Any Other Pinewood Derby Dads?

   / Any Other Pinewood Derby Dads? #11  
Axle/wheel prep, and weight.

One year, one of the fastest cars in our pack was by a family that had been out of town. The night before the Derby, the kid and Dad filed the nibs off the nail/axles, then polished them(chuck them up in a dremel. Then they cleaned up the wheels. Using the alighnment jig(available from Scout store/web), they got everything alighned.

That was it. Otherwise it was just a plain block, with a number penciled on the side. It was prefect on weight, just a tad under the limit.

That car flew!

We always had a car building day. One of our parent/leaders had band saw, sanders ect. Idea was all the kids had opportunity to build a quality car, regardless if they had access to the tools or skills at home. Usually had snacks, grilled some burgers and hot dogs, and made a fun event of it.

We never had a Dad class, but some Packs do. Kids build cars, Dad's build thier own.
 
   / Any Other Pinewood Derby Dads? #12  
Oh, and once the car is dialed, leave it alone. No playing with it and messing up alighnment etc...

FWIW, the local Tru Value by me carries Pinewood Derby cars, parts ect.

Beware of cars from other sources. Cub Scouts are not the only group that does this. The other cars are not the same size, wheel height ect.
 
   / Any Other Pinewood Derby Dads? #13  
Just brainstorming - Can you drill out the center of the wheels a little, so the "axle" (nail) doesn't contact as much of the sides of the hole? I think pretty sloppy would be best, so only a tiny area of the nail touches only a tiny area of the wheel's axle tube (smallest contact patch as possible).
 
   / Any Other Pinewood Derby Dads?
  • Thread Starter
#14  
Just brainstorming - Can you drill out the center of the wheels a little, so the "axle" (nail) doesn't contact as much of the sides of the hole? I think pretty sloppy would be best, so only a tiny area of the nail touches only a tiny area of the wheel's axle tube (smallest contact patch as possible).

It will be interesting to see what others say about this. My concern is that less surface area means the same weight is spread accross less area meaning more pressure. What is better for low friction... less pressure, or less area?
 
   / Any Other Pinewood Derby Dads? #15  
It will be interesting to see what others say about this. My concern is that less surface area means the same weight is spread accross less area meaning more pressure. What is better for low friction... less pressure, or less area?
Not a good idea to drill out the wheel. Think about it. The graphite powder packed into the wheel around the axle acts as the bearing. Too much clearance and the graphite falls out.
 
   / Any Other Pinewood Derby Dads? #16  
As has been said, weight high/back, smooth your axles (a drill press and a small file or piece of sandpaper work well), smooth your wheels (inside and out) and glue in your axles.

Aaron Z

As been said, weight low and ahead of the rear axle.

So many different opinions. :laughing:

Now he has to decided if he's gonna paint it green, orange, red or blue!!! :laughing:
 
   / Any Other Pinewood Derby Dads?
  • Thread Starter
#17  
As been said, weight low and ahead of the rear axle.

So many different opinions. :laughing:

Now he has to decided if he's gonna paint it green, orange, red or blue!!! :laughing:

Oh, the paint job is already decided. We're doing black and white stripes like a prison suit.

Remember? Robber car.
 
   / Any Other Pinewood Derby Dads? #18  
My youngest son and I built one a few years back. I think he got 2nd place in the actual race. Lots of info online. We went with a wedge stockcar like car. Drilled a cavity in the center of the bottom (could have been back a bit) and melted lead solder into the hole. The hole was slightly bigger deeper in the car so the lead couldn't fall out. We didn't have an accurate scale so it was a bit overweight. The leaders there drilled just enough lead out for it to be within the rules which made the weight close to max. It was fun. If we did more work on the axles it probably would have won but I wanted him to do most of the work. I was amazed at the paint jobs on some of the cars. Someone has connections, not hand painted like my sons. :D
 
   / Any Other Pinewood Derby Dads? #19  
Not a good idea to drill out the wheel. Think about it. The graphite powder packed into the wheel around the axle acts as the bearing. Too much clearance and the graphite falls out.

I would think lubricant is primarily to reduce heat & reduce wear ... not concerns over a quick, short run. Heck I dunno. I think I'd use graphite & just let it fall out as it travels.

Maybe what's needed is a mercury lubricant!! :licking: What?? :confused3:
 
   / Any Other Pinewood Derby Dads? #20  
Any tricks for smoothing the inside of the wheels? That's the only part that I'm having a hard time figuring out.

one word: CONE .

if the edge of wheel hub is coned= less surface for friction.

Just brainstorming - Can you drill out the center of the wheels a little, so the "axle" (nail) doesn't contact as much of the sides of the hole? I think pretty sloppy would be best, so only a tiny area of the nail touches only a tiny area of the wheel's axle tube (smallest contact patch as possible).

this trick been around for a long time - but a groove has been "cut" into the axles. AGAIN - its less surface area. the groove is hidden when wheel is on but can be revealed if your district doesn't allow it. our district did allow it for a few years then it was changed the last year we raced. you really need to find out the district rules. your local scoutmaster will NOT know. IF your car gets challenged after race, and if certain things are not allowed, car is disqualified.

I am just telling you all the things I have seen over the years.
 

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