No problem. I issued the "find Zero position sensors" command via the iOptron Commander interface and after a minute or so the mount was back in the Zero (home) position and the mount controller now knew where it was pointing. I did another goto to a target and then did another plate solve and I was back in business.
Built in plate solving would be a bonanza for us primitives who still sight alignment stars and build models manually. What would be nice is to do all this without needing a laptop (for field use).
I am puzzled at the statement (somewhere above) that servos are inaccurate. I remember reading that servos divide the 360 degree circle into about 2 million parts--my Argo Navis divides the circle into 10,000 parts.
Still thanks to the power of mount modeling I have 2 to 3 arc minute error with all sky pointing which is excellent for visual applications. But my plate solving paramount owning buddy has all sky pointing accurate to about 2 to 3 arc seconds. That's almost two orders of magnitude better.
Anyhow my 2 to 3 arc minute error is outstanding for the level of tech I have, it used to be that dscs were accurate to about 30 arc minutes. For people who used refractors with 3 and 4 degree (and larger) fields of view and looked mainly for bright Messiers because using a four or five inch apo, that was fine. For a guy with a C14 and a 40 arc minute field looking for 13th and 14th magnitude off-the-beaten-path objects it was frustrating in the extreme. With 2 to 3 arc minutes pointing error you objects will fall within the field of view of a ten arc minute eyepiece (such as an XW10 in the C14) and so you're in business. If you can't find it, it is likely not there to be found or too dim to be seen.
One of the issues with servos is that starting the slew can cause some slippage between scope and mount in the clutch. You can try to finesse that with an adjustment to the slewing software but it is a factor that servos can be so powerful that they accelerate faster than the rest of the telescope.
I haven't had a slewing stall since about 2004 when I got my AP900QMD push to and I've been much happier for it. I had a very rude introduction to go-to that did not go well for me.
I decided after that if I went to go-to again it would be an astrophysics or a parmount. Paramount doesn't really provide a smart hand paddle, meaning you have to have a laptop for control. Astro-physics won't build mount modeling into their paddle, if you want modeling, you need a laptop. Astro-physics wants you to rely on forced star aligns in the sector in which you are searching which is a late 1980s solution to the problem of pointing inaccuracy. We are so far beyond that. Everywhere except AP. And even AP has modeling if you want to run a laptop. They decided their visual users who want modeling in the paddle are an extremely small market segment. Maybe they're right.
I don't want to run a laptop because they consume a lot of power and become one more gizmo I have to run, and one that is not really built for field use. So Argo Navis it is. 1/2 amp or less power draw, built in modeling, unobtrusive display. And it never ever stalls because it is push to.
Edited by gnowellsct, 19 February 2019 - 05:23 PM.