Laser Manual

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Noisebridge has a laser cutter! This page has guidelines for using it.

See Laser_Manual/Workflows for software and usage details.


Contact list

Trainers

  • Dany Q (@danyq on slack)
  • R (@r on slack)
  • David (@broccoli on slack)
  • Lady Red (@mcscope on slack)
  • Andy lemons (@signal on slack)
  • Kyle (@kylesewing on slack)
  • Trent (@robbintt on slack)
  • Manish (@manishearth on slack and everywhere)

Who can use the laser cutter

Only people who have been trained by an official trainer can use the laser cutter, in order to prevent unintended damage to the machine, operator, and Noisebridge.

Full list: Laser_Manual/Who_can_use_the_laser_cutter

How to get trained to use the laser cutter

Route 1: DIY

  1. Read through the tutorial (currently unavailable)
  2. Ask a trainer if they will verify the content you learned in the tutorial
  3. Get your name on the list of users before the first time you use the machine

Route 2: Laser Safety Class!

  1. Laser safety training classes are posted on our Meetup. Size is limited to 5 students, so that everyone can see how to operate the laser.
  2. Get trained
  3. Get your name on the list of users before the first time you use the machine

The laser training class is pay-what-you-can, and the recommended minimum donation is $20.

Basic Safety

The laser cutter is generally a very safe machine to use. However, as with all industrial machines, you need to treat it with respect. The main safety concerns are creating fires, hurting your eyes or skin, getting crushed by the machine, and creating toxic fumes.

The basics:

  • ALWAYS MONITOR THE LASER BEAM CUTTING YOUR WORK!
  • DO NOT STARE DIRECTLY BECAUSE BURN-GENERATED VISIBLE LIGHT IS VERY BRIGHT!
  • USE YOUR PERIPHERAL VISION!
  • OPEN THE LID if you see a fire
  • BLOW IT OUT if the fire keeps burning
  • DON'T CUT UNAPPROVED MATERIALS!
  • MAKE SURE THE WINDOWS BY THE BATHROOM ARE CLOSED SO YOU DON'T FUMIGATE NOISEBRIDGE

Fire

Laser cutter with water and estop
The water squirt bottle is sitting on top of the laser, and the estop is the round red button.

You can really hurt yourself or burn the building down with this machine. If you follow the safety rules, the chances of you causing this is close to zero. Some materials are very flammable on the laser cutter, and shouldn't be cut. Never cut an unapproved material, or a material you can't identify. A laser beam can also initiate a fire if the speed of the cut is too slow or the laser power is set too high.


Ways to not cause fires:

  • ALWAYS MONITOR THE LASER CUTTER WHENEVER IT IS CUTTING AS FIRES CAN HAPPEN. The laser affects your material by heating it. Your job can change in seconds with the accumulation of heat in your material. Never leave the room while the laser is in operation. If you leave the laser unattended, your access to the laser cutter will be permanently revoked.
  • Use reasonable speed/power settings. Start with the recommended speed/power settings for your material. Be patient - resist the temptation to crank the power and speed to rush through your job. This can cause fires.
    • There will be some light when material is cut. This light at the point of lasing may be ok as long as it stays with the motion of the laser. If a flame appears while the laser is in operation, stop your job and try again with lower heat settings.
  • Know where the fire extinguisher is in case of a fire. The ONLY fire extinguisher that should be used on the laser cutter is the halotron extinguisher right next to the laser cutter. Other fire extinguishers are corrosive and will ruin the machine.

How to put out a fire:

  • Push the estop. (To turn the machine back on after the estop was hit, you need to switch the power switch on the right hand side of the machine off and on again).
  • Open the lid.
  • If it's small, try and blow it out.
  • If it's smallish, try and squirt it out with the water squirt bottle sitting on the right hand side of the machine.
  • If that doesn't work, use the halotron fire extinguisher to the right of the laser cutter. Aim it at the base of the flame.

Damage to eyes and skin

The laser beam can instantly and permanently blind you. It can also burn your skin.

  • The lid's window will block the infrared laser beam, but it doesn't block the visible light produced by the burn. THE VISIBLE LIGHT CAN BE BRIGHT ENOUGH TO DAMAGE YOUR RETINA! DO NOT STARE DIRECTLY AT THE CUT! Use your peripheral vision.
  • You don't ever want any part of your body in contact with the beam.
  • As long as the door is closed, you're safe to look at the laser. There are interlocks on the door that help ensure the laser never operates with the doors open. Don't disable them.

Crushing danger

The laser cutter is a dumb machine. It doesn't care whether your hand is in the way when it's moving. The head can move when the door is open. Always make sure everyone's hands are out of the machine before moving the head.

Also be very careful not to crash the head into other parts of the machine. Be very careful when moving the z-axis to not crash the head into the bed, and to not move the z-axis if the focus length acrylic circle is under the lens.


