Bart Dring at Inventables donated the Full Spectrum Engineering H12x20 Hobby Laser to us dead, after it blew its power supply one too many times. Bill P picked it up downtown ~9/20/15, got and installed a new power supply, and got it up to the point of being visible on the network and responding to manual jog controls.
We got cooling and exhaust running well enough to try the tube at the meeting on 10/1/15. We actually cut a few things that night.
There are some running updates of gory details in this Google Group.
The original (old, dirty, reduced power) laser tube cracked and died when cold air coming in the exhaust pipe froze the water in it before 12/19/16. We ordered a new tube for $130, and the laser was running again 12/27. Seems to be higher power. Created lots of discussion about monitoring and better air flow control.
Three critical bits of infrastructure for the cutter are water cooling for the tube, forced fume exhaust, and “air assist” – continuous downward airflow concentric with the beam.
The first pass at water cooling was a couple of gallons of distilled water in a blue recycle bucket with a Little Giant MA-1 submersible fountain pump, hooked up with a couple of feet of 3/8″ (?) vinyl tubing. A flow sensor has been added, and soon a processor will actually monitor it and warn users if the flow stops.
For exhaust, we removed the old furnace from the space (after getting landlord Rich’s OK), repurposed its circulation blower as the exhaust fan, and fitted that blower to the old furnace’s 8″ flue/cold air intake pipe. The blower has a split squirrel cage, with one half drawing cooling air over the motor and the other just moving air. A 4″ pipe fitting into the air mover side, connected with some 4″ flex dryer hose to the laser’s 4″ exhaust port. Bill, Daniil and Jim did much of this.
Rich is concerned about cold air coming in, so Daniil made and installed a downward deflector outside to keep rain out and some kind of damper to keep cold air out when the blower’s not on. The sheet steel was dumpster leftovers from some local business’ recent A/C work. (Need picture!)
The manual indicates compressed air via the “air assist” input should ALWAYS be used when vector cutting. We had a small, old air brush compressor for this task, but replaced it with a new, less noisy compressor. It seems to help considerably. It’s currently in the same power strip with the laser, so it’s hard to forget to turn it on.
FSE’s Retina Engrave 3D software controls the laser and makes it appear as a printer to Windows machines. We downloaded that software from the FSE site (thanks to credentials posted in a forum there) onto the Shapeoko laptop. It successfully found the cutter over wifi (with copper cable at the laser end) and could talk to it. The laser now has its own dedicated Windows laptop. The “printer” is shared, and other Windows PCs have been able to print to it without installing the RE driver.
The RE driver is quite rich and complex, so its basic use is covered in W88’s “Intro to the Laser Cutter”.
For personal and machine safety, we require members to be certified on the laser before using it unsupervised. The process is still under review, but the basic steps are:
- Watch the two part “Intro to the Laser Cutter” class video
- Spend an hour or two in a hands-on lab/practice session learning about and using the laser under the supervision of a certified member
- Create a “certification card” (engraved and cut on the laser, of course) with the user’s name and the date to be hung on the wall above the laser showing who’s certified.
User’s manual for the laser from FSE
Retina Engrave 3D software user manual from FSE
(Old) “Workshop 88 Intro to Laser Cutter” slide deck (pdf)
Intro to Workshop 88 Laser Cutter Video Part 1
Intro to Workshop 88 Laser Cutter Video Part 2
Laser settings for various W88 approved materials (editable – please contribute! Must be logged into Dropbox.)
Cutting and marking plastics with a CO2 laser by Synrad
Materials to cut/not to cut from atxhackerspace.
Note from Dan Meyer on materials to cut/not cut.
Beilstein (hot copper wire) test for halogens (pdf) (video)
Nervous System’s Quest for the Best Laser-cutting Plywood