Parts are different dimensions in X and Y axis!

kiptech

KipTech
Hello there,

The dimensions during plasma cutting are wrong.

When i cut a plate of 50x50 it gets 50x60mm...

When i cut a circle of 100mm's it gets an oval ...

I'm out of ideas! (check the postprocessor, checked the settings ten times, measured the rack and pinions, checked the drives, checked everything.)

Only idea; disturbed signals? but the machine cuts 10 times the same fault, over and over again.
 

kiptech

KipTech
@Stephen

Yes i did! The axis move perfectly when they go at G00 travel speeds, al dimensions are correct.

But when i'm cutting @500 mm/min or 750 or 1000 the measurements are off.



The problem is in my motor drives or Masso.

I did a movement check to see when they get wrong. Below a feedrate of 2000mm/min the measurements are off.

Ringing signals? Wrong signal timing? To bad i don't have an oscilloscope.

The steppers dont lose steps! They get more steps then needed in low speeds, as seems.
 

testyourdesign

testyourdesign
Try to disconnect one of the drives an run the other to see if its interference. Also check that Masso pulse rate is below 50Hz. Might be pushing her to hard. Which software version are you using?

Cheers, Stephen Brown
 

kiptech

KipTech
Thanks you Stephen!

I can try that!

It only occurs when driving very slow. Even with the drives in full step mode (They ren at 1/16st first) it s the same story.

I'm around the 22.5kHz right now. So that would be an issue.

In one of my test tho i heart that wen one motor runs at full speed and i activate (jug mode) the other motor, there is a different sound for a while and wen acceleration is done. So are they (X and Y) influencing each other?!



BUT another thing:

I don't have 100% faith in my motor drivers. There is some signal processing going on in these digital drives, so maybe there is going something wrong? One of the z-axis (same brand drive as X and Y) (there are two) is responding strange, i built in a very known brand drive and that problem was solved...
 

masso-support

MASSO Support
Staff member
@kiptech as a test can you please just put like a pin on the Z axis and draw something on the bed by putting a piece of paper. With this test basically we want the plasma to be off as plasma makes a lot of electrical noise, so this way we will know that if its not the plasma adding noise to drive signals.

Also if the size is always off by the same amount then its not noise as noise related movement will always be random and different.

What's your controller serial number and software version please.
 

kiptech

KipTech
I've done that! No difference...

I've cut a couple of 5 circles that all get the same dimensions, and are all eyeshaped...

Also cut like a dozen squares, they have to be 50x50mm but being cut as 50mm x 60mm... in the Masso screen there is a perfect square!



@MASSO - Support: Software v3.38 for Serial No.5A-2668
 

kiptech

KipTech
In the last test i tested two lighter stepper motor drives for the two z-axis. One of the drives is connected to the A axis output of Masso en runs great! The other drive is connected to the Z axis output of Masso and is stalling, squeezing, beeping, messing around! When i switch the drives, same happend but a bit different in sounds end so on.

Drive seems to be out of tuning and missing all the signals/ steps.

I later connected two drives of the biggest brand around and the run very well in each setting i make! On both Masso ports!

Maybe my stepper motor drives are not working well with Masso? Is there something going wrong with signals inside the drives?

The same faulty brand drives are on my X and Y axis.......
 

kiptech

KipTech
This are the drives i used in the original setup:

Smart Motor Devices (brand):

SMD-4.2DIN (two peaces for controlling the z-axis)

SMD-8.0DIN (two peaces for controlling the x- and y-axis
 

masso-support

MASSO Support
Staff member
thanks, can you please make a quick wiring diagram on how you have connected the X, Y and Z axis signals from MASSO to these drives.
 

kiptech

KipTech
Like in the description from the Masso Documentation (Leadshine and Geckodrive wiring diagram):



Masso - > Drivers

X and Y axis:

X step + to X step

Y step + to Y step

X step - lose @ Masso side

Y step - lose @ Masso side

X step - driver to ground

Y step - driver to ground



Z and A axis:

Z step+ to Z step

Z dir+ to Z dir

Ground to ground

A step to A step

A dir to A dir

Ground to Ground
 

kiptech

KipTech
PROBLEM SOLVED!!!

I yesterday renewed the motordrivers and swapped them for Leadshine drives (DM856's).

The problems dissolved as snow for the sun.

Probably at least one of the SMD8.0din drives whas doing strange things.

I also swapped the SMD4.2din drives to Leadshines. The SMD-drive on the Z channel of Masso worked well. But the drive A-axis channel don't worked well! I have tried three of those drives, but none of them worked well on that channel! The same drive on the Z-axis channel worked all great!



Thanks for all the information and tips. It helpt for the final solution of my problem witch kept me busy for two days in a row.
 

kiptech

KipTech
Still got one question about signals coming out Masso!

I found this information in the datasheet of the SMD8.0DIN drives, see the attachment, about signals that can be used.

But what signals with witch characteristics does Masso use? Maybe this information is good to supply to customers, so they can evaluate problems and bye drives and other gear.
 

Attachments

  • SMD8SIGNAL.PNG
    SMD8SIGNAL.PNG
    51.3 KB · Views: 20

kiptech

KipTech
@clover

Thank you very much! Nice diagram! I connected and testen the drives as mentioned! But problems still occur, stangly the drives seems to be working well (only the SMD4.2 drives though) when using an other system for providing Step/ Dir signals...

@masso-support

I would be very glad to have an inside view of the Masso signals.

I wonder if the SMD-drives get the wright signals from Masso (and are usefull with Masso).

And i wonder what signals do when propelling several axis... I mentions soms changes in dry movement of three axis the same time. My power subs are very strong and there is no drop in voltage ore so. Though i can hear small movements when motion is going from one motor, to two motors, to three motors and so on.
 

masso-support

MASSO Support
Staff member
as the motor/drive can take differential signals, it will be better to wire both negative & positive signals of X, Y and Z axis from MASSO like the below (as example) as then the peak to peak signals will be much higher, will also give better noise immunity.

DM542A-and-DQ860MA-Diff.png
 

clover

clover
maybe we are looking at a different model or datasheet.

You are spot-on @masso-support. I have deleted my previous post. Agreed best to use differential out/ins as shown in diagram by Masso above.

The EN+ would still need to be connected as per my diagram above although depending on the exact model the 1,000 ohm resistor may or may not be required. The SMD8.0DIN needs the resistor.

The En- will still need to be connected to Ground or Common.
 
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