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Laser. Cut. Files.

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))

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Convert all the files!

Convert all the files!
Thanks Tom!

It seemed like a simple enough request… While at Milwaukee Makerspace we were discussing creating snowflakes on the Laser Cutter, and I mentioned that there should be some existing art on OpenClipArt.org, but it was down that night, so I jumped over to Thingiverse and found this snowflake.

As a bit of background, I’ve been pretty damn good at file conversions in the past. Audio, video, markup, raster images, anything 2D has been pretty simple. I mean, I’ve been using Photoshop since version 1.0.7. I know how to deal with that stuff… but 3D? It’s a whole new nightmare world!

Snowflake

The file was an STL, which is meant for 3D printing, but we needed more of a 2D vector file. I know how to load a DXF file into the Laser Cutter, so I figured I’m import this STL into Google Sketchup (via a plugin) and then export as a DXF (via another plugin) and that would be it.

Well, that didn’t work. (Oh, and by “didn’t work” I mean I was unable to open the DXF file in Inkscape. At this point I was still waiting to use the Laser Cutter so I didn’t get to try importing it on that machine. I figured that as long as I was waiting, I’d try to get a format I knew would work.) On to the next idea.

I exported the STL from Google Sketchup as a DAE file, and was able to open that in MeshLab. Once again I tried a DXF export, but that one wouldn’t open in Inkscape either. Argh!

Snowflake

So I made a radical decision… Since I could view the file in MeshLab, I just did a screen shot so I could get a nice, clean 2D version of it.

Snowflake

Of course if I had known I was going to do this, I probably could have just done it in Google Sketchup by altering the view… Still, the MeshLab method seemed solid.

Snowflake

I then took the screen shot and opened it in Photoshop, did a little editing, and converted it to black and white. (I considered creating paths, and exporting them, but at this point I wanted to go with what I knew (or thought) would work, and that meant getting a clean PNG file into Inkscape to convert it from a raster to a vector file via trace bitmap.

Snowflake

So finally, I had my SVG file! A vector file I could open in Inkscape and export as a clean DXF file that I was reasonable sure would open and work on the Laser Cutter…

Snowflake

Oh wait, at some point along the way I had created an OpenSCAD file, to test the other DXF files. They wouldn’t render due to some weirdness, but the new one I exported from Inkscape did. This made me feel a little more secure that this file would work.

So how did it turn out? I don’t know!

The Laser Cutter was in use making ornaments, and I couldn’t stay late enough to get a chance to use it.

And just to be clear… while there were many steps in the process above, the whole thing took about 20 minutes from the first file export to getting what seemed to be a good DXF file.

I’ve converted a lot of files in my time, but doing so for these CNC machine is proving to be a new challenge.

Of course half the fun is seeing if it will work, you know, on the machine… which I hope to test at some point. :)

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Fire the Laser!

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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3D Modeling Update

3D Model

In the last month I’ve made some progress in my 3D modeling education, so I thought I’d provide an update. (Besides my last post, I got some good feedback on Google+) Oh, and just a reminder, my interest in 3D modeling all has to do with creating objects I can produce with a 3D printer like the MakerBot or the RepRap.

So what am I using (or not using) now? Here’s the list:

Google Sketchup
I’ve made some good progress with Sketchup. A few tutorials (and a lot of playing around) has me creating actual 3D models. You’ll want the STL Importer and STL Exporter to deal with STL files. Sketchup is nice, and I’m sure I’ll end up using it more as time goes on, but it’s not the end of my 3D quest.

Blender
Urgh… I’ve made no progress with Blender. Haven’t even tried. I may just wait until we do a Blender class at Milwaukee Makerspace.

123D
Still no Mac OS X version.

3DTin and Tinkercad
I talked about 3DTin last time. I haven’t used it since, but it still seems like a great way for kids to get into 3D modeling. As for Tinkercad, it seems like a more advanced version of 3DTin. Make: Live covered Tinkercad in Episode 17 if you want to check it out.

Inkscape
Say what!? Inkscape is a 2D drawing application. I’m still using it. I’ll often open vector files (SVG) and export them to DXF files and then extrude those to 3D files. Here’s a great Inkscape to OpenSCAD dxf tutorial that explains it all.

OpenSCAD
I’m still just barely using OpenSCAD, mainly in conjunction with Inkscape as mentioned above. I need to dig in a bit deeper, as time allows.

So what else is there? Well, I found Pleasant3D, which isn’t exactly modeling software, but it’s what ReplicatorG might look like if it were a full-on Mac OS X application. I’ve found it useful on a few occasions.

The other one worth mentioning is MeshLab, which may have some uses when it comes to converting or transforming files. I haven’t created anything with it yet, but it sure looks impressive.

So that’s my 3D modeling software update… Anything new to report from your desktop?

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Pac-Man Cookies

Cookie Cutters

Since I’ve been playing with the MakerBot at the Milwaukee Makerspace, I figured that I should print something useful, and what’s more useful than cookie cutters!

I got the idea from the GuruBlog CookieCutter-Editor. I ended up making the Pac-Man shape, which is the exact opposite of complicated. (Yeah, I’m saying it’s really simple.) I really just did the Pac-Man shape as a test, and after I posted it, Alex asked about the ghosts, so at that point I figured I had a bit more work to do…

Since I’m still dabbling in 3D modeling, and haven’t really nailed down a workflow yet, I decided to try something besides the CookieCutter-Editor. I ended up drawing the ghost in Photoshop, and then bringing it into Inkscape to trace it. I then followed this Inkscape to OpenSCAD dxf tutorial to convert the SVG into a DXF file, which I then exported and brought into OpenSCAD to extrude into a 3D model.

Printed Cookie Cutters

The Pac-Man shape from the CookieCutter-Editor had a wider edge on one end, which is what a cookie cutter should have. (You can see this in the 3D wireframe in the top image.) The ghost shape does not have this wider edge, because I don’t know how to create one yet! I solved this issue by printing the shape with a raft, which you can see in the photo of the printed cutter. It’s not the prettiest cookie cutter, but it certainly did work.

Pac-Man Cookies

And here’s our final product, the Pac-Man (and ghosts) cookies! My oldest daughter Emma did the hard work here. She made the cookie dough, used the cutters, baked the cookies, and frosted them. I was basically the “Technical Advisor” and showed her what colors to use, etc. She wasn’t 100% pleased with the outcome, mainly because she had to tweak the coloring and improvise a bit (Pac-Man is actually lemon-flavored) but she’s a bit of a perfectionist in the kitchen. :)

We’ll probably make more of these for BarCampMilwaukee6, and may throw a few more shapes into the mix if I get a bit time with the MakerBot before then.