Photographing Rocket Chute Deployment At 10 Km

April 22, 2026 by Bryan Cockfield 18 Comments

For those who haven’t been following along, [BPS.space] aka [Joe] is on a journey to launch a home-built rocket past the Kármán line where it will officially reach outer space. But one does not simply launch a rocket to outer space on the first try. The process is long and involves not only building a series of rockets, but designing and building propellant mixtures, solving aerodynamic problems, gaining several model rocket certifications along the way, and a whole host of other steps. He’s also documenting the entire process on video as well, which involves some custom camera work like this rocket selfie camera which will take an image of his rockets at apogee.

Like most problems in high-power rocketry, extremely tiny problems have a way of causing catastrophic failure, so every detail needs to be considered and planned for in the final design. For a camera that needs to jettison itself from the rocket at a precise moment after experiencing an incredible amount of forces, this is a complicated problem to solve. The initial design involves building a sled for a small deconstructed GoPro which uses springs and a servo to launch itself out of the rocket. The major problem with the design is that even the smallest torque on the sled will cause the camera to point in a random direction by the time it’s far enough from the rocket to take a picture. [Joe] tried a number of design iterations but could not get these torques to vanish.

One of the design limitations with this camera is that it won’t have any sort of parachute or tether itself to the rocket, so it will hit the ground at its terminal velocity. To keep that velocity down and improve survivability chances of the footage, the mass has to stay low. Eventually he settled on a semi-active control system by mounting a brass weight on a small motor, giving the camera module enough stability to stay pointed at the rocket long enough to take the video. Even though it hasn’t flown yet, admitting his first design wasn’t working at compromising on this solution which adds a bit of mass seems to be a good design change. We’ve been following along with his entire process so be sure to check out his actual rocket motor builds and teardowns as well.

Continue reading “Photographing Rocket Chute Deployment At 10 Km” →

Bulking Up A Lightweight Lathe With A Concrete Cart

March 5, 2017 by Dan Maloney 21 Comments

When it comes to machine tools, a good rule of thumb is that heavier is better. A big South Bend lathe or Bridgeport mill might tip the scales at ludicrous weight, but all that mass goes to damping vibration and improving performance. So you’d figure a lathe made of soda cans could use all the help it could get; this cast concrete machine cart ought to fit the bill nicely

Perhaps you’ve caught our recent coverage of [Makercise]’s long and detailed vlog of his Gingery lathe build. If not, you might want to watch the 5-minute condensed video of the build, which shows the entire process from melting down scrap aluminum for castings to first chips. We love the build and the videos, but the lightweight lathe on that wooden bench never really worked for us, or for [Makercise], who notes that he was never able to crank the lathe up to full speed because of the vibrations. The cart attempts to fix that problem the old fashioned way – more mass.

There are a few “measure twice, cut once” moments in the video below, as well as a high pucker-factor slab lift that could have turned into a real disaster. We might have opted for a countertop-grade concrete mix that could be dyed and polished, but that would be just for looks. When all is said and done, the cart does exactly what it was built to do, and there’s even room on it for the shaper that’s next on the build list. We’re looking forward to that.

Continue reading “Bulking Up A Lightweight Lathe With A Concrete Cart” →

3D Printed Rockets Are A Gas

February 12, 2017 by Al Williams 26 Comments

We’ve probably all made matchstick rockets as kids. And around here anything that even vaguely looks like a rocket will get some imaginary flight time. But [austiwawa] is making some really cool 3D printed rockets that use common CO2 cartridges as a propellant. You can see them in action in the video below.

You might think just sticking a CO2 cylinder in a 3D printed jacket isn’t such a big deal, but [austiwawa] really went the extra mile. He read up on how to make the rocket stable (by manipulating the center of gravity versus the center of pressure) and explains what he had to do to get the rockets flying like you’d expect.

In addition, the launch tube is pretty interesting. A 3D printed part holds a sharp point and a spring. You lock the spring and when released it punches a clean hole in the propellant casing. The actual tube is a long piece of PVC pipe. From the video, it looks like these little rockets fly pretty high.

Judging from the video, the rocket body and launcher came from TinkerCAD. The way [austiwawa] put the fins on was both simple and clever.

Of course, you could also use Coke and propane, if you like. We’ve also seen some pretty cool setups with compressed air. Check out the rockets in action after the break,

Continue reading “3D Printed Rockets Are A Gas” →

The Bicycle Can Tell Us How To Make It Better

May 28, 2012 by Mike Szczys 16 Comments

Over the years bicycle design has changed. Materials were upgraded as technology advanced, and accumulated knowledge helped bicycle builders make improvements along the way. But deep analysis with the intent to make meaningful improvements has not been widely embraced. Reasearchers at UC Davis are looking to expand into this frontier by letting the bicycle tell us how it can be improved. This is one of the test bikes they’ve been working on, which is mainly aimed at data harvesting. They’re hoping to find some real improvements based mostly on how the machine can get out of the rider’s way as much as possible. The thought here is that the rider’s body makes up 80-90% of the volume of the vehicle and should be accommodated in every way possible.

Sure, this could be a case of trying to build a better mouse trap. But listening to the discussion in the video after the break really drives home the complex issues of stability and locomotion that go into these seemingly simple vehicles. We’re going to guess the final recommendations will not involve making the bike five times taller.

Continue reading “The Bicycle Can Tell Us How To Make It Better” →

Miniature Balancing Robot

August 10, 2008 by rossfairgrieve 12 Comments

It might not be as elegant or technologically-advanced as a Segway or a motorized unicycle, but this easily constructed 2-wheeled robot might be a fun project for a free afternoon. The heart of the balancing mechanism is an SPDT switch with a button cell attached that reverses the motor when the robot begins to tip in one direction. It’s not controllable and it tends to fall over quite a bit, but it’s a good starting point and could be refined by lowering the center of gravity or figuring out a simple way to change the motor speed based on how far the robot has tipped over. There are no accelerometers or tilt switches so the components could be sourced from a parts bin, and its simple design definitely leaves a lot of room for improvement.