If you need something to weigh down your material, use the magnetic balls or beanbags that are kept near the laser; nothing else. Do not let the laser head crash into these; if it does immediately stop the job.


Be *very* careful to not put the beanbags (or any other material) in such a situation where they may be dragged by the head. The head should never bump into anything, and *especially* never drag anything.

Fumes

The laser cutter burns the things it's cutting, which can create toxic fumes.

  • ONLY CUT APPROVED MATERIALS. Cutting nonapproved materials can release really toxic gases, including chlorine and cyanide. These are really bad for humans, as well as being very damaging to the laser cutter.
  • The ventilation fan should always be running if the laser cutter is on, even if it's not cutting. It's currently wired such that you can't turn on the laser cutter without the fan turning on, but please make sure it's running.

Care of the machine

Please don't perform any maintenance on the machine (including cleaning lenses/mirrors or aligning mirrors) unless you've specifically trained on it.

The laser cutter is finely calibrated piece of machinery. Please close the lid gently, and do not push or jar the machine at any time. Do not lean or press on the tray - it's fragile, and needs to be perfectly flat for the laser cutter to cut properly. If you take the honeycomb bed or slats out, please be ULTRA CAREFUL with them - put them somewhere where they won't get damaged or warped.

Paying for your laser time

The laser cutter has parts that wear out over time, which can be quite costly to replace, especially the laser tube. A new tube costs several thousand dollars. Thus, we require people to pay for the time on the laser they use, so we can pay for new parts. The cost for using the laser cutter is $5 per hour of cutting time.

To figure out how much time your job takes, press the File button, select your file, and then select Work Time from the menu. It will tell you in hours:minutes.seconds.

There is a laser cutter donation box on the wall of the Sparkle Forge room. Please pay for the cutting time you actually use, even if you end up running your job multiple times.


Workflow and software

See Laser_Manual/Workflows for software and usage details.


Maintenance

Please don't perform any maintenance on the machine (including cleaning lenses/mirrors or aligning mirrors) unless you've specifically trained on it.

  • TEMP note: some check(s) may be included outside of maintenance so a user can trigger a maintenance notification
  • DON'T - let someone who has been trained do it
  • how to tell if the lens is dirty (or getting old?)
  • how to tell if the mirrors are dirty
    • Cleaning the mirrors
      • ethanol solution? isopropanol? - see manual.
      • fabric must be non scratch - see manual.
  • Checking and performing mirror alignment
    • Safety - remove gratings and any other reflective surfaces before any maintenance that requires disabling the door sensors.
    • TEMP note: in restrospect the alignment was a very dangerous situation. mirror paths were not checked before powering on the laser with the door open with many people around. (or maybe nigel is just insanely good at configuring mirrors... still... reddit.com/r/OSHA)
    • Tape test - mirrors 1,2,3 and their corresponding exits. Slightly propped laser tube.
    • vertical/horizontal alignment by brass dial.
  • Checking chiller tank water volume
    • Chiller alarm - what does it mean
    • Checking tank water volume
    • Refilling tank water
  • Cleaning the bed and waste drawer (this section probably should be moved to usage)



Signs:

  • Don't open front/back passthrough doors (for now)
  • Fire extinguishers - which to use for what fire
  • Approved materials
  • careful when raising bed, dont crash into laser head
  • move laser head out of the way before opening the lid
  • power off the laser before opening the lid ???
  • watch the laser while it is cutting


Todos:

  • Move the machine further away from the right wall so we can get to the power switch.
  • label the water squirt bottle as for fires and not to remove
  • acquire piece of copper for chlorine materials test
  • acquire vinyl record for testing
  • acquire propane bottle and nozzle




material notes

  • material selection - approved materials list
    • nothing that generates hazerdous fumes, particularly chlorine/formeldahyde
    • no aluminum or other metals (?? ryan claims these can be safely engraved in this machine)
    • nothing reflective
    • size constraints
  • laser configuration - power, speed
    • table of recommmended settings for various materials

How to get a new/novel material approved

  • consensus process
  • chlorine test

Chlorine material test

Before you cut any new material you *must* check that it is safe to cut; specifically that it will not produce chlorine gas when it is burned by the cutting laser. Chlorine is extremely dangerous in its gaseous form and so must be avoided at all costs.

To test a new material, you'll need a sample of the material, a small copper rod (about the thickness of a coat hanger), a pliars, and a handheld propane torch. We'll test for the presence of chlorine by burning a sample of the material in a high temperature propane flame and observe the visible emission spectra. Chrlorine produces a bright green light when burned, and so will be very obvious when you're testing your material.

First, turn on the ventilation on the Sparkle Forge. The switch for this is under the sign that says "For Non-Laser Fires Only", and above the non-laser fire extinguisher. Then, light the propane torch and set it to rest upright on a stable surface. Taking the pliar, hold the piece of copper in the blue part of the flame to heat it. As the copper begins to heat sufficiently it'll cause the flame to turn an orange color. A consistent orange color means that the copper has no residue material on its surface and so is clean enough to use as a test. If you observe non-orange flames when you burn the copper you may need to clean in further, either by waiting for the excess material to burn off, or by scrubbing the surface of the copper when it has cooled.

