Date
1 - 10 of 10
Strange Mount Behavior After Installing VCP4-P02-15
|
I am my 1100 GTO mount ready to install absolute encoders. George suggested that in the meantime I should install the latest versions of the GTOCP4 and Keypad Software.
I am currently running VCP4-P02-13 and Keypad version v5.010. I downloaded and installed the VCP4-P02-15 and after finishing the installation and restarting the mount, the RA and Dec Motors were switched. When the mount was "tracking, the Declination motor was running. I switched the cables, and the correct (RA) motor is now running, but I can't run this way in the field because the Dec motor branch of the Y-cable is too short. For the time being I will just reinstall the older software version, but I want to know if this kind of behavior is expected. Mike |
|
|
|
Roland Christen
Switching software versions does not change which motor is running RA and Dec. Something else is amiss. Contact Mike at AP during business hours.
Roland -----Original Message-----
From: M Hambrick <mhambrick563@...> To: main@ap-gto.groups.io Sent: Fri, Mar 17, 2023 1:50 pm Subject: [ap-gto] Strange Mount Behavior After Installing VCP4-P02-15 I am my 1100 GTO mount ready to install absolute encoders. George suggested that in the meantime I should install the latest versions of the GTOCP4 and Keypad Software.
I am currently running VCP4-P02-13 and Keypad version v5.010. I downloaded and installed the VCP4-P02-15 and after finishing the installation and restarting the mount, the RA and Dec Motors were switched. When the mount was "tracking, the Declination motor was running. I switched the cables, and the correct (RA) motor is now running, but I can't run this way in the field because the Dec motor branch of the Y-cable is too short. For the time being I will just reinstall the older software version, but I want to know if this kind of behavior is expected. Mike -- Roland Christen Astro-Physics |
|
|
|
Well, this is embarrassing. After reinstalling the VCP4-P02-13 and still got the same behavior, I finally figured out that I did in fact have the cables connected to the wrong motors. From the indoor setup I was using to upgrade the software, I had the CP4 sitting on the north side of the mount instead of the south side where it sits when the mount is attached to the pier. So, when I connected the shortest branch of the Y-cable to the closest motor, I was connecting it to the Dec motor.
Anyway, all is well. I am not sure we are supposed to say things like this nowadays, but in days gone by this would have been referred to as a "blonde moment" Reinstalling P02-15 Mike |
|
|
|
And just FWIW, now your PEM data is out of sync and its time to re-do your PEM curve. On Fri, Mar 17, 2023, 2:25 PM M Hambrick <mhambrick563@...> wrote: Well, this is embarrassing. After reinstalling the VCP4-P02-13 and still got the same behavior, I finally figured out that I did in fact have the cables connected to the wrong motors. From the indoor setup I was using to upgrade the software, I had the CP4 sitting on the north side of the mount instead of the south side where it sits when the mount is attached to the pier. So, when I connected the shortest branch of the Y-cable to the closest motor, I was connecting it to the Dec motor. |
|
|
|
Hi Chris
What is causing the PEM curve to get out of sync ? The cables are now connected to the correct motors. Curiously though, when I got the cable situation sorted out, I restarted the mount and connected it to APCC. Once connected, APCC showed that the PEC was disabled, and I turned it back on. I am getting absolute encoders in the near future. Is it worth the trouble to re-do the PEM curve ? Mike |
|
|
|
Roland Christen
A blonde moment, hahaha, love it 
Great that it's working for you.
Rolando -----Original Message-----
From: M Hambrick <mhambrick563@...> To: main@ap-gto.groups.io Sent: Fri, Mar 17, 2023 2:25 pm Subject: Re: [ap-gto] Strange Mount Behavior After Installing VCP4-P02-15 Well, this is embarrassing. After reinstalling the VCP4-P02-13 and still got the same behavior, I finally figured out that I did in fact have the cables connected to the wrong motors. From the indoor setup I was using to upgrade the software, I had the CP4 sitting on the north side of the mount instead of the south side where it sits when the mount is attached to the pier. So, when I connected the shortest branch of the Y-cable to the closest motor, I was connecting it to the Dec motor.
Anyway, all is well. I am not sure we are supposed to say things like this nowadays, but in days gone by this would have been referred to as a "blonde moment" Reinstalling P02-15 Mike -- Roland Christen Astro-Physics |
|
|
|
If the servo controller has moved what it thought was the RA motor but in reality was the DEC motor, when it is hooked back to the RA motor, the RA worm drive assembly gears and worm won't be positioned where the servo controller thinks they are. Thus the stored PEM data will now be useless. Using PEMPro isn't so bad. A person should re-do their PEM curve every so many years anyway. UNLESS your mount has Abs Encoders, which means your mount's PEM feature is no longer needed. On Fri, Mar 17, 2023, 3:23 PM M Hambrick <mhambrick563@...> wrote: Hi Chris |
|
|
|
DFisch
Do you know why blonde jokes are so short? So the brunettes can remember them
--
TJF MOBILE |
|
|
|
Thanks Chris
That's interesting. I wonder though if I put the mount back in Park before switching the cables back to the correct motors if they really changed position ? Regardless, I probably need to re-run the PEC anyway. This mount is 6 years old, and I have never re-run the curve. Doing so will depend on whether I get to set up outside before the encoder kit arrives. The weather has really been bad here. The last time I had my scope out was in early January. Mike |
|
|
|
If the RA axis motor wasn't moved at all during your experimentation and the servo controller never moved what it thought was the RA motor, then you would be good. However since you say that the wrong motors were moving, that hope sort of vanishes. Learning to run PEMPro is a good exercise anyway and it's sort of cool to see it analyze the RA periodic error and build a PEM curve for you. IMHO, it is actually rather pleasant to run. I think that a lot of people are afraid of PEMPro and they shouldn't be. "Always take the high road. There's less traffic." Observatory Engineer Summit Kinetics Honoka'a, Hawaii On Sat, Mar 18, 2023 at 4:22 AM M Hambrick <mhambrick563@...> wrote: Thanks Chris |
|
|
