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HDPE Sheet Cake

HDPE

In our last experiment recycling HDPE into usable form, we created a brownie pan full of plastic. While this looked impressive, it wasn’t the best idea for something that was going to be milled. It ended up being much thicker than needed, and finding a cutting bit with the proper LOC (Length of Cut) proved to be an issue. I was all set to mill a thicker piece, but we blew a fuse on the Shapeoko.

HDPE

I decided that I needed sheet material of a uniform thickness, so I ended up creating a simple press using two pieces of wood, with some spacers. Once I warmed up the HDPE block I got it out of the pan, onto the wood, and stood on it until it was squished flat(ish.) I then put some weights on it until it cooled.

HDPE

It turned out well! It’s a pretty uniform thickness now, and this was just under 1/3rd of a bread loaf pan, so I may need a bigger press if I want to do bigger melts. I can also make different presses with different thicknesses as well.

HDPE

Funky!

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Laser Pointer Switch

Laser Pointer Switch

I modeled a laser pointer switch which you can use with your cheap laser pointer to turn it on and do stupid things like throw it in the air while doing long exposure photography. (Actually, that’s not a bad idea! Or is it?)

Laser Pointer Switch

OK, these are really part of the Laser Maze we’ll be running at Maker Faire Milwaukee this year. The last thing I did for Laser Maze was the mounts, but Vishal is still doing most of the hard work on this project. (Thanks, Vishal!)

Laser Pointer Switch

If you want one, you can grab it from Thingiverse or Youmagine. And remember kids, laser are dangerous, don’t just go pointing those things around!

Laser Pointer Switch

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PPPRS KC 2015 Cars

Moxie Board

Hello Racing Fans! I thought it might be appropriate to show you the cars that raced at Maker Faire Kansas City for the 2015 Power Racing Series…

Mutt Cutts

Mutt Cutts was one of the cute cars. You may know it from the “Dumb And Dumber” films. Well, here’s a tiny replica. It wasn’t the fastest, but it was the furriest. This was one of those cars that we worried would tip over in every turn. It didn’t.

Sweet Tooth

Sweet Tooth, built by Collin Royster, a prop-maker in Kentucky, was a damn impressive build. The clown head and forks were for decoration only, and got removed for the races.

Phantom 48

Phantom 48 returned once again! These guys just keep refining their already fast and reliable car. The rat rod impressed us with its looks in 2013 and hasn’t changed much cosmetically, but from what I understand they’re constantly tweaking the code running on their controller.

Cartastrophe Jeep

The Cartastrophe Jeep also returned in 2015, and just like Phantom 48, their car looks about the same, and performs about the same. Fast and reliable, most of the time, except when it breaks.

KITT

KITT from OMG is the car from Knightrider, and it did good, not too fast, and not too much breaking down. A good mid-fielder.

Huminator

The Humninator, the only in the series with a full suspension system! The Humninator is a take on The Terminator theme, and a Hummer. A pretty fast car, though it suffered a bad failure in KC, Scott is fixing it up for Detroit!

Herbie

Herbie (The Love Bug) is just adorable, and is the work of Chris Lee (from Nashville’s Kessel Runners Racing) super-star Wars Nerd and prop-builder.

Minecart (Steve)

The Minecart (also known as “Steve” was a big wooden box that surprised us all with its speed and agility. There’s some great reasons to build your car as a big wooden box. An unexpected surprise with this one!

Dangermouse Mark III

The second car from the Cartastrophe was the Mark III from Danger Mouse. I am unfamiliar with the series, but the car is a wedge of cheese. It did well for the first showing.

Jurassic Rover

Jurassic Rover is another really nice build from our friends from the south. I can’t remember which state they were from, but the car was beautifully done.

Duct Tape & Zip Ties

Duct Tape & Zip Ties car is an old classic, build mostly from old bikes. It’s not fast, but it is (somewhat) reliable and goes for the “slow and steady wins the race” idea.

FUBAR Truck

FUBAR brought their old green truck all the way from New Jersey! Bill and his team keep fixing it and breaking it and racing it and having a good time. That’s what it’s all about!

LEGO Car

LEGO Car (as we called it) was built by a team of high school kids. The body was foam and kept breaking, there was a Razor scooter underneath for steering, they used 6 motors, of which between 1 and 3 worked, they blew their controller and used a relay, and they were known as a “rolling chicane” but they had fun and were a crowd favorite. Awesome.

Bigger photos? See them on Flickr. More will be added over time…

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OpenSCAD Slowness…

Sparkplug

Typically when I model 3D object with OpenSCAD I tend to create things that are simple and functional, but I had to create a piece that had some extra decoration to it, and wow did it slow OpenSCAD to a crawl!

I know about the special variable $fn, but I didn’t know about $fa and $fs, so I’ll have to start using those as well to see if they can speed things up. (I usually use $fn to go between “low res” and “high res” when it comes to rendering.)

OpenSCAD probably isn’t the easiest modeling software to use (unless you like writing code) but I like the fact that it’s open source, gets updated fairly often, is parametric, has lots of great info on using it, and there are a ton of free libraries for doing interesting things.

I was using Rhino quite a bit earlier this year, and while the Mac OS X version is now ready, it’s $300 for a limited time, and $500 after that, and is somewhat crippled compared to the Windows version. It can do some amazing things, so I’m still contemplating a license for it… Or I may find something else (open source, perhaps?) that fits the bill.

(I’ll probably be posting more about 3D software in the near future.. Stay Tuned!)

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Teensy++ 2.0 LED Pin

Teensy++ 2.0 LED Pin

Yes, this post is actually titled “Teensy++ 2.0 LED Pin” because it’s really specific. This is the solution to a problem that took me a while to fix. Actually, it didn’t take a long time to fix, it just took a long time for me to figure it out and implement it. (Maybe it did take a long time for me to fix…)

Anyway, when using most pins on a Teensy++ 2.0 (and probably every other Teensy) with Arduino code, you may have an issue using the LED pin as an input, because it functions differently than all the other pins. You might say “Hey, just use another pin!” but the project I did required every single pin on the Teensy++ 2.0. (Yes, all 46 pins!)

The code is below. The LED pin is sort of treated opposite of how other pins are treated. You short it with +5v instead of ground, and swap the risingEdge and fallingEdge typically used with the bounce library. 

// LEDPinButton

#include <Bounce.h>
 
Bounce buttonD6 = Bounce(6, 80); // LED Pin - tie to +5v instead of GND
Bounce buttonD7 = Bounce(7, 80); // Normal Pin - tie to GND
 
void setup() {
  pinMode(PIN_D6, INPUT);        // LED Pin - use INPUT not INPUT_PULLUP
  pinMode(PIN_D7, INPUT_PULLUP);
}
 
void loop() {
  
  buttonD6.update();
  buttonD7.update();
 
  // D6 - LED Pin - tie to +5v instead of GND
  // use risingEdge instead of fallingEdge
  // a
  if (buttonD6.risingEdge()) {
    Keyboard.set_key1(KEY_A);
    Keyboard.send_now();
  }
  if (buttonD6.fallingEdge()) {
    Keyboard.set_key1(0);
    Keyboard.send_now();
  }
  
  // D7 - Normal Pin - tie to GND
  // b
  if (buttonD7.fallingEdge()) {
    Keyboard.set_key1(KEY_B);
    Keyboard.send_now();
  }
  if (buttonD7.risingEdge()) {
    Keyboard.set_key1(0);
    Keyboard.send_now();
  }
  
}

You can also grab this code from github.