DIY Laser Etcher/Cutter

[ubooze]

Well, I know I am getting way ahead of myself, but still knowledge can't be harmful. I don't even own a mill!

What would it take to build a nice PC powered laser etcher/cutter? I think intergrating it into normal PC operation would be almost impossible for the average joe, so the next option would be building it on the CNC router platform.

Lasers could be one of these: http://www.co2laser.com/english/index.html

Table: http://www.ulsinc.com/english/laser_...ng_table1.html

Problems I foresee:
- Accuracy and speed and the same time. This thing needs little torque but it does need to be very quick and quite accurate in order to do a half-decent job.

- Power to the laser and air too the laser. If the main unit(head) moves to quickly the laser and its air supply, which ought to be used to blow away particles in order to prevent burning, may cause some sort of restrictions on how fast it can move. Of course a large company that does this day to day has the whole idea thought out, but use DIYers may find a problem in trying to prevent the cables and hoses from impeding in speed an accuracy.

- Control. Doesn't a laser need a focuser? Is that self controlled or does software/drivers play a role in this? Also, what could be done to control the intensity of the laser so that it cust when needed and etches when its supposed to? Conventional CNC should work, but I assume some sort of driver would need to be plugged in in order to convert spindle speeds in laser intensity, but is it possible?

- 2,3, or 4-axis? Does the DIYer make a simple X and Y axi(sp?) machine? Or do they also add the Z and a C? My idea was have a X, a Y, and a C and a manually adjustable Z in order to adjust clearance for larger objects.

-Construction. Should it be aluminum extrusions, plasic, tubes and bearing, roller blade wheels and channel, or plywood and drawer hardware? Cable driven or ball screws? I would say plastic or plywood should suffice for this overhead gantry type machine. Since the structure need not be extremely stiff and lightness of the assembly could help in the movement. Also, this construction would save money since the laser and table and controls would probably cost a lot more. But, will it weat, be reliable, low maintenance, and hold a decent accuracy?

-Safety. How to prevent it from blowing up.... well, actually more likely to just burn a hole through everything. Would a nice thick steel plate serve as a resting point? Maybe a plate submerged in a water. But then again the water may boil. That wouldn't be bad since it would give a visual indication of a problem since CO2 lasers are NOT visible.

I leave this questions before you and hope to see a good idea brianstormed by the community.

[abn]

How much does one of their 100watt lasers cost?

[Thrud]

Don't try to reinvent the wheel, by buy their parts you are going to pay more that if you went out and bought a new or used Haas 100W laser or a 500W for $150K or less. Plus you have no idea the danger that you are exposing yourself to with that kind of power in invisible laser light.

These are not toys, if you don't have a couple years of EE and advanced physics under your belt DON"T SCREW AROUND the risks are just too great, the benefits are not substantial enough.

You can buy a desktop laser engraving system with a 15W YAG laser in it for less than $20K - they will check your background and you have to have liability insurance before they will sell to you. It has safety interlocks that prevnet you from doing something stupid - they hope.

They are allergic to knumb nuts and lawyers too.

[Evan]

I second Thrud. Don't fool with laser light unless you know exactly what you are doing. A laser powerful enough to cut anything can blind you in a millesecond with even the slightest trace of specular reflection from any shiny surface.

[ibewgypsie]

Yep... Thrud is right.

I of course think I know it all sometimes still. I worked on a disc player trying to see why the tracking would hang up. With the cover off, ignoring the lil sticker on the box I ran the cd player for a half hour watching it. Sure enough burned eyeballs just like I had been welding without a helmet.

"Information Unlimited" has a set of C02 Laser plans you can build from lab glass. it is water cooled. It will cut light sheet metal.
The Head can be purchased complete for about $700. The electronics end is very simple and can be made with rudimentary knowledge.

Saftey can not be talked about enough, but if you are scared, Please stay under your mothers skirt tail the rest of your life. (my lil brother used to do "mean things to me" then run and hide and look out between my mothers skirt/knees) She'd of course whip me even thou I hadn't done anything to him yet.

ANY CNC machinery is dangerous. I have hardwired E-stops killing the power to the drives on my mill. Something about grabbing a mill during a tool change and it "coming on" comes to mind.

The robotic welders moving extreme speeds can stick the welding torch clean through you if the program/manual move is haywire.

With anything else, be careful and look at everything from all angles. They have closed in boxes around lasers for a reason.

David

[debequem]

Actually, desk top units start at just under 6K for a 15 watt system.

Marv

[Weston Bye]

Early in the advent of lasers came the somewhat humorous admonition to experimenters:

"Warning: do not look into laser beam with remaining good eye."