July 16, 2014

So I got this 3D printer. From a machine design standpoint, it’s one of the best hobby-grade ones out there, but still leaves a bit to be desired… but not bad, plus it hauls ass. It’s called a QuBd. The company has quite a bit of trouble shipping hardware in any reasonable amount of time (this one took about 8 months) but they’re cheaper than a Makerbot and probably more reliable…. except that they maybe glue a few more things than they should.

March 11, 2014

Behold the Pizza-Copter. This is version 2 of the original Pizzacopter flying pizza box, featuring more powerful motors and better flight software (which still needs to be tuned, as you can see, but you get the picture)

Also, this video is special, because it features the Kontraptionist, in the flesh. I’ve largely remained a man shrouded in MYSTERY up until this point….and I have to just give the disclaimer that I’ve let the beard go a little more than I ought to… and my hair…. and I could probably use to ditch the Crocs and take a shower…. but that’s not the point. You get to see a flying pizza box! It’s powered by a small lithium polymer battery feeding in to four high power brushless motors. It has a pretty short flight time, maybe only 2-3 minutes, owing to it’s terrible aerodynamic properties and the fact that I more or less have to “firewall” the throttles to get it to pop up off the ground as it’s quite heavy, but over-all I’m satisfied with its performance, especially given that it’s a FLYING PIZZA BOX!

February 28, 2014

I spent this past October and first half of November rebuilding the mechanics of this amazing piece for the American Museum of Natural History. It’s been around for about 10 years, and has seen it’s share of hacks, kluges and “there, I fixed it!” moments. It was about to head off to Singapore when the museum decided it needed a Kontraptionist tune-up. New bearings, new linear slides, a new motor, and countless cleanups, helicoils, bushings, shoulder bolts and more were added to bring this monster back to life once again. Enjoy the video. I have some other more pro footage I shot which I’ll try to upload soon as well - Photos of the innards are also on their way.

February 27, 2014

Here are the guts of the Zoetrope I got to work on this summer for the American Museum of Natural History. In it’s initial form, it used to feature a giant 1 HP AC gear motor. Needless to say, it was loud, and got HOT. Also, it was absolute overkill for this application. After all, it was turning a disk with dinosaurs. But the reasoning, perhaps, was that they needed very steady speed because there was no actual strobe sync going on, just two pots for duty cycle adjustment…. This combo was subject to clock drift and of course, the need for readjustment whenever it traveled between countries that used 50hz or 60hz electrical grids, since that would change the speed that the motor operated at. Also, let’s not forget the converter transformer for 220V operation. We decided to put an end to all that nonsense. First order of business was to put a new motor in. One that was a little more appropriate. I chose a brushless DC motor because I could always be sure that it would get the right amount of juice, and because of the high reliability of brushless designs. Next up, a universal power supply was used, which could take 110 or 220V power at whatever frequency and automatically convert it to the required 24V DC for the motor and the LED strip. This eliminated the risk and work in setting up the exhibit for international locations. Also added was an optical sensor to precisely measure the speed of the motor (the motor controller had a tach output, but the Arduino Uno only had one 16-bit hardware timer, and the jitter was too high to feed in to be useful in an 8 bit timer) The optical sensor simply read a black mark on the disk, which was used to set the period in the Arduino’s 16-bit timer. Read: No matter what speed the motor was turning at, the computer could always adjust the speed of the strobe to match the rotation. The result was a set of perfectly locked in place dinosaurs. The only setup required (or not required) was to set the speed to whatever the curator thought would work best for their visitors. Of course I had some fun with the startup sequence. Part of the magic of this exhibit is the technical end of what goes in to pulling it off. I made sure that as the motor spun up that the LEDs were on constantly, so the visitor could see what was going on, then once the final speed was reached, the duty cycle (percentage of on-time to off-time of the LEDs) was reduced, and the dinosaurs would morph from a blur of spinning bodies to a perfectly animated family of sauropods walking. 

