posts tagged with the keyword ‘lasers’

2012.01.30

NOTE: See the latest post on this subject: Laser. Cut. Files. (Part III)

In our last adventure, Laser. Cut. Files. I thought I had it down… sadly, I was wrong, and I’ve actually updated that post, and here’s a Part II to share more of what I’ve learned.

Inkscape DXF

This time I once again started with Inkscape, which creates SVG files. From there I export to a DXF file. This is, I guess, not ideal, but it sort of (mostly) works, so I’m still trying to perfect it. Mostly.

The issue I mentioned last time involved exporting a DXF file from Inkscape and then not being able to re-open or import that DXF back into Inkscape. I’d get some weird error, which I thought might be due to too much extension madness in Inkscape. Anyway, I ended up re-installing Inkscape and now I can open DXF files, but they just show up blank, so that’s not much better.

I did however finally find an application for OS X that allows me to easily open and view DXF files: SolidWorks eDrawings. This should help me see what crazy stuff happens to my DXF files between Inkscape on the Mac, and CorelDraw (yuk) on the Laser Cutter.

Here’s my most recent file loaded into SolidWorks eDrawings.

DXF File

Hey, look at that! I can view a DXF file on my Mac! And it was much easier than last time, where I screwed around with OpenSCAD to do it.

DXF File

But wait… as we zoom in, we can see that when the original Inkscape SVG file was exported as a DXF, it did that crazy thing again where it changes curves into lines! (Argh! I know that there are times when you want this for CNC things, but this isn’t one of them… and if I wanted them, I could do it myself. In fact… maybe I’ll just start doing it myself if I have to.)

For this control panel, it didn’t really matter, since the front of the button will be covering up the hole, but I’m still not happy with the results… And just so we’re clear, the results I want involve me doing the digital design in tools I can run on my Mac (that I like using) and then getting those files onto the laser cutter PC with minimal screwing around, and just doing my lazzoring.

A simple, clean, friction-free, non-annoying process that doesn’t involved having to mess around redrawing things in CorelDraw (yuk) because really, it seems like it shouldn’t be this hard.

Oh, and as for the Laser Cutter PC, Inkscape got installed, but I couldn’t get it to work with the Laser Cutter. Illustrator 8 was also installed, which can’t read SVG files, and couldn’t open my DXF files either. So sadly, for now, it’s that damn CorelDraw…. yuk.

2012.01.19

Inkscape

NOTE: See the latest post on this subject: Laser. Cut. Files. (Part III)

Update: I made an error in specifying which DXF export I used. I’ve corrected that below.

In my previous post Laser. Cut. Wood. I talked about cutting wood on the laser cutter at Milwaukee Makerspace, and I mentioned I wanted to talk about files… so read on.

The laser cutter can work with raster files or vector files, and since I last year when I got the Egg-Bot and had to dig into using Inkscape, I’ve become fond of that little open source vector drawing application. I’ve used it for 3D printing and for my cucoloris design.

When I started exporting DXF files from Inkscape for use on the CNC Router, Royce mentioned an Inkscape extension called Better DXF, and then Shane found Better Better DXF and then I found Big Blue Saw DXF. These all have their purposes, but for exporting a DXF file for the laser cutter, they were terrible. :(

Oh, before I tried the DXF files, I exported a PDF from Inkscape. I figured that since the PDF from BoxMaker went into CorelDraw without issues, it might be worth a try. No dice. CorelDraw said the PDF was “invalid” and couldn’t open it. Preview.app on Mac OS X had no issues, but since it didn’t work, I’d suggest not trying to generate a PDF from Inkscape to import into CorelDraw. I also tried an EPS file, and a PostScript file from Inkscape, since CorelDraw should have been able to open those. Again, no luck. On to the DXF files!

Here’s the results of my file tests. For each file, I started with the original SVG file of the Milwaukee Makerspace logo in Inkscape, and exported using the corresponding extension:

Format Results
Better DXF The file imported into CorelDraw scaled about 10 times too large.
Better Better DXF The file imported into CorelDraw scaled about 10 times too large.
Big Blue Saw DXF The file imported into CorelDraw scaled about 1/4 the actual size.
Desktop Cutting Plotter DXF The file imported into CorelDraw scaled about 10 times too large.
Autocad DXF The file imported into CorelDraw properly.

