posts tagged with the keyword ‘3dprinting’

2018.05.16

wetherosies

We the Builders is a project that uses crowdsourced 3D printing to assemble large sculptures. For the most recent build, they decided to celebrate the contributions and diverse identities of women and non-binary makers by scaling up a sculpture of Rosie the Riveter to monument-size and printing her in a spectrum of skintones. The sculpture will be over six feet tall and made up of 2,625 parts.

I posted about this on the Milwaukee Makerspace Facebook page and asked for people interested in helping, and a woman named Gwen was interested. Seems her grandmother was an actual “Rosie” back in the day. We met up at Milwaukee Makerspace and tried to print a piece for her, and because 3D printing is full of failure, did not succeed.

So I printed it at home. And then I printed more for me, and more for her, and in total I think we did 10 parts. Sadly had to hit the road for BAMF so I didn’t get to print more, but it looks like (as of writing this) there are less than 250 pieces and we’ve still got five days.

gwen

When Gwen showed up to pick up the pieces (she offered to ship them) she was wearing an awesome Rosie shirt depicting the sculpture, so I asked her to get a photo of it with the pieces, and she did!

Sadly I will not be making it to NOMCON to assist with assembly, but I look forward to seeing the final piece, and hear about what happens next with the Nation of Makers. (I will be at BAMF though, so I hope to see other #WeTheBuilders people there!)

brownpieces

2018.05.02

wire-bender-1894

We’ve got a project at Brinn Labs where we need to bend some 16 gauge wire. The wire bends very easily, in fact, too easily, and you can bend it by hand, but you can’t really get nice curves. I looked up “wire benders” and found “fret benders” which people use to curve the frets for guitar building.

wire-bender-plan

So I found this video titled DIY FRET BENDER – $5 USD FRET BENDER and I was in such a hurry I didn’t even realize the guy provided a bunch of design files! I guess I just often assume people don’t supply files, so I took a screen shot of the design and then dropped it into Inkscape and…

wire-bender-2d

I just whipped up my own design quickly. Since I didn’t want to screw around with using the CNC machine for this, I just exported the DXF and extruded it in OpenSCAD so I could create an STL file suitable for 3D printing. Since there’s a slot and not just holes, it’s not the most fun thing to make with a drill press. Typically slots require a bit more work than holes, with filing and other time consuming hand tool work that is often best left to machines…

wire-bender-render

I designed three parts, and then printed the body and three spacers and six guides. You’ll notice a small lip on the guide piece. That’s to just touch the inside of the bearing so they can roll smoothly. The bearings? Yeah, tear apart that fidget spinner! We’ll need three bearings.

wire-bender-1893

We’ll also need three 5/16″ bolts and nuts, though you could certainly use 8mm if you’ve got those handy. Hey, look, we’ve now got a wire bender!

wire-bender-1901

There’s a little room for improvement on this version… The slot could be a little narrower, and I’ve found that without pliers it’s a bit difficult to tighten the nut. I fixed that by 3D printing some nut knobs so it can easily be tightened by hand. (I already had my own nut knob design file, but you can find plenty on Thingiverse and Youmagine.) No photo because I added it later. :/

wire-bender-1898

This was a really simple build, and since fret benders often cost $50 to $100 (though I saw one for $25 on eBay) this was pretty dirt cheap. I don’t know if it’s up to the task of bending frets, but it should work fine for the wires we need to bend.

wire-bender-1911

If I get around to it I’ll clean up the files and release them. You never know when you might need to bend some wire!

2018.04.07

DSC32D_1794

I made a plaster bolt and painted it red. Sometimes I do things in the “wrong” way so I can see why it’s the wrong way and to see if it might work doing it the “wrong” way. Also, I like a challenge.

bolt-render

I started by using OpenSCAD and the thread-drawing modules for OpenSCAD and created a Metric bolt. I added the bolt head and rounded the edges just a bit.

bolt-mold-exploded

Once I had my bolt I used it to create the two part mold by doing a difference into a block, and then cutting the block into two pieces. I also added some alignment holes and pegs. (And I managed to forget to make the holes a bit larger than the pegs, but a drill bit fixed that easily enough.)

DSC32D_1779

DSC32D_1780

Here’s what my mold looked like printed in ABS plastic. Yes, I should have used a flexible filament for this so I could demold the cast, but I didn’t. Again, wrong, experimenting, etc. (I’ve got some flexible filament on order, so we’ll see how that goes.)

bolt-003

I taped up the mold and added some rubber bands to hold it all together. Somehow I missed getting a photo of the wet plaster, but I just poured/shoved it into the top and leveled it off…

bolt-004

Here’s the result after letting it dry for a few days. Oh, I didn’t have any proper mold release, or any good substitutes so I used some silicone spray. I don’t know if it worked that well. You can see some of the threads broke off. To be honest I was expecting much worse! It was totally stuck in the other half of the mold though, and I didn’t want to force it…

bolt-005

…so I ended up putting the mold into a bench vise and crushing it until it released the bolt. I know, in theory you should be able to use a mold more than once. But maybe part of the beauty of 3D printing it is that it’s low cost compared to silicone molds. I’m also thinking that a 3 or 4 part mold might be the way to go, rather than just two parts. At least for something like this.

