posts tagged with the keyword ‘3dprinting’

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.)

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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.)

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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!

2018.03.12

diii-cooler-0906

It’s been a while so it’s time for another RepRap Report! So what’s changed since last time? So much… I’ll try to hit it all.

I got rid of the BuildTak and moved to a PEI Sheet. I upgraded to the Micro Swiss All Metal Hotend which made printing ABS reliable once again.

I repaired fans, I replaced fans. And then I did it again. Once I got ABS printing up to speed I printed a DiiiCooler, which I finally installed, and still haven’t used (since I’m printing ABS at the moment.) And yeah, I’m waiting for some new extruder fans to arrive after last night’s hurried soldering session to repair another bad fan.

printer-enclosure-0904

If all of this seems silly, well, in a way it is, and it isn’t. When you buy a thing (be it a 3D printer or a car) you can go cheap knowing that things might break or need upgrades, or you can pay a lot more for quality out of the gate, with the hope that things don’t go wrong or are of a higher quality. I knew that getting the Monoprice Maker Select Plus meant compromising so I could afford a printer (which was replacing my old RepRap Prusa i2 kit from 2011) and I was fine with that. There are many routes you can go with a printer. I’m going the “cheap” route right now, I’ve got friends who work for the “expensive but reliable route” companies, and then there’s the custom build route. They’re all legit choices.

enclosure-lights-0905

Oh, I don’t think I ever mentioned my enclosure. It’s built from foamcore board and covered with the packing foam that the printer came in. The front window is a piece of Polycarb I got from Amazon. It works. It’s not pretty. That’s okay. Besides keeping the heat in, it keeps the cats out. Also important. I also added a set of 12 volt LED lights with an on/off/dimmer switch.

led-dimmer-0913

If I had to build an enclosure again (and I might need to soon) I’d probably go with foamcore again, but take some effort to make it look good this time.

filament-rod-0916

I still feed the filament from a metal rod hanging above my printer in the basement. It works fine. It’s not portable, and that’s probably okay. The drybox I was working on failed, and I haven’t had the energy to revisit that project. That’s okay for now.

Besides all that, I’ve been printing thing just. Nothing too exciting, but that may change soon. Happy Extruding!

2017.06.12

Meter in Mount

What do you do when you have a square thing and want to mount it in something but don’t have the ability to make a square hole? (Okay, I know it’s a rectangle in this case…) Well, you put the square thing in a round thing and then make a round hole.

With some current projects I’ve been thinking a lot about how things can be done using specific tools, or a limited set of tools. For instance, if you’ve got a 2-1/2″ hole saw you can make a round hole and then drop this into place and hold it down with two screws.

Circle

I started to model this mount before I even had the meter. I drew up a rectangle of the dimensions specified on the eBay listing for the item (hoping they were accurate) and I then drew a circle around it to enclose the meter and rounded it up to 2-1/2 inches as that’s a hole saw size you can actually buy.

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From there modeling the mount in OpenSCAD was pretty simple. It’s about 25 lines of code, and it the panel press fits perfectly. I added two ears to put some #4 screws through to hold it down to the panel.

Meter and Mount (Back)

I’m not totally jazzed about the open back. I supposed I could pour a lot of hot glue in there… Actually, at a minimum I may add some hot glue to the wires to act as strain relief so they don’t get pulled loose. (I supposed modeling some sort of strain relief mechanism into the mount would have been a good idea.)

Meter and Mount

And of course while this version is expected to mount (nearly) flush with the panel, I could easily make that mounts on top of the panel and just has a small hole drilled through it for the two wires. So… many… options.

Meter in Mount

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