Sorry for the delay, life....
@csorrows: The .8mm refers to the walls on all sides, but that means 2 .4mm passes for the walls and 4 .2mm thickness passes for the bottom and top of part. A bit overkill but I like things symmetric.
To answer the accel numbers:
Velocity setting 300x, 300y, 5z, 25e
Accel retract 2500
Accel travel 800
Accel max 800x, 800y, 200z, 10000e
Also an update, I just did another print with a travel set to 120mm, and temperature at 190C/45C. The print speeds were set low to print 40mm, outer perimeter 20mm, infill 60mm, and infill to 15%.
Heard the grinding noise, about layer 2.3mm, so about layer 11. Sure enough the layer shifted and I killed the print. But at 190C the first layer stuck a bit better. (I think 180C was my attempt to fix the blobby corners of the test cube)
I will try to print another print with travel at 90mm and see how that goes, and report back. After that the back cover comes off, and I will measure the voltages on the PS when skipping occurs, and on the drivers. Hope that poking the driver trim pot during a print won't affect the driver board.
Getting a bit frustrated, and appreciate everybody's help.