dcrlmtm

DCRL

A big part of the work I do is the process, and trying to find tools that fit the way I work, and are also available. “Available” may mean open source, or free (as it beer) or multi-platform, or some other criteria I come up with.

In my Digital Craft class we’ve used RhinoCAM to generate the G-code needed to run the 4×8 CNC router in the DCRL. RhinoCAM has a lot of options, as it should for a full-on commercial package. Meanwhile, I’ve been working on a Shapeoko2, which is a small and affordable hobby-level CNC machine. For a machine like this, I’d like to use a workflow that doesn’t require expensive commercial software, because at some point I may not have access to Rhino and I’ll need tools I can afford.

(I should note that I have used CamBam in the past, but being commercial software that is Windows-only doesn’t entice me to want to use it again.)

I’ve played a little bit with Easel from our friends at Inventables, but I’m also not a fan of hosted solutions that can disappear, or start charging for access, etc. At this point I start to sound extremely picky, but really, I’m just looking for tools I can rely on, that are not expensive, and run on the platforms I use. (Easel is actually really nice, and while it’s easy to use, I think that comes at the price of hiding some of the complexity and advanced features I want to learn. Still, if you just want to cut/carve/engrave, check it out.)

I stumbled up MakerCAM, and there’s a bunch more info about it on the Shapeoko wiki. Basically it’s a Flash application (!) that you can use online, or download and run offline, which provides all the basic needs of a CAM application. And it actually works.

Inkscape

I started as I often do, drawing a 2D vector file in Inkscape. (Oh, I should mention there is an extension for Inkscape called Gcodetools, but we’ll skip that for now.) Once I had my Inkscape file I saved it as an SVG, as you normally would with Inkscape.

MakerCAM

I then loaded the SVG into MakerCAM. Note that if you load an SVG from Inkscape you need to set the px/inch to 90 in the preferences. Once in MakerCAM it’s fairly easy to create the toolpaths and generate the G-code. If in doubt, check out the help page and the tutorial page for all the info.

GrblController

After exporting my G-code file I was able to load it into the Grbl Controller and run it on the Shapeoko. Now, Grbl Controller is no Mach3, but it’s also open source, and multi-platform, so there’s that. (Yes, I know the image above does not match the first two images, that’s because I went crazy with the hatch fill from the Egg-Bot extension for Inkscape. Just pretend you know what I’m talking about.)

Oh, if you want to “run” your G-code before you run your G-code to make sure it’s doing what you think it’s doing, check out OpenSCAM, which is a nice little simulator.

(And yes, I know of Chilipeppr for Grbl, but I’ve not dug into it yet.)

Prusa i3 Parts

I’ve got a box full of Prusa i3 Rework parts! Well, not the full box, but we’re working on it. When I say “we” I mean myself and my team. This is all for a class titled “Digital Fabrication and Craft: Machines that Make”, which Frankie mentioned recently.

The class so far has been a blast! We’ve talked about the RepRap movement, and open source hardware and software used for 3D printing, and we’ve even designed a coat hook (yes, a nod to Adrian Bowyer.)

For the first assignment we are build Prusa i3 RepRaps, hence all the parts. We have a few MakerBots in the DCRL and the other students have been frantically printing parts. Meanwhile, I’ve printed most of my team’s parts on my RepRap Prusa i2. I sort of like the idea of my i2 making an i3. I may print enough parts to build out a frame and then transfer my i2 electronics and extruder over to it. Or I may just build another 3D printer instead.)

We’ve talked a lot about machines that make, and a little bit about MIT and what they’ve done. If you’ve seen the Othermill, you may or may not know it originated from an MIT project called MTM Snap.

And there’s more! For the second assignment each student needs to design and build a machine that can make things, and then we need to make things. Yes, we are rapid-prototyping rapid-prototyping machines. It’s a class made for makers, for sure.

One thing I’ve come to realize over the years is that you can design and build a thing, and you can design a product, and you can manufacture a product, and there are always compromises in process, materials, complexity, cost, quality, and fifty other things. A recommended reading in this area is Confessions of a Hardware Startup. Here’s an excerpt:

Our obstacle was that Jonathan had never intended MTM Snap for production. It was a design challenge experiment: to see if he could build a machine without screws. This is a great feature if you’re trying to save money as a graduate student, but from a manufacturing standpoint it had two major disadvantages.

Go read the whole thing if you’re interested in this. Since I’ve also been designing kits that are meant to be assembled and disassembled multiple times, I’ve seen similar (but different) challenges arise. But honestly, this all fits under the heading of “design” to me, because I still think design is about solving problems.

I’ve also been thinking a lot about the machine I’ll build. I probably won’t build a drawing machine right now (more on that later) but there’s a reason I’ve been researching the Othermill and been hankering to use a Shapeoko. It’s all coming together!