Ok, I think I figured out a problem. Although I am still not sure if I am causing it.
I added a feed rate of 3 to the file (f3) only once at the beginning. I also have "use diameter for feedrate" selected in the toolpath configuration.
When I rapid the A axis with either a G0 A0 move in the MDI screen or use the A axis button in the MPG window or my shuttle dial I get about 300 as a reading.
When the program is running I get about less then 50 as a reading. About line 486 there is a big G0 A axis move from about 20 degrees to 120 degrees (about). The A axis accelerates so fast - above 1200 - the motor totally loses position.
So my question is why does it go so fast? I tried turning down the tuning but then the motor turns so slow during G1 moves it would take days to run the file. Or maybe I do not have the tuning set correctly? The other option is I turn the "use diameter as feedrate" off but again there is a huge difference in speeds between a G1 and G0 move.
Am I doing something wrong? This was a problem a long time ago but with version 1.84 it ran very smooth with the existing tuning.
![Huh ???](https://www.machsupport.com/forum/Smileys/default/huh.gif)
??
Dan.