Engraving and Cutting not lining up. Help Please!

[G-laserguy]

Hi Charlie,

is you your laser still running with X-axis acceleration =10000 mm/s ?
This could be a reason for your problem too. Set it down to 1000 mm/s for testing. If the result is better than, you can be sure that the problem comes from stepper -driver or -motor.
A mechanical problem is possible too or a undersized power supply, Wrong settings on your stepper driver or a bad fixed lens / mirror.


Diemo

[Tech_Marco]

Hi Marco,

Thank you for testing that out for me. My pulse unit is set to 10 pulses per unit (um). I originally had it set for 1 pulse per unit (um) and when the Yaskawa engineer came to assist with tuning, he told us that the pulses were "not pretty" and that could cause problems after hooking up his computer to the drive as the dsp was driving the axis. We then set it for 10 and he old me it was acceptable. Could you ask the engineer what else I can do to make this work?

If you have been following my postings with Charlie, it seems that you guys have pretty much the same equipment yet your machine doesn't have any problems but his is exhibiting the same problem as mine and he isn't running servos. My question is, is it possible we both have the same machine setting problem and yours is set correctly.

Would you mind sharing your speed setting in terms of mm/sec and are you running x-swing or x_swing unilateralism? What is the next step for us to resolve this problem?

Thank you,

David

I will try to do it tomorrow. Been very busy in last couple days.
By the way, mine got a little shift because the machine I have is kind of wore-out to some extended. I may need to change the belt or the motor for testing. I got beter stepping motor than the original one.

Marco

[liaoh75]

Hi Marco,

I know you are a busy guy and I appreciate the fact that you are still trying to find a solution for me. At the moment I've got a work arround for the problem. I will put test dots on my work on a scrap and measure the amount of shifting on the engraved part and shift my graphics the appropriate distance to compensate for the shift and we have a temporary work around. However, I hope that this issue can be resolved. If I can do this work around by hand maybe there is some way to achieve the same in my settings somewhere.

I've asked the Yaskawa engineer to come back sometime in the next week or two to assist me with additional tuning and modifying my units per pulse to 1 pulse = 20um. Is there any other questions I should ask the Yaskawa engineer?

Thank you for your continued support and effort.

David

[Tech_Marco]

I will get a new model DSP in about a month. It's currently under development. It is color LCD and support G-code. If the AWC-608 doesn't work out, may be you can give a try of the new board. It's desgined soley for me. It's from different company who works for CNC for 'N' years. Very strong background.

So, no panic. I'll try my best to get you a working machine!


Marco

[baccus61]

Hi guys,
Interesting problem!
I had problems with my set up, but not this problem, and Tim suggested I set my Acceleration speed to 30,000 which fixed it. It was a slop over fault which you guys don't have but maybe you could try the setting and see what happens.

When I need to align certain graphics away from the 0,0 home/reference point I just place a single dot in the 0,0 corner of the drawing and set the laser to cut/engrave (doesn't matter) at a power of about 2 watts which the laser won't fire on.
This pads out the graphic to where you actually want the image to be. Been doing this from when I first used the laser program from "those other guys" and is quite quick to do and you can measure everything from that point and be assured your graphic will be where you want it to be.
If you put a dot in the corner 0,0 and convert to bitmap it may pad out your engraving to where you want it to be. Just a thought.
Rich.

[liaoh75]

Hi Marco,

Can you give me an update on the new controller you mentioned that might solve my problem please?

Thank you
David

[Snin]

Hey liaoh75,

i've been reading this thread and was interested if you've solved the problem? We also had (and solved, and have again) a lot of troubles with shifting. We also have a servo system. It could be a related problem.

Have you tested if the zero position of the machine also shifts? I mean does the laser head return to the same location where it started or is that also shifted? In our case this position was also shifting. It's easy to measure: choose the origin, fire the laser once, run the job, fire the laser once. If the two dots don't line up you know that the position shifted.

If it does, I can tell some more about our case.

