Pinewood Derby..

[ironglow]

  I'll be helping my grand daughter with her Pinewood derby race car, which is part of a program in AWANA. Any hints opr tips for producing a competitor would be appreciated. Only fair and legal tips wanted, please.
   Do I have soimething in my gun maintainence kit to lube the wheels/axles. I was thinking on Break-Free with CLP or moly spray as used on bullets..What think you ?

[magooch]

I'd use silicone unless you use sealed, or shielded ball bearings--for which you should need no lube if they are new. 

 

[MGMorden]

I have fond memories of building this things.  Won several times in Cub Scouts .

Main thing to remember: aerodynamics and weight.  On the aerodynamics, keep it so that there are no areas that will catch wind.  Also, polish it up good.  When I built my best one of these I applied automotive paint and wet sanded the thing to a near mirror finish.  There were people at the event that thought that my car was store-bought .

The basic design that I usually used was to bevel the front "fenders" of the car coming down the side.  The rear portion I basically whittled down to where it came to a rounded point.  Almost like shaping it into a cone.

On the weight, basic strategy is to notch out a small cavity in the bottom-front of the car.  Melt and pour some lead in there.  You'll have a weight limit so you can't go all out, but the trick is to get as close to the limit as you can without exceeding it.  Keep a scale handy to check it.  If you bust your weight before the race you'll need to go outside and whittle off some wood (totally messing up your aerodynamic and sanding work.
 
And as you mentioned, make sure that you keep the axles lubed pretty well.

I might even have one of my old cars laying around somewhere.  If I can dig one up I'll post some pictures.

Good luck!

[crustylicious]

Graphite would be the lubricant of choice. In this instance any oil would be too viscous and actually slow you down.

[Questor]

No experience here, but what about dry-lube for guns? It has no grit or viscosity

[S & W 642]

Take a drill with you to the weigh in and if you car is over weight drill some of the lead out. use epoxy to get the lead to stay in the car. Use graphite on the wheels. polish the axles and polish the wheels make sure there are no blemishes on them. Make sure the wheels spin on the axles good. Buy several packs of axles and wheels and polish them all and take the 4 best that spin the longest. epoxy the axles in the car too. Make sure the axles come out of the car straight and not crooked as this will slow the car down. make sure there isn't too much play in the wheels after they are attached to the car. Hope this helps. My Dad taught me and my brother and we never lost. We did take third one time when our car was knocked off the track at the top but other than that we were always first.  

[Big Blue]

It's been a while, but I'd say get it as close to the weight limit as possible. Use the graphite powder on the wheels and try to get those wheels as close to straight with each other and the cars body as humanly possible. Good Luck!
Don

[briarpatch]

Drill and tap a 2x4 pine board to 1/2 inch. Do this in different depths and pour in some melted lead. After you make a few different lengths. and weights, cut a slot in them with a hack saw and screw them out.
On the  bottom front of the car, (you want the weight forward), drill and tap some 1/2 in holes and screw the weights in you made. Take the weight to the limit allowed. They are easy to screw out and cut off to adjust your weight.
Put the inside hub of the wheels in a drill chuck and while the wheels are turning use a small file or sand paper and remove as much diamater from the wheel as you can without cutting through. Just before finish, smooth them with a fine sand paper. also cut the wieth of the tire down and make them real narrow useing the same method. Be carefull not to put to much pressure on the tire while you are removing the plastic. go slow.
Put the small axles which are nails in the chuck and with a smooth sand paper cut the axle down where it is smaller than the wheel hole and very loose. Also sand or file the head of the nail on the inside to remove any burs where it rubs on the wheels. Dont forget the hub of the wheel and cut the diamater down a little to decrease friction to the side and the car body and smooth up the area it touches.Graphite is the lube of choise. Cover all friction points.
As mentioned make sure when you have assembled the car that the wheels are dead straight. When you set the car down on the track for the run dont just push down on it or drop it, this will splay the wheels and it will slow it down. Set it down easy and look it over to make sure it is as straight as possible for the run. Stream line the front and rear of the car.
   Try to keep other kids from handling it. They will damage it without realizing it.
One thing I always do is handle the car myself. Others will not take care of the car as you will. During the weight in or run I set the car.  
All rules apply, I say this that I not lead you astray.

