Messages

1

Mach4 General Discussion / Re: Pokeys 57CNC board setup

« on: May 28, 2019, 10:12:42 PM »

One thing you might want to check is the wiring of the motors, the manual is misleading for Pokeys57cnc.  This post has a good discussion about this, and a drawing.

https://www.machsupport.com/forum/index.php?topic=39468.0

I struggled for a while until I learned this.

2

Mach4 General Discussion / Re: Servo spindle stops briefly - How do I diagnose problem?

« on: May 16, 2019, 02:34:51 PM »

Oh yes, the settings are at Constant Surface Speed... and that I can do without.  I shall cut some air and see how it goes.

Thank you.

3

Mach4 General Discussion / Re: Servo spindle stops briefly - How do I diagnose problem?

« on: May 16, 2019, 02:32:35 PM »

Ok I will look into the max acceleration

Thanks again!

4

Mach4 General Discussion / Re: Servo spindle stops briefly - How do I diagnose problem?

« on: May 16, 2019, 10:23:27 AM »

Just as a reference I am currently set up with the Spindle Servo in DIR/Pulse Mode.

With the enable setup on an on board relay.  I have to do this because the DYN4 needs 24v on the enable pins.

5

Mach4 General Discussion / Re: Servo spindle stops briefly - How do I diagnose problem?

« on: May 16, 2019, 10:19:33 AM »

Thank you for the reply.   I will send a ticket to NFS.  Did you work around this?

This is far more frequent than I originally thought, it happens 2-6 times in a 20 minute cnc run. 

My biggest concern is safety, my Lathe has a chuck mounted on a thread.  It is a "Sherline" and sudden stops can cause the chuck to loosen or spin off due to momentum.  I had it spin off during a bench test for example at 300 rpm it was ... exciting.  Since I want to machine aluminium and plastics I expect to run at high speeds, so I am worried that at 2800 rpm the result could be catastrophic.

Any advice would be appreciated.

6

Mach4 General Discussion / Re: Servo spindle stops briefly - How do I diagnose problem?

« on: May 14, 2019, 11:08:55 AM »

New Information:
All motors appear to be stopping.  I just used a simple turning cycle from the turn cycles menu. 
Let it run and touched the Z axis stepper as it fed the cut.
The spindle stopped in the middle of the pass so did the stepper.

I suspected the Servo was acting up, but since both stopped.  It has to be a broader system issue, PoKeys board, Mach4 or other system issue.

Again any help would be apprciated

7

Mach4 General Discussion / Servo spindle stops briefly - How do I diagnose problem?

« on: May 14, 2019, 09:39:02 AM »

Problem:  My Lathe spindle rarely, and randomly stops during a cnc program. 

Background:  I finally have all of my motors running, system calibrated and I am now "air cutting" using "simple" g-code generated with the Mach4 turn cycles.  3 times now, the spindle has "briefly frozen <1sec" mid run and then continued.  There are no alarms raised, no software indicators or hardware alarms.  It is unclear if any steps are missed.

The Machine:
Mach4 Hobby (Windows 10 dedicated (current) I5 computer),
PoKeys57CNC,
DMM-Tech Dyn4 controller, 400W servo,
Sherline 4410 Lathe,
X,Y axis standard Leadshine steppers and controllers.
I am Air cutting so there is no load on motors.

I am puzzled and looking for advice on how to diagnose the fault and ultimately correct it?

Since the event is random and "rare" being prepared to capture diagnostics is a problem too, so if anyone can suggest test to "force" the problem that would also be a help.

Thanks in advance.

8

Mach4 General Discussion / Re: How to understand Spindle readings? I am confused..

« on: April 25, 2019, 08:56:48 AM »

Thank you Reuelt

I will get a choke I do not have one on hand.  I am using 24awg twisted pair I did not realize one was necessary. 

That being said I have read the voltages with a Keysight Multimeter and get 9.997v at the peak, 18mV at 0 both measured at DYN4 motor controller.   The odd thing appears to be the slope of the curve.  There seems to be a difference between expected "voltage-rpm" points and actual, I will create a table when I get more time.
 
I get a deviation of as much as +/- 30% between programmed speed and true rpms.  '+' error at high rpm, '-' error at low RPM

The folks at Artsoft say that what I am seeing is normal, Mach4 uses true rpms for thread cutting and I will be able to cut threads.

9

Mach4 General Discussion / Re: How to understand Spindle readings? I am confused..

« on: April 24, 2019, 10:23:08 AM »

I just received an update from the Mach4 team.   It seems this is normal behavior for the PoKeys57CNC.

Maybe I should consider changing that out...

10

Mach4 General Discussion / Re: How to understand Spindle readings? I am confused..

« on: April 24, 2019, 10:05:40 AM »

Thanks again, It would seem I am on the right track then.

I can pick an "informed" value for max range for each speed range I want and then select that each time.  Just seems a bit of a hack.

It looks like the "slope" of the actual Analog signal is different than Mach4's expected curve.   I get negative (-) errors at the high end and positive (+) errors at the low end.  Almost like Mach4 could use a "look-up" table rather than a formula.

I am using the DYN4 controller, I will look into it more.  I saw dead zones but nothing about slope.