Once the copper is burning, take the hot copper and melt a sample of the new material onto it. For example if you were testing a new form of plastic you can roll the hot copper rod on the material, melting some of it onto the copper rod's surface.

With this done, place the copper rod back into the blue part of the flame. Observe the colors of the emission spectra from the new material burning. If you observe a bright green color, then the material contains chlorine and thus *must not* be burned further. Ventilate your surrounding area to avoid breathing it in. If you observe no green color as you burn your material sample, then the material is likely safe to use with the laser cutter.

Here is a video example by Zach in NYCResistor with a known good and known bad material: https://www.youtube.com/watch?v=D0_4NLmeSTI


BANNED MATERIALS (NEVER USE THESE)

These materials must not be used in the laser cutter.

Bad materials
Material Notes
PVC Contains chlorine. Will produce hydrogen chloride gas when used which is extremely toxic and also damages the laser optics.
Vinyl Most contains chlorine. Will produce hydrogen chloride gas when used which is extremely toxic and also damages the laser optics.
PVC Foams Most contains chlorine. Will produce hydrogen chloride gas when used which is extremely toxic and also damages the laser optics.
Foam Core Usually made with PVC which is harmful as listed above.
Styrofoam Can cause flash fires
Polycarbonate Does not cut. TAP plastics sells both this and acrylic. Be sure to read your labels when purchasing material. Lexan is the trade name for Polycarbonate, while Plexiglass is the trade name for acrylic.
ABS or PETG Gives off hydrogen cyanide which can kill you and also may damage the laser optics.
Fiberglass Contains complex epoxies which will cause fires, chlorine, and cyanide. Also contains glass which will not cut.
Metals Cannot be etched by this type of laser. Also is harmful as the reflective surface may cause the laser to be reflected back up to the head, damaging it. If someone claims to be etching metal using this type of laser then they are etching a metal with a plastic coating, anodized surface, or some other etchable surface on top.

Known good materials

These materials are known to be ok for use with the laser cutter. The speed and power of the laser cutter will need to be set appropriately for the material and thickness in use. Below is a table showing the suggested settings when cutting or etching them.

Since upgrading the laser cutter to 150W, we have not tested and updated most settings. Please start at HALF the power as before and test carefully, increasing the power until you get a clean cut, and don't use power greater than 55% to prolong the life of our tube. (you probably won't be able to cut wood or MDF thicker than 1/4 inch or 6mm)

Old 100W Laser Cutter Settings for Known Good Materials

Good Materials
Material Engraving Cutting Scoring Notes
Speed (mm/s) Power Speed (mm/s) Power Kerf Width Speed Power
Acrylic (2.3mm or 3/32 inch) 400 5 50 55
Acrylic (3mm or 1/8 inch) 400 5 30 55
Acrylic (4.8mm or 3/16 inch) 400 5 20 55
Acrylic (6mm or 1/4 inch) 400 5 15 55
Cardboard (3-4mm, single corrugated) 200 55 400 10
Cardboard (6mm, two layers corrugated) 50 55 400 15
Cardstock (white, 100lb) 200 20 400 5 The higher speed reduces the amount of browning on the edges.
Fabric - Heat N Bond woven fusible 100 12
Fabric - KONA cotton from Fabric Outlet 100 7 You do have to pull the cut fabric apart (it's not a clean cut), but it rips at the cut cleanly.
Fabric - Silky fabric from Fabric Outlet 100 7 lovely clean cut
MDF (3mm or 1/8 inch) 400 5-10 depending on darkness 50 55
MDF (6mm or 1/4 inch) 400 5-10 depending on darkness 15 55
Plywood, Birch (3mm or 1/8 inch) 400 5-10 depending on darkness 50 55
Plywood, Birch (6mm or 1/4 inch) 400 5-10 depending on darkness 30 55
Rubber, natural (McMaster Carr #8525T53) 20 55
Silicone (McMaster Carr #1460N24) 10 55 Doesn't cut through all the way -- only enough to rip the pieces out by hand.
Sorbothane Rubber (1/8 inch) 13 50 Creates an inky black liquid. Washes away easily with water.
Sorbothane Rubber (1/4 inch adhesive backed) 6 50 Adhesive side up


The Laser Gallery contains some past projects and cutting tests.

Sourcing Material

In general, Amazon and eBay are pretty good resources.

For plastics: Tap Plastics is nearby Noisebridge, but is expensive. The Tap Plastics offcut bin is a great resource and a great deal. eplastics online is another option, and Mr. Plastics is cheapest but is in San Leandro.

For woods: Discount Builder Supply is nearby.