February 26, 2014

This past summer, I had the pleasure of rebuilding this stroboscopic zoetrope for the American Museum of Natural History.  The device features a 2 foot diameter disk with twenty four 3D printed sauropods and a precision optical tachometer feeding in to an Arduino, which controls the strobe frequency of the beefiest LED tape I could buy. The results are amazing. The camera (and it’s shutter crawl) do it no justice.  More on the internals and how it was done to follow. Let’s just say lots of low level Arduino timer functions were used. 

February 25, 2014
Here’s a fun Kontraption, and very clever if I might say so myself. We needed a curved track for a giant touch screen to ride on. THK makes bearings that are perfect for this, but they cost THOUSANDS of dollars and only come in a few different sizes. And take MONTHS to show up.. So? We made our own. What’s more, we had to be able to track the position of the carriage on the track. An encoder is the obvious choice for this job, but the mechanics of hooking a conventional encoder up to a curved track are not trivial. The solution was to make the track itself an encoder! Gray code (that funky tree-like pattern in black) was applied to the track, and an 8 channel optical sensor read it back in to an Arduino, where it was converted to it’s integer value of 0-255, then sent out to the computer over a USB serial connection to control the visuals. We made our own absolute encoder! Very fun stuff. Unfortunately, we can’t show the final finished product, but if you happen to be at the auto show in Geneva, Switzerland next week, stop by the TESLA booth. 

Here’s a fun Kontraption, and very clever if I might say so myself. We needed a curved track for a giant touch screen to ride on. THK makes bearings that are perfect for this, but they cost THOUSANDS of dollars and only come in a few different sizes. And take MONTHS to show up.. So? We made our own. What’s more, we had to be able to track the position of the carriage on the track. An encoder is the obvious choice for this job, but the mechanics of hooking a conventional encoder up to a curved track are not trivial. The solution was to make the track itself an encoder! Gray code (that funky tree-like pattern in black) was applied to the track, and an 8 channel optical sensor read it back in to an Arduino, where it was converted to it’s integer value of 0-255, then sent out to the computer over a USB serial connection to control the visuals. We made our own absolute encoder! Very fun stuff. Unfortunately, we can’t show the final finished product, but if you happen to be at the auto show in Geneva, Switzerland next week, stop by the TESLA booth. 

It’s good to start making chips again - Doing some CNC cutting of 1/8” aluminum sheet, 6061 alloy. This is a track for a point of sale display. A set of V-groove rollers will ride along it. Aluminum is definitely NOT the first choice for this application, as it’s relatively soft, however, because of the light loading and the simple fact that out current router can’t cut steel make it the best option we have. And it turns out, it’s perfectly adequate. 

It’s good to start making chips again - Doing some CNC cutting of 1/8” aluminum sheet, 6061 alloy. This is a track for a point of sale display. A set of V-groove rollers will ride along it. Aluminum is definitely NOT the first choice for this application, as it’s relatively soft, however, because of the light loading and the simple fact that out current router can’t cut steel make it the best option we have. And it turns out, it’s perfectly adequate. 

February 13, 2014
What do you do with an old and thoroughly broken Teddy Ruxpin from eBay? 
We rebuild him… Better… Stronger… Faster! With the help of  some servos, and a re-purposed Quadcopter flight computer, Teddy will roar back to life with more magic (and certainly a lot more social degeneracy) than ever before.
Our friend Will, who’s in charge of FreakFurz, had an art opening closing recently, featuring this bear,who was tasked with telling filthy NSFW tales of perverted ursine debauchery, earning him the name “Nasty Fuxpin”
The flight computer used for Teddy’s brain was chosen because it’s built to interface with servos - lots of them, and it’s based on the ATMega328P, which means you can run Arduino code on it.  Teddy’s SD card was then loaded with audio, which fed through an amplifier (based on the LM386 chip), then split between a rectified low pass filter (and on to an analog input in the flight controller) and also to the speaker. The original thought was to create a new tape for Teddy. This would have consisted of all audio tracks on the left channel, and the right channel would feature an 8 sub-channel PPM (pulse position modulated) signal to control all of his functions. This is the same scheme used in old-school radio controlled airplane transmitters. Simple, but effective.
Teddy’s head was fitted with three model airplane servos, which replaced the burned out originals. 
VIDEO HERE! Teddy does his impression of the famous “No No No Cat”

What do you do with an old and thoroughly broken Teddy Ruxpin from eBay? 

