ZWO Fan Vibration and Elongated Stars - Analysis and Measurement
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- เผยแพร่เมื่อ 31 พ.ค. 2024
- I took your advice and checked out the vibration produced by the ZWO ASI194MC fan and the possibility that is responsible for the elongated stars I was seeing. When I'm not doing astrophotography during the night, I'm doing vibration measurement and analysis during the day. So I took a small accelerometer and measured the vibration. Wow! That's a lot of vibration! Sure looks like fan vibration was my problem. Thank goodness it was not a broken primary mirror. Whew!
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James, you're winning man. You had me at accelerometer. Impressive level of testing to root cause and quantify. Glad you resolved it. Cheers
Thanks, Gerry! Who doesn’t love accelerometers? Hope this works for a while…
That star streak problem drove me nuts for a very long time. I was on the verge of buying a new mount when I accidentally ran across a CNC thread discussing the issue. Your analysis gave a much needed explanation of what is occurring. Very glad it solved your problem !
Amazing how many stupid little things can screw up a night of imaging…but that’s the hobby we picked. Thanks for watching!
Wow, This analysis is excellent. I was looking in to this issue myself and concluded for me it’s not the fan that is an issue. Love the extensive job you have done with proper vibration sensing equipment. Well done, you have really helped the community!
Thanks, Bengt! Amazing what we have to go through to take a picture of the night sky. Hope you track down your issue.
Best analysis I've seen for this problem which I learned about six months ago - thanks so much James!
Thanks, Peter! And thanks for watching!
I had this problem a few years ago with my ASI178MM-Cooled camera. I struggled for at leased a month of troubleshooting trying to figure it out. Then I found a post on a forum of someone that had the same shaped stars that I was getting who suspected the fan was the cause. I then pointed my scope to the zenith and took very short 0.25 second exposures, with tracking on and the fan on and then off. The difference was night and day. Pinpoint stars again with the fan off, as you can imagine I was overjoyed with this. When the fan was on, I put my finger on the camera housing and I could definitely feel some vibration. I bought a zero vibration fan on amazon and replaced it. I then recalled when I was around the scope a week or so before the problem, a bug or something got chewed up in the fan. It rattled around in the fan for a few seconds then dropped out of it. It had returned to its normal operating sound so I didn't think anything of it at the time.
This hobby…
Great to hear that the stars are back round again.
Somehow astrophotos look better with round stars. Who knew? Thanks for watching, Logan!
I also had the “fan streaking stars” in my ASI533. Decided to use these isolators with a straight new replacement ZWO fan. Job done. No streaking.
This is an irritating and sufficiently widespread problem. Would be nice if ZWO would take this seriously in their fan attachment.
Thanks for this video. I bought an AM3 and 2600mm during the winter sale but ever since I've been going crazy trying to figure out what is causing trailed stars even when guiding is exceptional. I've bought a new guidescope, new guide cam, new cable management, new mounting solutions and nothing fixed it. Last night I turned off the cooler after seeing this video and sure enough, that was it. New fan ordered.
Glad it helped. What focal length are you imaging at?
Just 500mm (740mm after crop factor). I've been using a nikon 500mm f4. I suspect that the ZWO adapter having a tiny little bit of play in it is the weak spot that is picking up the fan vibrations. Ran the test 2 times and both times the stars round up nicely with the fan off.
@@Aero19612
Wow! That’s very scientifically robust - thanks for sharing
Thanks for watching!
I love how James' "back of the napkin" formulae and "cartoon" drawings are worthy of college-level engineering classes :D. Excellent work as usual, and glad you were able to solve your elongated stars issue for less than the cost of dinner and a movie.
Well, not less than a dinner and a movie. I’m a cheap date! Thanks for watching!
Amazing! Who’d a thunk? Great job. Thank you.
Hi Bob. Who’d a thunk it? Not me! I had to be told about the problem by the viewers. Hurts to miss that one. Thanks for watching!
Excellent analysis. I'm glad I subscribed to your very informative channel
Thanks! And thanks for the sub.
