Jamming a wheel– again– on a mud-slicked rock, Da Xiong muttered under his breath and wiped his brow with a dirty sleeve. Out here, with no one but his dozing master to hear him, he could speak just a bit and break the facade he’d carefully sustained since before escaping the capital five years ago.
Progress along the muddy ground was excruciatingly slow even for a man of his size and strength, made even more so by the weight of the cart he half-pulled, half dragged through the puddles and stones.
Master Qie, as was his wont in the late afternoon, napped on his cushion undisturbed by the bumpy and intermittent travel. Qie had insisted– INSISTED! with a flourish of a silken sleeve, that Xiong load the cart with cheap wines at the last stop. For trade, he said.
Trade, indeed. Not that even the waiguogou would drink this swill. Or properly pave a road, for that matter.
Back home even this minor road would have been carefully laid with precision-cut flagstones. Xiong noted where cutting a swale on the left would immeasurably improve drainage, and over there one could very easily re-grade and straighten the path with an eight-crew and two days’ labor, and just a few li back they’d passed a fine, defensible junction where, if they’d had any sense at all, the locals would have sited a cistern and a toll collector.
Pfft. Barbarians. The only saving grace of plodding through this godsforsaken land was that Master Qie was now very, very far from the Imperial Censor and his torturers.
Ahead of them the tower waited, piercing the canopy and reaching three times again as high as the tallest tree. There were temples taller than this at home, but not many, and none made entirely of stone. A staircase spiraled to the top of tower, narrow and irregular and steep. They’d have to leave the cart and lug the wine up on Xiong’s back.
The glass orb at the top glowed dimly, brighter than the sun in the overcast sky. Xiong estimated the amount of sand, coal, and workers one would need to engineer a glass sphere the size of a house and concluded that either it was clever fakery or the waiguogou possessed a secret foundry bigger than the Emperor’s stables.
Or, most likely given the Eyrie’s inhabitants, it was magic.
Wizards. These people knew the importance of learning and careful study, even if they wouldn’t deign to apply their erudition to engineering a passable turnpike.
Tomorrow, the travelers would meet these mages and make a record of their Eyrie in Master Qie’s ever-thickening journal. Page by page the catalogue of strange places and people grew, but Xiong doubted anyone in the capital would ever read it. He still held hope, but daily became more and more convinced he and his master would never return from this land of fleas to silk sheets and polished rice and love left behind.
Da Xiong sighed and trundled forward. Perhaps, sweet Tianyu, he mused. Perhaps I will hold you again.
Longtime readers of this blog– both of them– know that here at Zheng Labs we’ve got a couple of rugrats running around the place. The older one’s in high school now, and has a practiced eye roll that earns perfect 10’s even from the Romanian judges. She’s not the subject of this post, although you can see photos of her pupal stage here and here, and some free 3D printable models to boot.
No, my friends, this week we bring to you the chronicle of my younger spawn and his adventures at the elementary school science fair. Each year his school puts on an open house for prospective families where they might explore for themselves the Hogwarts-like environment at one of Wisconsin’s fine public charter schools.
This open house features a gymnasium full of the kids’ long-term science projects, and is always a treat for those inclined to make things that go kablooie with papier maché, baking soda, and a little CH3COOH.
In years past procrastination and lack of interest have led my son to flail helplessly in front of a sloppy trifold when the time to present his project came, and this year we were determined not to repeat that particular learning experience. We got started early, enlisted a 3D printer, and won the science fair.*
*on “winning:” the event is actually noncompetitive and the school doesn’t give out prizes. I’ll define winning as spending a couple hours in the basement with my son, teaching him how motors and voltage and switches and soldering irons and burn creams work. Plus the look of unadulterated joy on Xiao Zheng’s face when the project worked: priceless. Scroll down to the bottom of the post for the big payoff video.
Also, the kid who actually won the science fair was the one with the trifold cheerfully labeled “Exploring Uranus.” That kid’s going places and has either fantastic or clueless parents.
