We have two laser cutters/engravers, a 40 Watt CO2 system and an 80 Watt CO2 system. The 40 Watt system is the popular OMTech DF0812-40BGE (aka the “K40” engraver). The 80 Watt system is the OMTech AF2028-80 cutter/engraver.
Both laser cutters/engravers are attached to an industrial water chiller to prolong the laser tube life. Additionally, both systems are attached to the makerspace dust collection system to evacuate smoke and fumes during the cutting/engraving process.
For the 80 Watt laser, we have a rotary axis kit that allows for engraving of cylindrical objects like baseball bats, shot glasses, coffee tumblers (see note below regarding metal), and anything else that can rotate! This system also has an auto-focusing sensor to speed up the process and produce more consistent cutting/engraving.
Can I engrave metal?
Yes and no. A CO2 laser is really not the best suited for engraving metal. The wavelength of a CO2 laser reflects off of most metals. Those videos you may have seen of metal being engraved were done with a fiber/galvo laser system. A fiber laser emits a wavelength about 1/10th of that of CO2 lasers (click here for more science!). Those are substantially more expensive than CO2 lasers, which are not cheap themselves! This short video goes over another big difference: speed. Most CO2 systems are XY-cordinate driven (aka plotter style). A galvo laser system has a stationary output lens assembly that dynamically, and insanely quickly, directs the beam to where it needs to go. This short video does a great job explaining the difference between the two.
So why did we say “yes”? You can purchase coatings that you apply to your metal piece and engrave that with CO2 lasers. The laser fuses the coating to the metal and somewhat simulates an engraving. It is permanent, but the coating material is relatively expensive if you are doing a lot and the metal object must be really clean (i.e. no oil) for it to work well.
Software
We have Lightburn licenses for each laser machine. It is easy to learn but also has the ability to perform fairly advanced operations (e.g. refocusing for deep cuts). There are numerous online tutorials for this software package but we recommend starting with the ones from Lightburn themselves!
So I just put my material in and it works first time?
Sure, if you’re good at winning the lottery on a consistent basis! If you are a machinist, or know one, you know the term “feed and speed”. There are two main factors that affect the quality of your engraving or cutting: the power of the laser (feed) and the speed at which it moves (…speed…). We started coming up with a chart of individual values to use for materials…but even minor variations in sources and thicknesses can cause problems.
We recommend you have on hand enough material to practice with and don’t mind losing, charring, or combusting into flames. The only gaurantees in life are death, taxes, and never being able to cut/engrave perfectly on the first try. Even a very consistent material like glass can have different behaviors depending on the color and texture.
What Can I Cut/Engrave?
Anything! Just kidding. As already discussed, there are some limitations. Bare metals are not possible and some plastics emit hazardous gases. This table, while not covering every scenario, should give you a good idea of what is possible (credit to Dallas Makerspace and ATX Hackerspace for developing this comprehensive reference). As always, if you have any questions, just ask!
Special Note: Acrylic is available either cast or extruded. Cast acrylic is the type best for etching and rasterization (i.e. making images in the piece). This is what is commonly used for signs and trophies. Extruded acrylic is better for cutting (and cheaper/easier to find!).
