Moving to the ZWO AM5 Mount! - FRA400 Imaging Platform Version 2 0 Update:
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- Опубліковано 7 вер 2024
- This video is a companion video to my post on Cosgrove's Cosmos, which documents the update recently made to my Askar FRA400 Imaging Platform.
After using the IOptron CEm26 mount for the past year, I have decided to move to the New ZWO AM5 Mount and take advantage of some of the features enabled by Strain Wave Technology.
The post covers most aspects related to this change and can be seen here:
cosgrovescosmo...
Some of the reasons for leaving the CEM 26 and aspects of moving to the AM5 are also covered in my last imaging project - IC 1848 - The Soul Nebula.
The posting for that can be seen here:
cosgrovescosmo...
And the video for that project can be seen here:
• IC 1848 - The Soul Ne...
Thanks - let me know if you have any questions!
Pat
Great video! I just ordered my AM3 mount that will be dedicated to my Redcat51. You can do a front to back balance off of the mount. Just wire everything together and take the setup off of the mount. Put the vixen on the bottom of the telescope on a pencil and as you roll it over the pencil mark the point where the front and back are equal in weight. When you put the setup back onto the mount put the mark that's on the vixen in the center of the saddle.
Excellent suggestion! This is a great way to balance a complete OTA. Dangling wires also seem to play a role, but this would establish a very reasonable balance point for AM series mounts! Thanks for sharing this great idea!
Thanks! Just got the FRA400 myself and really like it. I think the mount is next on my list.
The FRA400 is a really solid little scope - I can't say enough positive things about my experience using it! You are going to love it!
@@cosgrovescosmos I just got first light last night. Wow. I really love it. 👍
@calimark7448 Enjoy!
That's same my dilemma... Thank You Your answer :)
btw Your Rig is now perfect 👌
Thank you - Glad I could help out! The FRA400/AM5 is a wonderful combo - to make it perfect, I would love to swap from the current 1600 camera to a 2600 camera - then it would be perfect! :-)
@@cosgrovescosmos I agree, with 2600 turn into absolutely perfect :)
Great video. My AM5 just arrived 2 days ago and I'm waiting for the weather to cooperate so I can give it a spin. One feature of the AM5 that you neglected to mention is that it can be configured to use in AltAz so, two mounts for the price of one!
Thanks so much, Paul!
Of course, you are right - the AM5 makes for a great Alt-Az mount! As an astrophotographer, that use has not been an interest to me, but I should have at least included that capability in my overview.
Thanks for making an excellent point!
All the best,
Pat
Thank you for a really excellent video. I have had an AM5 for about a month. I use it with several scopes with weights ranging form 3-12 lbs. I’m generally well pleased.
The only problems I’ve have had have been associated with the fact that the main part of the mount moves with the RA axis. I use an ASIAIR and was putting it on the side of the mount which caused cabling issues. Also the power I was supplying was insufficient to power the mount, ASIAIR and camera cooler. I have a 300 watt power station for it now.
I paid very close attention to how you do your cable management. Instructive.
Thanks again. Will be following from now on.
Hi Peter - thanks for your comment and kind words. Glad my materials could be of some help!
The cable aspect of the AM5 can be challenging - I hope in a future version, they move the cable plugs to a stationary part of the mount. I have already learned on my other platforms the importance of decent cable management, so this was not a big deal, but it could be better. But despite that, I a super happy with the mount.
All of the best,
Pat
@@cosgrovescosmos Thanks, Pat.
I took a look at your web page. The story of how you got the astrophysics refractor is priceless. Like a lottery win.
It really was! The opportunity to get the gear was really once in a lifetime. But I must say that the fellow I bought it from - and his wife - are really wonderful and very interesting people and my wife and I felt fortunate to meet them. We are still in touch. Sometimes things seem fated to happen! The AP 130 is now my most powerful and capable platform for galaxy work and going after finer detail!
I've had my AM5 since Christmas, and I've been very pleased with it. It integrates very well with the ZWO ecosystem (however you feel about that).
I have an SvBony 80mm refractor, ASIAir+, EAF, ASI178MC, OAG and ASI120MM-Mini, and I've just piggybacked an old Canon T3 DSLR as well. I made a mount from some aluminum angle to attach the ASIAir+ to the left side of the DEC plate, and coil up the excess cabling in the space between the AA+ and scope tube.
