We’ve changed the name of our blog! We are now Cunning Turtle and our brand new webpage is at http://www.cunningturtle.com!

All future updates about our projects will be posted there. Go check it out!

Check out JaGe090879’s amazing time-lapse video of a Gecko being eaten by ants. A lot of times when I build something or do a tear down I want to record the entire process the same way. That way when I need to put it back together I can remember the steps. Using my PC and a simple script I automated my setup to record a snapshot every few seconds. It’s a bare bones setup and I’ve tested it to work on most windows Xp and 7PCs. Feel free to use it for your projects. [download after the break]

I can’t take credit for all the software, the webcam control is a derivative of rysiora from Poland’s work.  I just implemented the time-lapse portion. The whole program is written in AutoIT, a great free scripting language that lets you manipulate and simulate the windows user interface.

Instructions

Step 1) Download Exe
Step 2) Run Exe
Step 3) Set the timing (hit pgup/pgdn to increase or decrease while running)
Step 4) Hit F1 if you want to  take an instant snapshot
Step 5) Hit esc to exit
Step 6) Find your pictures in the same directory
Step 7) Profit

Got a computer with a webcam? Great!

Running Windows XP or 7? Excellent!

Running a MAC OS or Linux? Sorry the AutoIt language doesn’t work on those. Womp womp womp….

Download Program [exe]
WebCam Time Lapse

Download the source code [zip]
Webcam Time Lapse

Lego bricks are great for making models, but sometimes you can make real tools with them. If you want to work with foam you should definitely consider building this hot wire cutter. It’s a great tool because it doesn’t leave any dust and it cuts through foam like butter. A few years back I didn’t have any scrap wood but I had plenty of Lego pieces.

One of my hobbies is taking out the Airsoft gun and picking off innocent Lego bricks from a shelf. Eventually I got tired of picking up my fallen victims and decided to turn the Lego’s into a self resetting target range. I wanted to make a cool electronic range, but I figured there must be an easy mechanical way that doesn’t cost me $12 per servo and days worth of wiring. I looked on the internet and found some $60+ dollar targets and just knew I could redesign them using Lego pieces. Once I found the right angles and proportions for the pieces the thing worked like a charm. When I shot the bottom two targets they get locked in place. When finished I shot the top target to release the bottom two. I added a stop motion video on how to construct one at the end and some different views so you can build your own.

I got bored and decided to make a BB gun using my air compressor. The secret sauce is a one way valve that blocks air from the firing chamber but allows air in the other direction to rapidly propel ammo into the gun. This allows me to tube fed BB’s, even when the gun is inverted. It’s also much faster than gravity feed versions. Watch the video for some action shots and how to make the valve.

So I’ve been working on a new CNC mill and I’m using ACME rods to drive the x and y axis. An ACME rod has fewer turns per inch and allows the machine to move twice as fast. The only downsides are ACME couplers and nuts are expensive and difficult to make without $40 ACME taps. I stumbled onto Michael McKinley’s site and decided to try making a  homemade tap. He used a drill press and a file for his. I wanted to spice it up and used a Dremel and belt sander, it took 30 minutes and saved me a lot of money. Best part this trick can be used on any threaded rod as long as the material you are cutting into is soft. Michael’s site has a lot more detail on the angles of the flutes and how to cut the reliefs. I winged it since I was only cutting delrin plastic. I might fine tune it at a later date if I want to try some soft aluminum.

I colored the flute of the tap to show it more clearly

This was the first thing I tested the tap on, just some scrap Delrin plastic.

We took the Mega Claw to Maker Faire on Friday and it was amazing. We had a great time in the pre-events, plenty of free food, free beer and samples, yum! We also got to play in the hall of science’s playground without those pesky kids in the way. The machine took us hours to setup, but it was all in good shape. Things didn’t break until Saturday.

Saturday
We wanted to be fair so we made the game $4 play until you win. The color balloon that was picked up determined your prize. We quickly realized this wasn’t a good idea. People liked winning, but people had no idea what color was what. Also play until you win made the lines too long. Most players grabbed it on the first or second try, but some took 10 tries or more.

Later that day the machine started acting funny. Motors stopped moving and the claw wouldn’t open. Everything seemed to need more tweaking. Our hearts sank when we started hearing snapping noises from the joystick. Kids were hanging from the joystick and the U-joint inside was taking a beating. We had to repair the joystick about four times over the course of the day and we lost at least three hours.

Eventually the motors stopped working all together. We thought we burnt them out and it was the end of the Mega Claw. Even if we bought new motors, there wasn’t enough time to replace them all.

Sunday

We setup our demos, but we had no machine so we had to hang this shameful sign. We sold some of the prizes, but everyone wanted the machine. We finally cracked open the motors and it turned out the motors were fine, it was a broken bearing inside the gearbox messing everything up. We repaired it and like a phoenix rising from the ashes the Mega Claw was working! In fact it was working better than it ever had. The claw was grabbing superbly,  the sound effects were blasting and even the wind was on our side.

The crowds were amazing, everyone wanted to play. This time we got some tips from Saturday’s players and we changed the rules a lot. We learned people like options, we made it $5 play till you win and $3 for a single try. Also we dumped the color coded prize confusion. Instead if you grabbed a balloon you chose any prize. If you grabbed a balloon with a raffle ticket tied to it, you get both a raffle ticket for the Wii Grand Prize and something from the prize table.

We were so happy that at the last hour of Maker Faire we announced Death Match! Everyone could play for free balloons. (We didn’t offer the prizes or raffle tickets for death match, to keep things fair.)

Lessons learned
3D printed parts are good for prototypes, not for heavy use.
In a dusty environment  friction belts will become smooth
In a dusty environment dust lubed parts will become tacky
Kids are the ultimate stress test
Bring a net, Maker Faire is windy
It’s really fun to pop balloons