[davidmadewood]

Hi, I have been dealing with some motor issues on my ez-router scorpion Cnc. Partially stalling when jogging all motors. I can get my z-axis to always stall when jogging Y- full speed (500in/min) and jogging Z- It won't if running Y+ though...

Anyways after looking at the drives I noticed the following
Peak current was set to 4.2a (3.0A rms)
Pulse/rev was set to 2000
And dip switch 4 (off = half current, on = full current) is set to OFF

Would that mean the steppers are only getting 2.1A?

The steppers on the machine are all nema34 4.9a

[joeavaerage]

Hi,
I would guess the most likely explanation is the stepper speed. NEMA 34 steppers being larger tend to have higher inductance, and the higher the inductance the lower the speed at which the
stepper begins to miss steps at speed. Please post the specs of the stepper.

Try slowing all the axes to 1000m/min and then slowly step the speed up until the problem recurs.

The number of pulses per rev does not really have a large influence on speed...with one exception. If you set the pulses/rev too high then your CNC controller may not be able to signal the
drive fast enough. For example if you set the pulse/rev =10,000. You want to spin at 600rpm say, or 10 revs/sec. The controller would have to signal 10 x 10,000= 100kHz. But if you are using
a 25kHz parallel port then it won't signal that fast. Your setting of 2000 pulse/rev is a good number. Anywhere from 800 pulse/rev to 3200 pulse/rev would be fine. There is little to be gained
at higher counts and you risk running into the signalling limit I talked of.


Craig

[peteeng]

Hi David - So its been working fine and this is a new issue? If so sounds like a mechanical issue so check it mechanically before doing anything. What is a partial stall? Is this a stutter sort of thing? Does the Z axis and Y axis share a power source? I have found it best not to set the Z axis to half power when idle as the Z axis is weighty and it has to be supported when stationary. So try setting the idle current to full, means the motor will get hotter then usual. But if this machine has been working well for a while then its mechanical ie needs some TLC. Peter

[davidmadewood]

Thanks for the reply!
Here is some more info, and a video to see/hear the problem im having.

VIDEO - https://youtube.com/shorts/ceLjwyJ6xLQ
The orange cable in the video is the 3 wire unshielded cable for the SICK limit switch, It is not for the stepper! All 4 steppers wires have been replaced in the last few months, they are foil shielded.

We recently had ez-router send us a new BOB, ESS, and computer with mach3 loaded. They walked me through changing all the parameters for the upgrade and to be honest kinda left me high and dry and are not willing to work through these current issues we are having.
We had to replace the bob and they didn't make the one that came with it anymore and basically had us upgrade everything sadly.

Looks like the transformer for the drivers puts out 40v (view photo) and its distributed by the the red fused pcb board above the transformer (see photo). There is a giant capacitor you can't see behind that red pcb board.
I am unaware of the what brand the steppers are as they seem to rebrand or tear off any stock stickers?
Currently I have all the steppers disengaged with the machine and running free to try and isolate the problem further more and to try and rule out mechanical binding etc.

One test I will be doing shortly is making a few short cables to test from the Z driver to the Y motor etc and see if I can move the issue. The video only shows the Z binding, but I can get the Y and X to bind as well depending on the rapid movement I do.
I will also make a cable that will allow me to view the pinout voltage and see how if its dropping bad when running all the steppers full jog.

Final note - I don't have a spindle cable currently as I am replacing their SO cable they included with the machine with a IGUS shield cable.

[davidmadewood]

Here is the stepper drive Japanese translated,

[joeavaerage]

Hi,
so the wiring diagram shows the steppers wired in series in the top diagram and in parallel in the bottom diagram. So how have your drivers been wired?
To get best speed you'll need them in parallel.

Did you try reducing the speed as I suggested? What happened?

Craig

[davidmadewood]

I will be back in the shop tomorrow and will check, and also try some more speed changes.

I will say I did try moving both Y axis from 500in/min to around 250 and changing velocity and it didn't change the stutter.
The last test I did before I left a few days ago was I unplugged power to both Y drivers, and in mach jogged Y- full speed (nothing moving of course because power was unplugged at drivers) and Z+ and it still stalled the Z until letting go of Y.

[joeavaerage]

Hi,
well that sounds more like the controller losing the plot.
What motion controller are you using? a Parallel port?

