DSP question

[dimky]

Hello!

When I'm trying to cut material with 1mm/sec speed, laser doesnt emitt while head moving around table, but if speed is 15mm/sec everything is ok. Why?

[twehr]

Hello!

When I'm trying to cut material with 1mm/sec speed, laser doesnt emitt while head moving around table, but if speed is 15mm/sec everything is ok. Why?

Dimky,

I have had a couple of instances where it seemed it was not firing, especially when doing very slow work (cutting acrylic, etc). Here are three things you can check/do to try to resolve it.

• 1. Make sure your laser tube has not overheated (I had one instance where it got too hot because the water pump was vapor-locked and not actually pumping water).
  
  2. Ensure you have both the Min power setting and the Max power setting the same. (Some situations, having them different, and too far apart, will cause the laser to not fire. Generally, unless you NEED the "ramp" effect, Max and Min power should always be the same.)
  
  3. Turn off both your computer and the laser for a bit - long enough for the controller and the laser power supply and the laser to all cool down to room temperature. (Had this one time when could not make it work, no matter what I tried. Rebooting, resetting all failed to help. Gave up for the night and next day, all was working perfectly.)

Marco may have other ideas, but these may help in the mean time. Good Luck! Let me know how it turns out for you.

[dimky]

Ok! I'l try soon and let you know. Thanks!

[dimky]

Hey twehr!

Second thing about laser power helped! Thanks! Laser now burn at 1mm/s without problems.

Btw, what speed usually use to cut 5mm acrylic with 40w laser tube?

[twehr]

Hey twehr!

Second thing about laser power helped! Thanks! Laser now burn at 1mm/s without problems.

Btw, what speed usually use to cut 5mm acrylic with 40w laser tube?

Glad it worked for you.

Mine is also a 40watt, but I sometimes doubt its actual strength. The other day I was cutting 2~3mm at 90% power and 1.5mm/sec. The last time I cut 6mm it was 95% at .75 mm/sec (I think - been a while). So if you are using a high % and cutting 5 mill at 1mm/sec, that is probably about right.

I keep "hoping" my laser tube will die, so I have an excuse to replace it with 60w or 80w. Just need to extend the case and buy a larger power supply.

Good luck with your use of the DSP. I know I love mine. If I can ever be of help again, just let me know.

[dimky]

I'm planning the same, i have enough space in my case, but PS for 80w tube not cheap!

Sure, this Lightobject DSP controller is cool thing! Must have.

Here is my little homemade engraver, just finished first build stage:

http://www.youtube.com/watch?v=pGk4gq7IOxw

I'm trying to engrave portraits on glass. Result not so good as i expecting, so far. I can't adjust right parametrs in corel draw when converting bitmap to b&w 1 bit mode. Do you have this experience? How is your result?

[twehr]

Here is my little homemade engraver, just finished first build stage:

I'm trying to engrave portraits on glass. Result not so good as i expecting, so far. I can't adjust right parametrs in corel draw when converting bitmap to b&w 1 bit mode. Do you have this experience? How is your result?

I watched your video - cool. Mine is a converted Chinese laser. I want to build my own so I can get a larger work area. What size is yours? Do you have any drawn plans or documentation on what you have done?

I haven't done much with photos since installing this controller, but want to. I did find an "action" script for Photoshop that does a very nice job. The script is free, if you own a copy of Photoshop. I don't have the name of it (or the source) right now, but can get it later today or this weekend, if you want it.

[dimky]

All plans was in my head Working area is 500 x 400 mm. Not lare but enough for most jobs. Construction is very simple.

Sure, waiting for this action script.

[twehr]

Sure, waiting for this action script.

I just found the link on the web.

http://www.dogcollarlabor.com/smc/index.html

There you can download the script, or at the bottom, you will find a link to the "actions".

[dimky]

Thanks!

Here is my todays result in attachment, engraved on dirty glass. I don't like it.

I want to get something like in this video:

http://www.youtube.com/watch?v=xABps6dy ... re=related

[baccus61]

It's actually pretty hard to engrave on glass.
You need to reduce your dots per inch to something like 150 and make sure you have your laser focused really well.
The laser blows little pieces of the glass away from the surface so you won't get a very good engraving. Try 15 watts at 4" per sec and 150 dots per inch.
Now if you engrave the back of a mirror then that is different and a little bit easier.
You can do this at 300 dots per inch (2" focal length lens) and 100% power and 3" per sec speed. PhotoGrav does a good job at converting the picture to mono 1 bit if you can afford it.
Then paint the back of the mirror to bring out the picture. Black paint works well for this. Don't forget to invert the picture as you will be looking at it from the other side.
If you get very small horizontal lines in the engraving then you need to increase your dots per inch to about 340 or there-a-bouts.
Let me know how you get on.
Rich.

[twehr]

dimky, baccus61,

We have started a Photo Engraving Techniques thread viewtopic.php?f=47&t=298&p=743#p743 on the new CO2 Laser Discussion board.