What about 3D printing a spacer (between back plate and camera body) to provide more room for isolaters? I do like the iidea of lower fan speeds. I went with a Noctua fan as well as the isolaters. Now if the weather will break.
Yes, I think a spacer, maybe 4 mm, might do the trick. I just bought a Noctua fan (hasn’t arrived yet). Not planning on installing it unless this new fan has issues, but I am interested in testing it to see if it is truly different from a vibration perspective. Thanks for watching!
Nice analysis James.......glad it worked for you and you got your imaging improvements.
Thanks, Dave! Cheaper than send the OTA to Celestron. I’ll take my “W” and quietly walk off the stage.
As John 'Hannibal' Smith said, "Love it when a plan comes together." 🙂 Interesting analysis and solution.
But sometimes it’s better to just be lucky… thanks for watching!
Ser. you are a university of information!!! excellent information Thank you for the info I will be testing my sct8" to see if I can improve my stars 👍🏻
Haha. And the source of many problems… Good luck with those stars!
You and I do WAYYY different math on the back of our napkins! :) As always, thanks for the awesome insight!
Haha! Maybe you’re buying the wrong kind of napkins? Thanks for watching!
Well done!
Thanks for watching, Tim!
This was very timely. I got a brand new NYX-101 mount and I've waited over a month to test it. Had a clear night a few days ago but.... I live in Phoenix and the current night time temps are still over 100. When I tried my first light I had a number of issues. Nothing major and 90% of it were my fault but I noticed that my subs had egg shaped stars across the entire FOV. I knew I would get them in the far corners because my OTA is not flat there. What surprised me was the bad stars in the center of the FOV. Now I remember looking at NINA and my camera fan was running at 100% and my cooling was running at close to that to maintain a temp of 0C. Yea..... I was most likely shaking the daylights out of my optical path as you have demonstrated. Thanks much!
Hey Phil. Congrats on the new mount and finally getting a chance to use it! One note: the camera fan runs at a constant speed regardless of the cooling %. Anytime the cooler is running, whether 100% or 10%, you'll have the same streaked stars until you replace the fan. Bummer. Thanks for watching!
@@Aero19612 Hmm ok interesting. Then it must be related to something else. I got excellent images about 2 months ago with the exact same OTA on my EQ6R of M16. I have to wait for this oppressive heat to break so I can spend some quality time looking into it. At the moment I look like the guy piloting the plane in the movie Airplane sweating profusely everywhere. Not fun.
@@PhilFXPhoenix Can still be the fan. Given the range of motion caused by my fan, I would have expected to see stretched stars with the focal reducer. I didn't. So, did the fan "go bad" between the last image with the focal reducer and the first attempt without the focal reducer? Sounds coincidental, but possible. Next time it's < 100F, try taking images with the fan off, then repeat with the fan on. If you see the same artifacts with the fan off, then you know it's not the fan. Also try very short exposures, with fan off and the mount parked. Stay cool!
Great analysis. Love the level of your channel -- quite unique among astrophotography channels. I also had a fan vibration issue, which I first really noticed after I saw squiggly satellite trails. Turning off the fan, they went straight. I've installed the isolators you have, and that has reduce, but not eliminated the problem. I guess I need to order a new fan. (Equipment: SCT- HD11, ASI2400mc-pro (full frame) )
I’ve seen those wavy satellite trails with another camera, maybe my ASI1600. Looks like the next step is to develop a plug-and-play vibration isolation “holder” for the fan (or cut down the RPM to the minimum required rate). Thanks for watching!
Thank you!
Haha. You’re Welcome! Thanks for watching! It hurt you more than it did me.
@@Aero19612 Hardly. I just set the video to 1/4 speed and watch a half a dozen times!
Playing at 4x speed is funnier and cuts the watch time by 16x. More time for imaging…
Good news that you were able to solve the problem. Several months ago I changed the fan on my ASI 533MC because I started seeing a similar problem using my Meade SCT 10". I used a Noctua NF-A4x10 Premium Quiet Fan 40x10mm that came with the silicones included. All for only $15.🙂
I ordered one of those fans too. Not here yet, but I do want to test it…and have it as a backup if/when this new fan goes bad.
