PiDrogen3 blasts Sidmouth

Today was the culmination of the Sidmouth Science Festival and Team PiDrogen entered the rocket car contest:

It’s kinda difficult to get a good video of a rocket car, but here goes:

And we’re really chuffed to announce that we won the “pre-built” category with a time of 1.35 seconds, upholding our win from last year.

I wonder if this will help us with the Pi Wars Straight-ish Line Speed Test? 🤔

We flyin!

We’ve made a lot of progress today:

  • We’ve designed a new and (hopefully) improved back axle component, cut it on the Exeter Fab Lab laser cutter and fitted it.  So we now have a fully functional PiDrogen1.
  • Then we paired the radio control transmitter we borrowed from a friend to PiDrogen2.  So now we can drive both robots simultaneously.  This is going to be ideal for tomorrow’s marble obstacle course at The House of Marbles.
  • Then Phil got his Python 3 install working on his Mac.  Using this he wrote his first Python GUI using tkinter. (Well, when we say “wrote” we really mean “copied off the Tinterweb”).
  • Then that same Python app shockingly worked on our RPi via it’s touch screen.  The amount of excitement this caused in Phil seems to suggest that his Geekosity has reached new heights.
  • During all this we managed to blog our exploits with the back axle.
    …Juliet did her first ever head stand at the gym!

Like I said, “We Flyin'”.

So there’s good news and bad news…

The good news is that Nathy has been doing some driving practice in preparation for tomorrow’s “marble test” at the House of Marbles.

The bad news is that PiDrogen1 has suffered a structural failure:

The back axle, which is made from 3mm acrylic, has cracked. It is the first victim of Nathy’s enthusiastic driving style. Still, that’s what testing is all about… Right?

Luckily for us, Exeter Fab Lab is open late on a Thursday night. So here is the new, simplified, surely stronger replacement part:

All we need to do now is rebuild ready for tomorrow.

How about a tracked chassis?


At team PiDrogen we can’t make up our minds whether we like wheels or tracks best.  So we decided to try both.  Our wheeled chassis works nicely and we’ve had lots of fun driving that around.  So now we have cobbled together a prototype track unit from the Lynxmotion 2in track components that we picked up from Robot Shop UK.

Actually, calling it a “prototype” might be setting the bar a little high.  But building this has allowed us to work out the general dimensions of the whole unit.  Now we are free to get back to Fusion 360 and edit our existing design.  Once that is complete we can laser cut some 3mm acrylic sheet and build a test machine.

We can’t wait to put our two chassis designs head-to-head!