[briarpatch]

To make this fun for the kids and adults.  Get with the organizers of the pine wood derby and ask if the adults can have a car and run them. If they agree then let the fathers, grandfathers etc. make the speed demons and let the kids do their own.     
 

[ironglow]

  Thanks guys; that's just the kind of info I was looking for and I'm sure it will help. I was considering putting just a bit of camber on the wheels so they would only actually run on the ouiter edge of the wheel, instead of the whole face of it...sound logical ? The folks sponsoring this event are only their 2nd year into it and I doubt they have ever seen the wheels modified to look like a racing bicycle wheel or any super mods..so I may risk disqualification.
  I like the idea of using a power drill to slick up the axles & wheels..
  My grand daughter and I entered last year and we saw no visibly modified wheels or 3 wheelers..so I expect we may get booted if we're too radical. She did take second place, but we were careless with aerodynamics. We even had a girl driver with her head and blond wig sticking up out of the chassis. However, the first place winner finished far ahead..so your tips should help.
  The graphite you mentioned..not graphite grease..but rather dry graphite ..correct ?
 

[Heavy C]

Correct...graphite powder.  That and sanding the wheels smooth will do wonders.  My Dad and I even added a 200 gr 45 cal slug under the hood area to add some weight on the front end.  That car took off down that ramp like a bat out a....well you get the idea.  We took first place in my division and overall.  Good times.  Have fun and good luck!

[southernutah]

for weight i used some stick on wheel weights and made them a seat ,if to heavy east trim. take extra weights if you have to replace with more. 

[kctibs]

Keep as low profile as possible, +1 one the dry graphite. keep most of your added weight in the center. Good luck and have fun.

[Victor3]

 I was considering putting just a bit of camber on the wheels so they would only actually run on the ouiter edge of the wheel, instead of the whole face of it...sound logical ?
 
 but we were careless with aerodynamics.

  The graphite you mentioned..not graphite grease..but rather dry graphite ..correct ?  

 You want to do just the opposite with the wheels - angle them so that the inner edge of the wheels are the only contact points. This forces the wheels out away from the body as it rolls so they don't rub on it.

 Also, if your particular group's rules allow (some don't), set the car up so only the 3 longest spinning and most concentric running wheels contact the track. This can be done by raising the worst wheel just slightly, and offsetting a tiny bit of weight to the opposite corner of the car body to keep the bad wheel up.

 As far as aerodynamics go, car body shape has negligible effect on objects this small & light going the distance they travel. There's a good writeup somewhere on the net about it, done by aerospace enginners who did testing in a wind tunnel with various body shapes. The winner at my Son's Pack a couple of years ago had a car he named "The Flying Brick" It was just the basic rectangular shape the body came as, with a rough-textured red paint on it.

 You want to use graphite. Don't go nuts and pack the hubs though. Burnish it in with your fingers on the wheels' outer diameter, and on the body if the wheels can contact it anywhere (you should avoid building so that the wheels can touch the body though).

 Make sure that the car tracks straight for at least 10' when you roll it down an incline. If not, the wheels on one side are gonna rub on the protrusion on the track under the car, slowing it down.

 If possible, set up a simple track (We use a 12' long board with some cardboard strips stapled to the sides) at home and run your car down it as many times as you can. This helps to break in and smooth out any tight areas in the build.

 As was said before, you want to get right up to the max weight. I drill a hole and push a BB in and put a couple of staples in the wood in case the official scale reads heavier than mine. If it does, I remove BB and/or staples. I bring an extra BB and staples to add if it weighs light.

 My Son's car won 1st place out of ~35 entrants one year, 3rd out of ~90 another year. Other years, well, not so good. Lotta luck involved, and sometimes other guys build better cars (OR CHEAT!  )

 EDIT - One more thing. I have no 'scientific evidence' for this, but many guys swear that installing the majority of the weight just ahead of the rear axle helps for some reason.

