Re: RAPAS on Mach2

W Hilmo

“My head does not allow me to get my dominant eye (right eye) into the RAPAS with a telescope installed.”


I put my mount into Park 4 when using the RAPAS to polar align.  That gets the scope and cabling well out of the way.


From: <> On Behalf Of Terri Zittritsch
Sent: Tuesday, April 21, 2020 9:35 AM
Subject: Re: [ap-gto] RAPAS on Mach2


I thought I'd confirm, for those interested in using the Polemaster, that my exposure time increase did fix my accuracy issues in the fine tune step of polar alignment.
Last night, I measured a DEC drift of essentially zero again in PHD2 using only the Polemaster.      So if you're getting poor results, like I was, turn up the exposure time.   I was previously turning up both exposure and gain, last night after thinking about gain vs. exposure, I turned up just exposure and received the same good results.   So I have to retract my first post comments about accuracy, the Polemaster can do a very good job.

I also adjusted my RAPAS, to the best that I could do.. this is a tricky process, in the dark, with two small allan wrenches.    I tried some repeatability tests, plugging and unplugging the RAPAS.   There is some small amount of seating that I noticed.. that I need to wiggle (wrong word but don't have the right one) the RAPAS bracket, for the image location to stabilize.   It's more grabbing the bracket and flexing back and forth.. but it was repeatable and now that I know I must do it, it's ok.   Next time I will check how good the RAPAS polar aligns compared to Polemaster.

As a public service warning: 
Note, that while in the dark, be VERY CAREFUL about rotating a Mach2 with RAPAS attached.   My head does not allow me to get my dominant eye (right eye) into the RAPAS with a telescope installed.   So I have to rotate the scope to opposite side of RAPAS, for me it is west, and you have to be careful you don't go too far... because the mount/weights can and will hit the RAPAS and if the weights are up high, it doesn't have to go very far!    

I think APCC or the driver should have a message come up when you unpark Mach2 mounts, that warns you that you should remember to remove the RAPAS or pay careful attention to your rotation  and RAPAS so no collision occurs.  All of my prior mounts only had polar scopes on the RA axis of rotation, which never have to be removed, so I never gave it a thought.  


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