Pinewood Derby "racer'

[ajulia]

Hello all!! I have to put the plastic aside for a couple weeks to help my nephew in his derby race he has coming up in Boy scouts. I have never built one and the only thing I could remember about wooden carts is the non-wobble wheels and smooth tires. I have a couple questions a far as a "Starter Nose" which is on the instruction sheet and wheel assembly. I guess the less friction or how smooth the wheels roll is the key. I figure I'd ask the best of the best in scale building and see if anyone had time in these kinda builds. I will post pics later ( charging batteries) if necessary. IIRC some people have post them but I thought i give it shot! Thank you for your time!!

peace

ajulia

[m408]

Way back when, I helped a gf's son with one of these. As I remember, the track was downhill most of the way and then up hill to the finish. Check out the max weight rule, then load it up with fishing sinkers to get there. Main thing is wheel friction. Fit wheels to axles to eliminate wobble, smooth them, then add graphite. The kid won it all. Hope this helps.

[Guest roadkill2525]

I don't know if the troop/pack/den hands them out or you have to buy them (its been a long since I did one) but they come as a block with pre-cut axel slots, set of weights, axels and wheels. Hobby shops do sell pre-cut sets (hot rod, indy car, truck, etc), weights shaped like engine parts, decals, wheels, design templates and assorted stuff.

Most start with wedge style for aerodynamics, but since its for fun anything goes. Some tips are to debur the axels, smooth the wheel surface, use graphite lubricate on the axels, and evenly place the weights.

Remember to have FUN with this. If you have any questions send me a PM.

Here's three of mine and one my dad did for a Parents class. (L to R) '96 Placed third, '97 placed tenth, '98 placed third, and '98 Parents division cancelled because the lack of entries.

All were fun except the blue one, it was a royal PITA.

[Raul_Perez]

Tito, my friend!! Glad to hear that your helping out with the pinewood derby!! That's GREAT stuff for kids and adults!

Anyway, I ran several of these races when my boys were in the scouts. Milt and Michael pretty much covered it:

1) Debur the axles

2) Make sure the wheels are straight

3) Bring the car up to the maximum allowable weight

4) Use graphite on the axles

All of the cars that followed these simple instructions did really well. All the others were scrambling to add weight and graphite after the preliminary runs were over...

Good luck to you and your nephew!!

[randx0]

O.K. first you have to get footage of the competition,next no need to worry about aerodynamics the cars don't get going fast enough for that to come into play weight is the most important thing,check the official rules as some don't allow the use of the precut kits you get at the hobby stores. just have fun .I felt really bad building my sons pinewood derby car all by myself, but hey I .... We won. Just kidding ,well not really, it's not about winning so come up with a cool design as that's what I remember from my scouting days was the cool styling that showed up especially that metallic blue streamlined job. good luck

[bobss396]

Ohhhhh Pine Cars! They were a blast for us when my kids were cub scouts. I built a total of 10 cars with my boys over the years. It was during the last 2 years where I was able to build killer cars, but my kids still had a hand in them. They did all the body mods and paint and final assembly, I took care of the wheels and weight placement.

I had a Hardinge lathe at work and made up a nice arbor to true up the wheels, they were all within around .0005 of each other, concentric to the axle by the same amount. I beveled the wheels so they ran on a stripe in the middle. The backs of the hubs were radiused slightly so if they rubbed the body it was no big deal.

I milled out a pocket in the bottom and used those pine car weight sets. If possible, check the accuracy of the scale they'll be using and make it heavy but be able to take weight off. The scale our pack used went out to like 4 places, but they taped it up so it would just show one decimal place. my kids cars always weighed 5.098 ounces. The center of gravity should be 1.5 inches in front of the rear axle. You can see how the car balances on a pencil or anything round.

I have a chassis jig that I made from 1/4" thick aluminum bar stock. I clamped the block in place and drilled my own holes. The axles were a nice easy press fit. The car sat higher than stock in case the track was bumpy it wouldn't bottom out. I picked up the right front so the car ran on 3 wheels, not much, it was somewhere around .020.

Now you know MOST of my secrets, please disregard and go out and have fun with your nephew!