Best,

Jiskar

[AVRC]

I have this problem as well with a converted K40 running steppers (TB6560 drivers), but it is intermittent.
It happens regardless of how fast the engraving speed and accell is set and does it both in X-Swing and Y-Swing.

liaoh75 and snin, please try this procedure that so far gives me correct results.

Set origin where you want it with "origin" button.
Power off machine and wait a few seconds
Turn on machine
Send file from computer
Press "origin"
Press "box"
Press "start" to begin job.

Do not fire laser with button during above procedure. If you must, do it before power down.

I have been working on this for 2 days and this has always worked so far. I'm running latest v7 firmware.

-Craig

[wctx1977]

Hi David!

Have you solved your problem yet? I found myself today in a problem similar to yours while "cutting after engraving" a file. The problem was that the cut lines where not matching with the edges of the engraved image and after I messed with my system for a couple of hours, I finally got it corrected. The fix was very simple but like I said, I had to dig and dig with frustration until I found it and I hope it helps to solve your issue considering that your machine is running with servo motors but it won't hurt to give it a try. OK, if you go to System settings on laser cad/ manufacturer parameters, then check what option you have selected for pulse edge on both axis (x,y) Rising edge or Falling edge. In my case I had Falling edge on both (x and y) and I switched both to Rising edge and it fixed the problem. I don't know why or what that means but it solved my issue about lines out of alignment. Try this and run more tests between settings and see what happens. Good luck and let us know what happens.

Edgar G

[Telrad]

The switch from falling edge to rising edge fixed my problem too! (Not that anybody knew I had a problem.)

[AVRC]

Changing to Rising edge seems to have fixed my problem as well.
I no longer have to jump through the hoops listed in my last post (up 3 posts) to get it to keep aligned.

Thanks for the tip
-Craig

[liaoh75]

Hi All,

Thanks for continuing to keep this topic alive. Unfortunately, I've tried changing from falling edge to rising edge, but the results were the same. I'm still awaiting news of the new controller Marco is working on. Hopefully, that will solve my problem. Does anyone know of another controller that is also DSP based but not Made in China? I heard of one in Italy but I can't remember where I saw it.

I still have faith in the Light Object DSP and appreciate all the work Marco has put in to help me. Everything else works well and the DSP is rock solid for cutting and engraving in general. The only issue for me is the Engraving and Cutting on the same job not lining up. Heck, for all I know there might be something setup wrong in my servos. Marco, can you give us an update on that new controller?

Thank all the members that selflessly contributed to help me track down my problem. I'd been so busy over the last few months, I hadn't even checked back. I'm sure we'll find a solution.

David

[Tech_Marco]

The new DSP controller not doing cutting well. Keep looking for another one.
Let me send you latest OS and LaserCad see if it solve your issue.

Marco

[waltfl]

Hi
I can only say after some setback My machine is doing a perfect job with the setting " cut after engraving" I use this all the time to bring out more of some picture like depth and with all the text.
the most importand part to prepare the machine is to bring the acurate um measurment settings in the X axis and Y axis settings
the measuring on the test square should be done with cutting and should be done with a caliper.
greetings
walt

The new DSP controller not doing cutting well. Keep looking for another one.
Let me send you latest OS and LaserCad see if it solve your issue.

Marco

[shaneburton]

Hey guys after trying all of the suggestions here I am still unable to get this to work correctly. Here are my settings and a picture of the the cut after engravings that I tried to do. I did check that the Um is set correctly, and my 100mm square measures out perfectly *almost*. It is about .33 mm off on both axis. So nonetheless I am at a loss on how to fix this. Any help would be greatly appreciated.

On the engraving/cutting picture, I did a multitude of settings.

Each square is set to 10mm/s/90% for cutting and 150mm/s/70% for engraving. The left side is falling edge and the right is rising edge. Then from top to bottom it is X_swing, X_unilateralism, Y_swing, Y_unilateralism.

As you can see none of the settings work right. I did not mess around with the max_acc or max_speed settings.