Co2 Laser Cutters

denhac owns two CO2 Laser Cutters. Both have 35″ x 24″ bed (900 mm x 600 mm) cutting area. They’re available for member use after training. Our main goal with this training is to ensure that members who are new to the tool don’t end up breaking the machine. This page will talk about the machine itself, the required training involved, and resources available to you to make the experience as best it can be.

Training

While we have a few articles about using the laser cutter, some are considered necessary to read and understand BEFORE using the machine. Others exist to facilitate maintenance of the machine. Be sure to read ALL of the safety rules below, including the one about maintenance.

The general order for reading and then being authorized is:

1. Homework: Read: Laser cutter materials allowed / dangerous and the rest of this wiki page.
2. Join #help-laser-pew-pew channel on denhac’s Slack (members only) and post a message that you want to schedule a time to be trained include your general availability. We have 10+ laser trainers and usually run one class a week and try to find a time that works for everyone wanting to be trained. Generally weeknight evenings or weekends. All our trainers are other members volunteering their time and teach others for free. Please pay it forward and help improve denhac in someway. Once you get experience if you want to become a trainer post in laser slack!
3. Homework: Watch: Lightburn tutorial to familiarize yourself with the software before the class.
4. Training will cover:
   • Laser safety including beam path and safe materials
   • Emergencies and fires
   • Machine operation
   • Trainee must use the emergency stop button. Only you can prevent head crashes on hold blocks and laser fires!
   • Art of finding power and speed settings. Don’t use above 80% power Blue, 50% power white and overvolt the tube. Stop using and post in #help-laser-pew-pew slack if cutting power is reduced or things seem off.
   • Checking mirrors for smoke & cleaning
   • Demonstrate that you can use tool by creating small 2-3” nametag that includes an etch, engrave, and cut out border on some wood from the scrap pile.
   • Trainer may quiz and question as you create your nametag to gauge general comprehension.
   • Trainer will grant you laser approved role using slack /membership command.

Feel free to check out the other articles in the Laser Cutter category on the wiki, but they should be considered as informational and not necessary to be certified just to use the machine.

Safety

The laser cutter is an exciting and very useful tool. However there are safety precautions that should be taken when using this machine. It uses a concentrated beam of high power laser radiation to vaporize away material to cut and etch. It is capable of catching materials on fire very quickly. It is capable of causing serious burns, severe eye damage, and blindness. 

• Never operate with the case open! Safety lockout switches always prevent this in theory.
• Do not operate the laser cutter unattended! 
• Make sure you understand what materials are safe to cut!

Burn and Fire Hazards

1. This device uses a Class 4 Laser and is capable of producing severe injuries. It takes literally a millisecond to create a deep burn and significant tissue damage.
2. Never operate the machine with lid open. The window in the lid absorbs the specific wavelength of light created by the laser tube and is safe to watch through. We also have special glasses for that extra level of protection.
3. This device can ignite materials quickly and should never be operated unattended. DO NOT walk away from the laser cutter.
4. Make sure you are familiar with the location of the fire extinguisher when operating the laser cutter. There is a special halon fire extinguisher that is safe to use with the laser. Other fire extinguishers may cause damage to the machine.

Keep our Laser Happy

• Do not use power settings above 80% Blue laser, 50% White laser. Exceeding this soft limit overvolts the tube and burns out the gasses inside which greatly reduces the tube’s lifespan. There’s no hardware limit preventing it, but this is the equivalent or redlining your car. Our software automatically throttles down to this number but it’s best practice to only type in the max.
• Monitor the temperature gauge on the chiller, especially on longer jobs. If temps go above 24℃ pause the job and wait for it to cool off before continuing. Under normal circumstances our chillers always keep the temps cool but sometimes they break.
• If you notice reduced cutting power or things feeling weird, stop using and post in #help-laser-pew-pew slack. If cuts are requiring high power and/or multiple passes something is wrong with the device or your material/settings. 
• If you have questions, are uncertain about anything, or may have accidentally bumped something out of alignment please post in Slack #help-laser-pew-pew. We want to know about and proactively fix and prevent potential problems.

New White Laser

After many repairs and completely rewiring a new controller in the white laser cutter is ready to use!

If you’re trained on Blue you can use White. Read this first.

• Same focus tool: 3.7mm
• Nozzle moves instead of the bed. First loosen the lock screw, then use adjustment screw or move nozzle up and down with your hand to focus. Retighten locking screw.
• Yellow origin button is in center of arrow keys
• Roughly same capabilities and speeds as Blue. Blue is a 80W laser vs White is 70W. In theory white may be have some advantages including more precise faster speeds and slightly smaller beam width.
  • Try settings ~25% more power and a bit slower. 
  • Blue ⅛” birch: 35mm/s, 50% =>  White: 25mm/s, 50%
• No disable laser “nuclear launch key”. Has lid open safety features.
• White’s CW3000 water chiller is worse than Blue’s CW5000! Doesn’t have alarm capabilities for high temps or as good of cooling. Keep an eye on the digital temp screen. If it goes above 24° pause and wait for it to cool. Please post in slack if this happens – we may upgrade/replace it. 

Max power: 50%
Min power: 13%
Max material thickness: ¼”. Recommended ⅛”. Blue is going to be better for ¼”. White may take multiple passes.
Recommended fill speed: 300mm/s

Machine Maintenance

tldr: Don’t try to do anything you have not been specifically trained for. Instead, post on #help-laser-pew-pew if anything seems amiss.

Eventually, this machine will break in some form or fashion. Most likely, it’ll be the laser tube expiring, but we might also damage the mirrors and they need to be cleaned or replaced. Unless you have been explicitly authorized to do maintenance on the machine by someone who is themselves authorized to do maintenance, DO NOT open any of the side panels, mess with any of the settings on the machine, or try to fix whatever problem you’re seeing. Please just let us know about it. If you’re a member of the space and are interested in being authorized to repair the machine, we can discuss that.

If you are unauthorized, any attempt to repair the machine when broken, whether successful or not, will be treated negatively. Please just don’t do it.

Maintenance Schedule

Files & Resources

Blue

• User manual (searchable)
• User manual (original)
• Amazon

White

• Manufacturer Website (datasheet and manual links broken)

Specifications

Name	Blue Laser aka “Ultra Secret”
Model	OMTech USB690 / RYGEL-USB8B69U2
Year Released	2022
Serial Number
Software	Lightburn
Cutting Area	35″ x 24″ (900 mm x 600 mm)
Cutting Thickness	1/4″ / 6mm
Resolution Ratio	S4500 DPI
Power Max	80%
Temp Max	24°C (75°F)
Max Speed	400mm/s *
Max Current	20ma
Capacity	80W
Laser	Class 4 C02 sealed tube
Focus Lens	1.5″ (38.1mm)
Modes	Raster, Vector, Combined

Name	White Laser aka “White Laser” (because who names things?)
Model	gbos GH960
Year Released	2022
Serial Number	
Software	Lightburn
Cutting Area	35″ x 24″ (900 mm x 600 mm)
Cutting Thickness	1/4″ (6mm). recommended: 1/8″ (3mm)
Resolution Ratio	S4500 DPI
Power Max	80%
Temp Max	24°C (75°F)
Max Speed	400mm/s *
Max Current	20ma
Capacity	70W
Laser	Class 4 C02 sealed tube
Focus Lens	1.5″ (38.1mm)
Modes	Raster, Vector, Combined

* Depending on material

History

• 2022-06: Proposed and purchased
• 2022-11: New vent installed
• 2023-01: Chiller cleaned of dust buildup
• 2022-08: White laser cutter is ready to use