Pine Wood Derby [Archive] - Pro-Touring.com

CHRIS67

01-22-2008, 06:32 AM

It's Pine Wood derby time for the Cub Scouts. I let my son build his car and we got spanked last year (our first year) in the derby coming in 32nd out of 34 kids. Deciding that 98% of the other parents built the cars for their kids this year I did the same. I done a lot of legal modifications I'm thinking that I have a top 10 car. I've extended the wheelbase, grooved and polished the axles with 6000 grit paper, put as much weight as possible in the rear without lifting the front wheels, trued the wheels, coned the inner wheel hub, and broke in the wheels with graphite. I have about 30 hours into a 6" wood block.

Is anyone else building a car for their Cub? Any success stories?

:1st:

Samckitt

01-22-2008, 07:30 AM

I hear about that every year from a guy I work with. My son is not old enough for that yet. On one hand I feel that this is something the kids should be doing themselves, then I think it is good time for the father to spend with the child(ren). But most of the time it turns into a project that the parent works on, not together with the child.

69Nova

01-22-2008, 07:38 AM

Got any pictures of the car?

CHRIS67

01-22-2008, 07:55 AM

I'll take some tonight. My son did the painting and loaded it with stickers. Is there such a thing as a Pine Wood sleeper?

parsonsj

01-22-2008, 08:02 AM

Sounds familiar. My son and I got better each year, and almost made the regional finals our last year. In general, he didn't care as long as he didn't lose to ALL of his friends, and worried mostly about paint and stickers. It was my job to keep the wheels from falling off.

His pack didn't go overboard on making the event ultra-competitive, so it was a good balance.

jp

Jim Nilsen

01-22-2008, 08:03 AM

More than once I saw the kid that just bought the kit and just glued it all together and won the whole pack. You sure went to a lot of work. Dry film lubricant is better than graphite in most stuff i have ever worked with when you need a dry lubricant. The weight is really better right in the middle and maybe just a little forward to keep down wheel vibration up front.

It will be interesting to hear how it goes.

If you teach a kid how to do it with pride ,patience , and the understanding that you are doing your best and that is good enough for a pinewood derby car . Sometimes it is not all about winning but how you learn to deal with losing and go on not feeling you got cheated by someone else. It sure is fun to win if you can because the moments are rare when it comes to low tech odds.

Also make sure your boy can tell everyone what has been done to the car so he will feel better about himself when you talk about it with others .

Think SPEED

vanzuuk1

01-22-2008, 02:15 PM

Chris has your son even seen the car?

CHRIS67

01-23-2008, 05:21 AM

Chris has your son even seen the car?

No, I kept him blind folded when he was working on the wheels and painting it.:wedgie:

I don't want to be that Dad who does everything for his son and the boy doesn't learn anything from it; there are a few of those in the group already. I used the power tools and told him what I was doing along the way. There were times when he had enough of the car and I'd end up finishing, but all in all we did it together.

https://www.pro-touring.com/forum/attachment.php?attachmentid=21414&stc=1&d=1201091767

This year's wheels

https://www.pro-touring.com/forum/attachment.php?attachmentid=21415&stc=1&d=1201094251

69Nova

01-23-2008, 06:18 AM

All I see is red X's

CHRIS67

01-23-2008, 07:09 AM

Uploaded fine and previewed OK.

:dunno:

amx2334

01-23-2008, 07:37 AM

CHRIS67

01-23-2008, 08:27 AM

Last years before paint.
https://static1.pt-content.com/images/pt/2008/01/Picture003-1.jpg
https://static1.pt-content.com/images/pt/2008/01/Picture009-1.jpg
This year it will just look like a hockey stick. I want to make the front where the car sits against the starting pin as high as possible-this way the car starts rolling sooner as the pin moves.form follows function.Personally I think its all in the alignment.