We rebuild him… Better… Stronger… Faster! With the help of  some servos, and a re-purposed Quadcopter flight computer, Teddy will roar back to life with more magic (and certainly a lot more social degeneracy) than ever before.

Our friend Will, who’s in charge of FreakFurz, had an art opening closing recently, featuring this bear,who was tasked with telling filthy NSFW tales of perverted ursine debauchery, earning him the name “Nasty Fuxpin”

The flight computer used for Teddy’s brain was chosen because it’s built to interface with servos - lots of them, and it’s based on the ATMega328P, which means you can run Arduino code on it.  Teddy’s SD card was then loaded with audio, which fed through an amplifier (based on the LM386 chip), then split between a rectified low pass filter (and on to an analog input in the flight controller) and also to the speaker. The original thought was to create a new tape for Teddy. This would have consisted of all audio tracks on the left channel, and the right channel would feature an 8 sub-channel PPM (pulse position modulated) signal to control all of his functions. This is the same scheme used in old-school radio controlled airplane transmitters. Simple, but effective.

Teddy’s head was fitted with three model airplane servos, which replaced the burned out originals. 

VIDEO HERE! Teddy does his impression of the famous “No No No Cat”

Kontraptioneering presents  No No No Bear!

What do you do with an old and thoroughly broken Teddy Ruxpin from eBay? 

Turn him in to an internet meme, courtesy of a different internet meme, some servos, and a re-purposed Quadcopter flight computer!!

Our friend Will, who’s in charge of FreakFurz, had an art opening closing recently, featuring this bear, although he was tasked with telling filthy NSFW tales of perverted ursine debauchery rather than imitating some poor, frightened kitty. 

The flight computer used for Teddy’s brain was chosen because it’s built to interface with servos - lots of them, and it’s based on the ATMega328P, which means you can run Arduino code on it.  Teddy’s SD card was then loaded with audio, which fed through an amplifier (based on the LM386 chip), then split between a rectified low pass filter (and on to an analog input in the flight controller) and also to the speaker. 

This was early on in the firmware development. Later software gave teddy the ability to wiggle his nose, blink his eyes, get bored, and finally fall asleep. These are the fun projects.

October 24, 2013

We’re doing lots of stuff…and sometimes it’s wooden box design. This one is for some kind of step-up stool (I think?) The final pieces will be CNC cut from 3/4” plywood and then screwed together, and possibly glued as well. Note the corner relief cuts on each and every single inside corner - See a previous post about slotted construction here. These prevent you from having to go in with a file or other tool to manually clean out the inside corner, which can be an enormous time suck, plus it’s hard to do a really good job. So why not just let the robot do the work? True, they’re not well concealed, but there are ways to hide them better when appearance is everything. 

October 3, 2013
Tapping - creating threads in a hole so that it can accept a screw, bolt, stud, etc, using a tool called a tap (oddly enough). The tap is the actual drill-like bit at the end of the T-handle tap wrench or tap handle shown here. A chart is consulted, and a drill, slightly smaller than the diameter of the screw or bolt you’re planning on using, is selected and used to drill a regular old hole in preparation for the tap. Then, with a steady hand, some oil or cutting fluid,  and an eye for keeping the tap perfectly parallel with the hole you drilled,  literally screw the tap in to the hole. Now here’s where it gets tricky. There a re a bunch of different tap styles, and many of them, especially the most common type,  require you to screw the tap in, then after only a half turn or so, back out a quarter turn or more.. and repeat until you finally make your threads deep enough. Often,  you have to remove the tap completely to clear out the metal shavings… they gotta go somewhere, especially when the hole doesn’t go all the way through the work. However,  when it’s a “through” hole, you can use what’s called a spiral point, or gun tap. It’s got a special cut on the tip that allows it to push the metal shavings ahead and out of the other side of the hole, (illustrated beautifully above) often eliminating this nonsense of “forward a half, back an quarter” to the point of being able to actually put the tap in a drill or.. wait for it… a “tapping gun” and just blast threads in to holes all day long, with the help of a lubricant, of course. Now, that hole that took you 5 minutes to tap now takes 6 seconds, leaving plenty of time to tap the other 74 or however  many are in your future.  The only catch? Spiral point taps cost a few dollars more than “hand taps” which should probably be renamed “cheap, annoying taps” since almost any tap can be used by hand.

