institute. So, it makes sense that their measurements would be primarily in inches, not millimeters. However, they do a lot of business with international companies, so it would also make sense for them to have equivalent measurements in millimeters.
As shown in one of the graphics by Cuiv (@7:57), there is a page that clearly demonstrates 1.4 inches is 35mm (well, actually about 1.378 inches), 1.7 inches is 42mm (well, actually 1.654 inches), and so on. Hence why the same motors might be known by different NEMA numbers, or where there might be a “type” listed for a given motor designation. In short, they’re giving you both types of measurements - Imperial and Metric.
Most underrated comment here. Very insightful
With regards to stepper or servo motors, the term “direct drive” usually means that the driveshaft from the motor does not go through any other gearing or belt system before being attached to whatever the external load is. Someone else might take a direct drive motor and attach it to a gearing or belt system (maybe to reduce the speed and increase the torque), but the manufacturer hasn’t done that.
Compare LP record turntables - the really old ones were usually belt drive from a motor, but the newer ones are direct drive where the shaft of the motor directly drives the platter going around.
Thanks Cuiv. Great explanation, very helpful.
Glad you liked it!
Great video, thank you for the explanations
My pleasure!
Great explanation about these mounts Cuiv although I can't see me being able to afford one any time soon lol. I remember commenting before about the servo motors but at the time I did not realise the ones in your mount were brushless so a huge improvement to what my mount had as they have brushes & were know to wear out, the ONSTEP kit I fitted came with NEMA 17's & they are easily capable of slewing the RASA 11so Chad who builds these kits really did his homework.
The UMi 17 Lite is around $1250, we're finally seeing some reasonable prices!
@@CuivTheLazyGeek That's a much better price I'd be interested to see how it performs, although I noted that owners of these in the comments are very happy with them.
Thanks for such a clear explanation of these drives!
Glad it was helpful!
Nice work as always Cuiv! Would just like to mention though that it would be nice to see some coverage comparing these newer mounts to the older RST-135 if you ever have a chance to look into it! It looks like it has a servo motor but no encoders (for the cheap model) so I don’t know why mine guides so well 🤔
The WD20 with servo also guides very well! That said, unless someone sends me a loaner, I don't think I'll ever get my hands on an RST-135!
Planning on buying a SkyWatcher Wave 150i mount. I chose this mount based on 2 parameters, price and max weight capacity.
I love my Rainbow Astro RST-135E. Great mount, no issues so far over three years.
Hi Cuiv - The new Sky-Watcher stain waves do come with a power-down lock. So, if the power goes out on the mount, it will lock in place. Kevin Lagore did an entire review of the Sky-Watcher web cast last Friday. So no worries there.
Thanks for the explanation. I had no idea about the payload dependency on telescope center of gravity!
Glad to help!
Useful video Cuiv. Thanks
Thanks Jim!
Another timely video for my setup. Thank you, Cuiv! I got the PegasusAstro Nyx-101 as my first mount, and it's been fantastic. Now that I'm stepping up to a 10" Newtonian, though, I've been wondering how to figure out if I need a counter weight, etc.
That's awesome to hear! I think the Quattro 250P for instance would still be well below the 20kg limit (which unlike traditional mounts, doesn't need to be cut by a third for "true" capacity)
The load capacity on the Nyx-101 is a sweet spot. It costs more than worm gear mounts that are on the bottom half of its range, but it costs about the same or less than worm gear mounts that normally take heavier scopes. With counterweights, the Nyx-101 can handle an EdgeHD 11, which is my dream scope. So I went for the Nyx as the best balance of portability and load capacity.
Definitely my next mount is UMi. I checked their mounts and they have several models that have bigger payloads. And the price is reasonable. They also have a great community.
Yep, I'm surprised by how much love there seems to be for UMi!
If you haven't seen it, they have just released the UMI 17R which has a servo motor on the RA axis
I will be getting a SWG mount later this year but not to replace my EQ6-R Pro, which I will be permanently installing outside, but as an as well as mount to be used either in my back yarrd or taking to a dark sky site. Currently, with the price differential here in the UK, if you intend to set up a mount permanently I don't see the advantage in an SWG, but if you need to set up and take down every time then an SWG mount definitely has the edge. I'm sure the prices will tumble over the coming years and these mounts will completely dominate the market. Anyway Cuiv, thank you for another entertaining snd informative video.
