Derby Talk

I built (2) cars. One for my son, and one for the neighbor's daughter. After sorting through all the subtle differences between BSA and AWANA car kits, I settled on the most sensible speed secrets.
1. raised front wheel.
2. polished axles- (here is where I went way overboard polishing using the 600-2000 wet/dry sanding grit paper.) With AWANA axles, they are machined to start with. SO all you have to do is use the 2000 grit paper and then MOther's MAg Wheel Polish, and Billet. They looked like mirrors.
3. polished the wheels on a drill press using a square block and 2000 grit paper. Polished the edge of the wheels also with 600 grit. As for the bores, they looked very clean, so I spun a (cut-off) Q-tip in using the Nyoil and that was it.
4. filed the heads of the axles, 10 degrees.
5. weight distributed near the back of the car where as the balance point is 3/4" in front of the back tires.
6. I did not angle the left front axle in to create a rail rider. I thought that this could cause more problems than what I could fix. (even thought I had extra axles.)
7. Used the Nyoil as the directions stated. Tried to be very sparing, with a very light coat.

My son's car beat my neighbor's car in the 1st heat. Somehow they were paired together. (We have 60 AWANA kids.) Then during the second race something happened. Ben's car slowed down. I don't know if graphite got into his axles?? But something happened. He went on to win 4 races total, but my neighbr (Kaci's) car, took 1st place!!
My son was let down, but he won a prize for design. Ben decorated his car as a "Shark Attack." The judges loved it. So we went home with 2 trophies, and are going on to regionals in 2 weeks.
The fastest car there had extended axles, was a slender wedge, and had polished graphite wheels. After about 4 races his car slowed down.
It was fun. Nyoil seems to work well, as long as you can keep the grahite out of the axles.

Have any of you ever heard of waxing your cars before a race? That's the last thing that I did, and my car was .1 oz overweight!! They had to drill out some of my weight in the rear. I was soooo upset. I'm sure it had a lot to do with me loosing the race.
But overall I was pleased with the results, except Kaci's Dad will get all the glory, and he never touched the car. It's a good thing that they are wonderful people, and good neighbors.

I will get that axles drilling tool for next year and extend the axles. The jury is still out on the rail riding technique.
Again, thanks for all your kind and helpful support. You helped make my cars both winners!

Glad you had fun and the cars did well and there were some lessons learned. Just be careful of all the "I" in your thoughts above. Esp the one where you say "me losing the race". Unless you meant truly your own third car...then that was the kid's car and the kid's loss. Nothing wrong with kids learning to lose

Congratulations, Greg.
Yes. BSA "rules in the box" comment on applying wax. And Pine-Pro actually makes a "Pinewood Derby Racing Wax". I have even seen a claim that lots of waxing reduces wind resistance. We don't wax so I'm not sure how much a wax job is expected to weigh.
If the precision of the official scale is 0.1 oz (most are), your car could have been 0.05 to 0.15 oz overweight (assuming that the official scale was actually accurate).
Certainly debris from last-minute drilling can be attracted to the wheel bore by the lube oil. We weigh ahead of time and also build in a small amount of removable weight in case the official scale is inaccurate.
Were the elapsed times being reported? (Otherwise, it is often hard to conclude that a car has "slowed down" just based how they place relative to other cars.)
dna1990 said out loud what I was thinking. As you are already planning ahead for next year, also consider ways to get the kids more involved in the construction of their cars.

The kids worked with me a lot. I had them design their own cars, and cut them out at the church. They sanded the cars, primed and painted them...paint runs and all. We got stickers at Wal-mart together and the kids put them on their cars. I even had them polish the axles and wheels in the drill press. They watched me melt the lead. I agree that the kids should be as involved as much as possible. I used small screws, drilled pilot holes and mounted the axles for them.
Point well taken. I can always tell the cars that the dads built.

Glad to hear you didn't have them try their hand at melting lead. Again, congrats.

So based on the experience w/ Ben's car, do you plan to use Nyoil next year or try something different?

what is a heat for your race ?

3 lane track ?

some races consider a heat 1 run or 3 runs for a a run down each lane of the track (example of 3 lane track)

I too would be interested, if a timer was used or eyeball judging on a car slowing down after 4 runs. that sounds odd to me, even with poor lube work done, but have seen that with non prepped axles, where the burrs on the axle head grinded into the wheel.

but I actually typicall see peak runs for most cars in the 4 to 6 runs. not slow down. So if they had a timer, then i'm interested. But no timer. Then it may just be the cars they were racing or how they were setup on the track can also cause slower speeds.

I think to compare nyoil to graphite lube, you have to look to max-v test chart data on his site.

I'm glad the boys did well and everyone was pleased.


We have waxed before, but never found it to take us over the weight, but also scales differ enough that I come a tad light and add a little tungsten putty to get us to 5oz.

But now that we pretty much have gone with monokote. not sure waxing is really needed.

Sporty

Sporty, I only found a Q&A page. Could you post a link to the "test chart data"?

UPDATE: Is this it?

Thats one of them, I thought there was one, that also showed his max-v lube also. Theres also a lube Q/A.

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


I'm trying to recall alot from memory also, I thought the only advantage to the oils was that they would last longer, were equal in performance, if you got the application correct.
but in the link you have, you can see tube o lube often had runs faster. but it still comes down to preference and what the rules allow.
I tried tube of lube once and was not impressed. So a more fully data chart needs done, unless there is / was another. i thought there was, but I could be wrong.
I certainly feel that i'm shocked that hob e lube, was showing slowest times in that chart, as tube o lube was a dud for me when i tried it.
I have always stated I have had the best results with hodges. so until something else comes along better. Thats what we will use.
Different lubes are a preference for others and work for them. To me in the end if the user is happy with it. Then thats all that matters.

sporty