Pinewood Derby

[Aggie87]

Looking for some advice from those who have gone through this before. My son is in his first year of Cub Scouts, and he and I are working on a pinewood derby car, to be raced this coming Tuesday. I'll post a picture of his car once we're finally done with it.

Anyway, last night we were able to use a friend's band saw and benchtop sander, and got the basic shape cut. Now I'm wondering what the best method for getting this thing to weigh the right amount is. By rule, the car can weigh up to 5 ounces, and you obviously want to weigh as close to 5 but under as you can.

I've read that drilling holes in the bottom and adding fishing weights and then puttying over the holes is an option that seems to be used alot. There also seem to be weights that you can glue on to the bottom of the car, as well.

I was thinking of maybe just drilling wood screws into the bottom of the car, until it makes the weight we want. Any thoughts about this alternative? Seems easier and less risky that drilling and filling.

Any other ideas for how to get the car to race well?

[relyles]

I am in my fourth year as a leader of a unit and in the midst of preparing for our fourth pinewood derby. In working with my son I have prefered drilling holes in the car and filling it with weight, if for no other reason the weight is not visible. for some car designs this may be more difficult, but I think aesthetically this is the way most do it. Ultimately those closest you can get to the maximum weight without going over is all that mattera. I have read some who opine that it is best to have the weight in the front of the car, while some have said in the back. Again, I think the design of the car will dictate where the weight can be put.

[relyles]

Forgot the other ideas question - sand the wheels and axels to get any knots out. also, use graphite as a lubricant.

[Aggie87]

Thanks Ron, that makes sense.

I can see how the car would look alot better without screws sticking out of the bottom. And I don't know what the clearance from the underside of the car to the track is either, now that I think about it. Maybe I'll hit a hobby store and see if I can pick up some small weights that can be dropped into some drill holes, then putty over them.

One of my co-workers also suggested to me that if you just use the wheels as they are, there will be more friction with the track too. He suggested sanding the wheels into something of "V" shape, so less wheel rides on the track. I don't know if that's ethical or not, or if it's a commonly seen thing, but I want to stay within the intent of the derby, so if that would be frowned upon, I'll avoid it.

[paul secor]

Don't have any design advice, but I must have weighed a couple of hundred of those cars during the years I worked for the post office.

edit - I will say that I don't remember seeing any cars with screws on the bottom. Not that that means anything - perhaps no one thought of it.

Edited January 30, 2009 by paul secor

[Aggie87]

edit - I will say that I don't remember seeing any cars with screws on the bottom. Not that that means anything - perhaps no one thought of it.

The clearance between the car & track (which seems to be raised in the middle, between the wheel ruts or whatever you call them) is what bothers me about that idea.

I guess I could recess the screws, but if I'm going to that kind of trouble, it's just easier to drill holes and dump weights in there, probably.

I never thought of running over to the post office to weigh the car, either!

[Chuck Nessa]

I think Paul probably weighed ounces for a bunch of folks back in the day.

[paul secor]

I think Paul probably weighed ounces for a bunch of folks back in the day.

Go to your local p.o. and they'll get you a weight within 1/10 of an ounce.

[Chuck Nessa]

We always had trouble getting the nails/axles straight. Everything else seems really sophisticated to me.

[Tim McG]

In my experience...make friends with the men who control the Cub Pack.

You'll get the good lane for your pinewood derby car and the wieghting advice necessary to win.

Trust me on this one.

[relyles]

Up until this year I always had the scale the pack used in my possession. Maybe a slight unfair advantage. For what it is worth, since we have a very small unit we let anyone participate. Only scouts can go on to the district event, but the first two years my daughter had the fastest car. Last year she had the second fastest. My son had the fastest.

[relyles]

And before you get too involved - watch the movie "Down And Derby". Fun movie about fathers going overboard.

[Aggie87]

Race is later tonight, but here's what the car looks like:

I did the cutting and sanding, and my son did the spray painting and 'stickering'. Ended up going with a screw-on weight system that I found in a hobby store, versus drilling and filling. It ends up weighing 4.9 ounces with the extra weight, so that's good.

