Tag Archives: sparky phelps

Printing With Steel on the Printrbot Simple

printrbot

One of the most popular pages on this blog is Calibrating the Printrbot Simple. To be honest I haven’t been using my Simple much lately, what with the hullabaloo surrounding my Barbie-Compatible 3D printed armor Kickstarter. Just don’t have the time.

My mental juice can’t be occupied by all Kickstarter, all the time, so I took a few hours to mess around with Mr. Simple, and I decided to try an experiment that’s long been tugging at my frontal lobes. Can I print something recognizable, in metal, using my Printrbot simple and some clever engineering?

There are hobbyist metal printers on the way. I saw Vader Systems’ prototype at Maker Faire NYC, and can’t wait to get one of these bad boys into the basement at Zheng Labs.

But! Enough wishful thinking. Let’s get down to brass tacks.

I’m using baling wire for this project. You can get this stuff at any hardware store. Just make sure it’s not galvanized, because that can give off some nasty zinc fumes when it’s heated up. Also, I highly advise wearing protective gear.

wire

warning Attempt this project at your own risk! There is an excellent chance that you’ll completely junk your Printrbot, or at least melt the plastic collar at the top of the extruder nozzle. Have a fire extinguisher handy, just in case. Goggles, gloves, the whole nine yards. Be smarter than I was: under no circumstances should you down three mimosas before trying this, no matter how much fun you were having at brunch.

As a precaution, you’ll also want to cover the print bed in fire-retardant tape, unless you’re willing to deal with a flaming Printrbot.

I’m planning on doing this repeatedly, so I replaced the Printrbot Simple’s print bed with a piece of asbestos tile instead. Yay for Open Source!

I just redid the kids’ room with asbestos tile and had some left over. It’s cheap and durable and I can’t believe people just throw this stuff away. Watch this space for a blog post about turning old asbestos tile into cutting boards; I’ll be putting them on Etsy once I’ve cut a dozen of them or so.

Temperature is everything here and you’ll have to move quickly once you start, so be sure to have your gCode pre-generated. Don’t waste time slicing the model before you print.

Preheat the extruder as high as you can get it. I managed to get mine up to 275°C by disabling the firmware safeties and working under heat lamps in the basement. (Printrbot firmware hacking is a topic for another day.)

Even 275°C is way too low for melting steel, so you’ve got to help the Simple across the finish line by heating your baling wire up with a propane torch. Depending on the alloy of your wire that means somewhere around 1400°C, which should be within the range of a hardware store torch.

tip

Start the print and gently feed the hot wire into the Simple’s extruder. I epoxied a steel washer onto the collar of the extruder nozzle to protect it from the hot wire. Don’t lick the glowy part!

The print was a miserable failure, just your typical tangle of filament touched by His Noodly Appendage, ramen. This is what happens when you leave steel prints unattended:

print failure

The second time through I stayed with the print, keeping the propane flame focused on the wire as extruder pulled it in.

feed

With just a little filing and polishing the nose ring looks way better than I expected it to. Not bad for a printer kit that retails for $300, even if I did have to babysit the print the entire time.

yurenjiekuaile

Permit me a brief foray into my other hobby, studying Mandarin Chinese. It’s a remarkably concise language, so cramming the entire One Ring poem (to find them, bind them, yadda yadda yadda) onto the side of the ring is easy peasy lemon squeezy.

You can compress the whole poem into five characters, 愚人节快乐. Way fewer than required in the Black Speech of Mordor.

Flagrant stagecraft alert: I printed the ring and nose separately and welded them together afterwards; I haven’t tried printing anything with support yet.

You can download the STL files for the nose ring in the Baubles section of The Forge, or if you’re impatient or don’t have a 3D printer just grab one from Shapeways.

Pro tip: I found that copying my gCode into OpenOffice, coloring it pure red (#FF0000), and then re-pasting it back into Repetier-Host helped me get the extruder nozzle up to 282°C the second time around.

Finding Sparky’s Voice

In early February I debated whether to make a promotional video for my Kickstarter. The 3D modeling was done, the armor was printing reliably, and I figured the concept of 3D printed medieval armor for Barbie dolls would just about sell itself to the right crowd of people. Did I really need to invest the time in making a video?

SPOILER: I ended up making the video.