Good idea, now I'm thinking about putting a small "spoiler" on the front up high out in front so it rolls first. Thin out those wheels and cone the hubs to come off the line faster than heavier wheels
Alignment is big, but so are friction and weight.

You want the majority of the weight in the rear of the car, but ballanced 3/4" to 1" in front of the rear wheels to keep it from bouncing on the front end. Keep the weight of the car on the hill as long as posible to push it down the track.

amx2334

01-23-2008, 09:33 AM

CHRIS67

01-23-2008, 10:55 AM

our official rules state:
2) Only official BSA wheels and axles that are provided with the car kit may be used.

3) No "machining" of wheels other than to remove molding imperfections is allowed. Wheels may not be machined to reduce the contact of a standard wheel surface with the racing surface.

I machined the axles and coned the hubs.i am thinking of a wave type axle (think ARP wavelock rod bolts).i tried to get one front wheel up a little so it rides on three.still gotta go straight though.i did notice that our local rules dont say anything about "dry lube only" like the rules in the box.HMMM-time to put on my Smokey Yunick thinking cap.If it ain't in the rules it must be legal right?
i volunteered to help set up the track the night before. hoping to get a little track time in.i may make the weight adjustable front to back and see what the effects are.putting the weight up high only helps on a steep track.ours is pretty low.

be sure to put an arrow or something on it to show which way is forward.

Our pack's interpretation is you can not change the footprint of the wheel, ie. cutting a grove so less of the tire is in contact with the track. However you can sand down the official wheel to remove the injection mold and true the wheel thus reducing the overall weight of the wheel.

Maybe your pack's interpretation is different. I help set up the track too, but pack our rules state that we can only use previous year's cars to test the track.

One last tip that seem to help the winning cars last year. Break in the wheels once you have them on the car, spin them while watching a movie and every so often put a little more graphite onto the axles.

parsonsj

01-23-2008, 11:25 AM

spin them while watching a movie and every so often put a little more graphite onto the axles. Consensus among the pack daddies last year was that this was the most important thing to do. I had my son do it for hours while he watched TV.

jp

TonyL

01-23-2008, 11:27 AM

I ran my car on a belt sander with a really fine grit on low speed for hours adding graphite as it rolled. (I wish i had shots of that car. It was sweet.)

another sweet trick is to polish the axles. The rules say you have to "use" the axles. but if you remove a few hundred thousands off of them well..

A big part of friction that gets overlooked on a pinewood car is the area behind the brad end of the axles, make sure that area gets deburred or polished where it contacts the center of the wheel.

edit. here's where we learned it from

THE most important aspect of building a fast car. First, we take the axles and a small fine round file (you can get these at a hobby shop or hardware store) and file the casting burr from where the nail shaft meets the head. This may seem tedious, but it really makes a difference. Next, we place the axle (pointed end first) into the chuck of a cordless drill or Dremel tool. Take a piece of medium or fine grit sandpaper and tear it into 1/4" wide strips. While the scout holds the drill (don't forget your safety glasses), the parent/helper bows the sandpaper in a semi-circle around the axle. As the drill turns the axle, the sandpaper smooths it down. It's important that the axle is centered in the chuck of the drill to maintain accuracy and roundness. Don't apply too much pressure to the sandpaper or it'll snap in half. Trial and error is the best advice for this step. Next, move to finer sandpaper and repeat the process. Repeat this process with coarse steel wool, then fine steel wool and finally, ultra fine steel wool (you may have to clean off the steel wool fibers that get wound around the axle between steps). Finally, the axle should be fairly well polished, but we're not quite finished... the final step involves taking a 1/4"x4" strip of CLEAN cotton cloth and applying some car wax (or chrome polish) to it. Repeat the same process as with the sandpaper and steel wool until the axle is buffed to a high gloss. Use a clean, dry cloth to remove any wax residue from the axle. This may seem painstaking, but it WILL make a difference at the Finish Line!

amx2334

01-23-2008, 11:35 AM

Jim Nilsen

01-24-2008, 08:16 AM

I do it while reading pro touring threads.Hours and hours and hours.
Funny thing is last years winner said " I had no idea what I was doing. We just slapped it together one night." I saw the car and I believe him.Won by a couple hundreths of a sec.

