Come check out our new BIG LASER! We are back to cutting during all of our open hours.
Please e-mail any files you want lasercut to ten.xirtem|pohs#ten.xirtem|pohs even if you're coming in physically.
The 50 and 100 Watt CO2 lasers can cut and engrave a variety of materials with the power of light. It is a precise but destructive process, so care must be taken when making a project. It's one thing to make a mistake on a piece of 1/4" birch — it's another to burn a hole in a MacBook Pro. We prefer to cut materials we stock, but we will cut custom material as well. Any custom material that is not immediately identifiable may require a burn test to determine its chemical makeup. We reserve the right to refuse to cut unidentifiable materials. Materials that smell bad but are otherwise relatively harmless, including most plastics, have a stink surcharge. Please refer to the section below on materials for more details.
The largest piece of material we can fit in the small laser cutter is 12in X 18in. We van fit material up to 32in X 45in in the large laser cutter. Please allow for at least a 1/4" border around your artwork so that we can situate it properly. If you are getting your materials custom cut before bringing them in, please do not have the final outside cuts done. Letting us do that allows for best alignment of your artwork.
In order to be able to cut your file, you need to give us a vector drawing file. The preferred and most stable file format is EPS. If you are using:
Adobe Illustrator - save as EPS
Inkscape (open source vector drawing software Inkscape) - save standard SVG file
AutoCAD - save as DXF2000
Rhino - select your drawing, export as AI (Adobe Illustrator file), open in Illustrator and save as EPS
OpenSCAD (open source 3D and 2D drawing software) - export as DXF, open in Inkscape and combine all the nodes (you need to create continuous vector paths rather than hundreds of tiny segments), then save as SVG
Google Sketchup - install plugin to export SVG SVG plugin, export face cuts, double check your file in Inkscape to confirm proper export
For all other programs you might be using, save as EPS or SVG whenever you have the option. PDF files sometimes work but they have to be saved correctly based on your software's options so that they retain the vector graphics. All files make a roundtrip through CorelDraw, and we've found that EPS is the most reliable format for this.
If you are working in a software that will require several conversions, it is a good idea to include a 1cmX1cm square in your drawing so that you can check for any scaling issues. Sometimes curves don't translate properly between different formats so double check your curves.
You are always welcome to send us your file and ask us to check it to make sure that the final cut file looks like your original file. If you do that, give us a call to let us know. If you are physically coming to Merix to get something cut, it is a good idea to bring a laptop with you so that you can make modifications to your file if necessary.
Because of various inconsistencies between programs or even different versions of the same program, it is always good to save your file in a few different formats, especially if you will not have the option to work on it once at Metrix.
No matter which program you're using, we find that designs import best if all line weights are set to hairline (or .001 if possible) and if there is no fill to the line. However, if you must use fill, do not use stroke to outline your shapes. Using both stroke and fill will result in double cut lines. If you want to do a raster engrave, it can still be a stroke outline. It does not need to be a fill for the engrave to happen. See the section below on Optimizing your design for the laser cutter for more information on the different types of cuts.
Measure once, cut twice
You can double check your design for scaling issues and other potential fit problems by printing it out on an 11x17" proof on paper. We know your LCD is accurate, but you should always see how things look on paper before you cut your materials.
We can cut
- Acrylic (up to 1/4")
- Wood (up to 1/4"; not pressure treated, stained, or finished)-We carry 1/8" birch plywood already cut to size ($4 per sheet). Some specialty hardwoods cannot be cut with the laser. Be prepared for testing if you are considering using such material.
- Stamp Rubber
- Paper/Cardboard/Illustration Board
- Leather (up to 1/8")
- Polycarbonate plastic (very thin sheets only; thicker polycarb will simply smoke and melt)
- Kapton (for making solder paste stencils or other sort of useful stencils; doing this requires some set up so a set-up rate may be applicable)
We can work with, but not cut
- Aluminum: Anodized aluminum will, when lasered, turn a sort of ghostly white and have a slightly rougher surface texture. This seems to be a chemical change, and is durable.