DSC32D_1778

I think I could still use one side of the mold, so it wasn’t a total loss. (More like a 50% loss, which isn’t too bad for this experiment.) Enjoy the photos below. This is, of course, and art object, and not a functional bolt. I like the way it turned out, and I plan on doing more weird experiments like this. (By the way, it’s about 60mm long.)

DSC32D_1806

DSC32D_1795

DSC32D_1784

DSC32D_1787

See Also: Fail Of The Week: Casting A Bolt In A 3D-Printed Mold

2018.03.18

knob-rot

If you’ve ever used a potentiometer you know it can only turn so far. About 270 degrees of rotation is what you get out of most potentiometers, which is plenty. The problem with using potentiometers in museum exhibits is that while adults (typically) know that when the knob stops turning you should stop turning the knob, kids don’t always know this. Kids are notorious for going too far when it comes to physical controls.

pieces-stacked

So I’ve been working on a way to use potentiometers in an exhibit, but hide them down below in the cabinet, and expose a control knob to the surface that has limited rotation. About 220 degrees of rotation. I could do more, but the idea of using less than 270 is the key. If we don’t get too close to the beginning or end of the rotation limit, we should be able to prevent the potentiometer from being twisted too far and becoming damaged.

pieces-all

I drew up the parts needed to build an encased knob with a hard stop inside. In the final version the knob will be machined from HDPE plastic using a CNC router. I opted to 3D print the pieces for the prototype because it was quick and easy. (“Quick” is relative, of course, but I finished up the drawing and got the model printing at the end of the day, so the printer did the work overnight while I wasn’t there.)

pieces-3d

I drew all the pieces in Inkscape and then exported DXF files and brought them into OpenSCAD and extruded them to 1/4″ high. There’s a 1/4″ hole in a few pieces (and a slightly larger hole in the bottom piece) so that a 1/4″ steel shaft can be inserted. The shaft will be connected to the potentiometer. (I made a 3D printed prototype of that too, which you can see here and here.)

pieces-exploded

Here’s an exploded view of the assembly. Sometimes it’s tricky to design things like this using flat 2D shapes in Inkscape, but I’ve gotten used to it, and I think I’m pretty good at it. I should mention I also printed a paper prototype to help figure things out along the way. (And yes, the original plan was to laser cut the pieces out of foam core which would have made the most sense, but the laser cutter was not available when I did this.) The fact that I created 3D models did allow me to make the nice exploded view very easily.

pieces-stacked-orange

Here’s a quick assembly using hot glue. Just to test how it worked, as well as get a feel for the size of it. (I’ll have a follow-up post about the layout of the whole panel.)

knob-together

HDPE can’t really be glued, so we use screws (hidden when possible) to attach layers. We may be able to get away with fewer layers than I used here, because I used 1/4″ layers, but it might make sense to use 1/2″ or 3/4″ layers since we often get HDPE in those thicknesses. And of course we can pocket things out, and not just use a flat stack. (Again, this is a prototype.)

2018.03.18

bumps-on-fabric-0921a

I finally got around to 3D printing on fabric. It worked out okay. I need to experiment a bit more to perfect it, but for a first attempt, it worked out okay.

bumps

I used OpenSCAD to design a bump, and then made a field of bumps. (It’s a low-poly half sphere, actually. Really simple to do in OpenSCAD.)

bumps-openscad

Also really easy to generate a bunch of them in OpenSCAD by using two for loops. I know OpenSCAD isn’t for everyone, but if you think in code, it might work for you.

bumps-on-fabric-0923a

I used this organza fabric to print onto. It’s a mesh material, so the process of printing on it involves printing a few layers, then pausing the print, moving the print head out of the way, laying down the fabric, securing it to the bed, then continuing the print. The fabric gets embedded within the layers of the print.

cura-script-custom

My Maker Select Plus did not allow me to pause the print and move the extruder using the on screen controls, so I added some custom gcode to my print. Cura has a post-processing plugin that allows you to inject gcode bits into your script. I had make an edit to get it to work with my printer. And then I actually made my own version so I don’t lost the changes when I upgrade Cura next time.

bumps-on-fabric-0917a

So what use is this? It allows you to wrap a print around something. It an be used to create fake armor for cosplay, or to wrap anything cylindrical, or add an interesting texture to something. Over at Milwaukee Makerspace we may have something in the works for Maker Faire Milwaukee this year.

A post shared by Pete Prodoehl (@raster) on

Stay Tuned!

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