Re: Connecting ASIAIR Pro to a CP4 - Mach1


Kevin Cook
 

Hi Lee - You touched on two of my frustrations in using the ASIAIR PRO with my older Mach 1 mount (CP3).  I agree the guiding using the ASIAIR's PhD-lite is substandard compared to what the mount can do using the full version of PhD2.  I think the ASIAIR's PhD-Lite simply lacks the controls and the guiding assistant to optimize performance with the Mach 1 mount.  I am cautiously optimistic the soon-to-be-released multistar guiding for the ASIAIR will resolve some of our problems.

I have the same problem with the ASIAIR not recognizing the HOME position for my mount (I use Park 3).  After doing the polar alignment routine where the ASIAIR rotates the mount 60 degrees or so, it hardly ever returns to the HOME position when I tell it to do so.  I usually have to loosen the clutches, manually move the mount back to the Park 3 position, then cycle the power to the mount off and then back on.  Even that does not always work.  Sometimes I have better success doing the first GOTO to a target immediately after completing the polar alignment, without attempting to return to HOME first.  I will try your approach the next time I get the mount and scope set up.  

I have another ASIAIR-Mach 1 workaround that is related to the process you outlined about the home position.  I like to start my imaging runs with the target an hour or two east of the meridian and then track through the meridian without having to do a meridian flip.  Unfortunately, the ASIAIR software always wants to position the scope on the "correct" side of the mount (i.e., scope up, counterweights down) even when the target is very close to crossing the meridian and necessitating a meridian flip.  So here is my workaround:
  • Let's assume the target is M51, high in the evening sky this time of year but east of the meridian.  The initial ASIAIR GOTO (refined with plate solving) will place the scope on the west side of the mount, looking east toward the target.
  • Next select that target (say M51) on the AP hand controller.  Do not press GOTO on the hand controller, but instead use the right arrow key (labelled NEXT on the hand controller) to SYNC to that target.  At this point, the mount has not moved from where the ASIAIR positioned it, but the mount now knows it is looking at M51.
  • Using the meridian delay function on the Mach 1, press the RA/DEC/REV key on the AP keypad and using the NEXT arrow key on the keypad, select a meridian "advance" of 2 hours east.  This will allow the Mach 1 to acquire the target up to 2 hours east of the meridian, but with the scope on the east side and lower than the counterweights.
  • Now select the target M51 again on the hand controller and this time press GOTO so the Mach 1 slews to the target with the scope in the desired position.
  • Take a short preview exposure using the ASIAIR and have it plate solve that image.  The scope should be pointing close enough to the target for an easy plate solve.  Once completed, select Go to Target and Sync Mount on the ASIAIR control panel.  Done.  Now the mount starts with the scope positioned how I want it and seamlessly tracks the target through the meridian.  
  • Obviously, a variation of this process allows one to acquire a target earlier in the eastern sky, with the scope "correctly" positioned, and then using the AP keypad to instruct a meridian delay, the mount will track through the meridian, with the scope in the "incorrect" scope down/counterweights up position for another hour or two.
Kevin Cook


On Sun, May 16, 2021 at 8:43 AM Lee Decovnick <ursa@...> wrote:
Just an update on the ASI AIR Pro and the  Mach 1( CP4) ..The Raspberry Pi software/plate solve in the AAP does a wonderful job of polar alignment .. After two iterations of PA ,I checked it against SharpCap and RAPAS and it was dead- on with both. More importantly I was doing three minutes subs without guiding and saw nice round stars.  The AAP (PhD 2 light) auto guider is just ...um...ok... a bit of patience/ frustration to get the aggressiveness correct and the other setting needed more than bit of tweaking.

So to answer the question I asked above about resetting  to Park...The 'trick" is after you PA, do a long GOTO to the West side of the mount, plate solve, hit sync in AAP and got to park on the AAP. You'll be a bit or a lot off.. open the clutches and manually  move the mount to the Park position of you choice  and tighten the clutches. Do a long GOTO East, plate solve,  and back to Park and open and close the clutches again to get the mark lined up perfectly. I have hit every GOTO right in the middle of the camera's field of view since then.  And even after shutting off the CP4 and AAP, the postitioning/ GOTO was perfect two nights later.

I posted my first light pic at Lee D. Photos

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