- Glass: When lasered, transparent glass takes on a sandblasted texture. We haven't tested whether this is a useful way to score glass before breaking it.
We cannot cut
- Anything containing halogens (fluorine, chlorine, bromine, iodine, astatine, and ununseptium). This includes vinyl and many plastics (including teflon), as well as Moleskine notebooks or anything 'pleather.' If you’re not sure whether what you’ve got contains chlorine, you can check on the MSDS (if you can't find it there, ask the vendor or manufacturer directly) or do a burn test to check.
We will not cut
- ABS and other styrene plastics
- Stingray and most other animal hides
Standard Run (usually best value)
$3/min + material (if bought from us)
Small Production Run
$2/min + setup + material (if bought from us)
Setup will be charged at our labor rate. Please see the note below for details.
Surcharge for Acrylic and Leather (and other especially malodourous materials)
See this post for more information.
Any job that requires extensive set up or continuous attention from a technician will be charged additionally at our labor
rate. Labor is $50/hr, billable in half hour increments. Minimum labor is $25.
Discounts are available with membership
Basic members pay $2/min*
Full members pay $1.60/min*
*malodorous charge of $.50/min gets added on top of the discounted price
We have also introduced a 20% Thingiverse discount. See the blog for details.
Useful Additional Information
The laser gets rid of material along the line you give it. You should account for kerf (that is, the width of the cut) in your artwork. It is dependent on material. This number is the width of the cut in total; half of it will be on each side of your line. Additionally, the laser beam is slightly conical rather than a perfect cylinder, so your cut will be gently tapered (about 2°).
Kerf will vary depending on material type and thickness between .05mm and .2mm
Optimizing your design for the laser cutter
The laser cutter can do three different types of cuts: 1) It can cut straight and curved lines. 2) It can do vector engraving, which is similar to outlining. 3) It can also do raster engraving. Raster engraving cuts away large portions of material, leaving raised and lowered areas; this is good for rubber stamps, woodblocks for printing, and edge-lit signs.
Cutting and vector engraving are both relatively fast. Most cut heavy designs take less than 30 minutes to finish. The rated speed for cuts depends on the material in question. Hard turns require the laser to slow down and speed up, which reduces the effective speed.
Raster engraving takes quite a while, and raster heavy designs can take an hour or more to finish if they are large. Wide designs raster more quickly than tall designs.
With this in mind, you can minimize your cost by reducing the amount of raster engraving you do. You can reduce rasters by cutting things out instead of rastering them where possible. You can also rotate them so they align with the horizontal (long) axis of the machine.
If you want several types of cuts in your design, simply make each a different color. Also use different colors if you want different depths of etching or raster engraving. Cuts and vector engravings follow the lines in your design. Raster engravings fill an outline, so you can engrave inside of any closed curve.
If you have text in your file it will cut/etch/engrave as if each letter is outlined by a vector path. If you need single line text for clarity, minimizing cutting time, etc. you need to find a single line font or modify an existing font to make it single line.
For more information, see http://www.pololu.com/docs/0J24/5
Care of your laser-cut design
When you get your lasercut materials back, they may be covered in char marks or dust. Several things can be done about this, depending on what material your design was cut from.
- If your design was cut from acrylic, it may be covered in vaporised acrylic from the cutting. This can be cleaned up with a water-damp paper towel. If you clean it with alcohol, you will get tiny cracks near the edges. To prevent this, you should leave the protective material on.
- If your design was cut from wood, there may be discolorations on the sides of the cuts. This can be quickly sanded away with some coarse sandpaper.
- If your design was cut from stamp-rubber material, there may be some bits of rubber clinging to the finished piece; it wipes off easily with a moist paper towel.
People often like to use the laser cuter to create durable enclosures. This fingerbox generator produces SVG files that may be edited in Inkscape or Illustrator.