The AM5 isn't completely indifferent to balance. I found the balance point of the scope assembly over the handle of a wooden spoon on my kitchen counter, and it made a difference in the guiding accuracy. I had not seen consistent RMS errors below 0.5" until I did that.
I'm impressed with the stability of the beautifully-made carbon fiber tripod, and I like being able to rough-align the azimuth by just loosening the one clamping screw. I find that the 160mm pier extension provides an excellent handle, and really appreciate being able to one-hand my entire rig with the 300wh battery pack in the tripod sling.
I frequently get 2-pixel stars when the seeing is good, and I throw away very few frames. It's really satisfying, and has made observing a lot more fun.
Thanks for the comment. You are right - the AM5 is not impervious to balance issues - it just is significantly much more tolerant of misbalanced loads than a traditional equatorial. I would think that if your guiding is getting worse - you would want to make sure my balancing is reasonable.
All the best,
Pat
Thank you for your informative video.
Re balancing..I saw something presented by Cuiv the Lazy Geek for balancing an equatorial mount where he placed an amp meter in the motor power supply input and was able to balance the mount by balancing the power consumption of the motors... in other words the current draw needed to be the same which ever direction the mount travelled..both in RA and Dec..it would seem that such an approach could be employed to balance the ZWO AM 5... it may not need it but I expect with perfect balance it's performance would be better...You seem like the man to try it out. Thanks again.
Alex - that is an interesting idea.
On a worm gear, the load is all focused on a very few teeth -located at one position on the drive gear. The motor would have to strain to overcome the unbalanced load all at one point and in one direction.
However, on the AM5, we have 30% of the teeth engaged - BUT there equally distributed on both sides of the wave driver 180 degrees apart. Since it is on both sides, an unbalanced load would tend to pull one way on one set of teeth and the other on the set of teeth on the other side of the wave driver. With this arrangement, I am not sure the motor sees the same loads as a worm gear - and it may dilute the measure of power draw. But it is an interesting idea.
More than that, the software for my Powerbox Advanced plots out power draw from the supply so I could use the graphics from that app to directly measure things. I will have to try that out at some point.
The drive does not need precise balance - but to your point, having a good balance certainly should make things better - right?
Thanks for your comment!
CS,
Pat
Well I now have built a new pier for my new ZWO harmonic drive mount and have fitted it all ready to go however I have an old scope to go on this mount that requires cleaning the mirrors and a few little things and I have just started trying to fit the OAG, filter wheel, EAF, Camera..lost my old coma corrector and waiting on a new one coming tomorrow and I guess at some point I will try out the amp meter out of interest...but the balance in Dec will be spot on as I am doing the set up on an old EQ6 mount simply because I can move it around manually which is helpful when putting on everything.
I bought a counter weight rod and have a weight set aside...so...all good.
i Recently got a AM5 and ASIAIR Plus as a fast setup portable wider field imaging setup. it works fine although for higher magnification and multi filter LRGB and NB imaging i still prefer my AP 1100 mount and 6' APO refractor. That being said i have been very impressed with the AM5. At first I was concerned with cable management but it ended up not being an issue. Main thing i learned is to not attach the ASIAIR plus to the side of the mount. instead i attach it off the side of the upper dove tail. This eliminates all of the possibility of a cable snag. What ever setup you find works...run the telescope mount through ALL of the possible positions in the daylight looking for any chance of a snag. When i first got the mount I tried the ASIAIR on the lower side of the mount and one night found one position that did snag a cable and broke the connector....so yes the mount will have no problem breaking stuff if you run into obstacles. Rather than get the dedicated carbon fiber tripod i decided to try my existing ioptron heavy tripod and pier extension with it. The modification to use it was very simple and i can still use it with the ioptron tower pro. That is a very sturdy tripod. i was able to set it up so i can leave the pier extension on the tripod and the entire mount, scope,auto guide setup is one unit so takes me about 30 seconds to take out of my car and attach with three thumb screws. Like you i wanted the higher height to avoid the tripod leg. The scope is an Officina Stellare 80mm APO and focal reducer i have had for a few years that is superlative. i also have some some other scopes i will use with it....8' SCT HD hyperstar, and a couple of other refractors and a couple of camera lens also. Guiding is pretty good and the whole setup is rock solid. My friend has the same mount but with the lighter Red Cat scope which if you must have something you can put into a large case completely assembled is a nice setup. i am using a ASI 071 color camera and the ASI 290 camera for guiding. I am avoiding a mono camera and filter wheels setup as i am trying to get away from the additional complexity since i already have my AP and SBIG setup for that. i also do a lot of outreach so this setup will let me do fast auto stacking and/or video for public presentations.
