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DXF for LaserCut 5.3

lc014

I’ve been using LaserCut 5.3 to control a G.Weike LC1390N Laser Cutter, and since I use Inkscape to create my files, I thought I’d go over a few of the settings I use so that in the future when I forget I can read this post.

I won’t go too deep into using Inkscape for laser cutting, as it’s a topic I’ve covered before, and besides having to use DXF files instead of PDF files, nothing else has really changed.

lc000-inkscape

In the image above you’ll see a file being exported from Inkscape as a DXF file for a “Desktop Cutting Plotter” which, I guess, is one way to describe a laser cutter. :) I’ve avoided selecting the ROBOMASTER option, as that does strange things to DXF files. I’ve also avoided the LWPOLYLINE option. While the LWPOLYLINE option sometimes works, it sometimes causes issues. Don’t select either option when outputting from Inkscape to import into LaserCut 5.3.

I create my files using millimeters for units, and then export the DXF with pixels (px) specified. I believe there is still a bug in Inkscape that will screw things up if you choose millimeters for the export. (We’ll double check the imported size later to make sure it worked properly.) One more nice thing about Inkscape is that it’s easy to switch between millimeters and inches (or other units) on the fly while drawing.

lc001

When importing the DXF file into LaserCut 5.3 it may show some weird dialog. Ignore it. Files seem to import fine even when this shows up. Also, occasionally LaserCut 5.3 will not import a file, or will get an error. If that happens, just quit and relaunch it. That usually fixes it.

lc003

Our file has imported and looks okay. You’ll notice that the lines in the file are all black, well, actually they are all red here, as they are highlighted because they are selected. (Anyway, I forgot to set colors for some objects, but we’ll touch on that later.)

lc006-scaled

After importing your file you can check the size of it using the “Size” button in the toolbar to bring up the size dialog when your object is selected. It will show the length and height (well, it calls them both “length”) and some boxes where you can type in new values.

lc007.png

Pro-tip: If you fill in one value to scale your object, you can scale it proportionately by clicking the ‘…’ button on the other value. Here I’ve typed “100” in the x value box and then clicked the ‘…’ button on the y value box.

lc010

The other trick I’ve learned from the folks at Brown Dog Gadgets is to use the “Unite Lines” feature.

lc012

I just use the default settings it presents…

lc013

This combines the individual line segments that the DXF file is made up of into continuous lines, like a real vector file. It helps the laser cut things in a way that makes sense instead of jumping all around the object.

lc015

Here’s what I forgot to do in the above example. I’ve set specific items to specific colors in Inkscape, so that when I bring the DXF file into LaserCut 5.3 I can use the colors to change the order of cutting operations.

lc016

Here’s our DXF file imported into LaserCut 5.3 with the colors of the lines showing. Up in the right corner you can see where LaserCut 5.3 recognizes all of the colors in the file and allows you to choose individual settings as well as the order. Typically you want to cut inside pieces first and then outside pieces.

Finally, I’ve relied heavily on the work of others, and here are some links that might prove helpful when using LaserCut 5.3 and a G.Weike laser cutter. (And yes, some of it may conflict with what I’ve posted here. Again, if I got anything wrong, please let me know.)

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Milwaukee Makerspace Beer Stein

Glass

I’ve been using the sandblaster at Milwaukee Makerspace quite a bit lately, and I figured that I needed to push the limits of what is etchable by sticking vinyl on glass.

DRINK

I started with the word DRINK in Inkscape as text. I wanted something big and bold, so there would be a lot of etched area.

Paths

When exporting any text it’s a good idea to convert the text to art, or outlines. This changes it from editable text to vector artwork consisting of lines. Once this is done, you cannot edit the text anymore. Often I’ll save my original file with text, then make a duplicate I can convert to outlines.

Logo

I then grabbed one of the new logos Mike has been working on. There was some stitching lines inside of the shape, but testing indicated that the Silhouette did not cut it very well at the size I was using. (I should try various sizes, and perhaps a new blade.)

I exported both pieces of art as DXF files, like I usually do.

DXF Files

If I ever need to quickly check my DXF files I use Solidworks eDrawings. Typically I don’t need it, but it’s handy for troubleshooting.

Cutting

Once I have good DXF files I load those into the Silhouette Studio software for cutting, like I usually do.