Very good and informative video. I have bought a used ASI294MC Pro and the first things I did was change the fan to a noctua one with the rubber stand-offs. I did this because the fan made weird rattling noises (It was a larger insect that got stuck in the fan). The noctua fan is just great quality and very silent.
I bought one of those fans to test (hasn’t arrived yet). Thanks for watching?
Excellent video. One thing I'm confused about is if this effect was caused by a fan rotational imbalance causing flexure in the adapter tube, you would expect a circular blurring of the stars, not streaks. The thing that's not symmetric is the weight of the camera putting a pre-load on the adapter tube. Did you still get streaks when pointed near the zenith?
Totally agree about streaks vs circular blur. That’s a limitation of back-of-the-envelope calculations - they greatly simply the problem (otherwise you’d need a lot more than one envelope). I suppose the streak geometry could develop if you had a “bump” at one location in the fan outer boundary that the impeller hits at each cycle. The night that I discovered the streaks, I pointed several directions, but not at zenith. I’ve used that setup for years with no issues. That was the first time to use it with that camera at that focal length. I’ll likely never fully understand this issue.
What a great video. Once it cools off down here in the south, i look forward to doing some testing on my own asi294mc pro and asi1600mm. Ive had some issues with seemingly random star elongation. Itd be great to be able solve it with just a new fan.
Ridiculously hot. Yes, I was quite pleased to get off by simply installing a new fan compared with what I thought I was going to have to do. Random problems are the worst. Check you USB cables to the mount and guide camera. Good luck!
Brilliant! You are a super sleuth. I'll have to check my star shape with and without cooling. Thanks.
Hey Bob. Definitely try the fan off/fan on test. Easy to do. Thanks for watching!
Great video, waiting video about reducer backfocus on sct
Yes sir! It's on the list. I may do my video on the evaluation of the Antlia DualBand filter with the C9.25+focal reducer. That's where I'll show the stretched stars and then need to make changes. The next video will address those changes to the backfocus and the adapters I used.
Great analysis thank you for your work and for sharing it. I think your extra step for longer focal length isolations could be to shave down the thickness of those isolators, rather than sever the connection for three of the four. Make the isolators thinner, floppier, weaker, and I think you’ll gain the flexibility you want.
Absolutely. Shaving the down the isolators could work.
Hi James . It is a 12vdc fan correct ? Maybe try a simple DC Speed controller to reduce fan speed a little . Of course this would mean some testing of the cooling the Peltier would produce at various heat removal volumes as caused by slower fan speeds . Might be an interesting project . Thanks for keeping us involved ./srk
Yep. You’d have to try a lower spin rate and monitor the sensor temp to see if the fan could maintain the set temp. Then lower the spin rate and test again, etc. I can’t believe 5,700 rpm is the minimum required. Definitely an interesting project, Scott.
Great video and method, I can imagine how frustrating this can be for folks that don't have access to analytical equipment or knowledge about vibrations. Fingers crossed my touptek doesn't suffer from the same issue as I haven't had a chance for first light yet.
Haha, that’s also frustrating: get new equipment and can’t use it. Good luck and stay patient!
Time to grab my HP3561 and do the same, cause I have similar stars. Now I know it's not guiding most likely. Thanks James.
Good luck!
Very interesting analysis, impressive work. I was wondering if you had a 3rd harmonic resonance to give you the extra amplitude?
Probably not a resonance. I made lots of assumptions and guessed at a lot of numbers, so I’m guessing that’s why there is a difference in predicted response. Thanks for watching!
Great analysis. Is this a common problem with all ASI Pro cooled cameras? I'm looking for my first Pro camera for my C8. Thanks
Seems to be common when cameras are used at high focal length, say > 1000 mm. The problem isn't the camera per se; it's the cheap fan they use and attached with no vibration isolation.
Could this be a particular production run of these cameras? I have the 294MC Pro on a 10" SCT and EQ6R-Pro mount, zero issues with my imaging.
