I didn’t want to make a separate entry for these, so here are some small weekend projects that I have done:
This website’s header image
(You know, the music coming out of the chip thing).
I like listening to and creating music, and I like electrical engineering, so I wanted a header image for my website to reflect that. I originally photoshopped one that looked ok, but I eventually want to try something else. So I etched it. If you’re not familiar with the process, making circuit boards at home is done by etching copper clad FR4 with an acid, usually Ferric Chloride. I was etching some boards for other projects and thought it would be cool to try to do an “art” one. I also wanted to see how fine of lines I could etch. After exposing the photosensitive boards to UV light under a positive of my trace printed on transparencies, I cooked them on my stove in a bath of hot developer solution. Then I brought them outside and etched them in Ferric Chloride. During the first attempt, I ran into some problems:
Due to my lack of a hotplate, I had to use my stove to heat the developer. I left it in slightly too long and accidentally lost a bunch of resist that was supposed to stay on. Attempt two went better:
I took a bunch of pictures of it in different lighting conditions until I was happy, and then photoshopped (acutally GIMPed) it into the header image you see above. I’m pretty happy with how it turned out, and I was surprised I could get lines as thin as the ledger lines to actually develop and etch correctly.
Me and my friends like to make rockets out of random things that seem like they would be aerodynamic. In the past, we have had surprisingly good flights from a piece of bamboo, and really terrifying flights from a piece of PVC. In our latest designs, we tried a pool noodle with cardboard fins and some thoughtfully placed fishing weights. We had less success with rocket boats. See for yourself:
Here’s a launch from a rocket we just bought. The camerawomen was a bit nervous about it all… (And I have no idea why YouTube turned the video 90 degrees)
Cube made from matches
Me and a friend saw pictures of these online, and since we couldn’t find a lot of information on them, we built them from the picture we could find. It took about an hour the first time, but we can do it in about 20-30 minutes now that we know how to make them.
Tiny model Mammoth suspended in acrylic
I found these on Etsy and got them. On the first attempt, the models turned out great, but a problem with the acrylic suspension made the final product literally look like croutons. So after figuring out the problem, this is the second attempt. You’ll notice there is some sand looking stuff in the bottom of some of them. That’s the powder part of the acrylic mix. Not all of it got wet, so if we were going to try it again, we’d use a hypodermic needle filled with the liquid part of the acrylic mix to inject in the middle to make sure that all of the powder got covered.
These things have been around for a very long time. This one is made out of 2 water bottles. It took some experimenting to get it all to work. We first tried with straws and play doh, all of which failed miserably. The second try, we used aquarium tubing and hot glue. It worked great, and it turns out it also works underwater (which makes sense, because all it needs to work is pressure on the top tray of water). I wanted to try it in my pool with red dye in the bottom chamber so I could see it, but my parents weren’t too keen on getting red stuff in the pool. So I need to find a friend’s pool…
A simple clock I built from an anemometer I got off of my Grandfather’s old sailboat.
This is a hacked toy “piano playing hand”. When I saw these online, I knew I had to get one because for $20, it was a robotic hand! The original toy wiggled its fingers and thumb and played some really tinny 16 bit sound clips from famous piano concertos. I was a little disappointed to learn that it didn’t have separate control for each finger. It has 1 motor that, when moving forward, engages a gear that make all the fingers do a drumming kind of motion and when the motor goes backwards, the thumb moves back and forth. I took it apart, removed the speaker, cut the wires going directly to the motor and soldered them to a motor controller I got from a Vex servo. I connected the servo controller to the Vex microcontroller and this allowed me to use all Vex electronics to control a 3rd party motor. I actually did this when I was at school. It was the end of the year and teachers had given up, so me and a friend threw this together and put all of the electronics in an empty tissue box. We then proceeded to leave the box with the hand sticking out around the school and start moving the hand when people got close to it. While I would have liked a more dexterous hand, I have to give the toy designers credit for getting a robotic hand design that only uses 1 motor, but still makes 5 digits move.
My dad is a dentist and has a digital xray machine in his office, so I had him xray some chips for me.