zigzag lines in the chinese laser co2 cutting machine

Hi dear
As you can see in our attached photos, A 1390 Laser machine that contains: Ruida RDC6442G Motherboard & Leadshine 3dm580 Motion Controller, has a problem with Cutting the desired small patterns on the material, and the final output (typically letters) comes out with zigzag edges. Every parts of the machine has been repaired or replaced with similar parts but the problem still exists. We appreciate hearing your solution


For resolving protest in the laser machine LC1390 is reported plan when cutting in areas of the curve.
When cutting plan in areas of the curve
Test and the following tests conducted
1. belt tension adjustment and ensuring the safety belt
2. Y axis alignment of the rail wagons axis.
3. manipulation regulation speed and acceleration parameter and device parameters.
4. replacing the motor and stepper motor driver and changes in switch setting of test driver.
5. replacing the mainboard RDC6442 with Leetro MPC6565

Attention: In cases 1 to 4 no changes was observed in about 5 to about 20%was achieved
http://www.cnczone.com/forums/attach...d=366062&stc=1http://www.cnczone.com/forums/attach...d=366064&stc=1

i have same problem on RD1390.

Have you checked for backlash?

Is the bag set on the Chinese machine for engraving only?????????Attachment 366680

Are you in area with a lot of dust/sand? What grease/oil do you use?

[QUOTE=abyss;2066000]Are you in area with a lot of dust/sand? What grease/oil do you use?[/QUOTE

yes
the axes are cleaned and greased

I had the same issue and the problem is caused by the acceleration when changing direction, I use different software (lasercut5.3) so cant say where the setting is in your's however it was the corner acceleration setting in mine that was set to too high a value.

Try cutting a square that has been cut into 4 triangles and post those results. cut one at 90 degrees then another that has been turned 45 degrees as a whole. leave about 5 mm between sections. and make three squares of varying size from 30mm , 60mm to 100mm overall size... also include a circle for each set of squares that is equal in size to the associated square.... 30mm square 90 & 45 plus one circle 30 mm.. etc.

basically this makes 9 shapes to cut please post your results

Quote:

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Originally Posted by SignWave

Try cutting a square that has been cut into 4 triangles and post those results. cut one at 90 degrees then another that has been turned 45 degrees as a whole. leave about 5 mm between sections. and make three squares of varying size from 30mm , 60mm to 100mm overall size... also include a circle for each set of squares that is equal in size to the associated square.... 30mm square 90 & 45 plus one circle 30 mm.. etc.

basically this makes 9 shapes to cut please post your results

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Thanks for your answering
and I would appreciate if you send me vector of this.
I am waiting for your answering.
thanks

yeah... its not really up to me to create the files for you to test on your machine.. this will only take you a few minutes to create. I am not able to load a vector to this website. Im not familiar with doing so.

Here you have test files - not exactly same as mentioned, but idea is close.
https://www.cnc.info.pl/download.htm...158&special=97

it must be your focus lens or the head that carrying it check if there is any backlash

Check all your mirrors and lens to be sure they are not loose

Quote:

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Originally Posted by fixtureman1

Check all your mirrors and lens to be sure they are not loose

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This sort of makes sense. Something is loose someplace... OR there is an internal anomaly in the controller. When the head changes direction, is there any sort of rattle or mechanical/electrical noise? If you cut very slowly. will you get the same zig zag line? or does it go away ?

The purpose of the test file is to determine in which plane that the error occurs. It can only be one of two things... mechaincal failure/error/misadjustment of some portion of the drive system, or an electrical error.. ie excessive acceleration of either one of both axis.. If you did not adjust any configurations in your software and this error simply just began to happen... then look for loose parts... as Fixtureman suggests...Also, Check all aspects of your Y axi... It looks like your head is hitting a "speed bump" and then carries on normally once the oscillation stops only to repeat the process at the next directional change..

also try greasing the linear bearings that your gantry and focus head are mounted to.. You may need to acquire a grease gun with a needle tip in order to do so.

Quote:

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Originally Posted by SignWave

This sort of makes sense. Something is loose someplace... OR there is an internal anomaly in the controller. When the head changes direction, is there any sort of rattle or mechanical/electrical noise? If you cut very slowly. will you get the same zig zag line? or does it go away ?

The purpose of the test file is to determine in which plane that the error occurs. It can only be one of two things... mechaincal failure/error/misadjustment of some portion of the drive system, or an electrical error.. ie excessive acceleration of either one of both axis.. If you did not adjust any configurations in your software and this error simply just began to happen... then look for loose parts... as Fixtureman suggests...Also, Check all aspects of your Y axi... It looks like your head is hitting a "speed bump" and then carries on normally once the oscillation stops only to repeat the process at the next directional change..

also try greasing the linear bearings that your gantry and focus head are mounted to.. You may need to acquire a grease gun with a needle tip in order to do so.

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thanks for your anserwing
Attachment 367600
Attachment 367602
Attachment 367598

At what speed was done this test?
As can I see distortions of lines at "2017" are lower than 0.1mm and persist for 0.2mm. They are in both X and Y directions, so probably they are NOT related to particular axis. For me looks more like shaking of (for example) laser tube or mirror.
1. If you cut again in same place (just moving material by 2-3 cm) is this distortion exactly same?
2. Whats going on when you make speed 200% or 50% of previous? Size of distortion change proportionally?

Quote:

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Originally Posted by abyss

At what speed was done this test?
As can I see distortions of lines at "2017" are lower than 0.1mm and persist for 0.2mm. They are in both X and Y directions, so probably they are NOT related to particular axis. For me looks more like shaking of (for example) laser tube or mirror.
1. If you cut again in same place (just moving material by 2-3 cm) is this distortion exactly same?
2. Whats going on when you make speed 200% or 50% of previous? Size of distortion change proportionally?

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We search all of objects (such as lens, tube laser, mirror, axes, belt and etc.)- all of them are ok.
1. This distortion is exactly same in all of worktable.
2. When we reduce a little speed, It's not happen but when we reduce speed a lot, distortion a little reduce

I guess this problem is for motion controller, because We use RDC6442G for this machine and when we change motion controller and use other RDC6442G nothing happened. But we change it with other brand like Leetro MPC6565 it improve.
of course, we want use RDC6442G for these machines.

If you have good quality, sinus UPS (say APC) try work with it.
And check voltage (24V) in laser. Or even swap for the other for a while if you have.
Maybe there is a problem with poor quality energy supply what results in "laziness" and unstable of work motors / drivers ?