My family was in scouting for 20yrs and i have seen it so many times that you would place bets on the cars that were just blocks of wood and the full amount of weight.

After having dealt with injection molding machines and molds, if you are lucky enough to get the right set of wheels that are really to spec you are probably a lucky person. Molds tend to wear out in irregular fashion depending on how the sprew is placed. The pins that form the axle hole can wear,break,get stuck and broke and several other wear ploblems that occur and then a new pin will be intalled and the other worn ones will still be there. I bet there is at least a 20 to 30 mold or bigger making them and all being dumped into the same tote to go for packaging. Now if you just knew the size of the nail too!!!! I have always wondered what the actual size of the nails and wheels /clearance works the best right down to the .0005 . A lot of work for a Pinewood Derby car.

Try the car backwards just pushing it and see which way it turns vs going forward. good way to check the alignment.

Goodluck

TonyHuntimer

01-24-2008, 03:21 PM

My Dad had a lathe. He cut the wheels so that only a very narrow part of the wheel was left to touch the racetrack. We also did everything else you said that you did. We got first in the troop and first in a second event at a Jamboree (or something...it's been a while). :) I still have it and the trophys somewhere.

Tony Huntimer
RaceHome.com

shortrack

01-29-2008, 02:34 PM

make it run on 3 wheels.......make one of the back ones not touch.....less drag

kinda brutal but saw one where they simply painted the raw rectangular piece of wood up to look like a school bus and ran it.....looked like a brick.....took 2nd place

s10kool

01-30-2008, 08:06 PM

guilty as charged i did most of the building and let my boy do some of the sanding and well it turned out better than i had hoped ill get pics up it is his first year and well i had to make it cool lol

rocketrod

01-30-2008, 08:15 PM

My son, who is 7, AND I just built his first car. While I did do alot of it he picked and helped layout the design of the car. He also smoothed the outer perimeter of all the wheels using a drill press by himself. He mounted the wheel in the mandrel, secured the mandrel in the drill press and wet sanded all of the wheels, while I looked over HIS shoulder.:) He also helped polish the axles and painted the car. On the parts he was unable to do, I explained what I was doing and why. It was quite the bonding experience! Needless to say I felt like we had already won and we hadn't raced yet!

Well on race day the hard work paid off as he won 1st place in his divsion in which there were about 30 cars! Of the eight races he lost one race by 0.001 of a second! Later in the day the winners of each division raced to see who was the fastest in the pack. He finished a respectable 3rd and his car ran on average 0.0150 faster! He gets to go to districts on the 2/23 so we are going to make a few tweaks to the car.

We are allowed to modify the car for districts, but we reusing the body, but getting new BSA wheels and axles. Since we have more time my son will be doing the majority of the work (about 3-5 hours)! Here is what we are going to do:

Wheels - Buy a set mold matched wheels (#2,#5 or #15), square inner/outer hubs, cone & polish inner hub, polish inner bore and inner lip of wheel. When done we will soak the inner lip and wheel bore in graphite until final assembly.
Axles - Straighten axles using an axle press, remove rough edges from axle shaft/head, polish axles, taper the axle head and soak axles in graphite until final assembly.

Body - Make sure you car is maxed out on weight with the center of gravity (COG) of the car being between 3/4" (aggressive) -1 1/4" (conservative). In the first race we were at 1 1/16" and weighed 4.975 ounces. We plan on moving the COG to 7/8"-1" and adding 0.025 ounces to the car.

Assembly - Break in the wheels by spinning them while applying graphite as mentioned earlier.

