Solar Power for Small Pinewood Derby Car

If Colin Pillinger can get Beagle 2 to Mars then anything's possible. Go for it. Please post some pictures on CR4 so the interested reader can learn and be inspired by progress!

hello srock;read your thread,and wondered if you might have thought of the very small elec.motors used in rc airplanes or the one used in the air hog,they have good specs. and are not only cheap-small- but easily modified to your idea.tork is wonderful,and at the local wally world they are on sale,forgive me if i've over steped my boundry,hope this helps

hello its me again;forgot to tell you,look up discovery store on the discovery channel,also look Edmond's.google them both and you'll be surprised at what you find,good luck and i hope this helps.

Maybe a motor from a pager/phone/game pad vibrator (obviously remove the eccentric weight) ? Or there are some nice small motors in some kids toys...wait til after Christmas there will be plenty of broken toys .

Del

I don't know what a Pinewood race is but I built a solar powed race car some years ago & faced the same weight problems. The car was about 6" long & I built the body out of thin card with polystyrene wheels, I used a Ferranti solar cell & Portescap miniature motor but can't remember the specs now. This was for a solar drag race at an engineering show & we came 4th but we had no budget and were up against companies like Rolls Royce who made the competition their apprentices end of year project.

Hey I think I was part of a team in that ... square section guide rail? I made a chassis.. the guy doing the reflector screwed up the design.
My chassis way a Y shaped piece of high tensile aluminium tube (arrow shaft!) single wheel at the front which sat on the guide rail. We were eliminated pdq
Rear wheels were card an a very thin steel axle.

Del

The link below will take you to a Solar Powered Self-Recharging USB Battery (with Cell Phone Adapters). It weighs 8.472 ounces. You could dismantle it and just use the solar cells to power a small computer fan.

Key specifications - Solar panel capacity: 1.54Wh (5.5V / 280mA max) - Built-in battery: 2500mAh / 3.8V - Output voltage: 4.5V~9V (selectable steps: 4.5V, 5V, 6.3V, 9V) - Output current: 1000mA max - Output power: 4W max - Unit weight: 240 grams

http://www.dealextreme.com/details.dx/sku.4785

The following CPU fan with heatsink weighs 19.24 ounces. Remove the heatsink and I will be willing to bet that it weighs close to 2 ounces. It produces 77.85 cfm and is 80mm in dia.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835106113#spec

Here is a 40mm CPU fan that weighs 1.06 ounces but only produces 6.5 cfm.

http://www.lagoom.com/Antec_40mm_BB_Case_Fan/40MM_BB_CASE_FAN/partinfo-id-552767.html

Other than these, Google is your best friend!

To stay within those dimensions, I suspect there is not enough surface area of solar panel to provide enough energy to move the car. If your thinking energy to provide acceleration on the down hill (more edge) I estimate that the trade off between the flat panel solar collector and the loss of aerodynamics with such a panel will cancel out. Just a thought.

I looked up the Pinewood Derby & it says cars are powered by gravity only, are you looking to use the fan to push the car along? Why not use jet power, all you need is a balloon.

I let my kids design and paint their own cars (I do the cutting) and whether they win or loose, they have the sense of ownership that these events (Pinewood Derbies) are helping to foster.

Too many times I see kids disappointed because they are beaten out in both artistic and speed categories by obviously parent-designed and built racers.

I may be assuming this here and wish you success if this is not the case.

I am the comissioner for my local pack and my son never lets me help him build his car. He rather lose the race knowing he built the car himself than win with me building it. This car is for myself for a fun parent race after the event and to show the kids how solar power can help in our lives. Since I have to follow the rules about motorized wheels I can use solar power to help me push my car and the end of the race. I am not allowed to touch the car for a few hours so a conventional batter power would drain before the race. The remote controled helicopter idea is another possibility. All answers have been excellant so far

"a conventional batter power would drain before the race."

No it wouldn't. A battery will hold power for years, just look at the expiration date on Duracell's.

I am not allowed to touch car for hours. I would have to turn on fan 6 hours before race. I do not think battery could hold up but I might try a 9 volt

Maybe you could get some cheap solar powered calculators and remove the PV cells and batteries. The cells are small enough that you woudnt have to design the car around the cell - you could pretty must just paste them anywhere.

Some years ago, after my son's pinewood derby, we modified the car by affixing an Estes model rocket engine to it. That sucker went about 100mph before crashing into a thousand pieces! We put it back together, added some eyelets, and pegged out about 200ft of string as a guidance system. It was really great fun.

Being an old Scoutmaster and participated in 15 years of pinewood dirbys. My 20 yr old is an Eagle scout and won many. You are a thinking man and I would be interested in seeing your results. It would not speed up your car though. The fan would have to push the car faster than it goes already. You need a time of around two seconds. The fan would slow the car. You are limited to the material in the kit as well. The best way to speed up a car is polish the axles, wax the body and make it roll straight on three wheels. This gives up drag from one wheel. Use just the right amount of grafite. Good luck with your.........I mean you're sons car.

It would definitly be my car. He is either building a tank or a wavy wedge that looks like a flag. We have a parent race at the end and I am trying to get more parent involvement.

Maximum Velocity now sells a Pinewood Derby Kit that incorporates a battery powered fan out the back. Typical completed weight is about 4.7 ounces. Check it out at these links:

http://www.maximum-velocity.com/newproducts.htm

http://www.maximum-velocity.com/propellercarkit.htm

Here's another one someone built over at Derby Talk where they did the same thing, only the propeller fan was remote controlled. They also manage to get it directly at the 5.0 ounce mark:

http://www.derbytalk.com/viewtopic.php?t=3257

-Nitro Dan