I gotta say, even as a permanent mount, I've found SWG mounts to just *work* without needing babysitting like my EQ6R did back in the day. It's very pleasant! I think for you some of the cheaper mounts would be imported ones like the UMi 17 Lite (better specs than AM3 but cheaper for some reason), a lot of people seem to love to UMi mounts!
Thanks for all these details. I'd like to hear more about the usually larger periodic error and the influence of shorter or longer periods. I also wonder about the importance of the reduction rate which is very low for the AM5 but doesn't seem to have an impact on the popularity of this mount. Enough for Part 2? 😉
Bonsoir Cuiv
As far as I am concerned, I use the NYX-101 which carries my RC250 which weights about 20kg fully loaded (cams, Mele,...) with CW, and carried my Sharpstar 200 f3.2 (unfortunately, stolen in a Parisian parkin, 12kg, w/o CW. Nico made a great review of this mount along with AM5 and AM3. Interestingly, Pegasus (a European company, yeah!), just released a lighter version (5kg), with load capacity 14kgs (w/o CW).
I heard great things about this mount, spec wise it's very close to my WD20, which I adore!
In practice even though a stepper motor should move a specific amount, it does not mean it actually does move that amount (wind, out of balance, overweight, resistance in system, gear backlash, etc.). Hence an encoder / closed loop is used on higher end scopes.
Absolutely! And then you also have the precision encoders in the iOptron SWG mounts (although not sure how well these work with the SDE)
So glad you did this I’ve been trying to explain to so many about weight and counterweight with large center mass scopes. Now they will believe me. Lol.
Personally after trialing the AM5 i find it might be useful to remind people who use OAGs that strain wave mounts are really tricky. The constant motion means guiding images need to be good enough at 0.5-1s refresh vs the more necessary 2s for many of us with OAGs. OK OAGs imply a big scope (8”SCT and upwards) but we all wish to benefit from lighter weight mounts!!
After a seeing a UMi Cloudy Nights post I checked out and then bought the UMi17 lite. I use mainly shorter FL scopes on HEQ5 and AzEQ5 mounts which never gave me guiding as good as the Lite first night out (0.3” to 0.5”). Then the UMi17R was released with DC drive on RA promising even better performance - so I bought that too (special introductory deal)! I’ll keep one of the SW mounts for now but these are a no-brainer for me.
I did the same! Looking forward to comparing the Lite and the R
My ES EXOS2 PMC8 mount uses NEMA 14's and has plenty of torque to handle a 10+ Kg astrophotography setup with a counterweight. Being a worm drive mount, balancing of the mass is essential as worm drives can't handle the lateral torque imposed by a significant offset weight. NEMA 17 should be more than adequate for a Harmonic drive. FWIW, I would still use a counterweight on a harmonic drive to reduce the load on the gears and increase their longevity.
AM5 owner with C9.25 and Hyperstar, great combo!
Awesome to hear!
Hi Cuiv,
Very interesting. Do you know what is also what is the required electrical power to guide an unbalanced scope depending on the torque/strain wave gear type/... ?
How much current your type 20 gear needs while guiding?
Great question, I'm not sure at this point, I'll need to measure that at some point!
Ooooh. That sounds encouraging! Thanks!
As far as I can tell, direct drive means there are no reduction gears between the motor and RA and Dec. axsis. ( Worm gear, worm wheel.) Like a Tesla I'm assuming. Each wheel has a motor attached directly to it.
Thanks for the info! Or in this case, no reduction gears between motor and strain wave gears (rather than worm and wheel), thanks for the feedback!
Another interesting video Cuiv. I am going with a full ZWO system and was considering the AM-3. I think it will be capable of carrying both the Akar 80phq and the Celestron 8 Edge HD. Any thoughts?
Askar 80, no problem, Celestron 8 EdgeHD should be fine as well, although I'm not sure about how well guiding will work - if you use it for astrophoto make sure to use an OAG like the Celestron OAG!
@CuivTheLazyGeek cheers
Super and informative video!