Astute readers may have surmised that this year’s theme was space science, and the thrumming gymnasium was packed, absolutely packed with elementary school children wearing astronomy-related costumes. One kid was a dead ringer for Carl Sagan (red turtleneck included). Galileo and Halley’s comet were easily identifable from across the room. One young man made a fantastic Pathfinder rover hand puppet, a young lady was fetchingly dressed as the day and night cycle complete with helium balloons tied to her pigtails, and much aluminium foil was spent in the pursuit of knowledge.
Soviet science was well represented, too. The neighbor kid dressed up as Sputnik, and there was even a kid in full bright-orange Yuri Gagarin drag. Imaging getting that costume past the a 1950’s school board here in Appleton, Wisconsin, hometown of national disgrace and Ted Cruz lookandthinkandsoundalike Senator Joe McCarthy.
McCarthy’s grave is right down the street, should you feel the need to urinate.
I’d post photos of the science fair, but! Kids’ privacy issues. You know the drill. Local parents: if you’d like to share a photo of your kid’s costume, send it my way.
好久以前, back when Zheng himself was xiao, Dad and I spent many evenings in our basement laboring on school projects. In all fairness it’s safer to say that Dad did the heavy lifting and I just provided parameters, but man those projects were the envy of the other kids in elementary and middle school. I wish I had photos of the tornado diorama, or the sculpture of Zeus made of toilet paper, shellac, and Ivory soap flakes (!) or that Roman aqueduct we (Dad) made out of grout and PVC. Or the paper bag mountains with joint compound glaciers. Or the passive solar house model made out of foamboard reclaimed from the dumpster at work.
Thanks Dad, for doing those projects with me. I’m doing my best to pass your creativity down to your grandkids. Cir-cle of liiiiiiiiiiiiiiiife!
But I digress. This is a 3D printing blog first and foremost, and you’re here to read about the process of creation.
We got the trifold part of the project out of the way first, and settled into working on the costume part of the presentation. Our challenge: making a wearable model of Venus. Xiao Zheng’s first idea was to hand-letter the word “VENUS” on a piece of cardboard and hang it around his neck. He’s literal that way sometimes.
A planet-like sandwich board was also considered and quickly discarded as “stupid” and uncomfortable to boot. We gnashed teeth and rended garments for a while before remembering that his bike helmet has a GoPro mount on it, and would be a perfect platform on which to place a model.
The model of Venus itself is nothing fancy, just a lightweight ball of bubble wrap shrouded in painted tissue paper. It masses approximately 116 grams. The actual planet Venus masses 4.867 × 1027 grams.
I introduced my son to the joy of inadvertently huffing spray paint fumes in the garage, which he liked. Maybe too much.
Just attaching Venus to a helmet’s really not enough when the other kids are dressed up as Saturn V rockets, so we had to take it to the next level by making the model spin. I’ve got a bunch of old DC motors kicking around because of course I do, but we quickly realized that even if we could attach the motor’s axle directly to the model, it’d spin way too quickly.
So a few minutes’ modification in Maya and we’re off and printing. Pro tip: gaffer tape works astonishingly well as a print surface for ColorFabb’s PLA/PHA. Note that there’s a cup integrated into the top of this gear to give the planet more surface area for adhesives.
Next we’ve got to get the gears onto the helmet, and fortunately there’s a GoPro-compatible mounting system in the Forge. A few more minutes of vertex wrangling and a couple of test prints and the mounting system looks like so:
(You can download the models here if you’d like to take a peek at them.)
The rotation is controlled with a momentary switch hidden in the kid’s pocket. Hold the button down and Venus spins faster and faster. Of course, my kid’s teachers aren’t pants-wetting bigots and he’s white as Wisconsin snow and not named Ahmed, so nobody batted an eyelash at this suicide-bomber-looking pushbutton setup. It’s even RED.
Fun fact: Venus’ day is 243 earth days long. I learned this from the aforementioned girl dressed as the day-night cycle.
Everything’s gaffer-taped together to insulate the solder joints and the wires are hidden under clothing.
The project survived the entire night on one set of 4 AA batteries and finally met its demise when my son, in an all-too-typical display of spazzy exuberance, head-butted the kid dressed up as a Soyuz capsule during cleanup and Venus went spinning across the gym floor and into the hallway.
Lao Zheng out. Thanks again, Dad, for teaching me how to do a science fair project right.
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.
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.