Alignment - A lot of people over look this, but take the time to align the car. A poorly aligned car will negate all of your improvements to the body, axles and wheels. If you are raising one of the front wheels, or sanding one wheel smaller, make sure that wheel does not contact the center section of the track to maximize speed. For example, our car has the left front wheel raised, so we will align the car to drift to the left to ride the rail (this is what they refer to as a railrider).
Race Day - Apply graphite to the wheels as often as allowed. Show your son how to handle the car and align it straight on the track. I saw kids carrying them by the wheels, dropping them, etc., which can mess up the cars alignment and have fun and take lots of pictures!

WhiteG240

02-02-2008, 02:17 PM

Here are some pictures of pine cars my father and I built.

https://static1.pt-content.com/images/pt/2008/02/PineCars005-1.jpg
https://static1.pt-content.com/images/pt/2008/02/PineCars006-1.jpg
https://static1.pt-content.com/images/pt/2008/02/PineCars007-1.jpg

Most Creative...
https://static1.pt-content.com/images/pt/2008/02/PineCars001-1.jpg
https://static1.pt-content.com/images/pt/2008/02/PineCars002-1.jpg
https://static1.pt-content.com/images/pt/2008/02/PineCars003-1.jpg

CHRIS67

02-04-2008, 04:29 AM

My son, who is 7, AND I just built his first car. While I did do alot of it he picked and helped layout the design of the car. He also smoothed the outer perimeter of all the wheels using a drill press by himself. He mounted the wheel in the mandrel, secured the mandrel in the drill press and wet sanded all of the wheels, while I looked over HIS shoulder.:) He also helped polish the axles and painted the car. On the parts he was unable to do, I explained what I was doing and why. It was quite the bonding experience! Needless to say I felt like we had already won and we hadn't raced yet!

Well on race day the hard work paid off as he won 1st place in his divsion in which there were about 30 cars! Of the eight races he lost one race by 0.001 of a second! Later in the day the winners of each division raced to see who was the fastest in the pack. He finished a respectable 3rd and his car ran on average 0.0150 faster! He gets to go to districts on the 2/23 so we are going to make a few tweaks to the car.

We are allowed to modify the car for districts, but we reusing the body, but getting new BSA wheels and axles. Since we have more time my son will be doing the majority of the work (about 3-5 hours)! Here is what we are going to do:

Wheels - Buy a set mold matched wheels (#2,#5 or #15), square inner/outer hubs, cone & polish inner hub, polish inner bore and inner lip of wheel. When done we will soak the inner lip and wheel bore in graphite until final assembly.
Axles - Straighten axles using an axle press, remove rough edges from axle shaft/head, polish axles, taper the axle head and soak axles in graphite until final assembly.
Body - Make sure you car is maxed out on weight with the center of gravity (COG) of the car being between 3/4" (aggressive) -1 1/4" (conservative). In the first race we were at 1 1/16" and weighed 4.975 ounces. We plan on moving the COG to 7/8"-1" and adding 0.025 ounces to the car.
Assembly - Break in the wheels by spinning them while applying graphite as mentioned earlier.
Alignment - A lot of people over look this, but take the time to align the car. A poorly aligned car will negate all of your improvements to the body, axles and wheels. If you are raising one of the front wheels, or sanding one wheel smaller, make sure that wheel does not contact the center section of the track to maximize speed. For example, our car has the left front wheel raised, so we will align the car to drift to the left to ride the rail (this is what they refer to as a railrider).
Race Day - Apply graphite to the wheels as often as allowed. Show your son how to handle the car and align it straight on the track. I saw kids carrying them by the wheels, dropping them, etc., which can mess up the cars alignment and have fun and take lots of pictures!

Congrats!!! It's a good feeling working together; hopefully as my son gets older he'll be interested in cars so we can work together then too. Let us know how you do.

We have our pack race on 2/23 and we've anxious to see how we do. Our goal is to improve over last year and win three races.

