Centroid Community CNC Support Forum

Why does the pacific Scientific drives not work well with Acorn? I have it running on linuxcnc but the customer don't like linuxcnc and I am retrofitting the AXYZ from linuxcnc to acorn the weekend but your comments concern me about the drives not working well with the acorn. What steps/rev you were using?

bevins wrote: ↑Wed Sep 15, 2021 8:20 am Why does the pacific Scientific drives not work well with Acorn? I have it running on linuxcnc but the customer don't like linuxcnc and I am retrofitting the AXYZ from linuxcnc to acorn the weekend but your comments concern me about the drives not working well with the acorn. What steps/rev you were using?

I take it you have not seen the machine yet or looked at it in detail and you have been retained to convert it?
In general, if the drives are 5VDC logic, USE the DB25 on Acorn with a DB25M breakout board.

I have not converted an AXYZ router, but I was asked to quote refitting one. The PacSci drivers were set to 1600 steps per rev. That is the value to use assuming your machine is setup that way. You should find out for sure which model drivers it has and find the documentation for it before proceeding.

If its running on Linux, should be no real reason Acorn won't work.
Pay attention to the STEP/DIR signals and where they land on the current breakout board. Get the manual for the current breakout board, to see its pinouts. Do your research first.

Most problems with folks not getting stepper drivers to work with Acorn is miswiring/misconfiguration, Trying to get 5V logic drives to work on the Acorn headers instead of using the DB25 on Acorn.

My general .02
Good luck
Marty

Thanks Marty for your response.

I am the one who converted it to linuxcnc. I was just reading that people was having issues with pacific Scientific drives with Acorn.
And I don't see those drives in the Acorn Wizard. I am to be converting this machine this weekend so I hope to not have to scramble
to get this working.

bevins wrote: ↑Wed Sep 15, 2021 9:50 am Thanks Marty for your response.

I am the one who converted it to linuxcnc. I was just reading that people was having issues with pacific Scientific drives with Acorn.
And I don't see those drives in the Acorn Wizard. I am to be converting this machine this weekend so I hope to not have to scramble
to get this working.

Step and direction is step and direction.
Do you have the manual for the drives? Are they 5V logic?
Then USE the DB25 on Acorn.....
Order a DB25 male breakout board from Amazon to facilitate this.

I was planning on wiring step/dir to the terminals not the db25

bevins wrote: ↑Wed Sep 15, 2021 9:57 am I was planning on wiring step/dir to the terminals not the db25

Good,
Which model PacSci drives does the machine have? Do you have an electronic manual?

They are the 6410 Pacific scientific drives.

I am not using differential mopde I am using single ended.
Acorn +5v => step+, dir+
Acorn step- = > step-
Acorn dir- => acorn dir-

Definitely 5VDC Logic.
Drive Step+ to Acorn DB25 STEP PIN
Drive Dir+ to Acorn DB25 DIRECTION PIN
Drive Step- and Dir- to Acorn DB25 pins 18-25

For simplicity, leave the drives enabled and don't use the the enable pins.
You could run the enable circuit through an Estop contactor to DISABLE the drives if the Estop contactor is open (Fault or Estop button press)

It appears microstepping is possible with dipswitch settings.
Let us know how you make out.
Marty

bevins wrote: ↑Wed Sep 15, 2021 9:57 am I was planning on wiring step/dir to the terminals not the db25

And now you know why people have issues with many stepper drives, especially many legacy models.

Not sure what you guys are getting at. I upgraded the original to linuxcnc and it worked fine.
I am upgrading to acorn and want to use single ended mode cause the drives db25 are already set for single ended mode.

Gary, not sure what you mean by that. Can you clarify?