For for the first three DXF files, they didn’t work as desired. It appeared as though the curved segments were made into line segments. This would make sense for the CNC Router, as it would save a step in CamBam, but for the laser cutter it just made the curves not be curves. For the fourth one, this this is the one I originally thought worked, but alas, it imported way too big. (I think the lines remained curves though.)

Export DXF

So what worked? The AutoCAD DXF exporter. (Which still made the curves into line segments, so I’m not 100% locked into this, but it worked better than anything else so far.) It actually came in at the right size, which is what I wanted.

My warning for these DXF files are this: Always save your original SVG file! I’ve had hit & miss experiences opening the DXF files, even in Inkscape. YMMV, as I think my loading 3 different DXF extensions has somehow confused Inkscape as to how it wants to open DXF files. (Any advice here would be appreciated!)

Oh, it’s also worth noting that your vector file in Inkscape should have just a very thin stroke on the lines. How thin? 1 pixel, or less. Less than a pixel? Yeah, somehow you can use 0.05 px as a width. I don’t know how… You can also use 0.001 inches. Whatever, just make it thin to be safe. (And in CorelDraw, set your line to hairline to be safe.) This is fairly similar to what I do for the Egg-Bot, since the width of the plotting pen will determine the width of the line drawn, not the stroke of the line on your screen.

CorelDraw

So here’s our logo, which we imported into CorelDraw (successfully) and then added a circle around it, in red. To the upper-left of the circle you can see the darker rectangle outline that indicates the upper-left corner of the laser cutter platen.

I then ran the job with the following settings… Black and red have specific settings that match up to the colors used in your file. I also set them to vector output. (I think that if you set it to vector and your file has only raster data, the laser cutter will just beep at you, and not start the job.)

CorelDraw

Here’s where we go off-script and start experimenting. You may end up tweaking the settings and running the job again, or you might just re-run the job right from the control panel of the laser cutter. When I etched my sign, I ended up just re-running the job from the control panel until I was happy with how it looked. (Obviously you don’t want to removed the piece you are cutting from the machine, as you may not get it back exactly where it was.)

CorelDraw

Now here’s where it gets tricky. I was happy with the etching (which was the black lines in the file) but not the cutting around the edge (which is the red circle in the file.) So what I did was, deleted the black lines, left just the red circle, and then sent the job to the laser cutter again. Then I could keep running it until it cut through the wood, without running anymore etching of the logo.

Now, I don’t claim that this is the best way to do things, or the only way to do things, but these are my notes, as I’m learning, and I’ll keep adding to them, and will refer back to them, and if things get better, I’ll write that up as well. Oh, I’ve also whipped up a little Laser Cutter HOW TO you might find helpful.

I’ve got a few more laser cutter tips & tricks, but I’ll save them for next time…

(See Also: Laser. Cut. Files. (Part II))

2012.01.17

Milwaukee Makerspace Medallion

Since the dawn of time, man has battled against wood… no, that’s not right. What I mean is, since we got the Laser Cutter at the Milwaukee Makerspace, I’ve wanted to cut things out of wood with that powerful beam of light.

And now I have… mostly. Sort of. Yeah.

Boxy

My first (failed) attempt was when I cut a box, and tried to use whatever scrap piece of 1/4″ plywood I had lying around the house. (For you metric folks, that’s just over 6mm thick.) Since it was typical crappy plywood with layers and glue and stuff, it made some nice burns, but couldn’t cut through it.

Milwaukee Makerspace Medallion

Well, here we are, with a nice piece of wood cut by the laser. This piece of wood is 3mm thick. (For you non-metric folks, that’s about 0.118110236 inches thick.) The Milwaukee Makerspace logo is etched into the wood, which makes this piece of laser cut wood at least 125% more awesome.

