Acorn wireless MPG

[martyscncgarage]

I am using a wallwart 5v supply, it uses a 3 terminal regulator, less than 5 mv. ripple, same with 24v supply.

You are not using the 24VDC power supply that came with Acorn?
Did you double check your wiring against the file I referred to?
Double check all connections in the DYN4 DB25 connector

Marty

[bilorn]

I didn't get the latest Acorn issue, it came with a single 24 volt supply.

[martyscncgarage]

I didn't get the latest Acorn issue, it came with a single 24 volt supply.

Make double darn sure all your connections are correct and good to Dyn4, and you also have all the commons wired per the drawing.

Marty

[bilorn]

Hello Marty,
I am still having problems with axis drift and MPG stops working.

1. There is a lot of 60 hz hash on the step pins at Acorn when pins are not inverted.
When inverted the 60 hz hash is gone. When in the inverted position the drift is much less but still there.
It is not only the z axis but the x and y also. I ran a program to do a 4.5" x .625 pocket in .2" steps.
You could see steps in the x positive wall of the pocket, the minus side wall was smooth, on finish .010 pass
the cut it would not cut on the positive side of the pocket. There is also a like error on the the y axis but not as great.
This shows that extra steps are occurring when moving in minus direction, I believe this occurs because of direction pin noise
when in the minus direction.
The 60 hz hash is coming from the DYN4's, when they are powered off the noise goes. I am going to go over the D-shell
connectors on the DYN4's to make double sure of correct connections.
2. The MPG problem is due to a gremlin in the operating system, I can get it back by shutting windows down with xciever puck disconnected,
and rebooting it with puck connected and MPG turned on. On a couple of occasions CNC12 was affected, the touch screen MPG button
would stay lit and also the .010 increment was selected and not able to change it or turn off the MPG lite until program exit and restart.
Something is getting cobbled in the byte monster!

Thank you again
Bill

[bilorn]

PS;
I installed the shielded VFD cable, this made no difference at all.

[martyscncgarage]

Hello Marty,
I am still having problems with axis drift and MPG stops working.

1. There is a lot of 60 hz hash on the step pins at Acorn when pins are not inverted.
When inverted the 60 hz hash is gone. When in the inverted position the drift is much less but still there.
It is not only the z axis but the x and y also. I ran a program to do a 4.5" x .625 pocket in .2" steps.
You could see steps in the x positive wall of the pocket, the minus side wall was smooth, on finish .010 pass
the cut it would not cut on the positive side of the pocket. There is also a like error on the the y axis but not as great.
This shows that extra steps are occurring when moving in minus direction, I believe this occurs because of direction pin noise
when in the minus direction.
The 60 hz hash is coming from the DYN4's, when they are powered off the noise goes. I am going to go over the D-shell
connectors on the DYN4's to make double sure of correct connections.
2. The MPG problem is due to a gremlin in the operating system, I can get it back by shutting windows down with xciever puck disconnected,
and rebooting it with puck connected and MPG turned on. On a couple of occasions CNC12 was affected, the touch screen MPG button
would stay lit and also the .010 increment was selected and not able to change it or turn off the MPG lite until program exit and restart.
Something is getting cobbled in the byte monster!

Thank you again
Bill

I'm pretty sure at least one other user had the drift problem you have. I'm pretty sure it was a wire not connected or loose. Try and search the site for key word DYN and see if you can find it. I think you may be missing the 5vdc common some where.
If it was running, then something came loose. Review the wiring diagrams and check every connection.
I hope you find it.
Marty

[bilorn]

Hello all
I made one change and reran program that produced a stepped pocket.
The change was to add three ferrite bead to each of the cables going to the servo drives.
I placed them as close as possible to the Acorn. This almost got rid of the steps, they went
from about .040 to almost gone about .002 > .003.
My step and direction signals all are in the same cable, my next step will be to run
a separate shielded lead for each step signal.

[martyscncgarage]

Hello all
I made one change and reran program that produced a stepped pocket.
The change was to add three ferrite bead to each of the cables going to the servo drives.
I placed them as close as possible to the Acorn. This almost got rid of the steps, they went
from about .040 to almost gone about .002 > .003.
My step and direction signals all are in the same cable, my next step will be to run
a separate shielded lead for each step signal.

I use shielded cable for any step/dir signals connected to Acorn and ground the drain wire on the acorn end.

[bilorn]

What is the pulse width and amplitude of the step signal from the Acorn, I am having trouble seeing it with my scope. ( 50 mhz bandwidth )

[martyscncgarage]

What is the pulse width and amplitude of the step signal from the Acorn, I am having trouble seeing it with my scope. ( 50 mhz bandwidth )

These questions I can't answer, perhaps someone from Centroid can answer them.
You probably have seen this:
http://www.centroidcnc.com/centroid_diy ... manual.pdf

The outputs are open collector, that is they take the signals to ground, that is why the drive +step, +dir, +en signals must be fed +5VDC
That +5VDC power supply should come from the same power supply that feeds Acorn (Dual voltage supply)

Here are specs on Acorn
http://www.centroidcnc.com/centroid_diy ... manual.pdf