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:
The second time through I stayed with the print, keeping the propane flame focused on the wire as extruder pulled it in.
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.
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.
Chinese has many set phrases chéngyǔ 成语: four-word phrases that communicate an idea or concept quickly to someone who knows the cultural and historical context of the phrase.
Some are really easy to understand, like rén shān rén hǎi 人山人海 : people mountains people sea. This place is very crowded!
Others require some knowledge of Chinese history and literature, like máo suì zì jiàn 毛遂自荐 : Mao Sui recommends himself. If you don’t know a little bit about The Warring States period, you might have no idea why your pal Lao Wang yelled this as he jumped up to fix the paper jam.
English-sepaking fans of Star Trek: The Next Generation would do well to think of chéngyǔ as the language of Tamarians: just think of Darmok and Jalad at Tanagra, and how much Tamarian history Picard had to learn before he understood what the Tamarian captain was talking about.
I recently learned a Chinese expression: hè lì jī qún 鹤立鸡群: a crane standing among chickens. My understanding is that it’s used to describe someone or something that stands out from the crowd, but I wasn’t sure whether this should be used in a positive, negative, or ambiguous sense.
My American sensibility led me to think it’s positive, since we tend to celebrate the individual. Boy, that kid does math better than the rest of her class. She’s truly a crane among chickens, and we should praise her achievements.
Or should it be used pejoratively? That kid’s always showing off how good she is at math. She’s truly a crane among chickens, and we chickens should peck her down to size, post haste.
I’ve also seen the expression used by American expat bloggers, describing themselves as wildly different from the people around them. In this sense it sounds akin to the English idiom “sticking out like a sore thumb.”
I follow Hacking Chinese and through that learned about Lang-8, a lanugage-exchange site that pairs up native speakers from different languages. So I asked about 鹤立鸡群 over there and they say it’s overwhelmingly positive.
I’m also now completely hooked on correcting the English grammar of Japanese teenagers. I can only imagine how dumb I sound in Mandarin with my pidgin talk about my cold cup of coffee.
The characters on the sticks are kinda-sorta-puns– 吉 (second tone) can mean lucky, but 鸡 (first tone) translates as chicken.
He 鹤 (fourth tone) is a crane (as in the bird, not the construction equipment), but 和 (second tone) can mean “harmony” or “harmonious,” depending on the context. So if you know the original chéngyǔ that character makes some kind of sense.
A flamingo is a 火烈鸟, or fierce fire bird. Which is funny if you think for a minute about how threatening a pink filter-feeder can be.
I’m going to say my newly-minted chéngyǔ is unambiguously positive. You, my friend, are not merely a crane among chickens. You’re a flamingo among chickens. You are just that cool.
The next time you have folks over for cocktails, give the flamingo stick to the guest of honor. Everybody else gets a plain old chicken.
You can download these cocktail sticks for free. 干杯!
Halloween fast approaches, and I still haven’t managed to make that electroluminsencent Riddler costume I’ve been dreaming about for the last two years. But this year I did manage to come up with a nifty Hack-O-Lantern that uses an Arduino and a pair of diffusers that I printed on my MakerBot Replicator. Here’s what the animation looks like, including my new favorite function, derp().
My apologies for the soul-deadening ambient light in the video. The Hack-O-Lantern looks a lot cooler in person, although if I had more time I’d try to boost the voltage to the LED’s and brighten them up a bit. Right now they’re running off straight off the Arduino, and I didn’t want to burn out any pins by driving too much juice. Maybe next year.
You don’t need to use an Arduino to use these diffusers: if you’d rather just stick a couple of LED’s in there with a watch battery taped to the leads, that will work just fine. The LED’s in the top photo are running in series off 4X 1.2V NIMH 2500 mAh rechargable C cells, and they look great.
The diffuser has a slight lip on the back that you can use to score your pumpkin’s flesh before cutting.
Nightmare fuel, anyone? Here’s all 14 LEDs soldered to hookup wire, fed through the pumpkin’s eye holes.
Once I connected the LEDs to pins 0-13 on an old Arduino Duemilanove I had kicking around (SCORE for finding a set of headers I’d forgotten I ordered six months ago), I put the whole contraption in a plastic bag so the pumpkin guts couldn’t short the hardware.