[.54]

I remember when my son and I raced our car there was a boy that came with his mother. When I saw his car it was obvious that there was no man in this boys life and his mother had been the one to help with his car. It was the original block of wood, still in the original squared shape, with the wheels put on it. No paint or anything. I felt bad for the boy because I knew his mom and him must have just thrown it together at the last minute.
Funny thing was that plain block of wood ended up beating half of the other streamlined, painted cars in it's heat.

[no guns here]

PM me... don't have time for typing it all up now.  Been making 2-6 cars a year for the past 11 years.  We win nearly every year.


NGH

[ironglow]

  All helpful...thanks Guys..

[briarpatch]

This is a car I made about 20 years ago. It only lost 1 race. I was the first to run and it bottomed on the right side of the track, they would not allow a rerun. Everyone on the right side lost until it was fixed.

[briarpatch]

This is view of the threaded weights along with some screws for fine tune.

[ironglow]

Thanks for the help guys. Hunter, my grandaughter won the event. We want to thank you for your advice and assistance. Here's a video of her final run ..to become #1.  
     >delete<                                                                                         Again;....Thanks....Ironglow

[30-30man]

Take a drill with you to the weigh in and if you car is over weight drill some of the lead out. use epoxy to get the lead to stay in the car. Use graphite on the wheels. polish the axles and polish the wheels make sure there are no blemishes on them. Make sure the wheels spin on the axles good. Buy several packs of axles and wheels and polish them all and take the 4 best that spin the longest. epoxy the axles in the car too. Make sure the axles come out of the car straight and not crooked as this will slow the car down. make sure there isn't too much play in the wheels after they are attached to the car. Hope this helps. My Dad taught me and my brother and we never lost. We did take third one time when our car was knocked off the track at the top but other than that we were always first.  

I am the Awana Commander for my church.  This is about the best advice there is.  I think the pinewood derby is about to go for my group.  It and the olympics seemed to be more about the adults than it did about the kids.  The kids didn't really care about all that fierce competition.

[MGMorden]

I am the Awana Commander for my church.  This is about the best advice there is.  I think the pinewood derby is about to go for my group.  It and the olympics seemed to be more about the adults than it did about the kids.  The kids didn't really care about all that fierce competition.

Maybe the world has changed, but last time I competed I think I was at most 10 years old, and I remember it being a particularly fun part of my childhood.  I was big into scale models and such (still do build the occasional model) though, and I know that that hobby itself is dwindling in popularity as well.

[30-30man]

Don't get me wrong. I love the pinewood derby, but just stand back and watch one after about 30 minutes of competition.  The kids are running around the gym and could could care less about the cars their dads put together.  This activiy was suppose to bring clubbers and parents together.  I am just seeing cars every year that there is no way a Spark, T&T etc...ever laid hands on it.  We even had a parent last year to admit that they bought their winning car on Ebay.  They wanted their kid to go home with a $3 trophy, so they taught the kid it was OK to cheat.  This led to two parents almost getting into a fist fight in our gym.  Now, we are really playing down the competition.  We have a car build day and everybody works on their cars in the same location at the same time....I feel that this is the last year we do it though as we are finding other things to bring families together...Good luck on the car.

[Oldshooter]

Sorry I missed this thread before IG, But from what I read you had some great help and congratulations on the win!

Yes, there are always some that cheat and give the wrong message to the Kids. I helped my Son build his a couple of years, way back now, But we enjoyed the time together and as i remeber he did well but did not win. He did the work I provided the technical expertise. Winning is good, but the competition is the good stuff!  I could not have been prouder of him.

[boondocker]

Take a drill with you to the weigh in and if you car is over weight drill some of the lead out. use epoxy to get the lead to stay in the car. Use graphite on the wheels. polish the axles and polish the wheels make sure there are no blemishes on them. Make sure the wheels spin on the axles good. Buy several packs of axles and wheels and polish them all and take the 4 best that spin the longest. epoxy the axles in the car too. Make sure the axles come out of the car straight and not crooked as this will slow the car down. make sure there isn't too much play in the wheels after they are attached to the car. Hope this helps. My Dad taught me and my brother and we never lost. We did take third one time when our car was knocked off the track at the top but other than that we were always first.  

