Laser Cutter Materials

From Asmbly Wiki

There are a wide range of materials that our lasers can cut, etch or mark - but some simply don't work (eg metals) and some are extremely hazardous to either humans or the machine itself (eg PVC and Vinyl). It is therefore imperative that you check these lists before attempting to cut materials that you have not worked with before.

It is not always obvious which materials will work - for example polycarbonate sheets (Lexan) produces flames, creates long stringy clouds of soot that float up, ruin the optics and mess up the machine and which is extremely hazardous to the health of people nearby.

Yet acrylic - which looks, smells, feels and tastes just like Lexan - cuts smoothly and cleanly and is one of the best materials to use with the laser! So check and double-check what you're cutting. If you aren't sure, test the material. A simple way to test is attempt to flex the plastic. Under normal temperatures, acrylic is not very flexible. Polycarbonate is slightly bendable in most thicknesses under 1 inch.

The Magnificent Seven -- recommended material starting points

Apart from the NEVER CUT list below, there's a whole wonderiferous world of materials and techniques out there but for many (most) people the best way to learn the laser is to start with "ignore most of the options, do these simple things and you'll be fine".

These seven materials will give good results at reasonable prices and have well-understood and documented settings in the libraries:

  • Austin Fine Lumber 3mm Baltic Birch. A great material for experimenting and the default thickness for most of the boxes.py printables. They're a stone's throw from the space and really friendly
  • Austin Fine Lumber 5mm Baltic Birch. Comes in 5' sheets and they'll gladly cut it to laser bed size for free when you pick up.
  • Austin Fine Lumber 12.?? mm Baltic Birch -- best off doing this in Tarkin. The 5x5 size is preferable. This is meaty 1/2"ish material for structural projects, with a beautiful banded edge you can leave natural if that's your jam.
  • Lowes' "Revolution Plywood" 4.5mm (poplar/??) -- cuts easily, inexpensive, and has a redder side and a lighter side, both cosmetic, that you can use for fun contrast. Pro tip: order online, and as you start the pickup process ask the agent to call an associate over to the panel saw. Have them cut the work to 32/32/32 or 36/36/24 or whatever size will work best for your car/truck/laser bed etc. Cutting is free, waiting and wondering who can cut it for you is boring.
  • Lowes' Whiteboard/Blackboard
  • (NEED ONE RECOMMENDED SOURCE) Acrylic, 3mm (any thickness really, but that's the best size for "drops" and the one we have well documented). Read the notes at the link about "drops" and what to ask for so that you can order with confidence.
  • Flat or mirrored Glass (need exact source and part number)

Where to Find Materials

If you need material, you can try one of the places listed here:

Where to find materials to feed the laser.

NEVER CUT THESE MATERIALS

WARNING: Because many plastics are dangerous to cut, it is important to know what kind you are planning to use. Make has a How-To for identifying unknown plastics with a simple process.

Material DANGER! Cause/Consequence
PVC (Poly Vinyl Chloride)/vinyl/pleather/artificial leather Emits chlorine gas when cut! Don't ever cut this material as it will ruin the optics, causes the metal of the machine to corrode as chlorine is released and ruins the motion control system.
Thick ( >1mm ) Polycarbonate/Lexan Cuts very poorly, discolors, catches fire Polycarbonate is often found as flat, sheet material. The window of the laser cutter is made of Polycarbonate because polycarbonate strongly absorbs infrared radiation! This is the frequency of light the laser cutter uses to cut materials, so it is very ineffective at cutting polycarbonate. Polycarbonate is a poor choice for laser cutting. It creates long stringy clouds of soot that float up, ruin the optics and mess up the machine.
ABS Melts / Cyanide ABS does not cut well in a laser cutter. It tends to melt rather than vaporize, and has a higher chance of catching on fire and leaving behind melted gooey deposits on the vector cutting grid. It also does not engrave well (again, tends to melt). Cutting ABS plastic emits hydrogen cyanide, which is unsafe at any concentration.
HDPE/milk bottle plastic Catches fire and melts It melts. It gets gooey. It catches fire. Don't use it.
PolyStyrene Foam Catches fire It catches fire quickly, burns rapidly, it melts, and only thin pieces cut. This is the #1 material that causes laser fires!!!
PolyPropylene Foam Catches fire Like PolyStyrene, it melts, catches fire, and the melted drops continue to burn and turn into rock-hard drips and pebbles.
Epoxy burn / smoke Epoxy is an aliphatic resin, strongly cross-linked carbon chains. A CO2 laser can't cut it, and the resulting burned mess creates toxic fumes ( like cyanide! ). Items coated in Epoxy, or cast Epoxy resins must not be used in the laser cutter. ( see Fiberglass )
Fiberglass Emits fumes It's a mix of two materials that cant' be cut. Glass (etch, no cut) and epoxy resin (fumes)
Coated Carbon Fiber Emits noxious fumes A mix of two materials. Thin carbon fiber mat can be cut, with some fraying - but not when coated.
Any foodstuff ( such as meat, seaweed 'nori' sheets, cookie dough, bread, tortillas... ) The laser is not designed to cut food, and people cut things that create poisonous/noxious substances such as wood smoke and acrylic smoke. If you want to cut foodstuffs, consider sponsoring a food-only laser cutter for the space that is kept as clean as a commercial kitchen would require.
Material with Sticky Glue Backing Coats lens, cracks lens There are many normally laserable items such as thin wood laminates that you can purchase that become un-cuttable when the manufacturer adds a layer of peel-off glue on the bottom to attach them to surfaces. Examples include cork tiles, thin wood laminate, acrylic tiles, and paper stickers. Never cut these materials in the laser cutter if they have this backing. The glue will vaporize forming a coating on the lens that will coat it, cloud it, heat it, and then potentially crack the lens. The glue residue is worse than resin, and can't be removed without risking damage to the lens ... requiring a lens replacement.

