Staff Assigned: Brian Brown AO-8a won't bump mount

Discussion in 'Guiding and Adaptive Optics - StarChaser and AO' started by mike m benjamin, Dec 17, 2019.

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  1. Doug

    Doug Staff Member

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    Okay we'll look into the calibration thing further.

    My usual technique for testing the bumping is to use the Guide tab Move function (make sure auto-expose is off!). I just nudge it in 1 second intervals until it hits the AO bump limit, and then watch it do its thing.

    Those temperature sensors are pretty bulletproof. Why do you think it is reading incorrectly? What temperature are you getting?
     
    Doug, Feb 12, 2020
    #41
  2. Colin Haig

    Colin Haig Staff Member

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    Could you give us a side photo so we can see which way the camera is relative to the filter wheel and AO unit?

    The SBIG Aluma cameras have TWO temperature sensors - one on the back of the image sensor inside the sealed chamber, and one on the heatsink to measure its operating temperature.
    Attaching a sample FITS file would help - both temperatures are in the Header.
     
    Colin Haig, Feb 12, 2020
    #42
  3. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Here's a quick test image I took tonight after Doug was finished up. Doug I noticed that when I start the cooler the initial temp reads around 10 C cooler than what my pegasus sensor reads and my house indoor/outdoor sensor reads. Tonight was about -2c actual and I have the cooler set for -35 and the cooler power was only around 43%
     

    Attached Files:

    mike m benjamin, Feb 12, 2020
    #43
  4. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Here's a side image.
     

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    mike m benjamin, Feb 12, 2020
    #44
  5. Doug

    Doug Staff Member

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    Oh, that's completely normal.

    First of all, the cooler power doesn't actually go all the way down to 0%. It will pull down 10C while at "idle".

    Secondly, the cooler is very powerful. It can get to -40C from 20C ambient. So it totally makes sense that it's only doing 43% at -35C from -2C ambient.
     
    Doug, Feb 12, 2020
    #45
  6. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Great, excellent to hear. I like easy fixes.
     
    mike m benjamin, Feb 12, 2020
    #46
  7. Doug

    Doug Staff Member

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    I put a lot of time and effort into getting the Aluma cooling system to do a 60C delta, without making the camera large and heavy. So it's tickled my funny bone that someone thought that temperature was a bug.

    I'll take the bug report as a compliment. ;)
     
    Doug, Feb 12, 2020
    #47
  8. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Lol, no problem. The cooler is at least as strong as the one in my old STT-8300 and the camera is definitely smaller.
     
    mike m benjamin, Feb 12, 2020
    #48
  9. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Just an update, I used my 12" F8 last night, no issues at all. Worked great, these AO's are the best invention ever, I just wish I could use them with all my gear!
     
    mike m benjamin, Feb 15, 2020
    #49
    Doug likes this.
  10. Doug

    Doug Staff Member

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    I've got something for you. It's a patched plug-in with an update to the mount calibration process. Could you give it a try?

    Unzip the attached. Move the original file out of the program folder (keep it just in case!) and copy the new DLL in place of it.

    I'd like you to try calibrating the mount with it, and see if it guides correctly afterwards.
     

    Attached Files:

    Doug, Feb 20, 2020
    #50
  11. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Doug, as long as the clear skies hold up tonight, after I am done with ic 434 for the night I was planning on changing focal lengths on my flt132 and add the AO, so I can try out the new plug in. So I am guessing you want me to undo the drive calibration settings you came up with- uncheck manual settings, reverse Y and swap motor axis?
     
    mike m benjamin, Feb 20, 2020
    #51
  12. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Hi Doug, just finished trying the new plug-in, it works fine. I used the same method as you to move the mount into a bump, tries both axis several times, no problem.
    I am have the occasional bug during download using the autosave, it will freeze during download intermittently. The word downloading will be stuck in the box on the expose tab. Stopping the camera appears to make it reset but trying to expose any image (single, continuous or autosave) will cause it to freeze again during download. I have to disconnect/reconnect to fix the issue.
     
    mike m benjamin, Feb 20, 2020
    #52
  13. Doug

    Doug Staff Member

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    Are you running the latest firmware and DLAPI?
     
    Doug, Feb 20, 2020
    #53
  14. mike m benjamin

    mike m benjamin Cyanogen Customer

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    I am running the latest firmware (20) I wasn't sure of the dlapi so I downloaded and installed the latest to be sure. I am running off some darks right now, so far no issues Doug.
     
    mike m benjamin, Feb 21, 2020
    #54
  15. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Doug, I think I know the cause of the download hanging, the ambient temperature. On Friday it was -15 to -18c, it hung up four times during the night. Saturday was -5 and tonight is -2, no hang ups on either night. Maybe wrapping the camera body with a dew heater on the real cold evenings perhaps?
     
    mike m benjamin, Feb 23, 2020
    #55
  16. Doug

    Doug Staff Member

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    The camera will not be bothered at all by -30C ambient.

    Are you using a USB hub? If so that is very likely the cause of the problem. Desktop hubs use cheap ceramic resonators that go off-frequency in the cold. You need an industrial-quality hub.
     
    Doug, Feb 24, 2020
    #56
  17. mike m benjamin

    mike m benjamin Cyanogen Customer

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    Doug I am using the supplied thru cabling already installed in the CEM120, the mount is rated to -10c so it's not surprising that some glitches may occur. I keep a couple dew heaters wrapped around the dec and ra motors to keep them functioning well in the cold but nothing can be done with the internal cables.
     
    mike m benjamin, Feb 24, 2020
    #57
  18. Colin Haig

    Colin Haig Staff Member

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    Connect the camera directly to the PC.
     
    Colin Haig, Feb 24, 2020
    #58
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