Hey Dennis,
If anything, it may be a bad batch of fans - maybe that’s what you meant. The cameras are fine. And the “bad” fans are probably not an issue for shorter focal lengths. Keep an eye on your images. You’ll know how to quickly fix it. Maybe even consider getting a replacement fan for “just in case.” Thanks for watching!
@James
Try to lubricate fun or clean it
I try lubricant oil for electric fan with my zwo asi183pro
That’s a good idea. I’ll look into it. Thanks!
James, I never could get round stars with my 8" Edge HD. Got a bigger mount, larger guide scope, etc. I had noticed satellite trails that looked like a high freq sine wave,, perhaps servo? Then I heard of the fan issue with asi2600 cameras. I could feel vibration in the scope!
Yes. I saw those wavy satellite trails too. I didn't occur to me that was caused by the fan.
Impressive work! You should work for ZWO or one of their competitors!
Haha. I feel like I do work for ZWO - just an unpaid position.
Hi James. What do you think about isolating the entire back plate? The fan vibration has to be first transferred to the back plate then through the plate to the rest of the system. If there isn't enough room to isolate the fan perhaps there is more room for the while plate?
That would work in principle. On the practical side, we have to plug in a power cable and a USB cable through the openings in the back plate that will not allow for the free movement of the plate which is required for vibration isolation. I’m working on a 3D printed part concept that would provide isolation. I’ve got nothing but clouds in front of me so maybe I’ll make some progress on that front. Famous last words
I'm always amazed at your math skills. I love your videos. What was impact on the cooling ability of the fan by changing the aerodynamics of the original design?
I’ve been blessed with clouds since I swapped fans. I really didn’t change the aerodynamics, just got a version of the same fan that’s put together better. Will be interesting to see if these fans wear out and start to produce more vibration over time.
James do you have a link to the fan you replaced yours with?
The fan I replaced in the ASI294MC is the same make and model that ZWO used:
agenaastro.com/zwo-fan-for-cool-pro-camera.html
Some people are using a Noctua fan as a replacement, but it requires that you modify the power leads. From Amazon:
"Noctua NF-A4x10 FLX, Premium Quiet Fan, 3-Pin (40x10mm, Brown)"
are there any cheap accelerometers you recommend? I'm having the same issue and would love to test different mitigation techniques...
Not sure of any; however, your cell phone has an accelerometer in it. Do a search for apps that let you see the acceleration and save it to a file.
@@Aero19612 thank you...
Excellent video! I dont know if this problem exists for the 2600mm but my fan is really dirty. Is there video on just cleaning it? Disassembly instructions?
The 2600 uses a larger fan but it’s made by the same company, so I suspect some 2600 users are experiencing this problem. As for disassembly, do a TH-cam search for “ZWO fan” and you’ll get a list of videos that will demonstrate taking it apart. Thanks for watching!
apart from the maths which made no sense to me, the video was an excellent analysis of the problem, What you should add is what brand and where you can get the better fan and if you made any modifications to this fan
Don’t worry about the math - most people don’t care about that sort of thing. The fan is the same one that’s in the camera and is sold by ZWO and also carried by Agena AstroProducts (and other Astro product sellersA) - nothing special. Just taking my chances that I had a “bad” fan. Thanks for watching.
I had a fan vibration issue in the past too with a QHY camera, I eventually solved it by replacing the fan with a more expensive maglev type. I noticed this same problem when the camera was attached to my 9.25” SCT but at FR focal length. I narrowed it down by turning off mount tracking and just capturing star trails, the resulting trails were zig-zag in shape. After the fan upgrade I had perfect stars at FR focal length, I don’t image deep sky at native focal length though so I cannot attest to the fix being good there.
Interesting. Does QHY mount the fan the same way ZWO does: screwed to the back of the camera? Or do they have a legit vibration isolation system? Not sure why I didn't see this effect at 1318 mm. The length of the streak should have been obvious at that focal length as well. Thanks for watching!
@@Aero19612 the fan was mounted ‘self tapping screws’ to the back of the heatsink for the sensor via some quite poor rubber grommets, I replaced these too with more suitable ones when fitting the new fan.
The zig zag pattern was extremely visible in long bright satellite trails.
