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bit of an odd one Laser cuts well on Y but not quite on X

Posted: Sat Apr 06, 2013 4:10 pm
by twosoc
Hey, as the title says really, just assembled the new xy stages, checked everything was square, nearly tore my hair out to align it until I realised the first mirror was out of position by 25mm :D Oh how I laughed at myself....... Got my bed height right and tried it for the first time.

Using the same power and speeds I used to use on the old stages, my 50x50 box is spot on for size, but the cuts go all the way through on the Y lines but not on the X, its nearly there, but not quite. Its not an alignment problem as the Y parallel lines are both cutting evenly, Could it be a stepepr setting? I haven't changed the stepper drivers, as they seemed to work well, I've got the ECNC-2M542 driver,s and the 600x 400 lite stages, does anyone know the setting I should have them on?

thanks in advance,
Tim.

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sat Apr 06, 2013 4:33 pm
by Tech_Marco
Did you setup power correctly? For cutting, you need to set both Max power (straight line) and mini power (corner).
2M542 for Lite 4060? Humm.... The X motor is running 0.45A and the Y motor is running 1A. I don't think 2M542 can lower it's current than 1A.
Also, for the Lite 4080, I think the best resolution is "1/8" or "1/16"


Marco

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sun Apr 07, 2013 2:17 am
by waltfl
Hi tim
the stepper for cuttingneed to be set at a slow speed what speed did you set? by 12mm it should be no more then max 8mm/s
this is the x speed because usually the Y axis runs slower.there is another possibility if your bed is not level meaning the same distance from laserhead to material this could be one more reason that on some areas the cut does not get all the way .
greetings
waltfl

twosoc wrote:Hey, as the title says really, just assembled the new xy stages, checked everything was square, nearly tore my hair out to align it until I realised the first mirror was out of position by 25mm :D Oh how I laughed at myself....... Got my bed height right and tried it for the first time.

Using the same power and speeds I used to use on the old stages, my 50x50 box is spot on for size, but the cuts go all the way through on the Y lines but not on the X, its nearly there, but not quite. Its not an alignment problem as the Y parallel lines are both cutting evenly, Could it be a stepepr setting? I haven't changed the stepper drivers, as they seemed to work well, I've got the ECNC-2M542 driver,s and the 600x 400 lite stages, does anyone know the setting I should have them on?

thanks in advance,
Tim.

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sun Apr 07, 2013 3:58 am
by twosoc
hi, Powers all set Marco, whats the difference between power 1 and power 2? I've never been able to work that one out. Do you think I need a new stepper motor for the x motor? It does get quite hot.
Walt, I'm cutting 1.5mm mountboard, at speed 30 power 35, max 35 min. (I've not noticed a difference in changing power min). the bed's level, and square. Like I say, both horizontal lines cut beautifully, its just the horizontal ones that aren't quite there. I'll takea look at the resolution for it, I haven't changed that, I thought I'd see what people suggested before I messed about with something I didn't quite know.
Cheers guys.

edit :- just checked my settings I have the stepper set to half power, so it should be pulling 0.5A, the settings are on 800/per rev.

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sun Apr 07, 2013 12:37 pm
by Greolt
The other thing I would look at is the beam shape.

If you use an air assist nozzle, maybe the beam is partly hitting the nozzle resulting in a "quarter moon" shaped beam.

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sun Apr 07, 2013 2:36 pm
by twosoc
that possibly happened on the last laser, I noticed sometimes it would jiggle round and not always cut very well, but I've not got round to fitting it on this one yet. I think I'll have to just suck it up and either use more power or slower speed to ensure a good cut,

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sun Apr 07, 2013 3:25 pm
by Tech_Marco
The DSP controller can output two signals for two laser power supply simultaneously for dual tube system.
But what I was saying from my last post was that there was "Max power" and "Min power" for power 1 and power 2.

As I already mentioned, Max power is set for straight line traveling while the mini power is set for corner during cutting. If you found that the no fire or very light fire happened to the corner, then you may want to raise the power % on mini power. Let's say you have 80% on Max, I'll try 65% on corner.

Also, like Greolt said, double check the beam alignment. If the beam hitting the inner wall, you would end up 'broken' line during cutting. Plus, you may seem a 'flash' light coming out from the laser head instead of fine 'dot'.


Marco

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Sun Apr 07, 2013 3:33 pm
by Tech_Marco
twosoc wrote:hi, Powers all set Marco, whats the difference between power 1 and power 2? I've never been able to work that one out. Do you think I need a new stepper motor for the x motor? It does get quite hot.
Walt, I'm cutting 1.5mm mountboard, at speed 30 power 35, max 35 min. (I've not noticed a difference in changing power min). the bed's level, and square. Like I say, both horizontal lines cut beautifully, its just the horizontal ones that aren't quite there. I'll takea look at the resolution for it, I haven't changed that, I thought I'd see what people suggested before I messed about with something I didn't quite know.
Cheers guys.

edit :- just checked my settings I have the stepper set to half power, so it should be pulling 0.5A, the settings are on 800/per rev.

The "half current" I believe that it is the current used to lock up the motor when the motor is in idle (not moving). That's why stepping motor is getting hotter when it is not moving. You should use 2M415 in this case for the X motor or upgrade a higher current X motor.

800/rev (1/4) seems a little high. I'll change it to 1600 (1/8) for smoother operation and finer.

Marco

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Mon Apr 08, 2013 4:10 am
by twosoc
Ah right I see, I'll see if I can pick one up. Thanks for the clarification on res, I wasn't quite sure of the difference between when you stated "1/8" or "1/16" and how it related to the table printed on the motor driver, I'll give them a whirl.
Cheers, Tim.

Re: bit of an odd one Laser cuts well on Y but not quite on

Posted: Tue Apr 09, 2013 11:42 am
by twosoc
Hey, fiddled about with things, and I think it might be a stepper setting problem as I've got the x to cut well, but now the Y doesn't.

Its so frustrating, but I guess thats the fun of building your own :) Now my question is, I have both the steppers set to 1600 per Marco's recommendation, would both steppers be set to the same or can they both be different?