Wow! That's awesome, Star Wars home defence! I have soo many questions.

What's the power rating
Does it need cooling

For starters

Crazy ! But in a good way. Be Safe !

Do you know: http://www.lasersaur.com/

Dale,
Power is 80W. The Acrylic was cut using 40W. Could maybe do 1/4" with less. Cooling is done with a pond pump like the spindles. Setup is as easy as a spindle except for the mounting.

Fox,
Really crazy, I powered it thru my contactor so it will shut down if I hit the E-Stop. problem is finding the E-Stop with my remaining good eye.

Got a plug gauge and measured the holes. Supposed to be smaller than that. Once I get it connected to the controller I can shorten the on time and they should get smaller.

On the circles the ID of the hole is .526, the OD of the plug is .514, the kerf is
.012/2 = .006

My goal is to make the Dragon Fly (found on CNCZone).

I think that all the lasers I've seen have had the tube mounted horizontally, with the beam redirected with mirrors. Are you seeing any issues with the tube swaying back and forth with direction changes?

The advantage of the horizontal mount is that the moving head is really lite and can move like an ink jet printer burning graphics onto things. The X and Y rails need to be even an straight to use mirrors.
With the tube vertical I decreased the acceleration and deceleration to reduce the Gs on the tube. I have not found a definitive number for the max Gs the tube can take. My mount is solid to the Z plate. The risk of stopping or going too fast is breaking the internal structure in the tube. Mach3 adjusts the power with speed when burning graphics.

Very interesting!

Cool Stuff - Have I mentioned lately how much I love this platform !!! . MechMater's are a great bunch for sure !!!!

Now you've done it Fox, a DIY laser is going to bug me for weeks! :)

BECAUSE YOU CAN!!!
Loving it!!!

This is a good read. This is the thread where I got most of my info.

http://www.machsupport.com/forum/ind...c,12444.0.html

congratulations friend

A lasersauer is on my to do list for more than a year, but first I need the mm to earn it's keep.:D

Fox,
Have you seen this one?

http://www.openbuilds.com/

Impressive.....Congrats ;)

You mean the one based on the lasersauer? I must admit I have not dived into all the details, but on first glance the lasersauer looked like a well made open source plan and machine. But I might just buy a Chinese one http://www.wklaser.com/pro_195.aspx they are not bad and compared to a diy they don't cost much more. But like said, first things first. Make money with the mm, to regain costs and pay for a laser.

The folks at 'buildyourcnc.com' sells a 'black tooth' laser cutter -- looks a lot like the lasersaur project to me -- but one thing they do is to mount the laser on the CNC Y-axis carrier. Supposedly it manks keeps the alignment better and easier. ... Not sure if it does, but it is another method!

buildlog.net is another DIY CO2 Laser build. One thing they suggest is to NOT order the laser tube itself until right before you are ready to use it. Evidently they have a shelf life of 2 to 3 years whether in use or not. -- that may not be true, but it is my current belief from what I have seen posted.

The tube is charged with Co2, like all pressurized vessels, it will leak over time... for what ever reasons...

Cutting with a laser is sweet. Had to try the butterfly file. Reduced the size until the slots in the parts matched .015" (.38mm) card stock paper.

It was easier to cut than to assemble.

Then a seasonal theme.
Card stock
Free wood floor samples from HD
Glass tile, bright sunlight shows shadow

Chatter on edges is probably stepper motor related. . .

That is just too cool, well done!

...with a part that small, I would venture to guess the part moved and the stepper did it's job. How did you hold it?
On stuff that small I would "sandwich" what I was cutting or glue it to a sacrificial part and release it after cutting.

Note Sean this was cut with a laser so no physical contact to cause movement?

laser! Didn't catch that part...okay - stepper / microstep driver issue.

Unless he does not have gear reduction or a low steps per revolution, those marks appear to be 0.030" apart. I do photocarve and plastic plates with a 0.005" bit and have not seen a deviation like that. That would be worth solving. Even though it is laser cut I don't see how the steps would produce the sawtooth pattern. Unless it is transmitted vibration.

Laser tube overhang is very severe. IMHO, the laser tube mount isn't rigid enuf.

That could easily be checked, run the same file ultra slow. If the marks dissapear ken's correct. I would guess it's a combination of factors ( beam focus / material flatness / mechanical backclash / huge Z is swaying ever so little etc. )

I don't belief a slender 4' long tube mounted on one end with 4~8" spaced mounting would stay plumb over the course of traveling. It gravity defying... don't need Sir Isaac Newton to tell me that.
BUT then again, nobody said you can't do it, just not the best possible configuration. This patch job did works to a degree of satisfaction is a winner. It cuts after all.
This sure is a very heroic thing to do... I don't have the guts to run any laser tube this way without properly covering any possible/accidental/stray rays zapping around. I still want to be around for the next 40 or so years with all limps & any bodily organs still intact.

I have a 3:1 belt drive but this is very small steps. What I'll do is run some diamond shapes to see how the diagonals look up close. Also try it at different speeds to see if it changes.

Ken, the beam coming out of the laser is 6mm diameter. It is then run thru a focus lens the takes it to a spot .006" in diameter 2" away. The beam converges then expands. At 4 inches from the lens has expanded back to 6mm, another 2 inches away it is 12 mm. I think that the power density is decreasing by the square of the distance. By the time the beam hits the spoil board it makes a 3/8" smoldering dot that is not cutting at all.

John, i'm not sure how you were scaling but I notice a change in smoothness anytime I use the '[I]scale'[I] feature in Mach, not much but some.

John,
I'm aware of the power density & the science of LASER utility, but it is laser after all, one flash at the eye & anything can happen... Maybe its my excuse to stay lazy :p

Anyway, I do enjoy your work very much.

One the cut quality, we need max acceleration but with higher acceleration come greater force tilting the tube. slowing down isn't the solution. maybe just for testing, reduce the acceleration & see if the zig-zag get better. if it does, you need to improve the mounting rigidity.

I'll try the different speed thing to see what I get. I run it pretty slow to keep the stress on the tube low.
I have been scaling in Aspire and recalculating the tool path. I need to check to see if that area is a sieries of short lines or a smooth curve. May make a difference.
Gotta do the holiday stuff before I can get back to the dog house.

A friend ask me to cut some Angels for Christmas. I could cut 10 at a time with 20 Watts.
I picked up longer high voltage cable so I can install everything thru the wraps.

The Laser is okay but I want to get back to the spindle carving.

Cool Stuff!!

I've been busy doing a bunch of other stuff but here are some of my experiments.

Great work John.

What is the material of the plaques above?

What speed do you cut the lettering of plaques at?

Thanks Jason,
The plaques are marble, and I cut them at 40 in/min.

Love the snowflakes.
Very intricate and precise.

Mister Asshole as well. I would use a slightly different spelling, but I am from England.

Hi John.....
Well, since your posts on your laser.....it's been...twitching me pretty much to see how I may install one too, although not as intricate as yours, but say a more, modest low cost & lower install implication model !

Finally found one and committed to buy, it's now on "production" and should be ship to me any day soon !! :D
I come to you in hope you may share this "found out how to interface with Mach3 and Aspire's post processor" you've posted some time ago ( post 313, Nov.14) !

Thks