You can download ready files for laser cutting from Thingiverse Thingiverse
Exporting from EAGLE CAD
You will export the 'cream' layer (tCream or bCream) to an EPS file. The cream layer is a property of each part (including being automatically created for SMD pads in library packages/devices that you create).
Adjusting for kerf
The cream layer defined by a part is usually the same size as the SMD pad. The laser cutter will actually make a hole a little larger than what's in your file, due to some combination of laser kerf and melting of the stencil material. You need to update the cream layers on your board, making them slightly smaller than the pads themselves. From your board, open the DRC (Design Rule Check). Click on the Masks tab, and set the Cream Min and Max to 0.05 mm or 2 mil (depending on the units you are using). Click Apply. Your board's cream layers will be updated. Yes, this is surprising since it's labeled as a 'check' activity but does actually adjust the layers. You will, of course, need to do this for each board. Also note that this has no effect on parts with custom cream layers.
Generating the EPS file
From the Board, choose File/CAM Processor. (You should be familiar with this as it's what you use to create files for a board house.) Make the following settings:
- Device: EPS
- File: .eps
- Layer: select tCream (or bCream) and make sure no other layers are selected
Click Process Job. Your file will be created in the same folder as your board file, with its base name and the .eps suffix.
This works great as written for larger surface mount parts. However, it starts to break down for very fine pitch packages like TSSOPs, TQFPs, QFNs, and similar ones designed for the compulsively masochistic. The problem is that, for unknown reasons, the stencil openings are wider than specified in the Y direction and narrower in the X direction. It's a tiny effect, but significant for 0.5mm pitch packages with contacts on all sides. Poking around the Pololu FAQ for laser cut stencils indicates they have a similar problem and solved it by shrinking each opening more in the Y direction than in the X direction. There's no way that I know of in Eagle to do that on a per-board (instead of per-package) basis. However, there is a way to do it at the Gerber level.
Adjusting and exporting the Gerber
Each pad in a gerber file is defined by something called an aperture. The apertures for a well-formed gerber file are defined at the head of the file. SMD pads are almost always rectangular, and they are defined by lines of the form:
ADD<aperture #>R,<X dim>X<Y dim>*
There's no provision for rotation; the same pad in different orientations is defined by multiple lines of that form. Therefore, it is trivial to shrink the Y dimension more than the X dimension. Having modified your gerber, you can then open it in a program that can export it as an EPS or PDF file. The latter is more common; GerbView can do this, but costs money.
Exporting from gEDA
You want the paste layer; most likely the front/top paste. You'll also need Inkscape installed and the package which includes the program ps2eps, which is, unsurprisingly, called "ps2eps" in Debian.
As mentioned before, you'll need a EPS, SVG, or PLT file. As of Sep 2011, PLT export is not working.
You should be able to print the Gerber directly from gerbv to a Postscript file, but it mangled some pads. So here are some steps that worked:
1. In PCB, do "Export layout…" to PS which prints the multi-paged printout; disable all the printout options (align-marks, outline, and show-legend). Also, recommended to shrink the pads by 2mils, so enter "-200" in the ps-bloat box. Don't forget the negative sign! Finish by pressing okay.
2. Open the printout and print the paste page to its own .ps file. I used `gv` and "Saved marked pages…" (after marking the paste page, of course). Other options include using whatever standard viewer you have available and print just that page to a .ps file.
3. Then convert the .ps to EPS by running `ps2eps myboardpastelayer.ps` with your filename in the appropriate location. It creates the file myboardpastelayer.eps in the same directory.
4. Open the EPS in inkscape.
5. Ctrl-A, Ctrl-U, Ctrl-Alt-C (could run a long time on the last step). This sequence of operations is Select All, Ungroup, and Stroke to Path. This is necessary to create the outline for the pads.
6. Save as EPS again (my uniconvertor fails if you try to make .plt after using Stroke to Path in step 5 — perhaps future users will have better luck). Probably could also save as SVG if desired.