Perhaps the vibrations in my QHY were more than you were getting hence why mine showed up at FR focal length. 🙂
Thanks for the info on the QHY mounting method. Good luck!
@@Aero19612 just found another video from Robservatory on TH-cam - Fix the ZWO fan vibration issues. Same issue as yours, worth a watch.
Great video! What about 3D printing a tube shaped adapter that would allow us to run the fan on the outside of the camera, which would then allow you to run very thick isolators?
Thanks for watching. I am exploring 3D printing options where the plastic is acting like a spring to provide vibration isolation....we'll see
@@Aero19612 that’s a good idea. I just tested my 2600MM and my FWHM jumps 1.5” fan on vs off so I’m in the same boat. I’ll post an update if I print anything that ends up being helpful.
Great analysis. I had the same issue and came to exactly the same result. Im curious if you noticed if your satellite trails were wavey? I used this to calculate the frequency of the vibration (mine was quite extreme)
I have noticed wavy satellite trails in the past. It may not be possible to calculate the vibration frequency that way unless the satellite trail starts and ends in the single frame. Otherwise you don’t know when during the exposure that the satellite entered and exited the frame. Thanks for watching!
Great analysis James. I am on board with the induced vibration theory but according to this armchair engineer the radial accelerations should induce a near circular precession in the tube (coz gravity). To get football shaped stars would seem to indicate a single axis of oscillation and to go all the way with a solution would require locating and fixing the weakness in the setup. Can you re-arrange the stack up order? . Looking forward to your final conclusion and solution.
Hey Rob. Total agree. Why a streak vs a circular bloat. The simple insight you get from the back of an envelope cannot provide the answer, just an order of magnitude assessment of whether it’s a legit concern. I don’t think there’s much value in playing with the adapter stack-up - just not enough options. The OAG goes where it does and the filter drawer goes where it does and you’re left filling in the gaps. I need a one size fits all proper vibration isolation holder or find a reduced RPM that still works for thermal. No, the end of the story is not written. Thanks for watching!
Great work James. Do you have a link to the new fan?
The fan is the same make and model used in the ASI294s and probably the ASI1600 and ASI533. Look up the ZWO fan on Agena Astro (there’s a different model for the larger format sensors like the ASI2600 and ASI6200)
Could you put the fan on the outside of the case and use ducting to get the air flow to the fins? This would allow more of the isolators length.
That’s a good idea. I’m trying to dream up a 3D printed part that could hold the fan inside and still allow the motion required for vibration isolation. Thanks for watching!
James. Great work. we have chatted before. I have a similar scope setup ( SCT 9.25, Celestron OAG, Celestron Focuser) but mine is using a ZWO ASI2400 MC pro camera and a RST135 mount. So far I seem to be ok with imaging at Full FL 2340, but will be keeping an eye on my star shape in case the fan develops issues.
An idea for those of us without acccel equipment. For vib detection, I wonder if one could use a plastic shot glass with liquid and mount it on camera with modeling clay. Not precision but maybe good indicator on how smooth or rough? Take care
Hey Steve,
You could, but that doesn't quantify the vibration level. You might just be able to "see" the vibration. And then there's the risk of spilling your "accelerometer" in your camera. Try using your cell phone - it has a 3-axis accelerometer in it. There are apps that let you tap into the accel and provide real-time plots.
Hey. I didn’t say to be sampling a certain alcohol liquid before using the shot glass.😅 just using it as a rough indicator. I figure If you don’t see any ripples when fan turns on then probably no fan issues. I know, not an exacting measurement, but quick and easy. I guess could also use stethoscope for rough check….. (retired Mechanical Engineer) . Take care
What mount are you using with the SCT?
I’ve got a Sky-Watcher EQ6-R. I like the mount. Works about as well as can be expected without encoders.
The ASI2600MC Pro has a larger fan. It uses a 50x50x10mm fan vs. 40x40x10mm fan in the ASI294MC Pro. There also is much more room (thickness) to work with. I replaced my fan with a 15mm thick Gelid Silent5 fan. that actually pushed more airflow with less RPM and less noise and also added the Noctua isolators. Works great. But I had to solder the connector onto the fan lead. I think there is over 20mm of thickness to work with, so more room for isolators if you use stock fan. Noctua does make 40x40x10mm fans, but no 50mm fans.
