Hi HenryNZ,
In answer to your initial inquiry about using your mount with KStars/Ekos I suggest you use the standard "AstroPhysics" driver. I used this driver with my AP900 GTOCP3 very successfully the last several times I was able to image before my mount went down. In general it will work fine from Park 3 or any park position you define with the exception of a "Warm" initialize as I described in my previous post a couple days back as following:
- "When I was last using my AP900 I was using it with the standard "Astrophysics" driver as written by Jasem. I was able to run successfully through the night with meridian flips and correct parking (Park 3) as well as use the Pulse Guide feature. The only issue I had with this driver (as memory serves) is that if the mount was already initialized and I did a "Warm" connection then I would have to go and click the "Default" park button in the INDI driver, otherwise it would not park to Park 3 correctly. This is not needed on the first initialize ("Cold") connection as the Park position is not modified." -
In using the "AstroPhysics" and NOT the "AstroPhysics Experimental" driver I was able to get back to imaging all night with a programmed sequence and everything worked as expected including meridian flips and parking. I would program the sequence and get some sleep until the sunrise. Just follow what I said above if your mount is already initialized, either previously from a "Cold" start in KStars/Ekos or from your hand controller if you have it and initialized that way. If you have a GTOCP4 it will work the same as the GTOCP3 with this driver.
For details on using the standard or "legacy" driver see this section (even though it states to use on older GTOCP2 controller I had great success with my GTOCP3. The CP4 should also work the same.) :
indilib.org/telescopes/astrophysics/astrophysics-legacy.html
In answer to your last question to Mike, which I am sure he will respond to, the motors in the Mach1 and all Astro-Physics mounts made in the last 20+ years are servo motors and not stepper motors. Stepper motors and servo motors are controlled very differently so you would have to switch out the motors as well as the controller (OnStep in this case is designed to drive stepper motors). In addition the power and torque curve of these type of motors are essentially reverse i.e. steppers have the greatest power and torque in the low RPM region while servos have higher power and torque in the higher RPM region, This leads to a need for different gear ratios as well. This is a very general comparison between servos and steppers and may not hold for all cases, however ... etc. In any case it would lead to a challenge in getting the motors sized (to a matching size in this case (around NEMA 11 I think) if you are to use the existing motor and worm mounting blocks), gear ratios matched for acceptable performance and so on. Not impossible but does need a bit of planning and testing. So your suspicion of the difficulty in adapting the Mach 1 to OnStep is correct. It is certainly achievable but has to be weighed against many variables, each of which are dependent on the individual.
All that to say - try the standard "AstroPhysics" driver until the experimental driver is finished as it is currently being addressed per /Tom (wotalota) as seen in his posts. You can always to an indoor simulated run while testing the standard driver if your system is available. I hope this information will be of help.