I recently purchased the am5 mount, very happy with it. I only have a 65mm scope on it. I would like to buy a bigger refractor, just wondering what 100mm refractor I could get away with for this mount without counterweights. Rig is paired with zwo 2600mc pro and small guide scope and guide camera.
Thank you for yor videos, Fantastics all of them. I´m learning a lot. Several questions in the same comments: what do you think of warp astron wd17????, Is it compatible with ASIAIR?. Regards from Spain
Thanks for the video explaining strainvawe mounts . I just wonder how is their tracking performance? What RMS value they provide in good seeing with a good guider system?
With a good guider system, 0.5"-0.6" seems to be quite common - it's also what I get. You do need to have relatively high frequency guiding (1s) and multi-star guiding enabled. So overall, excellent results
Thanks Cuiv.
Excellent video once again Cuiv. What about the performance of these mounts in Alt-Az mode? I am really looking forward to purchasing one to use it for EAA. To just turn it on, plate solve and start imaging :)
Thanks for this very informative video, but what I would like to know is how big is the periodic error in arcseconds of each of this mounts. ZWO AM5 has 15 or 20 arcseconds error, what about the other mounts?
It really depends on the sample of the mount as well, so it's hard to tell. I've provided charts for some other mounts I've tested (WD20, UMi 17 Lite, EM31Pro) but they're only one sample each
Cuiv, do you know if there is any difference between the encoders on your WA mount and the Rainbow Astro 135E? Thanks for the great content, and look forward to further evaluation of the WA20. I am hoping this pushes ZWO to come out with a higher capacity mount themselves, as I enjoy the ZWO equipment---easy to use!
The WD mount encoders are absolutely necessary for positioning the mount, but aren't as high resolution as the 135E encoders - which are not necessary to positioning the mount, but can be used to track accurately without needing guiding.... If the PA is perfect and the atmospheric model is good and the sky model is good etc.
Merci Cuiv, très intéressant et informatif comme toujours, j’ai la Ioptron HAE29 et aurait bien aimé des spécifications plus précises!
Au final, tant que ça marche, c'est bien... Mais c'est vrai qu'on aimerait voir un peu plus de détails sans avoir à ouvrir la monture pour regarder dedans :p
So what about the payload with a CW? Is there a method to calculate it using the torque value and the distance to the RA??
It would be interesting for you to get your hands on a Rainbow Astro RST-135, since they were early adopters of making a strain wave mount, to compare to today's new offerings. The current offering is $3,895 US as compared to ZWO AM5 at $2,000 is there anything now that would justify the $1.895 difference or has Rainbow started trading on its name instead of innovation, design, and precision? The shocker is the $5,495 price tag for the encoder model version with a ± 2.5arcsec PE.
I think those early pioneers have been left in the dust, just like Nissan was left in the dust with electric vehicles... The iOptron HAE69EC also has high precision encoders, holds 31kg, has +-0.15" PE according to the latest video by Dark Sky Greek... And is the same price.
A UMi 17 Lite has the same specs as the default RST135... Yet is three times cheaper...
Hi Cuiv! Great video as always, thanks for the explanation about these drives, it's very informative. Quick question though, I'm a bit confused. I thought one of the advantages of these strain wave mounts were that I didn't need to bother too much balancing my scope, but looking at the image from ZWO I should actually center my scope with the center of mass so the tip of the scope is 20cm away from the axis? Am I doing things wrong? I have an Askar 120apo with reducer, oag and EFW, does this mean I'm setting my scope completely off balance and sacrificing tracking performance? So far the setup works great and I don't need CW but does this mean I could improve the performance by being more careful about balancing?
Anyways, thanks a lot!
Hello! No you're right, you don't need to balance your scope, you're good as is! The 20cm to the axis is about how far the bulk of the scope is from the RA axis, think of it as a 20cm vector to the RA ax
@@CuivTheLazyGeek Phew ok great, thanks for the clarification, I thought I was screwing up something! Thanks a lot for the quick reply, I just came back from a quick solar astrophoto session ;)
Very usefull video! How big can a starin wave gear mount get? In the near future, can we see mounts that support 55kgs? Thanks!
What are you going to mount that is going to weigh 55kgs?? I think the iOptron HAE69 is the closest but it's only rated for 31kg...
