Hi Jon,
> From: Jon Elson [mailto:el...@pico-systems.com]
> On 8/4/21 1:53 AM, John Dammeyer wrote:
> > In fact, a bit more work just now shows that the X axis is losing position 
> > in the positive(?) direction.   So on each return to X0 after a
> bunch of jogging back and forth (even without backlash enabled) shows as high 
> an error as -0.156".  And it's cumulative increasing in
> the negative count direction.
> >
> > That wasn't there when I first changed from the US Digital Encoders to the 
> > CUI encoders.  So either the encoder is slipping on the
> shaft or the way the wires are run is creating noise that changes the encoder 
> values.
> >
> Yes, you have some sort of issue there.� The CUI encoders
> have a plastic collet that has a clamp ring that has to be
> snapped down quite forcefully to close the collet on the
> shaft.� Sometimes the molding is not precise and the collet
> doesn't grip well.� Some people put a drop of superglue on
> the shaft to make sure it holds.� I hope you can find the issue.
> 
> Jon

I pulled the motor off the machine and then removed the encoder part.  No 
matter how hard I tried I could not rotate the plastic collet that turns the 
encoder disk.  On solid.  No super glue needed here.

Decided I'd put it back together and use the instructions Henrik Olsson gave me 
on interpreting the GP, GE and GT commands to his processor module.  Figured I 
would see if the 150,000 encoder counts were occurring in a 10" move in both 
directions or if just in one.

Wouldn't you know it.  Works perfectly again.  Doesn't matter how much jogging 
I do a 10" move in either direction from 0.000" to 10.000" reports as 150,000 
encoder counts;  as it should.  Now once again the DRO-350 and LCNC agree.

Since I didn't change anything I can only assume that perhaps the teensy tiny 
connector to the encoder has a poor crimp on one of the pins and the vibration 
over time caused an erratic connection.  Pulling it out and putting it back in 
resulted in it (temporarily?) being properly connected and now things work 
again.

I guess I'm going to have to wait until it once again screws up positioning 
while making something.  Then only remove the encoder cap, unplug and plug in 
the tiny connector and see if the problem is fixed again.  And I'm going to 
make up a second DB-15 to CUI connector for inside the end cap just in case 
it's intermittent that becomes permanent.

John Dammeyer





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