Advice on laser engraver

[kbraat]

Hey Angus: Is this the same laser that Jackie says you almost burnt the barn down with?

On a more serious note I am finding myself with an extra controller and motors and have been considering strongly building a flatbed laser to cut up to 1/4" ply and plexi (mainly) but know nothing yet about appropriate lasers and sources. Since I normally get these kinds of projects done so quickly () and this looks like a good place on this forum to start without hijacking, but rather supplementing, the existing thread, any added comments by those in the know on info to assist is welcome.

Dave,

I would skip the laser for normal plywood. The laser has some issues with cutting the glue layers on many types. We tried some oak and luan and some could catch fire easily. The Baltic birch cuts like butter - I just ordered a pallet of 1/8" for projects.

Acrylic cuts nicely. Polycarbonate cuts, but gives off corrosive, nasty harmful vapors.

[danhamm]

Dave we leased a 120 watt laser awhile back, and did cut plywood with it.. The problem with plywood is the tiny flaws and glue, any airspace and when you cut it it blows, instant fire..but saying that it carries on and you deal with the hot spot.
I didn't have a cnc at the time, so that is the reason for using the laser, the plywood was 1/2 in fir plywood.

[Xray]

@John, The best advise I can give you is whatever you decide on DO NOT BUY IT FROM SIGNWAREHOUSE !!!! They may be cheap but you will pay for it in the long run !!!

I actuqally have a very good off shore laser made by GCC http://www.gccworld.comthey are made in Hong Kong but they use American Tubes (SYNRAD) and internals so, that may be an option for you to.

And I suggest for your best audiance for this question you go register at www.sawmillcreek.org and ask this question in the Engravers forum you will find a much broader Laser user base there using all sorts of lasers. Epilog, Trotec, Kern, GCC ect.

Oh and if you have the funds $$$$$$$ KERN is the laser to own !!

Sawmillcreek is bizarre - I have been trying off and on to register there for months, it refuses to accept any user name I may put it. I have tried in multiple browsers, that site seems set up to refuse any new members.

[dana_swift]

First subject:

On the subject of fire when cutting plywood.. could you use C02 as the purge gas instead of compressed air? A bottle of CO2 seems cheap compared to replacing a shop.


Second subject:

Building my own CO2 laser cutter/engraver. I have been looking at the cost of laser components from:

http://www.lightobject.com/CNC-CO2-Laser-C11.aspx

Building a laser cutter would require a dedicated enclosure, and a good beam stop. I cant see where I couldn't build the enclosure with the bot, and probably the beamstop also. Anodized aluminum.. (dark black) should absorb the laser energy pretty well. Also it can hold a "bed of nails" to support the work.

Figuring I could build the laser I want for about $3000, vs purchase one for about $30000 and up, its getting its share of brain time. Its a whole lot easier to come up with enough $$$ to build one. Plus if it breaks, I know exactly how to fix it.

Dave R if you are really interested in building one, maybe we should chat.

I have also been thinking about building a machine that runs about 100 watts for cutting 1/2 and 3/4 plywood in one shot. Then later replacing the laser and optical components with about 400 or 500 watts and being able to cut steel and other metals.

Any thoughts?

D

[angus_hines]

At Doug. Yes, Sawmillcreek.org is set up to use a real name. Not a screenname so If your trying to use something like "ILIKEWOOD' or just "DOUG" yes it wont let you register that way. Its looking strictly for a first, last name format.

The owner believes that if you have to hide on the internet then your probably not going to always say good things, but, if your posting under your real name then you will think twice before posting spam or drama.

And I'll have to say, after being there for 6 years now IT WORKS !!! I may have only seen in that time 1 or 2 posts that are spam or the "your a F(*&ing idiot" type post.

So try again and if you still have issues I can get Keith Outten (the owner and creator of this new shopbot forum) to help you out !

