Pinewood Derby (1 Viewer)

[Cawdor]

Thanks for the info. Instead of coming in last every heat like he did last year, my son's car took 3rd for his age. He was very happy. I like how our pack does it 1st-3rd for each grade and 6 trophies for people's choice and den leader's choices. Most kids that spent time on their car go home with something.

 

[17seconds]

Finished up the car late last night by doing the wheels and axles. You can tell it's our first car and my son did all the painting and decorating.

Starting out in the garage with a glass of 2007 Chateauneuf du Pape

You can see I got the Revell axle driller and a #44 bit. I kept the rear axle stock since I cut off some of the back anyway, and drilled new holes for the front.

Graphite fingerprints all over the paint job

Biggest problem I had was getting the axles in straight. Nobody told me how tough that would be. I ended up splitting the wood in 2 places and my the camber on my wheels is kind of wonky but it tested out OK.

Back wheels

Lifted front left wheel

I shaved off about 1/16" on the front right side of the body to make a rail rider. I was able to get it to drift left 1.5" per 4ft without much tweaking. No way I'm going to mess with full wheel alignment, I've messed up the axles enough already. It drifts properly and the raised wheel looks good so I'm done with adjustments.

Here's my test ramp. A 6ft long 2x6 that I managed to smash into my thumbnail with all its weight at the bottom. Black/blue thumb today and ibuprofen.

It seems the graphite is not as effective after testing the car a lot. Any techniques for applying graphite after the wheels are on?

We won first in the pack! Undefeated in all races. Beat the other 6 Tiger cars by about 1 foot in every run, beat the other 7 cars in the final by a few inches every run. We are representing the pack at he district races at Qualcomm Stadium end of April.

It's so great for my son because he was really disappointed losing in the first heat of the raingutter regatta.

Thanks a lot for the tips in here, definitely would not have won without it!

 

[gameday]

Finished up the car late last night by doing the wheels and axles. You can tell it's our first car and my son did all the painting and decorating.

Starting out in the garage with a glass of 2007 Chateauneuf du Pape

You can see I got the Revell axle driller and a #44 bit. I kept the rear axle stock since I cut off some of the back anyway, and drilled new holes for the front.

Graphite fingerprints all over the paint job

Biggest problem I had was getting the axles in straight. Nobody told me how tough that would be. I ended up splitting the wood in 2 places and my the camber on my wheels is kind of wonky but it tested out OK.

Back wheels

Lifted front left wheel

I shaved off about 1/16" on the front right side of the body to make a rail rider. I was able to get it to drift left 1.5" per 4ft without much tweaking. No way I'm going to mess with full wheel alignment, I've messed up the axles enough already. It drifts properly and the raised wheel looks good so I'm done with adjustments.

Here's my test ramp. A 6ft long 2x6 that I managed to smash into my thumbnail with all its weight at the bottom. Black/blue thumb today and ibuprofen.

It seems the graphite is not as effective after testing the car a lot. Any techniques for applying graphite after the wheels are on?

We won first in the pack! Undefeated in all races. Beat the other 6 Tiger cars by about 1 foot in every run, beat the other 7 cars in the final by a few inches every run. We are representing the pack at he district races at Qualcomm Stadium end of April.

It's so great for my son because he was really disappointed losing in the first heat of the raingutter regatta.

Thanks a lot for the tips in here, definitely would not have won without it!

I haven't checked in on this thread in a while and I just saw this. Wow! Way to go 17Junior. Can't wait to hear how he does in Districts. Good luck!

 

[gameday]

OK, at the risk of being compared to a Trekkie, let me give this a shot. I am a cubmaster; one of my boys has moved on out of scouting; and my younger boy is a Webelo I.

As my boys progressed through scouting we did a lot of reseach and had a lot of success. Combined, they have over 30 Pack and District championship trophies. I am often invited to give seminars and workshops and I freely give out every single bit of advice I have. I have also hosted workshops at my house and over 60 boys have built their cars in my shop, and dozens of them have won Pack and District trophies.

There are many ways to build winning cars but here are the keys I stress:

1) your son needs to decide if he wants to build a cool looking car or a fast car. Rarely is a cool looking car fast. Fast cars are generally very basic and boring. Here is an example of a simple car.

