RC10Talk - The Net's Largest Vintage R/C Community

Due my severe procrastination problem , we have a Pinewood Derby Race this w/end, and just started painting YESTERDAY !!!
Its a First for both of us, since we didnt have one here when I was a Scout. They gave us a Kit a while ago, and before we decided on a Design, there were 2 Guys at our meeting one night with Scroll Saws. So we hurriedly came up with something, and let them cut it out. We could have done better, but the Saws were there, so. Of course NOW, I HAVE my own Scroll Saw . Blah, blah, blahow do I make it go as FAST as it can!?!?! Legally, of course. Advice, suggestions, links, anything appreciated.

When my boy was in scouts we would go all out on his cars. I found that leaving a substantial amount of slop in the wheels made the car the fastest

Ah, I remember mine, basically took the block of wood out of the package, painted it brick red and attached the wheels. I was not good at carving, didn't have woodworking tools, and dad wasn't much of a help either. No wait, I think he might have put the tires on it! The kid that won had carved a banana out of his, complete with yellow paint and I think a Chikita sticker.

I would imagine that a touch of lube on the axles would be a good thing. I don't recall if you can use fishing weights to make up for weight loss from carving and shaping the car, if so, weight it to the limit.

As a former Cub Scout and Eagle scout AND winner of the Pinewood derby, I have one word, WEDGE!


A wedge design cut, with a slight bevel to the bottom and using as smooth of face as possible, will make for a fast car. Also, the included axles/nail, chuck the axle in a Dremmel or drill and Go over each one with steel wool to de-bur the axle. Then, use a fair amount of graphite dust to make it spin. the same with the wheels. True the wheels down nice and smooth removing all burrs.


If you want to go for style, you can make it into any shape, if you want to win, I vote wedge.

I'll try and get something drawn up later to explain the cut. Can you get me the dimensions?



MOmo

I remember the powdered graphite being this secret magic stuff that my dad managed to borrow from his buddy. It worked for me as I remember (30+ years ago). Now we have google..http://www.derbydominator.com/

Y'ernat Al wrote:I remember the powdered graphite being this secret magic stuff that my dad managed to borrow from his buddy. It worked for me as I remember (30+ years ago). Now we have google..http://www.derbydominator.com/

Holy shamolians! Why do I get the impression that none of the things on that site are regulation or sanctioned? I'd ask the question "who'd spend that kind of money on a toy", but um, look at the audience we have here and it answers itself.

I know Since Monster is up against the clock...there's the "Short on Time" version available for $8.95 and instant download. Can't even get a swaybar shipped for that these days.

Multi time winner and Record holder here (our guys have a timing system, 4 lane track).

As mentioned work the nail axles with the dremel, we used emery cloth. Graphite lube, leave them a little loose. Really only need 3 wheels touching/turning.

Be careful working the wheels over, that can get you in trouble. We just cleaned up the little sprue where the plastic is injected, sanded just that spot.

Yep, wedge the begezus out of it. We used a pointy nose even, almost like an Indy car without wings. Nice and low. Fill in the axle slots, make it as smooth as possible, round off the rear top corners/edge.

But the real magic: The car starts on an incline, all ya got is gravity. The rear of the car is higher than the front, thus moves downhill more. Add lead as far back and as low as possible to maximum weight. I even made new axle locations farther back than the stock slots. Our cars (we have an open class too) would be right in the pack going downhill, then during the transition to flat would just spurt ahead, the rear weight was still pushing.

The first year my Son didn't listen, (he did box art ) but after that he did what I did. It worked great. (and yes he did everything on his car, and understood why, I'm not a total cheat!)

P.S. If you guys do the rubber band airplane thing on a wire, well I was unjustly accused of cheating there too! LMK.

Good Luck!

Y'ernat Al wrote:I know Since Monster is up against the clock...there's the "Short on Time" version available for $8.95 and instant download. Can't even get a swaybar shipped for that these days.

Nah, he needs to go with the Pro Speed Pack for $109.90, including the Pro-Body Tool for Extended Wheel Base, of course ...

On a serious note, Monster do check out that link, tons of great info! Who knew pinewood derby was such a cut throat sport!

We saw a lot of very artistic suff too. Sharks, whales, remember the Oscar Meyer Wienermobile? That one was pretty cool and very well done.

But the best might have been our leader, he just slapped velveeta cheese box sections onto the basic untouched block. Mmmm cheese. And finished third in old dude. So I guess take my previous advice with just a touch of salt!!!

Taller wheels = less rolling resistance

A tiny amount of negative camber on all axles. This helps to keep the wheels away from the body and allows only the inner edge of the wheels to touch the track.

aeiou wrote:A tiny amount of negative camber on all axles. This helps to keep the wheels away from the body and allows only the inner edge of the wheels to touch the track.

Don't you mean positive camber (top outward ) to keep the wheels off the body? I would think that would increase the axle/wheel friction as well as create other problems. Just speculating ...

negative camber will force the wheels out onto the axle, positive will push them inwards towards the body. Think of the force of gravity on the chassis/axles in relation to the wheel hub, not where the edge of the tire points.
hope that makes sense.

Right. You want to prevent the wheel hubs from making contact with the body of the car. With slight negative camber, the wheels will push out on the axels and away from the body. Polishing and lubing the axles with graphite, keeping the wheels from rubbing the body and only running on a smidgen of a contact patch are quick and easy and will go a long way towards making your car faster. Have fun!

Of course, if you are racing in my son’s pack, please disregard everything I suggested (except the have fun part.)