BlindSideCustoms

02-06-2008, 04:46 PM

well the best design is actually a wedge. you cut it down to about an inch in its thickest point at the back. all the weight is closer to the ground...even the top of the wheels are higher than the top of the car lol. i know this sounds crude but its a winning design and also i think the weight was supposed to be balanced in the middle cant remember that much, my dad worked for rjr and when i was a kid we saw the ones his co workers built "all did this design for their kids" and all won or came in top 2 or so. he had built mine out of some kind of wood at work but the problem is he used the wrong template, one for church groups so it was about 1/2" too wide if i remember correctly "this was 13 years ago" and i couldnt run it. won the race and wasnt able to go on to the regionals due to dq. lol

CHRIS67

02-25-2008, 04:09 AM

rocketrod

02-26-2008, 05:56 PM

The race was run yesterday and I placed 8th overall (2 first place finishes and 6 second place finishes on the day).

I helped a friend and his son build their car and I did exactly the same to his as mine and he ran 4th overall. The difference between 4th and 8th was 2 tenths of a second. The boys all had a good time and I saw lots of good sportsmanship.

Good luck to anyone still to run.

Congrats! :twothumbs So did you qualify for districts? At our pack the top 5 places from each division get to go to districts. If so, good luck!

We had our district race last Saturday, 2/23/8. There were over 300 hundred kids participating with 76 kids in my son's division. As I had mentioned in a previous post we reworked the car with my son doing about 70% of the work!

Anyway during the race they had problems with the electronic timers, which took over an hour to fix. My son raced four times and came in 1st three times and one 2nd place finish where he lost by 0.002!

Well as they tallied the results the difference in time between 2nd and 25th place was less than 0.02 seconds, but the 1st place car was .16 faster than 2nd place. I thought this was rather odd as the winners of all the other division races were decided by less than .01! Well several of the volunteers asked to see the 1st car's times, since it was so unusual for a car to win by that much at districts. Well the winning car's time were 3.152, 3.0xx, 3.0xx and 1.52x! Now it doesn't take a rocket scienctist to figure out somethings not right. Given the rules we raced by a car can not go that fast and typically a car times will be within a feww tentchs of a second or less. This one magical run was a full second faster than the any of the 1300+ races that day!! Anyway...I didn't argue the point.

Now the winners from each division, five in all, got to race in the district grand championship. Well since the 1st place winner from our division left early, he was even there for the trophy presentation, I asked the event coordinator if I could race in there spot if they were a no show. Well we ended up getting to race and finished 3rd out of 5 cars. The difference between 1st and 5th was less than .08 and the difference between 3rd and 5th was .005!

Overall it was a great experience and my son had a blast! He is already talking about the car he wants to build next year.

CHRIS67

02-27-2008, 10:04 AM

Congrats! :twothumbs So did you qualify for districts? At our pack the top 5 places from each division get to go to districts. If so, good luck!

We had our district race last Saturday, 2/23/8. There were over 300 hundred kids participating with 76 kids in my son's division. As I had mentioned in a previous post we reworked the car with my son doing about 70% of the work!

Anyway during the race they had problems with the electronic timers, which took over an hour to fix. My son raced four times and came in 1st three times and one 2nd place finish where he lost by 0.002!

Well as they tallied the results the difference in time between 2nd and 25th place was less than 0.02 seconds, but the 1st place car was .16 faster than 2nd place. I thought this was rather odd as the winners of all the other division races were decided by less than .01! Well several of the volunteers asked to see the 1st car's times, since it was so unusual for a car to win by that much at districts. Well the winning car's time were 3.152, 3.0xx, 3.0xx and 1.52x! Now it doesn't take a rocket scienctist to figure out somethings not right. Given the rules we raced by a car can not go that fast and typically a car times will be within a feww tentchs of a second or less. This one magical run was a full second faster than the any of the 1300+ races that day!! Anyway...I didn't argue the point.

