Pinecar derby

[User Name missing]

My son started Cub Scouts this year and we’ll be getting the Pinecar Derby kits here soon. This is my first time also, in which I can make my own. Just wondering if anybody had any tips or tricks.

 

[daniel3507]

Don't worry about winning and focus on having a good time with your son. I loved doing it with my dad every year. The best part was just coming up with a cool idea and building it with him. The race itself was never that great. I remember a lot of kids not having anything to do with their car and others getting busted for cheating.

 

[robertc1024]

Having won three between myself and my kids, I'd say it's primarily in the rolling gear. I made a fixture to chuck the wheels up in a lathe and got them nice and round. On my kids, I chucked up the nails that hold the wheels on and polished them to a mirror finish where the wheels turn around them. The nails also had burrs under the heads that we smoothed out. I haven't read the rules in years, I'd check to make sure that's all legal.

 

[lil_Blue_Ford]

I read up on it a number of years ago and there is a lot of stuff that can be done to them - some people go really crazy with it too.

The last one I was involved in we made a more rounded shape (as much as we could get away with - some of them don't want you rounding the bottom). Lacking a lathe, I did squirt powdered graphite in the wheel area, put it on the axle/nail and spun it using a dremel, adding graphite now and then till it spun quite freely. (I used a buffing wheel without compound and would just use it to spin the wheel).

Weight distribution can also help a little.

But the main thing is to have fun and involve the little one.

 

[superdave1984]

What he said ^^
Make sure that the places where the wheels go are square to the body or it will pull to one side. Get the nails good and burr free and use a little graphite on there. Never use oil of any kind. Folks will argue both ways about where to put the weights. I always put mine mainly in the nose which got it rolling fast right away but didn't maintain it through the end. Others pout them under the center of the car making it start off slower but carry it more to the end.

Either way, have fun with it and don't be one of those dads who does all the work. Show your son how to do stuff and let him have at it. You help him do the mechanical part, let him do the design.

 

[TheBobmanNH]

+1 to the graphite on the wheels, and making sure everything is round. At the speeds you're at, aerodynamics are nothing compared to rolling resistance.

Of course, my dad and I cheated like crazy... it was a real bonding experience.... haha.

 

[doorgunner]

TOP PRIORITY----It's your son's project...

take LOTS of pics......

help him to have FUN!

(Trust me on this.....my son is in Heaven)

 

[shane96ranger]

TOP PRIORITY----It's your son's project...

I lost sight of this over the weekend while working on my 7 year old daughter's school project. There were things she couldn't do, like use my saw, and my drill. But it turned into me doing all of the work at first, and my wife (the one who reminds me what I'm doing wrong) pointed out to me that it was her project, and it didn't need to be perfect. Now it's done, it works, and she loves it. And most of all, she helped.

P.S. She kept reminding me "Dad.... this is for one hundred points, it's just got to work".

 

[hopster]

i always had more fun coming up with the design of the car. the races were just a good place to show off.

 

[CountryBoy704]

I won it a few times in my scouting days, if you wanna win the guys have posted some really good advice thats what I did too. Just make sure you both have a lot of fun with it

 

[RonD]

5 ounces is the weight limit, including wheels

Get as close to 5oz as possible, but not over.

Weight farther back and higher is best, but not so that the front can lift when racing.

Gravity is the engine so weight is the fuel.
Friction is the brakes so as others have said the smoother the roll the better the go.

 

[Captain Ledd]

Graphite, keep the wheels straight, smooth and polish the wheels.

Keep the weight towards the back of the car, the more weight the farther back the better. This makes the majority of the weight fall farther before the car goes past the first hump, gaining more speed.

Use a very slim design, again, then you have to add more weight, which you put at the rear. Let your kid build the shape, Let your kid do most of this work, it's one of the least important parts actually in terms of effecting a win/speed. Have them help as best they can with the wheels even if it's just holding something like the polishing cloth. It is imperative they get on straight. Or teach them the basics and get it good or at least really close, then clean them up proper later if they made a few mistakes. They're little, finesse can come later, foundations are the important part.

Edit:

5 ounces is the weight limit, including wheels

Get as close to 5oz as possible, but not over.

Weight farther back and higher is best, but not so that the front can lift when racing.

Gravity is the engine so weight is the fuel.
Friction is the brakes so as others have said the smoother the roll the better the go.

Yes, almost forgot about that, I've seen cars fly off the track before. Just put the weight all around the rear axle. They'll have a lead/solder mixture there to help balance them during check in (they did when I did it), though I don't see why you couldn't predrill some holes.

 

[AllanD]

With me being the kid that was rewinding the motor armatures in my Aurora slot cars
when I was seven, I did stuff that wasn't even considered by the rules....

I actually replaced the nails with nails with very slightly larger heads...
because the stacked teflon washers I had inboard and outboard of the wheels

Or the wheels that were carefully lapped to a precise fit against those polished nails

the nails I used also had slightly larger diameter shanks to make them more resistant
to bending, because I wanted my car to roll straight rather than grind against the rails
so once I had it so it could roll straight.... it would roll straight.

I did not win.

Because a scout leader who also had a son in the competition DROPPED my
car while placing it on the track for the second heat.

After the scoutmaster who was the ultimate judge refused to disqualify
that asshole's son I screamed bloody murder.... even at 8years old I
understood the concept of "Conflict of interest"

And the NEXT YEAR only the parish priest from the church where we met
AND the competetors themselves were allowed to touch the "Vehicles"


a similar "accident" happened previously to my rubber band propelled "Rocket" when
it was released prematurely for the semi-final heat by one father while another had displaced the cushion at the end of the track. the impact shattered the glass bead
that the rubber propeller used as a bearing.

The following year I had spare propeller drive assemblies that I could change in seconds


We also had a competetion involving a balsa framed tissue covered rubber
powered airplane. all competetors were required to use the same Gullows Kit,
but even with fathers attempting to cheat I consistantly won that one

Dihedral is your friend if you want an airplane to fly straight.
Many didn't understand that the tissue needed to be wetted
to get it to shrink tight to the frame. AND that rather than brush on "Dope"
(nitrocellulose laquer) to seal and strengthen the tissue
that after shrinking the tissue I sealed it with hairspray
thinking (Correctly) that it could do the same job without
adding as much weight. (if it is supposed to fly weight is critical)

I then applied dope ONLY to the top surface of the wing and the underside of the tailplane
(these are the critical "Bernoulli" surfaces) but I used an airbrush to do it

The leading surface of the wing was actually protected with clear tape

I actually made all the stringers in the wings U-shaped in cross section
to trim weight where it wasn't needed.

Why bother? So I could add weight, a 2oz lead block that was mounted
on a length of threaded rod so it could be adjusted so I could "trim" the
plane to fly smoothly.


There were airplanes that were prettier than mine, from twice arms length,
but none flew better.

I did not use the tissue that came with the kit, I replaced the white tissue covering with a gold colored tissue then used dark blue dope. so it was all blue and gold...

 

[tmcalavy]

Your boy is young so you might want to steer him to basic aerodynamic shapes, like a wedge. They are fast and easy to make and have fun making adjustments. Let him build with plenty of hands-on, then you two can have a blast doing test runs at home before the race. It will do well against others, and before you know it he'll be helping you change oil, etc., at home...those years fly by fast, so make the most of it. I had a blue wedge in the derby back when Nixon was pres. It kicked butt and I still have the trophy. Ditto on the advice given so far on wheels, weight distribution, etc.

 

[adsm08]

Legos. Add Legos.