Hi Robert,
Good advice! When I got my cable management done I did just what you suggested and adjusted the cables based on observations of the motions.
I opted for the carbon fiber tripod mostly because this will be my portable scope and I do set it up in the driveway each night of use. However I am planning on a 4-pier Roll-Off-Roof Observatory and when that gets built it be mounted on one of the 4 concrete piers when at home, and on the tripod for travel.
Finally - I agree having one OSC for outreach is a real advantage!
All the best,
Pat
Thanks very much, very helpful!
So glad you found it helpful!
Great looking rig you have and was wondering if you might consider discussing your power layout. I see you have a Pegasus astro power supply but what is the smaller gray item. I'd be thrilled to learn more about how you have your power distro laid out. Thank you for all your time and look forward to more videos from you.
Hi Gary!
Thanks for the comment! I have had a few questions on this, so at some point, I probably will do a video on it. In the meantime, you can get a general feel for my wiring approach with this article on my website:
cosgrovescosmos.com/astrogear/wiring-and-cable-managing-your-telescope-platform
The gray box is a small USB Hub. While the Powerbox Advanced has 4 USB slots, one of them is for a dedicated USB 3.0 cable - it cannot do 2.0/3.0 cables, and I needed more USB 2.0 plugs. So I bought this little USB Hub and that did the trick!
Thanks,
Pat
@cosgrovescosmos Thank you Pat!!!
Excellent video.
Glad you liked it! Thanks very much!
Hello, and thanks for the video. How is the tripod and pier working out? Is everything at a comfortable height to reach when setting up and/or adjusting things? I ask because presently I am using a star tracker for my astro and want to upgrade to a lightweight Go-To mount. I plan to use the ASI Air to control as much of the process as possible, especially doing PA. I have a bad back and knees and can't squat or bend over anymore :). I realize we don't want the rig to be too high up off the ground, but I need something that is light and a reasonable height off the ground. Thanks again!
You are most welcome!
The tripod and riser have worked out fine. I have a bad back and knees, and I am 6'6" tall - and it is not a problem for me so I would think it would work out fine for you as well!
All the best,
Pat
I loved your video.
Thank you so much for saying so!
All the best,
Pat
Nice video. Interesting to hear about your experience moving to the AM5. However, comparing the guide logs of a brand new AM5 and a CEM26 with known issues (as you describe) isn't really fair to the CEM26. While it does help explain your motivation for moving to a new mount, it might have been a good idea to also include a guide log when your CEM26 was new--or at least was in better form--so we can get an idea of how the guiding compares with the mounts operating at their best. Just a suggestion. Also, impressive AP images!
Thank you for your comments. I was not trying to bash the CEM26 so much as to share my experience when going from the previous mount situation to my new one. Unfortunately, I do not have logs from my initial experience with the CEM26. But I can say that even out of the box, the best tracking I got from the CEM26 was about 1.25. This is a large error but not noticeable in the images I made with it, as I was using a short focal length system. But at its best, it was 1.25, and my very first attempt with the AM5 was sub 0.4. In fact, the other night, I finally had clear skies and shot another target with the system - and was getting 0.26 track errs all night long! Very Impressive. Now, to be fair, the AM5 costs almost twice what the CEM26 does. And - I am far from done with my CEM26 - I will be using it in a future platform once again!