@@CuivTheLazyGeek I know... I guess I am looking at mounts in the 31kg range but there is only one. Is there a technical challenge or just a lack of demand.
It could be the balance issue...
Crux T4000 is a harmonic drive mount that supports up to 180kg payload
Crux 320HD Supports up to 60kg
Early adopter of the AM5 and have been nothing but pleased
It's a great mount, like most of those SWG mounts :)
@cuiv I'd love for you to give your take on the JUWEI17-100 mount
Would be good maybe to cover polar alignment. As I see no polar finder. Potentially a drawback (e.g. if you have no asi air)
Super informative, Cuiv! Thanks so much. Just a question about the AM5 mount. I noticed in the specs that in RA it has a Type 42/Type 17 stepper motor and in DEC a Type 35/Type 17 stepper motor. At about 8:30 in the video you mentioned that the max torque for a type 17 motor would be about 28-30 N-m, but the ZWO specs (on their product page) still lists it as 16N-m, i.e., the same as the AM3. I ask because on one of my AM5 mounts I have a Stellarvue SVX90T with high-riser supports so this puts the CG much higher (about 32cm) than 20cm from the RA axis. I'm trying to figure out the maximum payload w/o counterweights for this setup, and how much of a counterweight I'd need to offset this. Thanks again!! Terrific information here.
Probably a typo on their site! I think it should have been 26 N.m, to match their 13kg payload without counterweight AC. If the CW is 20cm away from the RA axis and is 5kg, that should bring the total to 18kg, although they allow placing that CW up to 25cm away from the axis, for an additional 1.5kg, so 19.5kg!
@@CuivTheLazyGeek Ah, that makes me feel much better. Thanks, Cuiv!!
How are strain wave mounts for guiding a 8" or greater SCT that is equipped with an OAG and a guide camera like an ASI174mm mini? My understanding the PE is close to 20" with the strain wave mounts.. With sub 1" image scale on these OTAs can you get sub 1" total rms and quick response to RA/DEC spikes when using PHD2 in NINA or ASIAir? The current reviews I've seen on strain wave mount have been with refractors and guide scopes under 1000mm FL. I'm interested in upgrading to one of these types of mounts from my AVX and would love to ditch the counterweights but if a traditional GEM is better for higher focal lengths guiding then guiding performance is more important. I've read anecdotal evidence that SCT owners are using these types of mounts successfully. Thanks for videos
I routinely get 0.5-0.6" with my dual barrel frankenscope with a very quick guiding response on my WD20, I think it would be very appropriate for an 8 inch SCT.
And if you're using an AVX, literally any of these mounts would be a huge step up imo!
Thanks for asking this question.
Brother,
You have no idea how many of your videos I have saved in order to rewatch later when I have/get different gear. This video is among them.
Quick question though.
I am using a redact 51 based system at the moment and am saving to upgrade my SWSA 2i to a full goto mount. As I use an ASI Air for now I am thinking AM3. The RC51 etc.. is a small set up and would work on the AM3 but I'm wondering if the extra few hundred dollars is worth waiting a bit longer to get the AM5 just for future upgrading? In your opinion.
As a bit of background (in case this changes your answer) I do intend to have two set ups at some point. The larger set up will likely be a RASA based system and other than swapping cameras or other accessories the mounts won't be interchangeable.
it's the "other accessories" bit that makes me think it might be worth waiting a bit longer to get an AM5.
Thanks for sharing your journey.
J
Aha, that is a difficult question! Note that the ASIAir can work really well with other mounts like the UMi ones. The UMi 17 and 17 Lite are known to be compatible, and are considerably cheaper (the 17 Lite has better specs than the AM3, but costs $250 less). The UMi 17 and upcoming 17R are true replacements for the AM5, but cheaper (in particular the 17R looks like a great deal, similar to the WarpAstron WD17).
Well I'm saying basically: don't limit yourself to ZWO just because you have an ASIAir :)
What strikes me with these mounts is that the connections are either on the front (AM3, AM5, SW Wave 100i) and on some at the back (HAE 29, SW Wave 150i). Which option is best? I'm considering buying such a mount, but I find a few things unclear; the software to control the SW Wave mounts (worse experiences with Sky Watcher pro app), the prices via a Dutch dealer and whether these mounts can also be used from areas without internet/wifi network
The best would be to have power at the base of the mount (so not on a moving part) and be able to have the USB control port on the DEC saddle so the PC or ASIAir mounted on top would never move in relation to the USB port. But overall right now the port positions work decently overall.