The only problem we had was when I was nailing the axles into the wood, the wood around the pre-drilled holes started to chip off. So I'm not sure if it is as aligned as I'd like, but we'll make do. I also tried to smooth down the wheels and axles a bit. Should be fun!

Thanks again for the advice!

[Chuck Nessa]

The only problem we had was when I was nailing the axles into the wood, the wood around the pre-drilled holes started to chip off. So I'm not sure if it is as aligned as I'd like, but we'll make do. I also tried to smooth down the wheels and axles a bit. Should be fun!

Thanks again for the advice!

I mentioned this problem above. Good luck!

[Aggie87]

It's derby time again - our race is this coming Saturday. My son and I finished our car today though, so we're ready!

We came in 6th place last year, out of about 40-45 cars. The cars that all won last year's race weren't really "car" shaped, but more aerodynamic. My son decided he wanted this year's car to look like that, so he came up with the design in our picture. He also decided he didn't want to paint it this year, but use some full-body stickers he'd seen. Kind of like those tattoos you wet and stick on your arm as a kid, except you have to cut them to the car's shape, then wet and stick 'em on.

The biggest problem we had this year was with so little wood left in the design, there wasn't much room for weight. I was able to drill holes in the front and rear areas, and put some 3/8" cylinder weights in, but still had to put additional flat weights on the bottom to get up to the 5 oz. limit.

Looking forward to the race!

[Brad]

Those days are long over for me but in a way I wish they weren't. Were the weights in front? I'd think you'd get your top speed quicker.

[Aggie87]

Those days are long over for me but in a way I wish they weren't. Were the weights in front? I'd think you'd get your top speed quicker.

I didn't have alot of options with that design. The only places available for drilling were around the front and rear axles, so there's weight around both of those. That still didn't get it up to 5 oz though, so I had to use some additional weights that are stuck to the underside of the car, pretty much running the length of the car.

The weight is pretty well spread out on the car, so hopefully it will at least be competitive - we'll see!

[Ed S]

Wow! Pinewood Derby. Brings back some great memories. My father, brother and I would spend a lot of time working on our cars. We always got our asses kicked, but no matter what place you finished back then, I can tell that right now - the memories are priceless.

Thanks for that.

[Aggie87]

I remember my cars when I was a kid as well, Ed It was a blast, and I enjoyed working with my father.

We had our race this morning, and my son's car came in 10th place, out of about 45 cars. He was a little disappointed, but still had fun. He got an award for best paint job - even though ours was a body sticker type thing, lol.

I think our car was fine, weight wise and design wise, but we should have worked a little more on aligning the wheels and making sure they stayed aligned. I think that's what hurt us today.

All in all a blast though.

[Chuck Nessa]

It's derby time again - our race is this coming Saturday. My son and I finished our car today though, so we're ready!

Looking forward to the race!

The car seems to be influenced by Avatar.

[relyles]

By coincidence I spent a lot of time the past couple of weeks on the Pinewood Derby because I am a leader of a pack. Today was the race and all the kids had fun. Every year my daughter actually builds a car and this year in the "friends" division her car came in third out of about twenty cars. IN the past five years she has been more obsessed with building her car than some of my scouts have been. The first two years her car beat all my scouts - which did not make them very happy.

[Free For All]

I remember Cub Scouts. We'd go to someone's house and nail bottlecaps to a board and spraypaint it (it's a shoe cleaner, duh) and then eat cookies and Koolaid until we passed out. Good times.

I had the blue shirt, yellow scarf and little cap. It was fun but I never went much further with it.

Good for you relyles, for being the leader of the pack! (cue motorcyle revving)

[JSngry]

It's derby time again - our race is this coming Saturday. My son and I finished our car today though, so we're ready!

Looking forward to the race!

The car seems to be influenced by Avatar.

I think it's one of Prince's guitars only not purple.

[Aggie87]

This year's model:

Race is Saturday, I'm excited!

[Shawn]

Rad!