[danhamm]

Some thoughts...yes, We went through it about 11 years ago...we copied the universal laser, with the exception ours was a larger format, some where back in the "shopbot archives" there will be a few mentions of it..
But I think they had a server crash or change over with a loss of records somewhere in the early 2000's..
Our first problem was control board we tried to buy one from Universal but they wanted the old one in exchange..unuh..after a lot of searching we recieved one from reseller parts supplier..at a very high price.. our next problem was software, we bought drivers from another manufacturer to get a larger format output. we finally got operational...somewhat..
The control board excitation for the laser output was unstable and unusable, the seller was not sympathetic at all, as it was driving a different tube than oringinally meant for.. researching we discovered some interfacing electronics was missing, so with some help got that resolved.
Testing... we live on 100 acres very rural, closest Neighbour 1/2 mile,
Our shop is quite close to the highway about 400 ft. on this particular day a pickup came in and a fella jumped out, we had the shop doors open, nice weather.. he came up to me and said.. every time I go by here my CB radio goes crazy.?? what do you do here.? so....
After some investigation we discovered our little laser was braodcasting on the 10 meter band, quite nicely..
Now this laser tube was a synrad enclosed tube, its frequency was somewhere in the 27-28 megahertz range...when excited..
It was easily fixed with a little grounding and shrouding...

The laser worked fine, but was basically useless... if you think 3/d on a shopbot is slow..try rastering a 4x4 image at 1000 lines per inch at 20 inches a second... we spent "some money" on speeding it up .. but the faster you go the more power you need, laser wise and axis wise so after
a lot of learning and researching...we bought a larger format 100 watt machine..

[Xray]

At Doug. Yes, Sawmillcreek.org is set up to use a real name. Not a screenname so If your trying to use something like "ILIKEWOOD' or just "DOUG" yes it wont let you register that way. Its looking strictly for a first, last name format.

The owner believes that if you have to hide on the internet then your probably not going to always say good things, but, if your posting under your real name then you will think twice before posting spam or drama.

And I'll have to say, after being there for 6 years now IT WORKS !!! I may have only seen in that time 1 or 2 posts that are spam or the "your a F(*&ing idiot" type post.

So try again and if you still have issues I can get Keith Outten (the owner and creator of this new shopbot forum) to help you out !

Makes sense, in theory. Most internet users who have been on forums nearly a decade, use of screen names is such a habit that its nearly compulsory. Problem with this method, and I'm sure I'm not the only one, is my actual name [Doug Kramer] is already in use ... So now I have the choice of registering under a false or modified name, or not having an account.
With all those hoops to jump through, I think I'll go with the 2nd option. I think the theory that using real names will keep the trolls at bay is a very stretched theory anyhow, as anyone could just register as Joseph Stalin Jr, and troll away, just as well as if they registered as Trollguy99.

[SomeSailor]

@John, The best advise I can give you is whatever you decide on DO NOT BUY IT FROM SIGNWAREHOUSE !!!! They may be cheap but you will pay for it in the long run !!!

I actuqally have a very good off shore laser made by GCC http://www.gccworld.comthey are made in Hong Kong but they use American Tubes (SYNRAD) and internals so, that may be an option for you to.

That's funny. They are the same units. A Pinnacle M Series from Sign Warehouse is identical to a GCC Laserpro. And yes, they use American tubes. I have a 65W Pinnacle with a Coherent tube. It's been running wonderfully since 2004. Never had a problem.

They are Laserpro enclosures that are just branded by Signwarehouse.

[John Rucker]

Hey John,

I have a 30 watt Universal in my shop as well as my bot. It has been a great compliment to my business. If you have any questions you may contact me at Four One 9- nine four four 6 five 6 five. or send me an email ... Rick (at) ToledoLaser dot com.

Rick Wyatt

Thanks Rick!! Sounds like you have almost the exact setup I'm thinking about. Did you install the laser yourself? I have been talking with Universal and they are pushing me to a dealer but I prefer to do the install myself. I just don’t see what the big deal is other than the venting and air supply. What did you end up doing for the venting and air supply? Thanks!!

[RickWyatt]

Install is fairly simple.... However, a knowledgeable rep would make sure it goes smoothly(not to mention it may affect the warranty) .

For ventilation I used a 1hp dust collector from Harbor Freight and piped it out of the roof of my building. (smell from burning leather could bother neighbors!)

As far as air supply.... I do not have the air assist option, nor have I found a need for it yet.

I do have a rotary attachment and honeycomb cutting table.

Rick