After the vinyl is cut, I use transfer paper to attach the vinyl to the glass, and then mask off the rest of the glass to protect it in the sandblaster. (Oops! Photo not available!)

Sandblaster

Sandblaster… here we come!

Logo etched

The logo turned out well…

DRINK etched

…as did the “DRINK”.

Drinking Glass

A fine looking glass!

Etched logo

Close-up of the etch. Looks good!

Combining the vinyl cutter with the sandblaster can produce some great results! It’s a pretty simple process, really. I’ve had a few members ask me about this so I may end up doing a demo or a short class showing how it’s all done.

Disclaimer: You should never drink alcohol while operating power tools. Also worth noting is the only beer I really care for is root beer. I got this mug from the dollar store for… one dollar! I just wanted to see how it would look etched.

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Cutting with the Silhouette Cameo

OpenClipArt

I (briefly) mentioned the Silhouette Cameo cutter in a previous post, but I thought I should dedicate a full post to it and how I use it.

I treat the Silhouette Cameo like a CNC machine, and have a similar workflow to the one I use with the laser cutters at Milwaukee Makerspace. I know the Silhouette folks have the Silhouette Online Store where you can buy ready-made shapes to cut, but we’re makers, and we make our own things, so I use Inkscape and if I need a shape I hit up OpenClipArt and find what I need. (Note: All the art on OpenClipArt.org is in the Public Domain, which means you can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission, because permission has already been granted.)

My daughter wanted a kangaroo cut out of vinyl to give to her friend, so I found a kangaroo on OpenClipArt and cut it for her.

Kangaroo in Inkscape

The files on OpenClipArt are in SVG format, which are perfect for Inkscape, as they are the native file format, meaning you can open them right up with no conversion necessary. Here’s our kangaroo in Inkscape. (I won’t go too deep into vector artwork, but if you don’t know, you can scale up and down vector art with no loss of quality, as it’s comprised of lines defined by fancy math, and not a set grid of pixels like raster art, or a digital photo.)

Resizing in Inkscape

The final piece was to be about 4 inches wide, or roughly 100 mm. (You can work in Imperial or Metric measurements in Silhouette Studio—and Inkscape—so use whatever you’re comfortable with.)

I resized the document to 4″ x 3″ using the Document Properties dialog box…

Resizing the Kangaroo in Inkscape

You can see our kangaroo will need to be shrunk to fit within the confines of the document…

Resizing the Kangaroo in Inkscape

Resizing something proportionally in Inkscape is pretty simple. Use the arrow tool, hold down the control key, and move one of the corner points. There’s actually more than one way to resize things, but for eyeballing it, this will work.

Resizing in Inkscape

OK, once we have our artwork the proper size, we can save it (still in SVG format) and the we’ll need to save it as a DXF file so we can get it into Silhouette Studio.

Select ‘Save a Copy…” from the file menu…

Kangaroo in Inkscape

Select “Desktop Cutting Plotter” from the file type menu. (You’ll see it has ‘dxf’ in the name as well, and you may have other DXF options depending on your Inkscape installation, but this one works for me.)

Kangaroo in Inkscape

You shouldn’t need to check either checkbox, just leave the options as they are.

I should note that when exporting DXF files for other purposes, such as loading into OpenSCAD for 3D modeling, we would have needed to convert all the curves to straight lines before creating our DXF file, but the Silhouette Studio software will work just fine without this step.

Kangaroo in Silhouette Studio

OK! We now create a new file in Silhouette Studio, and you can just drag and drop your DXF file onto the canvas. Once it’s there you can resize it as desired. (Wait, didn’t we size it in Inkscape already? Yes we did, that was just my way of teaching you one more thing about Inkscape. You’re welcome!)

Once you’ve got your artwork sized and positioned, you can do your cutting with the appropriate settings.

Kangaroo cut from vinyl

Here’s our final version of a white kangaroo, which my daughter gave to her friend. Hooray for CNC machines that can cut vinyl!

(You may be saying, “Hey! That kangaroo looks larger than the 4″ x 3” one you mentioned above! And yes, it is. After cutting one, a much larger version was requested, so that’s the one you see here.)

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The Aluminum Velociraptor

Velociraptor Silhouette

I’m not an expert on dinosaurs, but the velociraptor is one of the more respected of their ilk (so I am told) and you really do have to respect such a clever girl properly, so I grabbed this velociraptor silhouette from OpenClipArt knowing that I’d find a use for it some day…

Save as DXF

Since I can now easily cut things like paper and vinyl (did I mention I picked up a Silhouette Cameo?) I opened the SVG file in Inkscape and exported it as a DXF so I could import it into Silhouette Studio.

