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MPG Pendant very jumpy

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Hello, I'm having issues with my pendant wheel being very jumpy or jerky.

I have a new setup. Everything seems to be working fine.  CNC router (previous Chinese DSP controller).   I'm desperately trying to get it safely in production cutting lexan shields for local medical staff, etc.

I'm generating Gcode from Fusion 360 and so far I really like it.

I've got my "steps per revolution" set pretty close (I need to cut some calibration squares to really fine tune it but thats a later issue to work out).  I've got my max speeds, and acceleration set pretty conservative.  Movement during running the Gcode looks really smooth. Sounds beautiful. Cuts awesome.

I have my "pulses per revolution" set at 3000 per axis.   (All axis have nema 34) .

The motor drives dip switches are set to 1600 (I didn't change any of that from previous Chinese setup).

The bad part is when I use the handwheel. It moves ... It's just really jumpy. Unpredictable.  All the other videos I see people using it looks awesome. Smooth.

Example, moving any axis by cranking the wheel pretty fast results in surges and jumping. One tick at a time is fine.

 

Any ideas?

Hi @dreyfusduke

Could you confirm if you are using the G2 or G3 Masso.

Cheers Peter

@dreyfusduke

Further to Peter's request what version of software are you running?

The reason is that Hamel posted My MPG not working properly earlier today, with similar problems after a software update.

Regards,

Arie.

I am running a  G3 controller that they emailed me v3.46.1  on just March 15th.

Mine is also a 5 axis controller.   I have it configured for use on a rather large cnc router that has a 4th axis as well.   I have not even hooked up the 4th axis yet as I am still working on the table top getting it ready.   I do have the Y and B axis slaved together and using a sensor on each side for the auto-squaring of the gantry.   That is why I chose the 5 axis version.   That seems to be working about as correctly as well.

I do have some questions about the "axis resolution" of the pulses per rev....   As I stated earlier, I have mine on 3000 for each axis.   I can't really find a lot of literature explaining how to best set this.    I know that more, or faster pulses = less torque for a stepper motor, but when I see some of the Youtube videos of people setting up their Masso, I see people using anything from 1000 to 6000.   Any quick explanation of this?

Quote from dreyfusduke on March 29, 2020, 1:14 am

I do have some questions about the "axis resolution" of the pulses per rev....   As I stated earlier, I have mine on 3000 for each axis.   I can't really find a lot of literature explaining how to best set this.    I know that more, or faster pulses = less torque for a stepper motor, but when I see some of the Youtube videos of people setting up their Masso, I see people using anything from 1000 to 6000.   Any quick explanation of this?

The setting in MASSO needs to match the setting in the driver, so if the driver requires 1600 pulse to rotate the motor one revolution, you need to tell MASSO that it requires 1600 pulses per rev.

MASSO uses the PPR and Distance per Revolution to calculate how many pulses need to be sent to move spindle the required distance. That is why you need to get DPR accurate and PPR correct.

In regards to the MPG, I'll leave that to Peter as he has access to the equipment to test it.

Regards,

Arie.

Arie,

In my case, I believe this fixed my issue. After setting Masso to the same as my dip switches, the handwheel is much more reliable. It does as expected now. 🙂

I set the distances pretty close. Now I will cut some squares so I can fine tune it.

Thank you guys again for the wonderful support.

 

I would call this solved.

Well.... Nevermind....

I changed everything to 1600 (per dip switch settings) and now another issue came up....

I ONLY changed the 3000 to 1600 and now just my Z axis will only move in the down direction no matter what.  Even using mouse or MPG.

Ummm....   Bugs?

As in if you hit plus.... It goes down.... Hit minus.... It goes down.

Even if you invert in software.... Still down.

Hi @dreyfusduke

We currently have a ticket open for jumpy movement on the G3 using the MPG and you might have given a clue us with your resolution change so thank you. We are still working on this.

With regards the one direction of travel check that you didn't accidently disconnect your direction wire when changing your resolution setting. Changing resolution won't cause a one direction of travel issue but simply changing the resolution back will test if I'm right.

Cheers Peter

 

 

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