Craig

[davidmadewood]

EZ-router sent a smooth stepper. So ethernet!
Im wondering if it would be happier with mach4? I know smooth stepper doesn't remained mach3 anymore?
Mach3 was what ez sent on the new computer

[peteeng]

Hi David - Binding and stalling are different. Binding is a mechanical issue. Stalling if the motors are disconnected is another matter. Dial down the acceleration to a small value plus set the max velocity at a small number say 1000mm/min. Run each motor and if stable start ramping up the accel until it stalls. Then back it down a little. Then increase velocity and do same again with accel. What is your usual max velocity? Plus you will need to check your microsteps and actual movement is correct eg if you tell the machine to move 100mm it actually does move 100mm. Each axis should be independent. If not then it maybe an undersize power source if a single PS is used to power many axes.. Peter

500in/min is quite fast (12500mm/min) in the past did the machine do this easily? if it did my guess is that the accel is set too high. Takes a bit of time and space to get to 500in/min.

Listening to the video, if the sound is only that drive and not some other drive the motor is loosing sync so back down the accel. In the image its 0.05g so try 0.01g (100mm/s/s or 4in/s/s)

[davidmadewood]

Thanks for the info, I will test this out tomorrow and report back.
Yes it would rapid back to home fine when It was on the older computer and ez routers old bob board which used a parallel port.
I had other issues that I believe pertained to the unshielded spindle cable they provided, (lost steps etc) but that doesn't pertain to this current problem, and is also why im replacing it with a new igus cable.

[peteeng]

Hi David - it would not go to home at 500in/min? Homing speeds are usually set separately? Peter

[davidmadewood]

On the old setup yes it would do rapid moves fine and not stall.
As it stands now with the "upgrades" It might make it home without stalling but often times one of the axis will stall.

[peteeng]

Hi David - By "rapid" do you mean it moved at 500in/min? Peter

[peteeng]

Hi David - so chain of events:
1) You had a machine that worked fine
2) You decided to upgrade the machine and you where sent "BOB, ESS, and computer with mach3 loaded" and it did not work
or the BOB failed and they recommended replacing the lot? so then you got the "BOB, ESS, and computer with mach3 loaded" and it did not work
3) The supplier does not want to help past this point....

Peter

[davidmadewood]

Sorry I am confusing.
1) Yes, for the most part it was fine until the original BOB failed.
2)BOB failed and they sent me their new BOB version, a ESS and new computer with mach3 loaded.
3)Via the the phone they helped get the machine moving with the new components, but after facing these issues they have not been interested in continuing their "lifetime support" which has been a bummer obviously. The machine was made in 2009 from them.

[davidmadewood]

Hi David - By "rapid" do you mean it moved at 500in/min? Peter

Yes, when moving with z-axis in the air from one cut to another it would move up to 500in/min if it had enough room to get up to speed depending on the cut,

[peteeng]

OK so for now we can assume that mechanically the machine is good and the fault is due to the new stuff. So work through each axis, set a low accel and velocity and work them up until you max the velocity, then max the accel. Back the accel down a bit once its going fast in a straight line. Check that your settings are correct for movement ie 12" is actually 12" because if this is incorrect then vels & accels are incorrect.... change one thing at a time and work things up slowly... Peter

[davidmadewood]

OK so for now we can assume that mechanically the machine is good and the fault is due to the new stuff. So work through each axis, set a low accel and velocity and work them up until you max the velocity, then max the accel. Back the accel down a bit once its going fast in a straight line. Check that your settings are correct for movement ie 12" is actually 12" because if this is incorrect then vels & accels are incorrect.... change one thing at a time and work things up slowly... Peter

Sounds good! I’ll give it a go tomorrow and report back.
Thank you
David

[davidmadewood]

Sorry for late reply, was on an anniversary trip with the wife!

Here is what I have tested so far.

Adjusting the motor tuning seems to have no effect on my problem with stuttering steppers.
As seen in the video below, I lowered the Y axis tuning down to 10in/min with 15 velocity and whenever I would jog Y- and would jog Z+ the Z will always stutter.

I have posted photos of my ESS mach3 settings as I just have no idea if they set these correctly from factory,
I have also posted most of my other settings.
Im on the newest version (last version) of mach3.
Computer is running windows 10, I believe the set the computer up as a Cnc computer and turned all the unnecessary crap off in windows.
Would it be worth buying mach 4?

To make sure this wasn't just an issuing when jogging around in mach3 manually I made a simple program where it went full speed Y- (250in/min) with some tabs added in there to get movement on the Z and same problem happened when Z was plunging.
Lastly I measured the power supply for the drives and Its 60v, when measuring power coming into the drives while jogging, they are all pretty consistent in loosing maybe 2-3v so somewhere around 57v. Not very substantial.

VIDEO - https://youtu.be/V5obfUgBsl8

More photos on next page**

Thanks for you help everyone...