Re: PMC-EIGHT


Wes Mcdonald
 

Dino

The motor count settings are the number of motor steps per full rotation of the wheel.  These values are hardware related and should be left as set by the application.   If you change those the mount will lose track of where it is pointing.   The applications make the assumptions that so many motor steps equals so many degrees of rotation.  In the case of Explorestars, ascom or the asiair drivers the steps per degree are known and used to compute sky position.

The number 47 relates to the sidereal rate being employed.  You can alter this number if you wish to make your mount run a bit faster or slower than sidereal.  For example the king rate, lunar rate.   They are all about one count away from 47 which is the sidereal rate.   If you have a g11 this number would be different owing to the drive train.  Exos2 and iexos are the same and require 47 to run at sidereal.

The firmware works fine with the asi air however you probably need to make sure you get the correct version.  Someone that  uses it can advise you, the asi air code is not supported by ES and I have no experience with it.

The thing about the exos2 is that it has dec backlash that can lead to calibration issues for guiders.   So you should adjust the dec axis to have as little as you can without binding.  Robert Hoskins wrote a tuning document that goes into (among other things) tuning up the mesh.   Look for it in the files section of the main or mounts subgroup.  Cannot remember which, might be in both places.  Even when adjusted however many users still experience backlash.  To overcome this we use camera end heavy mount weight bias, and PA error to force dec corrections to be mostly unidirectional.  This works fine unless you have wind or other disturbances that lead to dec guiding reversals.  In those conditions you might notice intervals of dec error with apparent refusal to respond to guiding pulses as the backlash is absorbed.  

Wes




--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired

Join MAIN@ESPMC-Eight.groups.io to automatically receive all group messages.