I dithered and hemmed and hawed for a day or two while I weighed the pros and cons of investing even more time in the Kickstarter. Eventually the creative itch won out over the practical hurdles of lighting, shooting, and editing with less-than-professional tools (my vendetta against Apple Motion 5 continues unabated) and after much gnashing of teeth and rending of garments I released this to the world:

I’m glad I did because people really seem to enjoy it. It’s also on Youtube and Vimeo now, BTW.

Acquiring scenery and minifigs for the video wasn’t a problem, but I clearly needed a Big Bad. I rooted though every bookshelf and toybox in the house and came up empty. The Zhengspawn are growing up quickly, and are more interested in playing with software than they are with plastic. Clutter is the enemy, so only the most cherished or useful toys remain in the house.

Candy Crush is also the enemy, but no matter how many stakes, silver bullets, DDT, UV, and Slim Whitman Indian Love Calls I use, I can’t seem to rid Zheng Labs of that particular infestation.

Last year’s purge resulted in an unfortunate paucity of plastic dinosaurs in the storage tubs, just when I needed one the most.

Ever supportive, the Lovely and Talented Mrs. Zheng3 dropped by the local thrift store, popped some tags, and returned with Sparky. She found him in the discount bin for a dollar, on account of his non-functional pushbutton speaker.

Sparky is a generic-looking therapod carnivore with very broad feet. Artistic compromises were clearly made during his design, but I think the size of his forearms pegs him as a reasonable attempt at an Allosaurus, with a little pre-1990’s tail anatomy thrown in for stability’s sake.

sparky full

I’ve spent a lot of time with Sparky, and now I’m curious about his origins. Somewhere on the Internets there’s an expert on cheap plastic dinosaurs who can take one look at Sparky and identify him immediately. Until that person surfaces, our only clue is a “MADE IN CHINA” stamp between his legs, which narrows his origin not at all.

The wear patterns on Sparky’s maw, brow, and toes suggest that he was extensively played with in the past. He’s definitely attacked his fair share of villages. Sparky, at some point in his life, was loved. The discount bin would be too ignominious an end for such a loyal toy.

wear pattern

To the workbench with you, my Jurassic friend.

Whoever sculpted Sparky did some nice work, especially with the reticulated scale patterns on his skin, but the person or people who inserted his speaker botched the job a bit; I think a hole saw was used to access his chest cavity but the opening was messily enlarged with a knife at some point before the speaker was jammed inside.

sparky hole

With some prying and pulling I’m able to extract the speaker assembly, hopelessly mangling it in the process. It uses two LR41 batteries, which are easy enough to come by, if redonkulously expensive when purchased as singletons.

Sparky’s noisemaker is a simple affair. A speaker is connected to a small circuit board, activated by a (gray) plastic plunger that completes the circuit by touching that solder squiggle in the middle.

But wait, you say? How does nonconductive plastic complete a circuit? There’s a circular swatch of black, conductive somethingorother glued to the bottom of the plunger. Any EE’s who swing by, please tell me what this stuff is called, for curiosity’s sake.

If you squint and turn up the contrast on your monitor you can see a dark circle in the southwest corner of the circuit board. That’s where the recording of Sparky’s voice is stored underneath a blob of epoxy. A little more on that later.

speaker

Two fresh batteries later, here’s what Sparky sounded like straight from the factory. Turn your speakers down, it’s a bit unpleasant.

Hmm. That roar sounds familiar. Here’s Godzilla, king of monsters:

Here’s the two of them, side-by-side with a little bit of audio cleanup in Audacity. Sparky is first, followed by Godzilla. Big G is sped up by 90% with an accompanying change in pitch to make Sparky.

waveforms

It appears to me, at least, that someone just ripped off Godzilla when Sparky was made. I’m offended.

A little research tells me that I won’t be able to hack Sparky’s audio chip and record my own roars. Apparently the audio is burned onto an IC at the factory and then covered with a little black blob of epoxy. “Flip-chip” technology, this sorcery is called, and working with it is beyond any magic I possess at Zheng Labs.

I’d love to be able to hack these chips because they show up everywhere, especially in Happy Meal toys.

I do have a toolbox full of electronics, and I might be able to cobble together a replacement roar for Sparky after the Kickstarter is finished. At the very least, I can print him a new bezel for his speaker today.

sparky fixed

Guy can’t be walking around with a nasty hole in his chest, now can he?

Also. All the time I’ve spent on TVTropes? It actually paid off: see how many tropes I managed to cram into one video, and post in the comments below:

I’ll give you the second one for free: Action Girl. Or is it Badass Princess? Reasonable people can disagree.