Working inside that cavity gives you a lot more respect for brain surgeons.
If you’ve carved a pumpkin recently, you’ve probably got some seeds kicking around. Here’s what I’ve been doing with them lately:
Zheng3 Szechuan Pumpkin Seeds
approximately 1.5 cups of pumpkin seeds, washed.
1 tablespoon doubianjiang
1 teaspoon light soy sauce
1 teaspoon hot chili oil
2 tablespoons peanut oil
1 tablespoon Szechuan peppercorns
Mix everything except the peppercorns in a bowl and toss to coat. Set aside for an hour to marinate.
Toast the peppercorns in a wok over medium heat until fragrant. Crush with a mortar and pestle.
Spread the pumpkin seeds and marinade evenly on a flat baking tray. Bake at 350° for about 20 minutes. Sprinkle with the crushed peppercorns and serve.
If you can’t find doubianjiang and you’re not willing to wait for a shipment from Amazon you can probably substitute some garlic powder mixed with Sriacha rooster sauce.
Approximating the flavor and mouthfeel of Szechuan peppercorns is more difficult. Try this:
Dip a jalapeño pepper in powdered laundry detergent and suck on it for 30 seconds. Then put your lips across the terminals of a 9V battery.
I started using a Wacom Intuos 2 tablet in 1999 after struggling with a mouse-induced repetitive stress injury. I’ve been holding the same stylus pretty much every day, for hours a day, for the last twelve years.
Over time, the nibs eventually wear out, and I’m left wondering where I left that tiny bag of replacement nibs I bought from Wacom three years ago to replace the tiny bag of replacement nibs I lost six years ago.
Now I have a Replicator, and I can print my own highly precise pieces of plastic. I’m a big believer in Taking It Just A Little Too Far, so I’ve designed a nib based on the slicing end of a Shaolin spade.
The Shaolin spade (月牙铲, or yuèyáchǎn for my fellow xuésheng) was the favored weapon of drunken monk Lu Zhishen, made famous to those without an interest in classical Chinese literature by Max Brooks’ Zombie Survival Guide and the fine Kurt Russell vehicle Big Trouble in Little China.
The nib should work for any Wacom stylus. Here it’s pictured in my Bamboo, which I use for work when I’m traveling.
My original plan was to include the Shaolin spade in the Zheng3 Cocktail Arsenal, but the tip is too wide to be thrusting through maraschino cherries. It should make a dandy calligraphic nib for those so inclined.
If you’re the kind of person who cares enough about the quality of a digital brush stroke to 3D print custom nibs for a Wacom tablet, you deserve a step-by-step tutorial on how to do it.
This is a really precise, but very simple print. The nib’s shaft needs to be sized so that it fits the bore of the Wacom pen and can be removed with the tiniest effort, but not so loose that it falls out when one begins to draw with the stylus.
I did a lot of trial and error to get the nib diameter correct, because my four-dollar hardware store calipers produced a measurement that was way, way too thick to fit into the pen. A radius of .065 cm seems to do it when printing with the following method. I’m assuming there’s some contraction/expansion/plastic real-world-weirdness that doesn’t show up when the design isn’t all vertices and electrons.
Note that I’m printing with PLA.
HBP: 45° C
Layer Height: .2
Number of shells: 1
Feedrate: 25 mm/sec
Travel Feedrate: 55
This print is so small and delicate that any extruder-induced jiggling of the Replicator is likely to shift the plastic off your platform. I got good results by slowing the print heads down. Here’s how I did it:
Generate your gCode from within ReplicatorG using the above settings. Then do a couple of find/replaces in your favorite text editor:
Replace F750.0 with F100.0
also replace F1500.0 with F100.0
There’s probably a way to do this from the GUI but for some reason I’m more comfortable mucking around in the ASCII.
Run the print. Your instinct will be to pull that new nib off the build platform and jam it into your stylus ASAP. Don’t. Give it a few minutes to cool so it doesn’t warp upon removal.
It’s easy to remove a fresh nib from a Wacom stylus. Just grab it with some pliers and pull gently. Scissors are useful for removing a worn nib; cut slightly into the plastic of the nib with the blades and then pull it out.