Safe Materials

The laser can cut or etch. The materials that the laser can cut materials like wood, paper, cork, and some kinds of plastics. Etching can be done on almost anything, wood, cardboard, aluminum, stainless steel, plastic, marble, stone, tile, and glass.

Cutting

Material Max thickness Notes WARNINGS!
Many woods 1/4" Avoid oily/resinous woods Be very careful about cutting oily woods, or very resinous woods as they also may catch fire.
Plywood/Composite woods 1/4" These contain glue, and may not laser cut as well as solid wood.
MDF/Engineered woods 1/4" These are okay to use but may experience a higher amount of charring when cut.
Paper, card stock thin Cuts very well on the laser cutter, and also very quickly.
Cardboard, carton thicker Cuts well but may catch fire. Watch for fire.
Cork 1/8" Thin cork can be cut, but the quality of the cut depends on the thickness and quality of the cork. Engineered cork has a lot of glue in it, and may not cut as well. Avoid cutting thicker cork (5mm). Engraves well, cuts poorly.
Acrylic/Lucite/Plexiglas/PMMA 1/2" Cuts extremely well leaving a beautifully polished edge.
Thin Polycarbonate Sheeting (<1mm) <1mm Very thin polycarbonate can be cut, but tends to discolor badly. Extremely thin sheets (0.5mm and less) may cut with yellowed/discolored edges. Polycarbonate absorbs IR strongly, and is a poor material to use in the laser cutter. Watch for smoking/burning
Delrin (POM) thin Delrin comes in a number of shore strengths (hardness) and the harder Delrin tends to work better. Great for gears!
Kapton tape (Polyimide) 1/16" Works well, in thin sheets and strips like tape.
Mylar 1/16" Works well if it's thin. Thick mylar has a tendency to warp, bubble, and curl Gold coated mylar will not work.
Solid Styrene 1/16" Smokes a lot when cut, but can be cut. Keep it thin.
Depron foam 1/4" Used a lot for hobby, RC aircraft, architectural models, and toys. 1/4" cuts nicely, with a smooth edge. Must be constantly monitored.
Gator foam Foam core gets burned and eaten away compared to the top and bottom hard paper shell. Not a fantastic thing to cut, but it can be cut if watched.
Cloth/felt/hemp/cotton They all cut well. Our lasers can be used in lace-making. Not plastic coated or impregnated cloth!
Leather/Suede 1/8" Leather is very hard to cut, but can be if it's thinner than a belt (call it 1/8"). Our "Advanced" laser training class covers this. Real leather only! Not 'pleather' or other imitations .. they are made of PVC.
Magnetic Sheet Cuts beautifully
NON-CHLORINE-containing rubber Fine for cutting. Beware chlorine-containing rubber!
Teflon (PTFE) thin Cuts OK in thin sheets. See https://www.ulsinc.com/materials/teflon ; the issues listed in https://en.wikipedia.org/wiki/Polymer_fume_fever should not matter because our lasers are fully vented and exhausted.
Carbon fiber mats/weave
that has not had epoxy applied
Can be cut, very slowly. You must not cut carbon fiber that has been coated!!
Ethylene-Vinyl Acetate (EVA) Foam OK to cut This material does not support a channel so even though thin pieces cut super easy, that doesn't scale the same way for thicker pieces.
Coroplast ('corrugated plastic') 1/4" Difficult because of the vertical strips. Three passes at 80% power, 7% speed, and it will be slightly connected still at the bottom from the vertical strips.

Etching

All the above "cuttable" materials can be etched, in some cases very deeply.

In addition, you can etch:

Material Notes WARNINGS!
Glass Green seems to work best...looks sandblasted. Flat glass should be engraved in our cutter as we have no rotary device. Round or cylindrical objects like bottles or glasses will have distortion.
Ceramic tile
Anodized aluminum Vaporizes the anodization away.
Painted/coated metals Vaporizes the paint away.
Stone, Marble, Granite, Soapstone, Onyx. Gets a white "textured" look when etched. 100% power, 50% speed or less works well for etching.

Marking

Cermark is the brand name of a marking compound containing molybdenum that costs ~$50-100 for a 12oz spray can, which can be sprayed onto stainless steel, brass, aluminum, copper, nickel, glass or light-colored stone/tile before being etched to leave behind a permanent dark black mark. Some people have had some luck using dry moly lube spray to the same effect. It is thought that the molybdenum sulfate in the dry lube breaks down to molybdenum which either oxidizes or reacts with the underlying surface to create the mark.