Tapping - creating threads in a hole so that it can accept a screw, bolt, stud, etc, using a tool called a tap (oddly enough). The tap is the actual drill-like bit at the end of the T-handle tap wrench or tap handle shown here. A chart is consulted, and a drill, slightly smaller than the diameter of the screw or bolt you’re planning on using, is selected and used to drill a regular old hole in preparation for the tap. Then, with a steady hand, some oil or cutting fluid,  and an eye for keeping the tap perfectly parallel with the hole you drilled,  literally screw the tap in to the hole. Now here’s where it gets tricky. There a re a bunch of different tap styles, and many of them, especially the most common type,  require you to screw the tap in, then after only a half turn or so, back out a quarter turn or more.. and repeat until you finally make your threads deep enough. Often,  you have to remove the tap completely to clear out the metal shavings… they gotta go somewhere, especially when the hole doesn’t go all the way through the work. However,  when it’s a “through” hole, you can use what’s called a spiral point, or gun tap. It’s got a special cut on the tip that allows it to push the metal shavings ahead and out of the other side of the hole, (illustrated beautifully above) often eliminating this nonsense of “forward a half, back an quarter” to the point of being able to actually put the tap in a drill or.. wait for it… a “tapping gun” and just blast threads in to holes all day long, with the help of a lubricant, of course. Now, that hole that took you 5 minutes to tap now takes 6 seconds, leaving plenty of time to tap the other 74 or however  many are in your future.  The only catch? Spiral point taps cost a few dollars more than “hand taps” which should probably be renamed “cheap, annoying taps” since almost any tap can be used by hand.

September 30, 2013
Old “linear bearings” used in the walking T-Rex exhibit for the American Museum of Natural History. These weren’t the original bearings. Somebody else put these in. These appear to be out of a filing cabinet of some sort, and no amount of grease (in spite of somebody’s best efforts) will ever fix a poor design decision.  REAL linear ball bearings are being installed in their place. When these lost their marbles (literally) the entire mechanism began to shake and shimmy, causing a pretty serious series of cascading failures behind them. 

Old “linear bearings” used in the walking T-Rex exhibit for the American Museum of Natural History. These weren’t the original bearings. Somebody else put these in. These appear to be out of a filing cabinet of some sort, and no amount of grease (in spite of somebody’s best efforts) will ever fix a poor design decision.  REAL linear ball bearings are being installed in their place. When these lost their marbles (literally) the entire mechanism began to shake and shimmy, causing a pretty serious series of cascading failures behind them. 

September 25, 2013
Played tourist today - The 100” Hooker telescope at the Mt. Wilson observatory. 100” is the diameter of the main mirror in this telescope. BIG telescopes use curved parabolic mirrors, kind of like magnifying bathroom mirrors, instead of lenses, since they’re a lot easier to manufacture at these enormous sizes. Mirror diameter is equal to the light gathering power of the telescope. Big mirrors allow you to view very dim objects. Big mirrors also usually have LONG focal lengths too, which means greater magnification. A truly awesome instrument that I’d like to see a lot more of in the future.

Played tourist today - The 100” Hooker telescope at the Mt. Wilson observatory. 100” is the diameter of the main mirror in this telescope. BIG telescopes use curved parabolic mirrors, kind of like magnifying bathroom mirrors, instead of lenses, since they’re a lot easier to manufacture at these enormous sizes. Mirror diameter is equal to the light gathering power of the telescope. Big mirrors allow you to view very dim objects. Big mirrors also usually have LONG focal lengths too, which means greater magnification. A truly awesome instrument that I’d like to see a lot more of in the future.