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Author Topic: machine pauses after spindle/laser is triggerd  (Read 13335 times)

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machine pauses after spindle/laser is triggerd
« on: July 10, 2009, 02:28:47 PM »
i just built a laser cutter/engraver using smoothstepper and gecko320 and dc servos. all seems to work fine but when i try to cut something. it lights up the laser and pauses for about 1 second or so then starts to move. this would not be a problem if whatever i am cutting did not catch fire. i have no pause delays in the code. i am using pwm to control the laser power. any help would be great!

Offline Chip

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Re: machine pauses after spindle/laser is triggerd
« Reply #1 on: July 10, 2009, 02:56:18 PM »
Hi, Dave

Have you checked the Spindle Setup in Port' & Pin's setting's.

Chip
Re: machine pauses after spindle/laser is triggerd
« Reply #2 on: July 10, 2009, 06:10:37 PM »
All of the deleys are set to zero. Is there something specific you think I should look for in that menu? Thanks

Offline Chip

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Re: machine pauses after spindle/laser is triggerd
« Reply #3 on: July 10, 2009, 07:23:42 PM »
Hi, Dave

No just the delay setting's, There is a post on this issue, I'll try to find it, Hear it is, I don't think it was ever resolved though.

 http://www.machsupport.com/forum/index.php/topic,9086.0.html
Re: machine pauses after spindle/laser is triggerd
« Reply #4 on: July 11, 2009, 03:18:23 AM »
thanks for the read yes this is the same issue. but no one has fixed this yet! i will keep trying
Re: machine pauses after spindle/laser is triggerd
« Reply #5 on: August 15, 2009, 11:06:21 PM »
Guys,

I'm having the same problem with a pause after M3 to turn laser on. I'm using the spindle output in PWM mode to control laser power.  

I need to cut intricate shapes in paper and fabric. And then make slits around the perimeter of each shape.

The first problem is the pause as discussed in this post which is burning up a lot of time (pardon the expression).
This has a secondary effect of creating a round burn spot much larger than the normal curf at the start of each slit and anywhere else a cut starts.

It would be helpful if the solution to this also included the ability to vary the power based on xy feed rate since my corners are also getting burnt round.

I have also tried to use the z axis to control the laser power but when I start moving the Z axis, the voltage jumps to 5V and dosen't drop back to 0V even after the Z-Axis has reached it's destination.
Other issues I can't get my head around if this turn out to be the answer:
1. how to cause the Z-Axis to turn on and stay turned on (would I tell it to go to 7million?)
2. how to setup the motor tuning for the Z to vary the PWM from 0 to 5V
3. how dro scaling would fit into the picture (As i've read in some other older posts)

So far I love Mach 3 but this is really throwing cold water on the project.

Please help... I'm getting desperate!

Thanks in advance.

Roger
« Last Edit: August 15, 2009, 11:09:54 PM by RogerJames »

vmax549

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Re: machine pauses after spindle/laser is triggerd
« Reply #6 on: August 16, 2009, 04:13:01 PM »
OK for the corners CV should provide constant velocity.  IF not then it would be your CAMS job to provide the laser support code as far as laser power per feedrate.

Z axis feed to control the laser power,  NO

THE M3/delay with g1 has ALways been there and will probably never be changed even if it could be, Lasers are the only thing that would have an issue with this.

There may be a way around that by setting the  ACCell rate of the spindle output to a slower rate so the power would RAMP up preventing overheating/burning.

WOuld help you test but don't have a laser(;-) to play with

(;-) TP


Re: machine pauses after spindle/laser is triggerd
« Reply #7 on: August 16, 2009, 05:29:52 PM »
TP,

It sounds like you have experience with the M3 delay. Is this something that is well known? If the M3 delay can't be fixed, I'm going to abandon this method of control and look for another method of control. Do you know if this is part of Mach3 or some broader issue?

As for CV mode, how would the CV mode be used to produce a relationship between spindle speed (laser power) and feed rate?

Thanks,

RJ

vmax549

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Re: machine pauses after spindle/laser is triggerd
« Reply #8 on: August 16, 2009, 05:44:37 PM »
CV mode maintains a constant velocity of motion through curves and stops and starts. I t does not control spindle speed. IF you NEED to vary the speedle speed/laser output during a curve then that is the CAMS job not mach's

I would suggest try  slowing the accel curve in the spindle axis setup so the laser would ramp up to full power in the same delay as the motion(;-)

What values are you using to TUNE the spindle output when you used PWM output?  I come up with 60/1000/35 to match the .5 sec delay

(;-) TP
« Last Edit: August 16, 2009, 05:57:09 PM by vmax549 »
Re: machine pauses after spindle/laser is triggerd
« Reply #9 on: August 16, 2009, 08:54:03 PM »
Maybe I am missing something here but couldn't you just use another output other than what is designated for the spindle?

For example... let's say you use Output 4.  Set it to be used on a pin which is vacant.  Connect a 5VDC relay to that output and use that Relay to control your spindle.  Shouldn't be any delay there?

Then yiou would just need to create an M Code command to trigger the output from your program.  Not quite sure how to do that but I bet there are those smarter than me who could help???

Just a thought...

Sid