CCDops and STi calibration problem

Discussion in 'Specialty Cameras SG-4, AllSky, ST-I' started by Wilfrid Ouellet, May 6, 2015.

  1. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

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    I have a STi mounted on Orion ST80CFT with 2in diagonal on G11 Losmandy with Gemini 2. Main telescope is VRC10 Mallincam. I am new to astronomy but my friend working with me has more then 25 years experience, using the same guidance setup (except he has a Titan mount) and we can not find the problem.

    When we try to calibrate, CCDops deactivate Y+ and Y- relays every time. We have tried new cables, another STi camera, another computer, Windows XP, Windows 7, worm gears adjustments .Parameters in Gemini 2 are the same on both mounts. My graph result is a straight line instead of a X and I have zeros on Y- and Y+.
    Calibration.jpg

    What else could we do? Is it software or hardware issue?
     
  2. Tim Puckett

    Tim Puckett Guest

    Wilfrid,

    Are you sure the DEC motor is actually working? is the Dec Motor to Worm Coupling tight?
    Doug might have a solution but I am thinking mechanical.

    You can always call me if you need help to debug it by phone or team viewer.

    Regards
    Tim
     
  3. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

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    The DEC motor is working properly when use with the Gemini, I have not check if it is working when calibration is in action with CCDops.
    The other thing could be the R.A. imbalance propose by Losmandy, my mount is perfectly balance so I should maybe unbalance as propose. We also think that the R.A. movement is not as smooth as the DEC movement when clutches are release. I want to lubricate the R.A. shaft so it move absolutly free without any restriction. It could be as simple as this but I will wait for others suggestions ... if any.

    Tks Tim.
     
  4. Doug

    Doug Staff Member

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    Most likely suspect is the tracking interface cable. I know you say you replaced it, but it really is the obvious candidate. So please double-check it.

    Also check the connectors they plug into. I've occasionally seen a defective RJ-11 cable damage the connector it plugged into - all it has to do is push one of those little wires out of its slot and it won't connect properly. If this happened you can usually "repair" the socket using a pair of tweezers (carefully!).
     
  5. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

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    Thank you all, but all cables we verified and we did tried another RJ11 cable just in case. Fortunately I went through disassembling my G11 mount to see if bearings and gears were alright and I found out that my RA worm gears were assemble a little bit to tight. I was difficult to turn the gears with mi fingers while the DEC gears were easily turning. I re-adjusted them slightly loose (no back lash) and re-assemble everything with Teflon (PTFE) lube on gears and bearings (in winter it gets in the low -25C!). Did crossed my fingers ... and I got the nicest cross I could ever get doing calibration! Tks Tim and Doug for your suggestions anyway.
     
  6. Doug

    Doug Staff Member

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    LOL there are so many things that can go wrong with guiding - that's on the list right up there with balance problems. I'm just too used to people blaming our software for problems caused by a bad TIC cable!
     
  7. Wilfrid Ouellet

    Wilfrid Ouellet Standard User

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    Right on Doug. And I tought that we did ajust correctly the worms gears with a filler guage but obviously we were wrong in the process . The tools were right but finally the way we did the adjustment created the problem. You also mention the balance problem and we also tried to off-balance pointing east without success. Right now the mount is perfectly balance but I am waiting for the RA extension sold by Losmandy to finalize the installation and probably off-balance the mount as suggested. Tks again.
     

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