Now the winners from each division, five in all, got to race in the district grand championship. Well since the 1st place winner from our division left early, he was even there for the trophy presentation, I asked the event coordinator if I could race in there spot if they were a no show. Well we ended up getting to race and finished 3rd out of 5 cars. The difference between 1st and 5th was less than .08 and the difference between 3rd and 5th was .005!

Overall it was a great experience and my son had a blast! He is already talking about the car he wants to build next year.[/quote]

Congrats! We had an issue with a fast car that came off the track and got a DNF. He went from first to last, so next year I think we need to throw out the slowest time.

Get them into cars young, even if it is only Pine Wood Derby and hopefully their interest will continue as they get older.

Only the top 5 make it to the district, so we missed it by a few hundreths of a second. We still had a great time and looking forward to next year. I thought we had a good design for the car (hole in the center) until I saw yours. Less weight in the front and more in the rear.

rocketrod

02-27-2008, 05:53 PM

Get them into cars young, even if it is only Pine Wood Derby and hopefully their interest will continue as they get older.

Only the top 5 make it to the district, so we missed it by a few hundreths of a second. We still had a great time and looking forward to next year. I thought we had a good design for the car (hole in the center) until I saw yours. Less weight in the front and more in the rear.
My son will be 8 soon and this is one of the first activities where we got to design/build something together and you could tell he enjoyed it! He has already asked if he can help put the Camaro back together this summer! It should be a fun summer.

Midwest Performance

02-29-2008, 04:43 PM

My car (unlimited class)
https://static1.pt-content.com/images/noimg.gif

others
https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif
Hope this give someone some ideas. Sorry had to remove some to get it to post.

Later Kevin

TonyHuntimer

07-14-2010, 03:05 PM

Here are some pictures of pine cars my father and I built.

https://static1.pt-content.com/images/pt/2008/02/PineCars006-1.jpg

Most Creative...

Finally found my car, so I thought I'd resurect this thread...

Your cars are awesome! Nice work!

Here's mine. It's silver-plated...to lazy to polish it for the picture:
https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif

Now I'm not bragging about first place...I'm just showing you that when I was 9, I was already set on course to be a Big Block Chevy guy! Hence the great Pack #454! Nice!

Tony Huntimer
RaceHome.com

BonzoHansen

07-14-2010, 06:31 PM

LOL, the wienermobile.

We did this last year. True to the mid year 2nd gen that loosely inspired it, it was more show than go. But my boy sanded his but off and learned to spray paint.

https://static1.pt-content.com/images/pt/2010/07/PD2009c-1.jpg

https://static1.pt-content.com/images/noimg.gif

bonecrrusher

07-15-2010, 09:34 PM

I most be bored - I just happen to be home...

Here's my fleet:
https://static1.pt-content.com/images/pt/2010/07/img1279257872977-1.jpg

The gold one was the money shot - got my second place in my districts wayy back in '94.

Black one had the wide bodykit & felt test stripes on it to show aerodynamics from my Jr High wind tunnel science project..... Damn that was a long time ago!

mikester

07-20-2010, 08:23 PM

I built one for my son many years ago. Yup, built the whole car on my lunch hours at work. The guy in the shop next to me built one with his son and blew away the competition so he gave me a lot of tips and since I had all the stuff needed at work I built it. My son did the final touches. Paint, decals, fake windows. He made it look like a NASCAR car. I put the axles in a lathe and polished them. I turned the tires a little so the were beveled for less contact. Even put on little pieces of teflon tape on the body so the wheels would have less friction. I even melted solder into the bottom for the weight and filled it with epoxy. All that and he got beat in the first run by a kid that took the block of wood, cut it on an angle and screwed a washer to the top. Pretty funny.

PinewoodDerbyDen

08-02-2011, 10:38 AM

There are a lot of tips, tricks & links on the PinewoodDerbyDen.com web site.
Have Fun!!!