2) note that my son did not use the pre-cut axle slots. It's much better to drill new axle holes as far forward and as far back as possible. Try and find a floor drill press to do that. Don't have the front wheel extend past the front of the car.

3) try and place your weight so that the center of mass is about 3/4th of an inch in front of the rear axle. You can measure that by placing the car on the edge of a ruler to see if it balances there. Another goal is to have 1 ounce of weight on the front wheels and 4 ounces on the back.

4) file and polish axles. An easy way to do this is to put the axle in a dremmel tool or drill and get it spinning. Use a fine file to file off the ridges on the axles. Dont' take off to much material. Less is better than more. Then use wet and dry sandpaper to progressively polish the axle. Start with 600 grit and work your way up to 2500 grit. You can then use a micro polish and to put on the finishing touch. Wash and dry the axle thoroughly after that.

5) BSA changed wheels 2 years ago and the new ones are pretty good. Prior to that the old wheels had a molding bump that had to be shaved off. I wouldn't suggest messing with the new wheels unless you have access to a lathe of some sort. As a side note, don't place wheels on axles and spin them until after you've filed the axles. Otherwise the unpolished axles will make tiny grooves in the bore of the wheels that are nearly impossible to identify and remove. You should verify all wheels spin freely and don't wobble. If they wobble go to the scout store and get new ones.

6) get some high quality graphite from one of the pinewood derby websites. Place the wheel on the axle, squirt graphite in, spin the wheel hard 10 times. Repeat the process 4 times for each wheel. Graphite consists of crytals that must be crushed to be effective. Do not squirt fresh graphite on the wheels unless there is time to break it in.

7) push the axles/wheels into the axle holes. The wheel should be the width of a credit card from the side of the car.

8) roll the ar on a clean, flat surface to make sure it rolls relatively straight. If it moves towards one side or the other more than an inch over a foot you need to make an adjustment. Pull the axle and wheel out of the front hole and try and place a very slight bend in the axle. Do not do that while it is in the car or you will break off some wood. Place the axle/wheel back in and re-roll it. Rotate the axle until it starts rolling straigher.

9) put the car away and do not mess with it again until the race. Most disasters happen during this time.

Here is a thread on building an outlaw car for the dad's race. Most of the concepts also apply to building a scout class car.

Bumping this again. This is still basically what we follow.

Main difference is step 8, since we do a rail-rider.

Thanks, Disco. How did little Stu do at Districts?

I think I mentioned previously that my boys are out of Scouts. However, this season several boys came by to use my shop and get some tips. I did no work on their cars other than cutting the blocks on the table or band saw. That is just too dangerous of a process for little guys. And without exception, every boy who came by took either 1st or 2nd at their Pack, and placed in the top 3 at Districts. They were pretty pumped.

 

[17seconds]

Finished up the car late last night by doing the wheels and axles. You can tell it's our first car and my son did all the painting and decorating.

Starting out in the garage with a glass of 2007 Chateauneuf du Pape

You can see I got the Revell axle driller and a #44 bit. I kept the rear axle stock since I cut off some of the back anyway, and drilled new holes for the front.

Graphite fingerprints all over the paint job

Biggest problem I had was getting the axles in straight. Nobody told me how tough that would be. I ended up splitting the wood in 2 places and my the camber on my wheels is kind of wonky but it tested out OK.

Back wheels

Lifted front left wheel

I shaved off about 1/16" on the front right side of the body to make a rail rider. I was able to get it to drift left 1.5" per 4ft without much tweaking. No way I'm going to mess with full wheel alignment, I've messed up the axles enough already. It drifts properly and the raised wheel looks good so I'm done with adjustments.

Here's my test ramp. A 6ft long 2x6 that I managed to smash into my thumbnail with all its weight at the bottom. Black/blue thumb today and ibuprofen.

It seems the graphite is not as effective after testing the car a lot. Any techniques for applying graphite after the wheels are on?

We won first in the pack! Undefeated in all races. Beat the other 6 Tiger cars by about 1 foot in every run, beat the other 7 cars in the final by a few inches every run. We are representing the pack at he district races at Qualcomm Stadium end of April.

It's so great for my son because he was really disappointed losing in the first heat of the raingutter regatta.

Thanks a lot for the tips in here, definitely would not have won without it!

I haven't checked in on this thread in a while and I just saw this. Wow! Way to go 17Junior. Can't wait to hear how he does in Districts. Good luck!