Thanks, Dale. I ordered one of those Noctua fans to play with. I suspect this won’t be the last video on fans and/or vibration.
@@Aero19612 My first ASI2600MC Pro, back in June of 2020, had a bad fan out of the box. I had stars that looked like grains of rice. I quickly determined that it was the fan due to me being able to see the stars elongate in real time while zoomed in and focusing (with or without a Bahtinov mask) when I turned the fan on and off. I took a video of it and sent it to ZWO and they replaced the camera with a new one, which didn't have the issue. I've since replaced the fan on that one with my one I mention above. I bought a number of fans and chose the one I liked the best. Back in 2020, I initially bought a Noctua 40mm fan to fix myself before I sent it back to ZWO, but realized only when I opened up the camera that the fan size doesn't match and they didn't sell the larger replacement fans at that time like they do now. I'm glad to see you solved your problem, but really liked the way you analyzed the problem with sensors and engineering, so now we all have more information on how to deal with this better. I wonder if the DUOs have a better fan mounting method?
@dalehollenbaugh6084 I doubt the Duo has any different fan mounting method. If ZWO is going to blindly send out new cameras because a $10 fan is causing too much vibration, they should seriously look into a cheap/effective vibration isolation system.
Information video. I wonder if a maglev fan would make any difference if you can get one to fit.
Turns out Sunon do. If I have the problem I might try one.
I definitely applaud your efforts. The engineer in me is screaming "YES, that's exactly how I test"! I have to ask though... did you test the fan on vs. fan off performance before going through all the extra steps? I don't have the fancy vibration tools you have but I did use an accelerometer app on my phone a couple months ago when this vibration issue was blowing up in the AP circles. I attached the phone to the camera and captured the data and exported the file. It was pretty high rate, I think over 100Hz. I saw no appreciable evidence of an issue with my 183MC-P or my 294MM.
We had a long string of clear nights with no Moon, so I spent that quality time imaging with the ED102/ASI1600 at night and this vibration testing during the day. Just before the clouds moved in, I put the C9.25 outside to test the replacement fan. A cell phone accel should pick up the “bad” vibration. Not sure what % of fans are “bad”. Based on my empirical low-sample statistics (i.e., 3 samples), it’s about 30%.
I have a n ASI 071 OSC cooled camera that i tested. No issues but as preventative I decided to put in the latex stand offs. I tested before and after with my Vibrometer and frankly in both cases it was no difference . I have seen no evidence in m long focal length images either. Being curious I decided to test and measure the vibration on my other cameras....an SBIG STL 6303e huge camera with a nearly full 35mm chip size. It has a motorized internal filter wheel for 2" filters. After opening the case for the SBIG I discovered that the fan was the exact same size, brand and model of the one in the ASI 071! I have a few friends and when they checked their ASI camera there was no evidence of an issue and a couple of them are imaging with 2800mm focal length SCTs for high magnification imaging. I use refractors from 80mm to 152mm aperture and focal length of up to 1200mm. I also image with my 11" SCT and sometimes a 14" SCT so if I had any vibration issues it would be evident.
So I suspect this isn't a big issue although could be found on other cameras also. I researched fans and found that they are quite cheap so if it was an issue it might be faster to just change out the fan. I also noted the wire from the motor runs pretty close to the cooling radiator array and I made a point of making sure that wires were away from any area that it could transmit vibration. One thing I did note on the SBIG.....it was an older camera (around 2007 or so)... there was some minor dust buildup on the fan blades. I used a small paint brush to brush that dust off and looked for any chips on the fan blades...there were none. I can see how any dust buildup could cause an out of balance harmonic. That SBIG has had no vibration issues either up to 2800mm focal length but in both it and the 071 ZWO there was a tiny but negligible vibration picked up by the Vibrometer but it was so low to be of no consequence. I also have an ATIK one shot cooled camera and it had NO detectable vibration.
