I've recently started using a Losmandy Titan mount and have found that the default worm period in PEMPro does not give the best results for my mount.
This is my first Losmandy, so I don't have a great deal of experience with these mounts, but I've been pretty happy with the PE, which is around 8 arcsec peak to peak. Not bad given that it will be used with a self guided slit spectrometer.
But my asperger's will never let good enough go unchallenged, so I started messing about with PEMPro in order to reduce the PE to as little as possible.
The default worm period in PEMPro was 319.13sec, which was about what I had read on the web. Ive also seen a number of PEMPro uploads with the period at 319. After running PEMPro for a while a PEC curve was built to fit to fit. Once uploaded the curve ran the mount at between 2 and 4 arcsec most of the time with spots going back to around 7 arcsec, so not much of an improvement at all...
Attachment 1 shows the plotted data from PEMPro with the 319 second worm period. Kinda curvy, but with lots of noise. The seeing here has been rubbish this last week, so I assumed that had something to do with it.
There is a function in PEMPro which allows you to view each cycle, so I flicked through and noticed that every second cycle showed real similarities, so I change the worm period from 319 to 638 seconds and WHAM, all the noise vanished and a distinct set of curves appeared with less than 1 arcsec var. for the curves. Attachment 2 has the 638sec curves.
The PEC is ready to upload whenever the damn clouds vanish.
Grateful for any advice or comment on these curves please
Gday Bob
I dont know what the gears in the gearbox in the Titan are, but it looks like the drivetrain may have a PE that is 2x the period of the worm.
The Meade LX200s have a gearbox that resets every 3x the period of the worm ( as do many Celestrons )
If the PEC table "inside the mount" can only store data for 1 turn of the worm, there is nothing you can do about it.
Meade got around it by making a PEC model that is actually 3 turns of the worm, but that has other problems as well.