Thanks! I'm assuming we'll get smoked because there will be nearly ideal cars there. Car is in a ziplock bag in the garage until race day. Not going to change anything other than adding more graphite the night before and go.

 

[Brony]

Our derby is this Saturday. I can't wait. Only because I'm sick of doing work on these things. I have two daughters so I'm doing 2 cars. Turns out one car became my test car where I learned most of my lessons. The second car almost resembles a pinewood derby car, so that's nice.

As I suspected, most of the tips in here are useless to the man who doesn't own a vise, band saw, or drill press.

I am thankful that I picked up a Dremel that has allowed me to turn a piece of #### into merely a turd. So to speak. At least I won't get accused of having a car that clearly dad did everything.

 

[chet]

OK, at the risk of being compared to a Trekkie, let me give this a shot. I am a cubmaster; one of my boys has moved on out of scouting; and my younger boy is a Webelo I.

As my boys progressed through scouting we did a lot of reseach and had a lot of success. Combined, they have over 30 Pack and District championship trophies. I am often invited to give seminars and workshops and I freely give out every single bit of advice I have. I have also hosted workshops at my house and over 60 boys have built their cars in my shop, and dozens of them have won Pack and District trophies.

There are many ways to build winning cars but here are the keys I stress:

1) your son needs to decide if he wants to build a cool looking car or a fast car. Rarely is a cool looking car fast. Fast cars are generally very basic and boring. Here is an example of a simple car.

2) note that my son did not use the pre-cut axle slots. It's much better to drill new axle holes as far forward and as far back as possible. Try and find a floor drill press to do that. Don't have the front wheel extend past the front of the car.

3) try and place your weight so that the center of mass is about 3/4th of an inch in front of the rear axle. You can measure that by placing the car on the edge of a ruler to see if it balances there. Another goal is to have 1 ounce of weight on the front wheels and 4 ounces on the back.

4) file and polish axles. An easy way to do this is to put the axle in a dremmel tool or drill and get it spinning. Use a fine file to file off the ridges on the axles. Dont' take off to much material. Less is better than more. Then use wet and dry sandpaper to progressively polish the axle. Start with 600 grit and work your way up to 2500 grit. You can then use a micro polish and to put on the finishing touch. Wash and dry the axle thoroughly after that.

5) BSA changed wheels 2 years ago and the new ones are pretty good. Prior to that the old wheels had a molding bump that had to be shaved off. I wouldn't suggest messing with the new wheels unless you have access to a lathe of some sort. As a side note, don't place wheels on axles and spin them until after you've filed the axles. Otherwise the unpolished axles will make tiny grooves in the bore of the wheels that are nearly impossible to identify and remove. You should verify all wheels spin freely and don't wobble. If they wobble go to the scout store and get new ones.

6) get some high quality graphite from one of the pinewood derby websites. Place the wheel on the axle, squirt graphite in, spin the wheel hard 10 times. Repeat the process 4 times for each wheel. Graphite consists of crytals that must be crushed to be effective. Do not squirt fresh graphite on the wheels unless there is time to break it in.

7) push the axles/wheels into the axle holes. The wheel should be the width of a credit card from the side of the car.

8) roll the ar on a clean, flat surface to make sure it rolls relatively straight. If it moves towards one side or the other more than an inch over a foot you need to make an adjustment. Pull the axle and wheel out of the front hole and try and place a very slight bend in the axle. Do not do that while it is in the car or you will break off some wood. Place the axle/wheel back in and re-roll it. Rotate the axle until it starts rolling straigher.

9) put the car away and do not mess with it again until the race. Most disasters happen during this time.

Here is a thread on building an outlaw car for the dad's race. Most of the concepts also apply to building a scout class car.

Bumping this again. This is still basically what we follow.

Main difference is step 8, since we do a rail-rider.

Is there a good way to drill axels if you don't have a drill press?

 

[gameday]

OK, at the risk of being compared to a Trekkie, let me give this a shot. I am a cubmaster; one of my boys has moved on out of scouting; and my younger boy is a Webelo I.

As my boys progressed through scouting we did a lot of reseach and had a lot of success. Combined, they have over 30 Pack and District championship trophies. I am often invited to give seminars and workshops and I freely give out every single bit of advice I have. I have also hosted workshops at my house and over 60 boys have built their cars in my shop, and dozens of them have won Pack and District trophies.