Craft Plywood

And what kind of wood is this? It’s not crappy plywood I found in the basement. I ended up going to the hobby store and buying a nice piece of wood, which you can see on the label, says it’s 1/8″x4″x12″ craft plywood. It wasn’t too expensive at $1.25, but I can’t really get larger pieces than that at the hobby store, so I’ll need to look elsewhere. (Oh, the receipt listed it as “Baltic Birch Plywood” which is what I want. (Baltic Birch is what they use for MakerBot frames. If you’ve got a recommendation on where to get it, especially local to Milwaukee, let me know!)

As my previous post mentioned, the laser cutter is just 25 watts, not super-powerful, and it may need a good cleaning, but if you’re willing to make a few passes, or a few passes plus a dozen, you should be able to cut the right type of wood, if it’s not too thick.

In my next post I’ll talk about preparing the file, as well as some tricks for multiple passes with the laser cutter.

Stay Tuned!

2011.12.27

Dana is right.

This year for Christmas I got my wife the one thing every wife wants… an admission that she is right.

But not just any admission that she is right, but a wooden plaque with the words “Dana is right” laser etched into it.

I made it a few weeks ago at Milwaukee Makerspace on the Laser Cutter we have there.

So whether it’s an argument discussion about the name of some actor, what we should have for dinner, or whose car we should take, she can just tell me, and point to the sign. What could be easier!

(I’ve already been told I may need to make one that says “Doctor Prodoehl is right” that she can take to school and put on her desk. It should make dealing with students easier. Also, I may be able to go into business making these for all my friend’s wives. Although doing so could negatively affect the number of friends I have.)

2011.12.04

I finally got some quality time with the Laser Cutter at Milwaukee Makerspace, and I have to say, I’m fairly pleased with the results!

Milwaukee Makerspace Logo

I started with the Milwaukee Makerspace logo (in SVG format) in Inkscape, and exported it as a DXF file. (I also kept the stroke of the width just 1 pixel for all the lines.)

Once I had a DXF file, I was able to import that into CorelDRAW, which is what the PC that controls the Laser Cutter uses to do the work. There’s a bit of trickery in CorelDRAW between raster and vector artwork, but doing it this way with a DXF file at just one pixel wide seemed to force it to work in vector mode, which is what I wanted.

Laser Etched Wood

Knowing the power and speed settings for the Laser Cutter are tricky, and require a bit of experimentation based on if you are etching or cutting, and how deep you wish to etch or cut. The nice thing is, as long as you don’t move whatever your material is, you can run the Laser Cutter multiple times to go deeper, or complete a cut. In many cases this may be the way to go… (More on that later!)

It’s worth noting that some materials should NEVER be cut. Since our pals at PumpingStation: One already have a list, I’ll point you to the NEVER CUT THESE MATERIALS list on their their wiki. The also have this cool list of laser settings. (Yeah, we’re working on that as well. We have a different laser, so we need to start from scratch.)

Laser Etched Wood

Here’s a close-up of the etching into wood. I ran it a few times. If you’re doing a vector cut, it just traces around the outline, and goes super-fast. If you are using raster artwork, it’ll behave like an old dot-matrix printer and go line-by-line and take forever. Shane did this Periodic Table and it took almost two hours. (It does look pretty amazing though!) I’m still not 100% sure what CorelDRAW does with each format. I tried to import an SVG file but it seems to convert it to raster format. The DXF kept its vector format, so I’ll stick with that for now.

Laser Etched Plastic

After I was satisfied with wood, I moved on to plastic. When I say plastic, I mean “plastic” and I don’t know if it’s acrylic, or plastic, or what kind of plastic, or anything else, so I’ll just leave it at that for now. (And yes, we’ve got a nice scrap pile of plastic at the Makerspace to experiment with.)


Laser Etched Plastic

This is just an outline of the logo, but we should be able to use a filled-in logo (in raster format) and create the effect of frosted glass, and then we can do this Floating Glow Display project from Make with our laser-etched plastic. Hmmm, it looks like I just gave myself another project to tackle!

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