This drove me nuts. Almost got rid of my C11.
Yep. Nice to know that a $3,000 telescope can be brought to its knees by a $10 fan. Thanks for watching!
Toroidal fans are all the rage now. Would they have lower vibration? Would you be able to run them at lower speeds?
Interesting. I’ll have to look into those! Thanks!
put a resistor inline to reduce fan speed ( sucess on risingcam 571) and i wonder about the future of piezoelectric computer fans in small devices
That’s a good idea - I’ll look into it. I just saw something on the piezoelectric fans. Interesting.
To support my hobby I have a drone business. Drones have damping systems to keep the camera smooth while the props shake the drone. When I saw you post this I thought about how well a similar system would work - something as simple as rubber grommets. Your work seems to suggest that the original fan was not balanced - aircraft have a similar concern for balanced props. If you had a system like A-P shops or even Discount Tires does to locate the imbalance point it would seem a bit of shaving of the impeller in the right spot would work too.
Hey Shawn. Grommets won’t work here. Your drone camera isn’t imaging at 2300 mm so vibration isn’t as big a deal. For the telescope application, we need a legit vibration isolation system with a lot of flexibility and minimal damping. The grommets are fairly stiff and have lots of damping. Haha. I would love to see the look on Discount Tire faces when I ask them to balance a 40 mm diameter “tire” that spins at 5,700 RPM. Find the right spot to shave is very problematic. Thanks for watching!
Thanks for the explanation. My suggestion on the balancing of the fan was me thinking that there must be some device for smaller engineering devices or at least a device that would test and determine the more evenly balanced fans. Of course, they may be so cheap as to preclude such and endeavor.@@Aero19612
Right. In effect, that's what the accelerometer does. Better balance = lower vibration. I need to come up with some vibration isolation support for the fan. Will have to think about that... Wish I had a 3-D printer. I could probably make a $ or two
People are putting them to good use. But you would still need to test the balance of the end product.@@Aero19612
So why is this just a ZWO phenomenon, are they just using poorer quality fans than everyone else, or are their camera body frames too thin/low mass?
I'm not sure if it's just a ZWO issue. Maybe it is. Or maybe 10x more people have ZWO cameras vs QHY. And there could be a fan vibration isolation designed into other cameras. There certainly isn't one in the ZWO cameras. There also appears to be significant fan-to-fan variability in the Sunon fans that ZWO uses.
Are there particular reasons that you are sticking with ZWO cameras and filter wheels?
Why not to get QHY or Moravian cambos? Their prices little bit higher, but quality you get in return is by miles better.
I fought these battles, made transition to non-ZWO world. Improvement is in every aspect: cleaner background due to calibration, FWHM is always
The filter wheel works fine - no problems there. I like the ZWO cameras I have. They could/should have put more thought into the fan support to prevent vibration transmission. Oh well. There are solutions for that. I certainly would not buy a whole new camera because of the $10 fan.
@@Aero19612 It is not only fan problem. I had 294mm and 294mc. One day, it calibrated fine; another day, as bad as it gets. It ruined a lot of image-hours. Filter wheel was rubbish as well. ZWO advised “spin it in one direction only, otherwise, we cannot guarantee accuracy “.
Just great. Finally, I had enough. Got rid of every ZWO I had. Their resale value is quite high.
I'll keep an eye on my ZWO equipment and see how it behaves. Other than this fan issue, I've been pretty happy. As you say, things can change.
Kinda of the long way around changing out a bad fan eh…
Astrophotography is a long way around to have a picture of M 81, but we do it anyway. You can “assume” a fan is bad and “assume” that a replacement fan is better and then go outside at night to see if you’re correct. When possible, I prefer to measure and know the fan is 5x worse than another fan and measure and know the new fan is 5x better than the old fan. But, I agree, assuming requires less effort than knowing. Just not my style.
My brain hurts…….
Impressive info.
When in doubt don’t buy ZWO, be it fan vibration or oil leaks.
My brain hurts too. I think ZWO has good products. But they also expanded their product line very quickly and may have lost some quality control in the process. My hope is they’ll get it together. Thanks for watching!