A Look Inside A DIY Rocket Motor

[Joe Barnard] made a solid propellant rocket motor, and as one does in such situations, he put it through its paces on the test stand. The video below is not about the test, nor is it about the motor’s construction. Rather, it’s a deconstruction of the remains of the motor in order to better understand its design, and it’s pretty interesting stuff.

Somewhere along the way, [Joe], aka “BPS.Space” on YouTube, transitioned from enthusiastic model rocketeer to full-fledged missile-man, and in the process stepped up his motor game considerably. The motor that goes under the knife — or rather, the bandsaw — in this video is his “Simplex V2,” a completely DIY build of [Joe]’s design. For scale, the casing is made from a 6″ (15 cm) diameter piece of aluminum tubing over a meter in length, with a machined aluminum forward closure and a composite nozzle assembly. This is a pretty serious piece of engineering.

The closure and the nozzle are the focus of the video, which makes sense since that’s where most of the action takes place. To understand what happened during the test, [Joe] lopped them off and cut them roughly in half longitudinally. The nozzle throat, which was machined from a slug of graphite, fared remarkably well during the test, accumulating only a little slag from the propellant, a combination of powdered aluminum, ammonium perchlorate, and HTBP resin. The lower part of the nozzle, made from phenolic-impregnated linen, did pretty well too, building up a pyrolyzed layer that acted much like a space capsule’s ablative heat shield would. The forward closure, whose sole job is to contain the inferno and direct the exhaust anywhere but up, took more of a beating but stood up to the challenge. Especially interesting was the state of the O-rings and the way that the igniter interfaced with the closure.

Post mortems like these are valuable teaching tools, and while it must be heartbreaking to destroy something you put so much work into, you can’t improve what you can’t measure. Hats off to [Joe] for the peek inside his world. Continue reading “A Look Inside A DIY Rocket Motor”

Push Button, Receive Bacon.

Members of the Rabbit Hole hackerspace spent the last weekend competing in The Deconstruction, a 48 hour hackathon competition. The hackerspace’s theme was “Light it up!”, so members created some awesome projects involving light. The star of the show was their bacon cooking machine. The Rabbit hole made the “Push Button. Receive Bacon” meme real.

A broken laser printer was gutted for its drive train and fuser assembly. Laser printer fusers are essentially hot rollers. The rollers melt toner and fuse it with paper as it passes through the printer. The heat in this case comes from a lamp inside the roller. That lamp also puts out plenty of light, which fit perfectly with the team’s theme.

The Rabbit Hole members wasn’t done though, they also built a pocket-sized infinity mirror from an empty Altoids tin. The bottom of the tin was cut out, and a mirror glued in. A filter from a broken projector made a perfect half silver mirror, and some LEDs completed the project.

The members also built a fandom art piece, consisting of 25 fans connected together in a skull shape. The eye and nose fans were lighted. When the fans were plugged in, they kicked for a few seconds before spinning up. Once they did spin though – there was a mighty wind in the Rabbit Hole.

Click past the break for The Rabbit Hole’s Deconstruction video!

Continue reading “Push Button, Receive Bacon.”

Watching 50 Teams Build Something Cool

Last summer, we here at Hackaday participated in the Red Bull Creation Contest. Basically, twelve teams were given webcams and instructions to build something cool. The teams live streamed their build process, and the best of the bunch won a trip to the New York Maker Faire. [Jason Naumoff], the guy behind this build-off is doing it again right now. It’s called The Deconstruction and it pits 50 teams on 6 continents to build something cool while streaming their project to the Internet.

The Deconstruction is a little bit different from Red Bull’s contest – first, the teams don’t have access to ludicrous amounts of energy drinks. Secondly, there’s no set theme for the group entries. It’s a free-for-all build off where teams can make anything they’d like.

We’ve really got to hand it to [Jason] for pulling this off. He MC’d the Red Bull Creation Contest live stream – nearly all 72 hours of it – and was entertaining right up to the very end. You can check out the official stream on the main Deconstruction site, or you can check out the individual team streams here.