Tag: 3d

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2D plates from 3D objects

brocstl001

One of my, uh, “hobbies” is figuring out alternative workflows, or ways of solving a specific problem. I often do this with a bias towards open source or free software, because I like to know how to do things, and share how to do things, even when you don’t have expensive commercial software.

If you remember reading about Broc’s model in one of my Digital Fabrication posts, he mentioned using the “Unroll Developable Srf” function in Rhino to create flat pieces. Well, I have access to Rhino at UWM, but any piece of software on my own machines is preferable because I have easy and immediate access to it 24 hours a day, 7 days a week.

Broc's STL in 123D Make

With this in mind, I set about trying to do what Broc did, without using Rhino. I ended up using 123D Make from Autodesk. It’s not open source, but it’s (mostly) free if you’re willing to create an account and share your personal info.

Broc's STL in 123D Make

123D Make has a bunch of nice options for breaking 3D objects into “slices” that can be assembled using various methods. (Supposedly there’s a beta version that does finger joint boxes.) It took a bit of tweaking things, but I was able to create slices just like the ones Broc made in Rhino.

Broc's STL in pieces

The output from 123D Make was a vector-based PDF file with all the parts in 2D.

Broc's STL in pieces

The PDF was easily imported into Inkscape, where it can be set up for being cut by a CNC machine. There’s a minimal amount of clean-up needed to remove any attachment tabs that the application generates. Try as I might, it did not allow me to put a value of zero on some of the parameters. Maybe in the next version. :/

(Oh, you could always print out paper templates and cut things the old fashioned way if you’re not a CNC user.)

Here’s a great promo video 123D Make that shows some of the slicing capabilities.

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3D “Drawing” Pens

3D Drawing Pens

3D Drawing Pens

There’s a number of so-called “3D Printing Pens” on the market now, or coming soon, though in reality I think they should be called “3D Drawing Pens”. I mean, you don’t have a “2D Printing Pen” do you? Pens are for drawing, they are not printers that print.

I know a lot of people are excited about these things, thinking it’s the cheapest way to get into 3D Printing (if they work) because you’ve probably seed some amazing photos of things people are creating with these things…

Well, here’s my thought on these pens:

If you’re terrible at drawing in two dimensions, you’re probably going to be terrible at drawing in three dimensions.

Yeah, if you’re a skilled artist who knows how to work a pen, you might make some awesome things. That’s how art works, but don’t expect to pick one of these up and create a masterpiece the first time.

That said, I do think these “3D Drawing Pens” are interesting, and I look forward to see where they go, and I await an open hardware version.

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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.

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MKE3DP – 3D Printer Fans Unite!

MKE3DP

As you may know, I finished my RepRap recently. But here’s the thing, you never really finish a RepRap. It’s a beast in need of endless tweaking. So yeah, it’s a never-ending project (if you want it to be) and I’m okay with that. I mean, once you get to the point that it works, you can start using it to upgrade itself. How many tools can do that!?

Of course you can actually make useful things, functional things, or just pretty things. There’s a lot a 3D Printer can do. I’ve only been at it for less than a year and I’ve still got a lot to learn.

So anyway, yeah, I’m really enjoying this 3D Printing stuff… so I figured, why not share it with others? So join us for the first Milwaukee 3D Printing Meetup! We’ll be meeting on Sunday, July 1st, 2012 at 1:00pm. We won’t be at our space because we’ve partnered with our friends at UWM for this one! Show up at UWM’s Kenilworth Square East Building, 3rd Floor; Room 368 on 1925 E. Kenilworth Place.

If you’ve got a 3D Printer, bring it, or just show up and learn about them. If things go well and there’s interest, maybe we’ll turn it into a regularly scheduled meeting.

(More info? It’s also on the Milwaukee Makerspace site and you can RSVP on Facebook if you want to see who else will be there.)

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Leap Motion

Say goodbye to your mouse and keyboard.

The Leap Motion looks interesting. OK, it looks awesome. Sort of… I mean, I’m all for “new” interfaces for computers, but the whole “say goodbye to your mouse and keyboard” bit? I don’t buy it, and I don’t want to buy it. More accurate than a mouse? Again, I’m not convinced. And as for the “more natural” part of it, while it’s true I’ve been using my hands and fingers my entire life, I’ve been using a keyboard for more than 30 years, and a mouse for over 20 years, and at this point, it’s pretty damn natural. Nothing feels “unnatural” to me about using a keyboard and mouse. If something better comes along, I’d be happy to try it. The iPad does a really good job of using a touch interface, and for specific tasks, it’s wonderful, and much better than a keyboard and mouse, though I feel a lot of that has to do with how and where I use an iPad.

In the air

I’m not really sure how signing your name or writing in thin air is natural or better/easier that the alternatives. Sure, it looks like it could be fun, and I do see the possibilities for new things, but I made the joke(?) yesterday that what we really need is a method of using computers that requires us to keep our arms in the air for 10 hours a day. I know we should all use standing desks and be on the move, but I also really like sitting at a desk, supporting my arms, and using a keyboard and mouse. For the great majority of what I do with a computer, it works well.

Alright, with my complaining out of the way, I’ll heap on the praise now. I love this thing. The Leap Motion opens up some possibilities. We’ve played with 3D scanning using the Kinect and while it sort of works, it could be better. Hell, if the Leap Motion can do at least as good as the Kinect at 1/3rd the price, I’m sold. (Also, it’s not a Microsoft product, so it earns points there as well!) I can also see using the Leap Motion with Processing as a great physical computing device. Yeah, I’m excited. $70? That’s cheaper than some Logictech mice!

So while I’m not ready to ditch my keyboard and mouse yet, I can see some great possibilities in the Leap Motion. I’m not exactly ready to (pre-)order one yet, as it’s sort of vaporware at this point, and they don’t expect to ship until December 2012 or January 2013. That’s 7 to 8 months out, without any dates slipping. (Dev kits may be out in 1 to 3 months, so there’s a chance we may get a better idea of what it can really do at that point.) The pre-order thing makes it feel like a really long Kickstarter campaign, so I’m taking a “wait and see” approach on this. Things move fast, and who knows, within 6 months a competitor may come along with something better. Still, it’s damn interesting.