Hi Robin,
Great to know its working with the G11 as well. John would be a happy man.
I've also tested it with the eqascom simulator with stellarium showing the scope slewing east and then west.
Very nice work and thanks from me as well.
one thing I noticed is although the rate and duration are the same in both directions, it doesn't go back to the same position. that's because the stars are constantly moving west at sidereal and that would explain why John is seeing the return trail shorter.
the basic math
tracking rate is 15arcsec/sec
so 1deg = 3600arcsec in 240secs.
so if we enter 240 in the program and slew east, that would mean that the star would be more or less at the same place as you're travelling east the same rate as west. i've tested this with the scope in stellarium and it stays put.
so simple solution would be
slew west at 120s, thats sidereal x 2 for half the duration, and then stop tracking. the star would then drift to the start point at sidereal.
that would give the complete V.
Then resume tracking at sidereal.
so you don't really need to adjust the tracking rate and you could default it to 120, but just start west instead of east.
This is what the eqmod script does as well.
what do you think?
btw, there's a small demo video I captured here showing the reticle moving the way it is and your software
https://www.dropbox.com/s/hgv0rvl5uc...align-demo.avi
Cheers
Alistair