All those mounts can be used from an area without connectivity.
The drivers are different. The lesser known brands like WarpAstron or UMi use OnStep (which is very good, I wish every maker used it), ZWO and iOptron have their proprietary drivers but they work from PC or ASIAir. I don't know what the SW Wave mounts will use, but I assume it will be the usual SW stuff. Hopefully the mount can be directly controlled via EQMOD.
I have the ZWO AM5 and have taken 30s - 180s subframes without guiding @2400 mm FL + with great success. So - maybe you don't need guiding after all?
Are you still using the Stellarmate Pro? I was thinking of buying one.
I still use it, but now I'm on NINA again because of my dual barrel frankenscope that requires synchronized dithering, which I believe the SM doesn't support... I'd recommend waiting as the Touptek Astro station is around the corner and it would be good to see how it performs!
Very interesting. So if I put strain wave gears on a properly balanced fork mount then I have essentially zero weight on the gears since there is no offset on either axis!?
I am looking to upgrade from myEQ6 R Pro to a more wind stable mount for my Skywatcher 8” Quattro and 10” Quattro. Weight is not an issue since I use a trolley and don’t travel. With the lighter weight of strain-wave mounts I see no advantage in my situation and am planning to upgrade with a conventional heavy mount like the CQ350. Any thoughts on that plan given my wind sensitive location. Thanks, R Smith
UMi17 user here 😎
Hello Cuiv. Nice video! Can you tell us more about the method you used for calculating maximum suported weight of the telescope by using the torque values? Is possible you overlooked something? I ask because looking at the AM5 Mount specs shows the same amount of output Torque 16N m as on the Am3 mount, but the AM5 does suports much more weight comapred witht he Am3
They definitely have a typo there - I think they copy pasted from the AM3 without thinking. Reverse engineering from 13kg, it would mean expecting 26NM, and then a 5kg CW at 25cm would add 6.5kg capacity to 19.5kg (which they are free to round up to 20 :) )
@@CuivTheLazyGeek thank you for the answer. I was also thinking that they might have entered the wrong torque there, which is also weird to have this mistakes on the official specs. Recently got the Am5 mount and was thinking to calculate what would be the largest weight of a 10 inch telescop that i could use on the mount but the 16nm of torque just did not made sense if i used this calculation formula
Lazy Geek? I'm lazier. I just watch your videos & let you do all the work. Thank you for being less lazy than me! Calculator? That's for gas mileage right? 🙃
Hahaha glad I could do the work for me!
13kg w/o counterweight is kind of minimum standard for this type of mount. I'm looking for the bigger payload mount, the mount's weight isn't issue because I'm planning it to the permanent observation.
BTW, my original Umi 17 is absolute excellence, but unfortunately it took me no any interested in the new servo Umi 17R
For bigger payloads right now I think it's between the WD20 and the HAE69 (which has higher payload :))
Umi mentioned 🎉
hey fenice!
And soon to be tested!
@@sonacphotos the whole gang is here lol
How to calculate the mount capacity in the AltAz mode? There are virtually zero torques about both Az and Alt axes, assuming that the scope is balanced about the Alt axis.
Good question! I don't have an answer per se, but that would then per up to the forces on the top of the tripod/base of the mount. My guess is that as long as the tripod doesn't tip over, you'd be good :) but it's just a guess!
Thanks!
Glad this is helpful! Thank you so much!
Every other video I've seen (not related to mounts) have said that strain/harmonic drives can't be back driven easily or at all. 🤔
Chouette vidéo, merci à toi !!!
De rien :)
Servo motors have another significant drawback, along with their advantages, of course - they do not like forced stops when turned on. For example, a telescope meets a column or tripod, the current in their winding increases sharply and, as a rule, this leads to their burnout. Perhaps the manufacturers foresaw this point and installed some kind of protection in such a case, but when choosing between a servo drive and a stepper motor, I vote for the servo drive.
Good point! I haven't had issues yet and my guess is they have some sort of over current protection...