@@cosgrovescosmos Thanks for your reply. I understood your motivation, but someone might think that your CEM26 guide results represent a 'normal' result for that mount. I have no experience with the CEM26, but I assume it isn't that bad usually. However, it is interesting to see that your AM5 is doing much better than the CEM26 at its best. I am trying to decide between a CEM40 and an AM5, which is how I found your video. Obviously, the CEM40 is more capable than the CEM26, but I don't know if it can match 0.26 guiding. Still, something about harmonic drives gives me pause. There is always a learning curve with any new technology--or any technology applied to a different application. ZWO has already changed the gearing in the AM5, which I imagine was in response to issues they were having with the early units. I am also skeptical about the "no need to balance" claims (which may be related to the change in gearing since people probably ran the mounts too close to the point where a counterbalance shaft is needed). Mounts should always be balanced--or in the case of harmonic drive mounts 'ideally unbalanced' (which means unbalanced to some optimal degree, since harmonic drive mounts perform better with some unbalance). Excessive loading with small gear teeth could have caused failures, which may be why ZWO reduced the gearing (just a theory). I expect that in the future the mount will be able to evaluate the amount of unbalance and guide the operator to achieve ideal unbalance (similar to what iOptron did with some of their equatorial mounts in the past, although they were trying to achieve perfect balance, not ideal unbalance). They may even tell the operator when the counterbalance shaft is needed. There are some other things I like about the CEM40 vs. the AM5, but it is an older technology and probably will require more maintenance than the AM5--similar to what you saw with your CEM26. Another concern is using the AM5 for solar, since it is impossible to guide during the day without special (expensive) equipment. I suppose solar exposure times are short enough that the relatively large periodic error of the AM5 isn't a deal breaker, though. Have you used your AM5 for any solar photography?
It is certainly true that the AM5 and Wave Strain Technology are new to astrophotography (but not to other product domains). Moreover, ZWO is new to mount technology in general. So, given all of this, I think there is clearly a risk for early adopters.
I have always been an early adopter, and I am comfortable in that role.
I will also say that I am in no way taxing the AM5 with my load. I have seen folks putting some pretty hefty loads on the AM5, and I am not surprised that, in some cases, problems have arisen.
But my sense is that the Wave Strain is the future, and I like learning about it firsthand early on.
So far, I have been fortunate in that I have had no problems, and I am getting results that greatly outstrip my previous experience. I use two CEM60 mounts on my two large refractor platforms, and I love this mount. Very reliable and great performers for the price. But on their best day, I can get about .5 error on them, and the AM5 is coming at half of that.
As for your question about solar - no, I have not tried using the AM5 for solar - at this point, I am pretty much a deep-sky devotee!
Thanks,
Pat
After more thought I feel I should correct some of my comments. It is true that strain wave drives perform better when under some load, but I believe it is likely that there is a range of 'good unbalanced loads' rather than a single 'ideally unbalanced' load. This is not to say that the SW drives will not function under no load, but having the gears 'locked up' by some loading is better than a no load situation for consistent motion. The thing to avoid, of course, is overloading the SW drive which could lead to failure. In use on mounts the load on the RA drive will change as the telescope changes position: vertical loads will be minimal loads, and horizontal loads will be maximal loads, because the mount load is necessarily unbalanced. Indeed, there is no way to balance the load on existing mounts, other than trying to balance it off the mount and then reproducing the setup on the mount. I have read that some people do this (roughly), which may be a good idea because it reduces the maximum loading which reduces stress on components. However, it may also reduce the loading below the minimum 'good' load for a significant portion of the RA travel (rather than just when the load is close to it's highest point). It is worth noting that a simple weight specification for a mount is insufficient to determine the actual torque applied to the mount gears. Torque is force (load weight) x moment arm, which means that loads farther from the rotation axis exert more torque. So putting your guide scope on top of your telescope can mean it is farther from the RA rotation axis, which means it exerts more torque than you might expect. This is not a problem with normal EQ mounts because the load is balanced by counterweights (although the mass of the equipment plus the counterweights causes another type of load in the form of inertia). However, it could be an issue with strain wave mounts because the load is not balanced. If I owned a strain wave mount I would probably try to balance it somewhat, leaving it unbalanced by not by too much (assuming I could figure out what "too much" was). I wouldn't bother for a small refractor setup, of course, but for heavier rigs I would rather err on the 'less torque' side.
I follow your logic here, and it makes good sense. As you say, I think this plays out in the most extreme when folks are putting significant loads on with longer-length tubes that can really torque the system. While SW mounts do come with an optional shaft so that counterweights can be used, there is no good way to really balance the load since when the power is off, they apply a brake to the RA axis. Too bad there is no way to force the brake off, so the axis swings more freely, and you fine-tune the balance for a heavier load. This would make everything more robust. My use right now is with small-scope platforms, and I am not worried about this. But the performance has been so good that I have thought about someday shifting my larger scopes to an SW mount. I guess I am in no hurry, and I will watch how things evolve in this space before I do that, as my current mounts are meeting my needs for now.
