Hello Guest it is September 18, 2019, 08:56:36 AM

Author Topic: Waterjet Diagonal lines  (Read 1326 times)

0 Members and 1 Guest are viewing this topic.

Waterjet Diagonal lines
« on: March 29, 2017, 06:03:07 AM »
Hi All,

Recently i encountered a problem when cutting diagonal lines.
First i tried to look if there were any hardware problems, some bearings were a little loose but nothing serious.
My second step was looking if the problem still occurred when using the axis separately.
This resulted in clean cuts.

The wavy pattern can be traced back to the tool path. Here you can see the "point" dance around the actual cutting line.

Does somebody have any idea how to solve this?

Thanks in advance,

Jim  
Re: Waterjet Diagonal lines
« Reply #1 on: March 29, 2017, 03:45:51 PM »
I'd say you have lots of backlash in your X and Y axis. If belt drive I'd think the belts are too loose. They tighten up and stretch then the gantry jumps forward repeatedly.

Offline rcaffin

*
  •  1,003 1,003
    • View Profile
Diagonal Lines not smooth
« Reply #2 on: March 29, 2017, 04:58:08 PM »
some bearings were a little loose but nothing serious
LOL  If you can feel any looseness at all, that is far, far too much. Fix the mechanics.

You probably won't see the problem with single axis cuts. But it is still there.

Cheers
Roger
Diagonal Lines not smooth
« Reply #3 on: March 30, 2017, 03:09:41 AM »
@rcaffin

The mechanics is fixed. The machine sounds and rides good, all the bearings are tightened.
Mach3's tool path show's the wavy pattern inside the program. 
Machsupport said : It could be EMF or Noise in the system. Do you have access to an Oscilloscope to test with?

Not sure how to test this...
Re: Waterjet Diagonal lines
« Reply #4 on: March 30, 2017, 03:15:03 AM »
@garyhlucas

We do not use a belt drive. We use a system of linear guides and gears.
Do you think backlash is still an issue?

Offline Davek0974

*
  •  2,577 2,577
    • View Profile
    • DD Metal Products Ltd
Diagonal Lines not smooth
« Reply #5 on: March 30, 2017, 04:18:14 AM »
@rcaffin

Mach3's tool path show's the wavy pattern inside the program. 


If the tool path shows the wavy lines it can only be a file issue surely? - not electro-mechanical.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives
Diagonal Lines not smooth
« Reply #6 on: March 30, 2017, 04:56:45 AM »
I can try a different file.
I export my .DXF's from Solidworks, ik can try some autocad files to see is there is any change.
Re: Waterjet Diagonal lines
« Reply #7 on: March 30, 2017, 09:21:32 PM »
Don't try a different file. Just type in the G-code to cut a single diagonal line and use that. Then you know it is not related to how the file was created. Also if your motors are servos this could be excessive servo lag. A servo has feedback and can't actually correct it's path without an error to detect. So if it is slow to recognize the error it will suddenly make a correction to get where it is supposed to be after it has already cut in the wrong place.