Silhouette Studio

Now, typically when I export DXF files from Inkscape for 3D printing or laser cutting I need to first remove all the curves by making them straight lines, like I did for my MAKE piece, but the Silhouette software doesn’t mind the curves.

Velociraptor MacBook

A quick cut of the vinyl and I’ve got a Velociraptor stuck on my aluminum MacBook… but wait, there’s more!

Paper Dinosaur

Since I also had a test cut made with paper, and there was some pink foam in the workshop, and we were planning an aluminum pour at Milwaukee Makerspace the next day, I had this crazy idea to use my drill press as a makeshift mill and cut out a piece of foam in the shape of the velociraptor. (You may remember Kevin’s FEAR that was made in a similar fashion.)

Mill Press

I jammed the base up into the foam so the bit was sticking all the way through so I could just run it and not have to lower it. I was then free to use both hands to move the foam around and cut it. (My jigsaw broke last year, but even if it still worked, I don’t think the cutting area of the blade would have been tall enough to fit the pink foam piece I had.)

Obviously using the CNC Router at Milwaukee Makerspace would have been more precise, but I really didn’t have time to do use it. (This was all pretty last-minute.)

Foam Dino

It worked pretty well! With the first attempt I used too large of a bit, but the second try turned out good. I ended up bringing both of them to the casting.

Velociraptors with sticks

For the aluminum casting you need a box, so we built a box and attached some foam sticks to each piece. We used a glue gun, but you need to be careful not to melt or deform the foam too much. I’ve been told that using the glue gun before it gets too hot, or unplugging it and letting it cool before use might be helpful.

The wider sticks in the center of the body are mean to funnel the molten aluminum down to the piece, while the smaller stick on the tail is meant be a vent.

Petrobond

The next step was packing the pieces in petrobond, which is a casting sand with oil in it. You need to tamp it down and pack it tight. (Somehow I managed to do a pretty good job at this.)

Cast Aluminum

Here’s the pieces fresh out of the box (after cooling of course!) There’s also a tiny bird up in the corner. We had a snake/worm shape as well, but somehow it disappeared in the process. Kevin (who helped me with all of this) then chopped my dinosaurs from the big chunk with a bolt cutter.

The Aluminum Velociraptor

And here’s my (mostly) done Aluminum Velociraptor! I’ve still got some cleanup to do, and then need to decide how to finish it, but that’s another project, and yeah, I’m already planning some pieces for our next pour in a few weeks!

Big thanks to Bret, Matt, Kevin, and everyone else who helped make this happen. It was an awesome event, and pretty amazing to show up with some pink foam and walk away with a cast aluminum piece. (Here’s a short video of the event.)

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Mold Making

I’ve been digging into OpenSCAD lately and managed to come across this Flickr photo with the most minimal of explanation of how to do a reverse object in OpenSCAD, but it was all I needed…

Space Invader SVG

I started with the SVG file of the classic Space Invader character, sized to the width and height I wanted, and then exported it from Inkscape as a DXF file.

Space Invader STL

Once we’ve got the DXF we can pull that into OpenSCAD and extrude it into a 2.5 dimensional object. (It might be 3 dimensional, but I’m not going to argue 2.5D versus 3D right now.)


linear_extrude(height = 10, center = false) import("spaceinvader.dxf");

After we compile the code we can then export our object as an STL file. We can then pull that STL file into OpenSCAD again for the next step…

Space Invader STL (reversed)


difference() {
	translate([40,42,2.5]){
		cube([90,70,14.5], center=true);
	}
	# import("spaceinvader.stl", center=true);
}

You’ll need to tweak those numbers of course, and as for the # at the start of the import line, that’s to show us the object even when we can’t see it, as it were… sort of. It’s an OpenSCAD trick I learned from Mark Finn at BarCampMilwaukee.

So now that we’ve got the object dropped into a block (at the proper height) we can then export it as an STL file, which could be cut on a CNC machine, or 3D printed.

Space Invader G-code

I’ve not yet attempted to 3D print this, and I’ve had not much luck in printing things that are water-tight. I might try getting some silicone to coat the piece which would make it water-tight, and food-safe.