Re: Do I need a storage scope to tune a G320?

Thanks Dan!
Matthew




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dan Mauch" <dmauch@s...>
wrote:

> 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