This was very informative since I want to buy one next week. But I have one question, can the saddle be switched around to have the tighting knobs on the other side?
I have not tried this, but the saddle looks like it is held onto the mount by four bolts. Seems like you could remove those bolts, reverse the saddle, and then bolt the saddle back on. I could be wrong, but it seems doable. Can I ask why you would want to do this?
@@cosgrovescosmos I ask because it appears it can be switched and I use my left hand to tighten. My apartment is so small, I don’t have much space to the right side, so It would be so much easier for me to setup every time from the left side. Thanks for your quick reply.
@@southbronxny5727 Ahhh - I see now. Another thought. I tend to keep my small setup on the AM5 together all the time. It's light enough to carry it to where I would use it. If you were likely to use it in the same way, then you would only scope on it the first time, tighten it, and then leave it. If, on the other hand, you need to disassemble the rig each time, I can see why you would want to rotate the saddle.
You explained things very well. Which guiding system and guiding exposure time do you use? In which bortle area are you located?
Thank you!
I a using PHD2 on a laptop for guiding - with a 50mm Williams Optics Guide scope and an ASI290 Mini Guide camera. I use a 1.0-second guide exposure time, much shorter than what I use on other rigs, and this seemed to work well for me.
My skies are Bortle 5.
All the best,
Pat
Great video Cosmo. I have heard the AM5 can't do meridian flips. Is this true?
Hi Craig - thanks much!
Most mounts allow you to move some number of minutes past the meridian and, at some point, force a meridian flip. Usually, you set your control software to do the meridian flip at a point BEFORE the mount forces the flip. That way - if your commanded flip fails for some odd reason, the mount-driven flip will kick in, and you don't have to worry about gear crashes.
The default AM5 procedure is to get to the meridian and STOP. I guess that prevents a gear crash, but it is odd behavior for a mount.
I had only one clear night to test before the MONTHS of cloudy winter weather descended upon me - but what I did was set things up to call for a meridian flip just before the meridian rather the 5 minutes after the meridian as I would normally do. That seemed to work fine for me.
Having said that, I understand that there is a version of the AM5 driver and mount firmware now available that changes the mount behavior and lets it go beyond the meridian for a number of minutes, so you can call for the meridian flip like you would with any other mount. I have not yet had a chance to test this.
Thanks! Regarding the wobble in the iOptron mount: I have had a similar problem; I solved it somehow; I think the locking screws had become loose -- there are two sets of screws, one with a lever, the other with a hex wrench. In any case, an AM5 may be in my future -- thanks for the excellent coverage. I am especially happy about the little pier :-) One question, though -- the tripod legs don't seem to expand very wide, and in some positions, the whole setup looks perilously close to being blown over by a strong gust. Any thoughts on that?
Thanks much for posting the comment! I'm gald you found it useful!
I'll be digging into the CEM26 issue soon - I thought others would have encountered the same issue by now- and it sounds like you have run into this as well!
You are correct to be concerned about tip-over on the TC40 tripod. Others have had an issue with larger scope arrangements - especially with longer scopes. A fabric "shelf" comes with the tripod that attaches to the legs and hangs below the scope - ZWO recommends that you add weight to this to make things more stable. I have seen some people use exercise weights in this, and others put their off-site battery packs there - as they tend to be heavy.
For myself and the scope I am using - things seem quite stable. I have tried it in many positions, and I am confident that I have zero risk of tip-over.
If I were going to put a heavier or longer scope on it, I would NOT use the TC40. Instead, I would use one of the Tri-Piers that are out there. They are more heavy-duty and can provide better support for a heavier or leveraged load.
I can't understand why they positioned the power inlet and the USB connection at the front. That's the reason I haven't bought it.
Agreed - it was not the best choice in my mind either. After my extensive experience (like one whole night), it seems that my cable management is handling things...
Would you that the am5 mount could also serve as a good visual mount as well.
Yes - I think it would work just fine in that application!
I have an AM5 and generally use it on lighter scopes. How do you think it will handle my FRA500?
I think it will do just fine. Depending on the weight, you might need to go to a counterweight, but I highly doubt it. I have seen people putting HUGE scopes on these drives and getting good results. Best of luck!