first pinewood derby experience

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Nicegy525
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Joined: Sun Jan 21, 2018 2:06 pm
Location: Vancouver, WA

first pinewood derby experience

Post by Nicegy525 » Sun Jan 21, 2018 10:35 pm

Hello All,

My son and I just competed in our first PWD with our scout pack yesterday.

I am happy to say we both took home 2nd place honors.

My son and I built a scout legal car for his race. We canted the wheels, raised one front and aligned to ride the rail. Polished the axle and had as much weight centered near the rear as possible.

Not sure on exact track specs. It is a wood track with a gradual curve (favorable for moving the weight more toward the rear) and I believe 35' long. Each car ran one time in each of 4 lanes. It went undefeated in his Den with a best time of 2.497 @ 197.96

we took 2nd in each of the 4 final races with a best time of 2.478 @ 199.48. We lost by .053 seconds!

His car won Cub Scout Favorite as well. (i had my automotive paint shop do a candy emerald paint job)

I ran my car in the outlaw class and had wired two small drone motors with 4 blade propellers. It had a contact switch resting against the start pi to activate when the pin dropped.

the fan car ran a 2.13 and took 2nd in the outlaw class. The winner (the scoutmaster) had brought a ducted fan and ran a 1.58.

I can honestly say I am hooked and a looking forward to next year! Im planning a co2 powered car as well as a razor bearing wheel gravity car.

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Speedster
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Location: Toledo, Ohio

Re: first pinewood derby experience

Post by Speedster » Mon Jan 22, 2018 4:59 am

Welcome to Derbytalk.
Beautiful car. I know science was used to build it. I do have one question. What did you use to polish the bores?



Nicegy525
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Joined: Sun Jan 21, 2018 2:06 pm
Location: Vancouver, WA

Re: first pinewood derby experience

Post by Nicegy525 » Mon Jan 22, 2018 12:34 pm

Speedster wrote:
Mon Jan 22, 2018 4:59 am
Welcome to Derbytalk.
Beautiful car. I know science was used to build it. I do have one question. What did you use to polish the bores?

We left the wheels completely stock out of the box. The rules made it seem like we were not allowed to modify them in any way. Looking back, I think we could have polished them, and we will certainly do that next year.

I used sand paper to polish the axles. Insert the nail into my drill, use a small jewelers file to remove the burs and profile the nail head. Then start with 100 grit, 220 grit, 400 grit and 1000 grit.

I think we left some time on the table. We could have built a different body to concentrate more weight in the sweet spot and we probably could have done better with the axles. Also the wheels.

it also didnt help that during our practice runs several nights prior, one of the scouts didnt pull the starting gate down enough and the car jumped off the starting pin and fell off the top of the track, breaking the right rear axle groove. I had to fill it in with wood glue and hope it held (which it did)



Speedster
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Joined: Sat Feb 18, 2012 2:48 pm
Location: Toledo, Ohio

Re: first pinewood derby experience

Post by Speedster » Mon Jan 22, 2018 2:19 pm

I suspect all rules will allow you to polish the wheel bores. The common product is Novus 2 and a fluffy pipe cleaner, or a Walgreens paper cotton swab shaft, or other things sold by the vendors. Polishing the bores will benefit your team. Remember, the nail does not turn. I'm well aware many folks go to 3000 grit sanding on the nail and then polish with Brasso. I do not use any grit of sandpaper on the nail. I remove the 2 casting marks under the head and that's it. No, I do not remove the casting marks on the shaft. I depend on that shiny Zinc finish. I do, however, spend a lot of time on the wheels starting out with checking them on a concentricity gauge to see if I have 3 decent ones. I don't use any wheel that is more than .003 out of round.
I wish you and your team the very best.



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