Cutting
| Material | Thickness | Notes | Warnings |
|---|---|---|---|
| Many woods | 1/2″ | Avoid oily/resinous woods | (F) Be very careful about cutting oily woods, or very resinous woods as they also may catch fire. |
| Plywood/Composite woods | 1/2″ | (E) These contain glue, and may not laser cut as well as solid wood. | |
| MDF/Engineered woods | 1/2″ | (E) These are okay to use but may experience a higher amount of charring when cut. | |
| Paper, card stock | thick | Cuts very well on the laser cutter, and also very quickly. | (F) Cut single layer at a time. Multiple layers catch fire easily. |
| Cardboard, carton | thicker | Cuts well but may catch fire. | (F) Watch for fire. |
| Cork | 1/4″ | Cuts nicely, but the quality of the cut depends on the thickness and quality of the cork. Mostly, the cut depends on the glue used as a binder. | |
| Acrylic/Lucite/Plexiglas/PMMA | 1/2″ | Cuts extremely well leaving a beautifully polished edge. | |
| Extruded Polystyrene | 2″ | Blue or Pink rigid foam insulation. Expanded Polystyrene (usually white and made of small white balls) is not OK at this time. (foam coolers) | (F) Please watch it carefully when cutting. Uses fastest speed possible and lowest power needed to cut through. |
| Delrin (POM) | thin | Delrin comes in a number of shore strengths (hardness) and the harder Delrin tends to work better. Great for gears! | (T) Contains formaldehyde (a known carcinogen) in the smoke generated during cutting. Advisable to keep ventilation system running for a couple minutes after cutting to clear out all of the smoke. |
| High density (48 lb/ft3) urethane board. | HD version of tooling/model/precision board. https://www.inventables.com/technologies/precision-board-plus | ||
| Depron foam | 1/4″ | a type of extruded polystyrene: http://depronfoam.com/ . Used a lot for hobby, RC aircraft, architectural models, and toys. 1/4″ cuts nicely, with a smooth edge. | (F) Must be constantly monitored. |
| Foam Core | any | Cuts extremely well on the facings. The center can shrink and melt away if too much power or too low a speed is used. | (F) Watch it carefully. Paper coated foam core is best. Be careful that your facing material isn’t waxy, plastic or something on the prohibited list. |
| Gator foam | Foam core gets burned and eaten away compared to the top and bottom hard paper shell. | (E) Not a fantastic thing to cut, but it can be cut if watched. | |
| PEVA or EVA Foam – (Poly) Ethylene Vinyl Acetate | 1″ | Expanded foam rubber. Used for flip-flop soles, exercise foam floor mats, exercise equipment padding, foam sheets for crafts. | Smells bad – can result in charred brown edges. |
| 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 | (E) Gold coated mylar will not work. |
| Styrene, Solid | 1/16″ | Smokes a lot when cut, but can be cut. | (T) Keep it thin. |
| Cloth/felt/hemp/cotton | They all cut well. Our “advanced” laser training class teaches 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″ or 4 oz). Our “Advanced” laser training class covers this. Smells like burning hair when cut, so let vent before opening after cut. | (T) Real, veg-tanned leather only! Not chrome-tanned real leather. Not ‘pleather’ or other imitations! |
| Magnetic Sheet | Cuts beautifully | ||
| NON-CHLORINE-containing rubber | Fine for cutting. | (T) Beware of chlorine-containing rubber! Use only rubber labeled “laserable” or “chlorine-free”. | |
| Teflon (PTFE) | thin | Cuts OK in thin sheets | |
| Carbon fiber mats/weave that has not had epoxy applied | Can be cut, very slowly. | (E) You must not cut carbon fiber that has been coated!! | |
| Coroplast (‘corrugated plastic’) | 1/4″ | Difficult because of the vertical strips. Three passes at 80% power, 7mm speed, and it will be slightly connected still at the bottom from the vertical strips. | Test. This data many be referring to the old lasers. -gorman 2018.01.18 (Coroplast is typically Polypropylene) |
Engrave
| Material | Notes | Warnings |
|---|---|---|
| Glass | Green seems to work best…looks sandblasted. | |
| Ceramic tile | ||
| Anodized aluminum | Vaporizes the anodization away. | |
| Painted/coated metals | Vaporizes the paint away. Metals can be marked by pretreating with CerMark or equivalent. Our lasers will not cut or etch uncoated metals. | See below for powder-coated metal. |
| Powder-coated metals (DIY Powder Coat) | Vaporizes the powder coating. | Read the powder coat jar ingredients – MUST NOT CONTAIN PVC. Some brands like Harbor Freight are not laser safe because they are PVC-based. |
| Stone, Marble, Granite, Soapstone, Onyx. | Gets a white “textured” look when etched. | 100% power, 50% speed or less works well for etching. |