Every year, [ilektronx] and a few other guys get together and compete in a ‘no holds barred’ pinewood derby for kids of all ages. Of course this results in an immense amount of engineering to push a wooden block with wheels down a track, and [ilektronx]’s car is no exception. He won the competition with electronics from a remote control airplane bolted on to a piece of wood.
The electronics for [ilektronix]’s build are pretty much what you’d find in any small electric RC plane: a cheap transmitter / receiver combo sends commands to an ESC which powers a small brushless motor with a small LiPo battery.
Like all good pinewood derby cars, the success of [ilektronix]’s entry relied on the overall design. The wooden chassis cleverly hugs the raised guide in the track, and the slight downward angle of the propeller keeps the car from popping a wheelie when it is released from the starting line.
You can check out a video summary of the pinewood derby competition after the break. Also shown are a few of the other derby cars, including an amazing futuristic tank entry built by [Ken Cook]. [Ken] spent the better part of a year on his build, and the amazing detail of making his own tank treads by hand made him a shoe-in for the winner of the ‘style’ competition.
[youtube=http://www.youtube.com/watch?v=VYP2-NnhME0&w=470]
A “no holds barred” competition was won by a guy with a battery powered propeller? Sad.
We used to put CO2 cartridges in the back of derby cars, and I know a guy who used model rocket engines.
Where are the flame throwers and blades to demolish your competition? Sounds like “no holds barred” turned into “slightly more interesting than stock”.
@brad-
The “holds” at these things are usually “can’t damage the track”.
I’m not impressed.
I am impressed.
no holds barred? I don’t see a G model rocket motor Powered car anywhere. Guarantee it’s faster than anything that was raced.
And yes if you angle it down and place it closer to the front it will stay on the track and go like hell.
Can you tell me how close to the front of the car and what angle it needs to be to work?
FYI: This takes place inside an LDS (Mormon) meetinghouse where open flames, rocket motors, CO2 cartridges, guns, gunpowder, and other dangerous things are not allowed. The Latter-Day Saints are pretty strict about keeping people safe and their buildings intact, so “no holds barred” in this case had to fall within the limitations of what these guys could do inside their meetinghouse.
I was about to mention that.
I know the design of gym from anywhere, haha. Complete with the chair storage beneath the stage…
Hold it outside? Make the track out of ASTM A500 steel?
Surely there is a solution to these problems so a rocket-powered sled can compete!
Obligatory mythbusters reference: https://www.youtube.com/watch?v=mrbhyJhCvTg
And supply all the kids and other visitors with protective gear for when someones rocket engine goes flying off the car and hurtling towards a kids eye?
Why do these things always feature somebody who has a limb in a sling or cast?
To prove it was a no holds barred event, I guess?
Church Ball…
They need to start holding pinewood derby competitions where the cars go up the track instead of down.
A few years ago at my pack, we had a “no rules” event for the parents. The main goal there was to make sure parents (usually dads) didn’t overtake the build process for the children for the design competition. In essence, it was a “distract the dads” race.
I basically did the same thing as this: propeller, controller, battery from a defunct RC airplane. I had to comply with weight rules, however, so my body was cut/sanded down to the bare minimum. My power/weight ratio was astronomic.
After beating everyone (including overpowering another guy with the same idea but a weaker transmitter on the same frequency), I went up the track at the behest of about 30 cub scouts. Got a good amount of airtime, too. We thought about making an uphill competition, but it never went anywhere. (Not many makers amongst the parents.)
I was not willing to risk ever giving it full throttle. On the uphill race, I let off on the transition so that I could catch it. The car, even with the less agressive prop, has enough thrust to go straight vertical.
What will these Mormons think of next?
We’re a creative bunch. ;)
it is in a Mormon Church House, however CO2 would not be forbidden. open flames yes, but not co2.
either way it is a fun activity for adults.
-1 for calling a propeller powered thing “jet” powered.
The usage of the word “jet” comes from the classification of RC plane that the electronics come from – A park “jet” (Profile F-22 to be precise). Hence the quotes.
Jet engines can have propellors too. They are usually called “turbines”. They both do the same thing – suck air in the front, push it out the back.
Wrong. A propeller pushes air, a turbine is pushed by air. In a jet engine the exhaust pushes the plane along, the turbine simply drives a compressor that sucks air in to feed the reaction.
Unless it’s a turbofan! ;p
Thanks to the music used in the video, GEMA is blocking it in Germany.
You know what’s funny? These guys just did it for fun, taped it, and shared it. And a bunch of full grown men on the internet are criticizing the hell out of it. You guys need to chill. I enjoyed the unique pinewood derby designs, and thank the dudes involved for sharing.
The cars were lined up, race about to start and my finger on the battery box for the electric fuse. Go! and what do you know my motor didn’t start, the cars were well past half way down the track when finally the rocket fired off! sending the bat mobile down the track in a blink of the eye. I’ve got a picture and a hi-8 tape of the race somewhere but i also still have my rocket powered bat mobile.
The whole thing went well except for the fact i forgot to remove the ejector cap so after the race when the rocket burnt out (we had someone catch the car at the end of the track) the rocket blew out of the car which scared a few people. Good times.
I was the first person to put a rocket engine in a pinewood far as i know so lets start a list of years when people did this. The first time i used a rocket was 1996, pack 316
costa mesa.