Designing my Outlaw Pinewood Derby car.

Was toying with different ideas for propulsion for my Pinewood Derby car. As a Den leader I'm running in the outlaw class so there are no rules. Car just has to be able to sit on the track and make it to the bottom. I decided I wanted to take it up a notch and add some propulsion to my car. I was looking at a prop driven like an air boat but a prop with enough thrust would be too big. I started looking at Ducted fans that the "jet" RC planes use and just the ducted fan assembly without motor was going to run me a good $30+. I have an RC speed controller and electronics to run it but would have to invest another $50-60 in a motor too. I don't want to put $100 into this thing. Then I started thinking, you know what else uses a ducted fan? A hair dryer. $9.88 for a hair dryer from Wal Mart. Couple of minutes with a screw driver, some wire cutters, and a soldering iron and I have a ducted fan assembly. No it won't give me the thrust of a hobby grade plane propulsion system but I think for the pinewood derby it will do for now.

This was my first test run just strapping it to the top of my son's car using a 4xAAA battery pack for 6V. From a standstill it won't move it but if you give it a slight nudge it will continue to move and not stop.



Swapped out the 6v pack for 9V. With 9v it will push the car and it will accelerate on level ground. I think that should be more than adequate to defeat all of the gravity powered cars I will go up against.

I'm going to put a Normally closed limit switch on the front so while it's against the starting gate the motor will be off. I'll have a covered SPST switch on the car so you will put it at the gate, flip the switch on, and the car will go one the gate drops.