RE: [CAD_CAM_EDM_DRO] Do I need a storage scope to tune a G320?

You really don't need a scope to set up the G320's.
I have set up quite a few G320 3/4 axis systems on my work bench on
motors with 500 CPR encoders and less.
Simply place a large pulley/flywheel/handle on the motor shaft and
scure.
With no computer connected turn the shaft a bit to feel what effort it
takes to fault out. Then next time use less force.
Turn the flywheel again below what it would take to fault out and
release it sharply. If it hammers violently it is overdamped. Hit the
error/res switch and reset. If it sits there and vibrates it is probably
under damped. If it comes quickly to a stop and doesn't make any noise
it is set correctly. Keep increasing the gain for the stiffness desired
until any movement of the shaft causing the drive to fault then back off
a bit. Reset the dampening to correspond and retest.
You will generally find that your setting for gain and dampening are
similar in that if you have the gain turned up half way, the dampening
will also be turned up half way.
The biggest problem is setting the acceleration on the software but if
you have the G320 set in the manner described above it will reduce the
time it takes to setup the software. For the software start with a slow
accelleration curve and keep shortening up the acceleration curve until
it faults then back off about 15% on the acceleration.
Remember that the geckos G 320's have an 8 bit error amp and thus there
is only 4 bits (128 counts) before it faults. On a system using a 250
CPR encoder, 2/1 ratio timing pulleys and a 5 TPI ballscrew that works
out to be 250X4X2X5=10000 CPI. So 128 counts would be .0128 of axis
linear movement before it faults. In practice the error amp will
keep the axis error quite low.
Dan