I am with 642 on this one, powdered graphite and polish the axles. True the axles so it runs as straight as possible ( less rubbing on side of track the better.) I used to polish the  axles with compound inn my fingers the wax with carnuba after. My girls would do all the decorating and planning and I would tweak the chassis for them. Awanas is a great thing for the kids, I miss them days and the grand kids just joined last year, their dad helped them there.

[ironglow]

  AS we worked together on the car, I was scrupulously careful that everything was done to make it run well, but just as scrupulously persistant that everything be honest and fair.
  I look at it this way; I wanted to make sure we competed completely honestly! If we did win it would be an earned win and she could savor it, if it were unfairly done I would know, more importantly..she would know..and MOST importantly, God would know.
  I started the axles with 250 grit paper and woprked to 2000 grit. My nephew, who has built cars for his son in scouts, gave me some graphite with molybdenum mixed in with it for lube, spaced the wheels wioth an equal thickness spacer all around. Placing the weight toward the rear, I drilled holes and press-fitted 4@ .44 magnum slugs..finished off with a hole with BBs to get to exactly 5.0 ozs, using a postal scale.
   30-30 man is correct, in that the kids don't "sweat" it that much, although I must admit..most all the adults in this event were polite and courteous.
   One thing I did notice however, since the whole event was rather casual, and not near as "legalized" and argumentative as some pinewood events. After weigh-in and between heats, the kids were walking around, socializing with their cars, nobody overseeing the competeing units, even though much of the time, they were sitting on the judge's table. Curiously, at least two of the cars which were very slow, by the end of the competition were among the top cars.
  The one in the video which came close to beating the "pink peril" for instance, had come initial weigh in grossly overweight and had to be "unloaded" of much of the weight. He started very slowly, among the bottom 2-3 but at some point, suddenly gained a lot of speed..beating some formerly very quick cars. Were I to do the officiating, I would only allow the officials to take the final heat winners from the finish line and re-weigh them again before calling the win.
   The top placed race winners, did not win any "beauty prizes"..even though some could have easily placed...but that is OK.... that way the prizes were spread around and more kids were made happy.   

[skarke]

The Pinewood Derby is really fun.  Check the rules (they are all basically optional by the sponsoring organization, but here's a common list)

http://www.abc-pinewood-derby.com/pinewood_derby_rules.htm

Here's also some thoughts:

1.  What can an 8 year old do? Lathe turning wheels works great, but....
2.  Graphite restrictions levels the course.  Let's face it, there are some pretty slick dry lubes out there for $10 to $100 per vial, but is this reasonable?
3.  5 oz max is pretty standard.  As with regular cars, the closer to 50/50 weight distribution you can get, the better (ask an engineer)

I've always thought that there should be an "unlimited class" for the Dads.  I was always able to whip my kids pretty badly with my car, but I was always way more proud of them for the, uh, well, less aesthetically pleasing vehicles that they assembled. 

[mcwoodduck]

The only three thinks I can tell you are:
1) make the wheel axels as strait as you can.  You may want to change the nails out for longer ones that meet in the center as well as a washer.
2) get as close to the maximum weight as possible.
3) dry lubes work best.  the moly idea is a good one.

[ironglow]

Mcwood ;
     That graphite mixed with moly was something my Nephew loaned me. It was in a tube just like the graphite but was called HobbyLube.
  I suppose he got it from a pinewood site on the web.
   

[Victor3]

After weigh-in and between heats, the kids were walking around, socializing with their cars, nobody overseeing the competeing units, even though much of the time, they were sitting on the judge's table. Curiously, at least two of the cars which were very slow, by the end of the competition were among the top cars.

 One of my Son's races had a cheater like that. Unfortunately, this event had a 'pit stop' table where repairs could be done between heats. I knew it could be a problem and asked my Wife to watch it. One of the Dads went to the table and put a ton of hot glue on the car because "The weights were coming loose". We asked one of the officials to re-weigh the car, but he said "We operate on the honor system."

 I asked, "Even when it's obvious that cheating is going on?" No response.

 Mr. glue gun's car came in 1st, and my Wife and I made sure everyone knew why.