@@CuivTheLazyGeek But I don't think it's worth checking))
Hello Hello, I am not sure if you have reviewed the hem27 of iOptron. One thing that is plenty bad and difficult, is the iteration process to stars to align. Even after having perfectly centered the ipolar the hem does never reach alignment. I send hours every night and it does not work!! I can align in other mounts in just minutes and this "marvel" ends up in a waste of time. I have seen other review videos on the hem27, and interestingly enough no one mentions, or shows how to align with the "iteration" process. It just does not work! what is your experience on this matter?
This means you can put more weight on the mount as long as you balance it enough with a counterweight
i always worry about tripod stability wihen there are no counterweights as the weight is to the front and side. is the tripod any different and this is not really a concern?
It's a good point, and yes you do need a good tripod - and ideally with one leg pointing to the Celestial Pole, so that tipping worries are alleviated!
Great info
My understanding is that a strain wave mount is simply an equatorial mount, no better or worse than a comparably well-constructed German equatorial mount. The only real advantage over a GEM is that for lighter loads the mount doesn't need counterweights, making it lighter and more portable than a GEM. But for larger payloads you still need weights (either counterweights or weights to hold the tripod in place) in order to prevent the rig from toppling over once the payload is off center or a strong wind comes along.
I don't understand the hype about strain wave mounts. They are superior for one particular niche (portable, small-payload rigs), but they're not going to revolutionize the hobby.
I take it you haven't used a SWG mount yet? If you had you wouldn't think that :) now that I've experienced these mounts (especially the WD20), I'll take a SWG mount over a GEM every time (except maybe an Astrophysics or 10Micron mounts :)) - they just perform more reliably in my experience, with very consistent guiding, no weird nights where the mount performs mysteriously, etc. Give me the choice between an HEQ5 and UMi 17 Lite (same price, same payload) - UMi 17 Lite for sure!
@@CuivTheLazyGeek Have you actually run a controlled test? Two comparably priced mounts (which should account for build quality) with the same payloads? Or are you remembering problems with GEMs of a different quality with heavier payloads? I smell a lot of confirmation bias in what you're saying. (I'm not saying SW mounts aren't good, just that for other than portability with small payloads they're not superior to GEMs.)
Yes! I've run CEM60 vs AM5 (cheaper) and WD20 (similar price) which I've run in parallel for a while. Since I came in as a skeptic of SWG mounts due to a prior bad experience as an early adopter of the Crux 140Tv SWG mount, I would have expected the confirmation bias to lean towards the CEM60 but it didn't.
I’m guessing the real payload for astrophotography is somewhere in the middle of the maximum payload instead of near 100% of the recommended payload (similar to the advice for traditional worm geared German equatorial mounts.
Actually no! I've found that the mount doesn't really care! You might go from 0.5" at the bottom of the range to something like 0.7" at the top in terms of guiding. When I switched from single barrel to double barrel scope on my WD20... Nothing at all change. Exactly the same performance. It's really impressive!
Loving the vids! :-) ps. Our should do a vid on the seestar vs. your 50mm dyi smart scope if you still have it.. :-D
Thank you! Oh the Seestar would trounce the DIY Smart Scope. It's just better AND cheaper... but you don't get the satisfaction of building it yourself
You absolutely CAN tell servos to move a certain amount, and to move to certain positions. That’s literally their forte.
That's the forte of steppers - servos will require an encoder for precise positioning afaik :)
Cost is the major deterrent currently. If they don't come down then meh
I honestly think it's getting better and better - the cheaper ones are getting towards $1,000, while being easier to use and guide. Give me the choice between a UMi 17 Lite and an HEQ5 (roughly same price), I'll go for the UMi every time
@@CuivTheLazyGeek unfortunately UMI 17 is unavailable in australia unless it's a private import, it becomes very expensive as the heQ5 is cheaper due to numbers available here
@17:55, try clicking on the Specifications tab and all will be revealed.
I believe direct drive means there is no gearing between the motor and the device your rotating.
I agree - but I don't see how it can be done, there has to be something, so for now I've given up on explaining that part
Direkt Drive means that the motor is coupled to start at full speed instead of accelerating
No, that is not the definition of "direct drive".
I am a happy owner of a UMi17.