Big Ol' Laser, by Awesomenesser

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Re: Big Ol' Laser, by Awesomenesser

Postby awesomenesser » Fri Sep 09, 2011 6:32 pm

TLHarrell wrote:I would hope there is some sort of an alert condition prior to the safety loop being tripped. I've had a couple projects ruined due to my laser stopping in the middle of a run. Once from a USB glitch, once from the new computer going to sleep in mid-job. Give yourself time to respond to a condition.


I haven't planned everything out yet but did figure I wouldn't want it breaking the safety loop immediately. I figure I could set up a buzzer and have it give you a minute or so to respond before it breaks the loop (It would also have a ignore option).

Talking about glitches and tips for a successful build, The first time I plugged in my laser cabinet I set up mach3 so I could jog the axis around and tune the motors. I then turned the cabinet off and went and ate dinner. When I returned I flipped the cabinet on... and that is when it happened... I heard the most terrible noise of 60000V arcing and the flickering of blue and orange coming from under the laser power supply. I panicked went for the power switch but realized I don't want to be anywhere near the frame and unplugged the outlet. By the time I got it unplugged the power supply had shut itself off. At this point my heart just sank because I figured I not only just destroyed my expensive laser ps but my motor controllers, power supplies, and my laptop. I took a few seconds to figure out what happened and couldn't figure it why, but the laser ps had arced out of the high voltage connector then into the laser power supply case, the laser was not hooked up at this point in my build and the power supply was suppose to be unplugged but wasn't.

After a while I finally figure out what had happened because this shouldn't have been possible. While at dinner mach3 crashed locking up my computer, one note it looked like it was still running so it tricked me. The laser power supply was hooked up to the interface board so it was fully functional. When I returned from dinner and flipped the laser cabinet on I didn't know is that somehow the pc was sending the fire command across the parallel port and the estop was not on. The laser supply fired the laser releasing 60000V arcing out of the high voltage connector and back to the case a full 3 inches through the air. After a few seconds the power supply realized it was arching and shutdown right as I disconnected the power cord.

Luckily not only did the power supply take this hit, it works perfectly and so does all of my electronics and my computer. So I was quite lucky I was not injured in this accident.

The moral of the story:

1. Do not plug in the laser power supply before it is connected to the laser
2. Leave the estop on when you turn on the cabinet
3. Don't trust mach3 or at least make sure it is still responsive before turning the laser on
4. Oh and don't trust Chinese products to be fully up to safety spec. (I am pretty sure those connectors are not suppose to allow arching 3 times their length)
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Re: Big Ol' Laser, by Awesomenesser

Postby awesomenesser » Sat Sep 10, 2011 7:20 pm

I decided to swap out the e-stop switch because I already had a nice industrial switch in my pile of random junk. Why not use the fancy one that lights up. I mounted the stop in the top skin because I don't have enough room in the front skin. Just a note I used a harbor freight unibit to drill all the holes in the skins, they work rather well and they don't leave burrs.

P1010030.JPG
The top mounted e-stop.


I also finished up everything on the back of my unit so I decided to put it in its final location and hook up the ducting. One note this inline fan works perfectly, I would highly recommend getting one. I am using a fan speed controller with it and can only turn it up 3/4 before the laser starts whistling from the airflow through the case (You can play a tune by covering up different inlets).

P1010048.JPG
Side view of the ducting.

P1010047.JPG
Another side view of the ducting.


I also received my table surface from en-graves laser this morning. I decided to go with the "LaZer Cutting Grid" because it looked like the best option. It was $100 before shipping but I believe it will be worth it to get the best vector cuts. I will be posting a video soon of me cutting the new front panel out so we will see how it works. (Honey comb would still be more effective if somebody would spit a sheet up.)

P1010062.JPG
The laser cutting gris by the nozzle.

P1010065.JPG
The cutting grid from above.
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Re: Big Ol' Laser, by Awesomenesser

Postby J45on » Sat Sep 10, 2011 8:07 pm

I love your table / grid is it mounted or just free standing ?
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Re: Big Ol' Laser, by Awesomenesser

Postby naPS » Sat Sep 10, 2011 8:27 pm

I did a little write-up about it here : http://www.toddknapek.com/
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Re: Big Ol' Laser, by Awesomenesser

Postby awesomenesser » Sat Sep 10, 2011 8:56 pm

J45on wrote:I love your table / grid is it mounted or just free standing ?


It is free standing right now. I am going to cut some acrylic tabs that hold it in place on the extrusion.
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Re: Big Ol' Laser, by Awesomenesser

Postby awesomenesser » Sun Sep 11, 2011 7:19 am

I just finished cutting out my new interface panel. I made a video of the cut so if you are debating building a 2.x then take a look. Here is a link to the video in HD link. The laser cutter worked rather well, at least I have no complaints. I want to thank Bart for all the long hours assembling these kits and maintaining the site. I certainly would own a laser cutter if it wasn't for him. Thanks!!!



Here are some pictures of the new panel:

P1010071.JPG
The panel right after the cut.

P1010077.JPG
The acrylic with the paper removed.

P1010080.JPG
The interface panel with all components.

P1010084.JPG
The backside of the panel.

P1010089.JPG
The panel mounted in the laser cutter.

Front Panel.png
I say it looks fairly similar.


Now to just finish the wiring...
Last edited by awesomenesser on Sun Sep 11, 2011 9:53 am, edited 1 time in total.
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Re: Big Ol' Laser, by Awesomenesser

Postby awesomenesser » Sun Sep 11, 2011 9:50 am

And the wiring is done...

P1010094.JPG
The finished front panel with wiring.

P1010097.JPG
Testing of the wiring.

P1010102.JPG
The inside of the installed front panel.


Now to cut a pile of plastic into whatever I want...
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Re: Big Ol' Laser, by Awesomenesser

Postby educa » Tue Jan 24, 2012 7:26 am

I could not hear very well in your youtube video, but how much air per minute are you blowing out of the nozzle?

I think I heard 70 to 80 liter / min ? Am I right? It looks soo much ?

How do you pump that ?


Regards,
Bart
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Re: Big Ol' Laser, by Awesomenesser

Postby awesomenesser » Tue Jan 24, 2012 8:06 am

educa wrote:I could not hear very well in your youtube video, but how much air per minute are you blowing out of the nozzle?
I think I heard 70 to 80 liter / min ? Am I right? It looks soo much ?
How do you pump that ?
Regards,
Bart


I have a 70 Liter per minute pump that I bought off of ebay (My first post in this buildlog has more info about my whole build). One thing that I have discovered is when cutting acrylic in order to get the very clean and clear edges/sides you can't use much air assist at all. So during acrylic cuts I have a decent size hole (around a 1/4 inch) cut in the side of the tube to let most of the air pass through. I can still feel the airflow coming out of the nozzle mainly to protect the lens. But when cutting wood, cardboard, and thick paper I seal the hole up to get maximum airflow. The air pump is very loud and placed directly under the laser cabinet so that is why it was so audible.
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