Re: Mach1 Unable to Find Home Position Suddenly

Dale Ghent

The accuracy of your PC clock and, by extension, the clock in the mount control box, is crucial regardless of the situation.

I presume you are initializing the mount using the A-P ASCOM driver from your PC (that means if your hand controller is connected to the mount, it is in EXT mode and you do no select the location info to initialize with from it.)

First, ensure that your ASCOM driver has the "sync PC time to mount" option set.

Second, ensure that your PC's clock is accurate. I know it's common to have observatory computers cut off from the network, which means that they cannot avail themselves to the services of NTP servers that any modern OS will automatically try to connect to. If you choose to have your PC cut off in such a way, you will need to sync it from an external source such as a GPS or keep adjusting the time by hand. if your PC is connected to the internet, ensure that Windows is syncing to NTP servers. On Windows 10, that would mean going to Date & Time settings and ensuring that "Set time automatically" is set to On.

If you don't have an accurate time app on your mobile phone, you can quickly call the US Naval Observatory master clock at +1 202-762-1069 for an automated readout and prompting of the current time down to the second. There is a service for Mountain time at +1 719-567-6742.


On Mar 21, 2020, at 10:56 AM, Mikko Viljamaa <> wrote:

Thanks Ray & Rolando,

So as long as I have had the Mount, about two years now I have never used park from the last position - this without any issue. I did go out and tried both; unpark from 3 and park back to 3 results the Dec axes to miss its mark about an inch. I then manually swung the Dec to match the mark and chose to unpark from the last position. Did a slew and sure thing, the mount returned to park 3 nicely. I then did the same exercise a dozen times and the worst Dec miss was maybe a quarter of an inch - which I have seen before and I'm not worried about. I might have a narrow window tonight to see how things go in real life and if the mount points where expected and Platesolve finds the target immediately,

The LST / RA difference is off about 2 minutes, is this an issue?

- Mikko

<View recent photos.png>

Join to automatically receive all group messages.