Bob

[RJWood]

Hello my friend,

everyone who responded gave you the best advice, so I say for the final touch, Lay down one of your nice smooth paint jobs on it. It will fly down the track.

does your nephew build models? this could be the start to him trying plastic kits. Keep up the great work.

Ron

[m408]

And here I thought that properly wiring an engine bay was tricky.

[bobss396]

Like I said, we had fun with the pine cars. Some kids totally built theirs, some of the dads built them for the kids, some of the moms helped their kids. I saw one father, his son wasn't allowed to TOUCH the car. It was shaped like a 1/2 of a hard boiled egg cut the long way and had this onxy black finish. The car had a custom built case with it. I told my kids, play with it before the race, but if you crash it or drop it, it won't be fast. Some kids had demo derbies in the hall BEFORE the races.

The best thing I ever saw was a father and son who came into the school on pinewood derby night at the last second. Obviously this guy just got in from the city and still has his suit on. The car was painted with poster paint, they used the numbers that came with the kit. The two of them sat at the table and assembled the wheels right there. It wobbled but the kid was happy. No weight added, no material removed, talk about box stock. The car was a winner in the first round! But wound up losing in the next one.

Bob

[mikelo]

You have received a lot of good info so far. The only thing I would add is to carefully inspect the axels (nails). Mine had flash on the underside of the head (the part where the wheel goes). After I ground that down, I polished the nails, matched them to a wheel & used the graphite. Remember to have fun with it. It is meant to promote time with father & son, so let him work on it also. My daughter is in Awana and they have an adult class for those parents who just have to have it done their way. I did one last year just to see how interested she would get. Now she can't wait till next year. I will help her with cutting it, but I think she is going to sand & paint it. Post some pics so we can see how it turned out. Oh, in case you are interested, here is the one I did last year. It took best design and was tied for the fastest.

[RodneyBad]

You have received a lot of good info so far. The only thing I would add is to carefully inspect the axels (nails). Mine had flash on the underside of the head (the part where the wheel goes). After I ground that down, I polished the nails, matched them to a wheel & used the graphite. Remember to have fun with it. It is meant to promote time with father & son, so let him work on it also. My daughter is in Awana and they have an adult class for those parents who just have to have it done their way. I did one last year just to see how interested she would get. Now she can't wait till next year. I will help her with cutting it, but I think she is going to sand & paint it. Post some pics so we can see how it turned out. Oh, in case you are interested, here is the one I did last year. It took best design and was tied for the fastest.

That has got to be the Baddest Pine car EVER!!!

I never had the chance to do that

[randx0]

I just remembered a tip which I think actually works once the wheels are on, spin the wheels to get them "seated" on each axle. it's kind of like custom fitting each wheel to it's axle. you can't spin them to much I know it sounds like an april fools joke but it really isn't.

[ajulia]

Hello all!

Gents please forgive me . I was posting my thank yous the other day and my computer started its config. updates and shut down on me while i was still logged in . So if it looked like I was just sitting here watching again please forgive me. Couldnt connect to the net till tonite and notice Ive been logged on since. With that being said thank you all for responding and the low-down in the wood racers. I have to say this is one project Ill remember for ever. Besides having to carve all this wood it is fun. He wants to go with a metallic blue body and flamed on the sides. I have spoken to a couple friends at the LHS and said that the weight is actually heavier than most racers. The contest will allow a max. of 10 oz. and any tires as long as the oil doesnt leak onto the track from the axles. He's very intrigued at just having the car and building it with his Uncle T'. They also have an adults run so Im thinkin of tweeking mines. ILL probably be hitting you guys up on the PM end. I knew I came and asked at the right place. Will post progress pics within the next day or so!! Sorry for the delay in response!

peace

ajulia

[CB]

That has got to be the Baddest Pine car EVER!!!

I never had the chance to do that

I am totally with you on that Zukiholic!! WOWSERs, Mikelo! That is one awesome ride. Wish I coulda got a nice blurry photo of it flying down the track! Ajulia, sounds like your nephew has it goin on with the colors and designs! Best of luck to ya both, and have a blast!

######'n