There are many ways to build winning cars but here are the keys I stress:

1) your son needs to decide if he wants to build a cool looking car or a fast car. Rarely is a cool looking car fast. Fast cars are generally very basic and boring. Here is an example of a simple car.

2) note that my son did not use the pre-cut axle slots. It's much better to drill new axle holes as far forward and as far back as possible. Try and find a floor drill press to do that. Don't have the front wheel extend past the front of the car.

3) try and place your weight so that the center of mass is about 3/4th of an inch in front of the rear axle. You can measure that by placing the car on the edge of a ruler to see if it balances there. Another goal is to have 1 ounce of weight on the front wheels and 4 ounces on the back.

4) file and polish axles. An easy way to do this is to put the axle in a dremmel tool or drill and get it spinning. Use a fine file to file off the ridges on the axles. Dont' take off to much material. Less is better than more. Then use wet and dry sandpaper to progressively polish the axle. Start with 600 grit and work your way up to 2500 grit. You can then use a micro polish and to put on the finishing touch. Wash and dry the axle thoroughly after that.

5) BSA changed wheels 2 years ago and the new ones are pretty good. Prior to that the old wheels had a molding bump that had to be shaved off. I wouldn't suggest messing with the new wheels unless you have access to a lathe of some sort. As a side note, don't place wheels on axles and spin them until after you've filed the axles. Otherwise the unpolished axles will make tiny grooves in the bore of the wheels that are nearly impossible to identify and remove. You should verify all wheels spin freely and don't wobble. If they wobble go to the scout store and get new ones.

6) get some high quality graphite from one of the pinewood derby websites. Place the wheel on the axle, squirt graphite in, spin the wheel hard 10 times. Repeat the process 4 times for each wheel. Graphite consists of crytals that must be crushed to be effective. Do not squirt fresh graphite on the wheels unless there is time to break it in.

7) push the axles/wheels into the axle holes. The wheel should be the width of a credit card from the side of the car.

8) roll the ar on a clean, flat surface to make sure it rolls relatively straight. If it moves towards one side or the other more than an inch over a foot you need to make an adjustment. Pull the axle and wheel out of the front hole and try and place a very slight bend in the axle. Do not do that while it is in the car or you will break off some wood. Place the axle/wheel back in and re-roll it. Rotate the axle until it starts rolling straigher.

9) put the car away and do not mess with it again until the race. Most disasters happen during this time.

Here is a thread on building an outlaw car for the dad's race. Most of the concepts also apply to building a scout class car.

Bumping this again. This is still basically what we follow.

Main difference is step 8, since we do a rail-rider.

Is there a good way to drill axels if you don't have a drill press?

you can use a regular drill and this tool: http://www.maximum-velocity.com/pro-body.htm

However, IMO the most important step is to drill the axle holes precisely. Without a drill press that is VERY difficult.

BTW, you'll need a #44 drill bit.

 

[dnurk]

Great thread with tons of good info. A couple of questions if I may....

1. Our front right wheel is the raised wheel. Do we want the car to steer slightly right or left? It is currently steering right (toward the direction of the raised wheel.).

2. It looks like we should have the wheels a credit card width away from the car body. I'm assuming that means the center of the wheel where the axle goes through? That appears to be closer to the car body than the actual part of the wheel that contacts the ground.

3. Related to the above, would we want all 4 wheels spaced the same amount from the body? Do you want one closer and the others a bit farther away so only one wheel is making contact with the rail?

Thanks for the help in advance.

 

[Disco Stu]

Great thread with tons of good info. A couple of questions if I may....

1. Our front right wheel is the raised wheel. Do we want the car to steer slightly right or left? It is currently steering right (toward the direction of the raised wheel.).

2. It looks like we should have the wheels a credit card width away from the car body. I'm assuming that means the center of the wheel where the axle goes through? That appears to be closer to the car body than the actual part of the wheel that contacts the ground.

3. Related to the above, would we want all 4 wheels spaced the same amount from the body? Do you want one closer and the others a bit farther away so only one wheel is making contact with the rail?

Thanks for the help in advance.

1. Right2. Correct

3. Ideally the front dominant wheel (front left in your case) should be inset roughly 1/16". That keeps the left rear wheel off the rail. My son accomplishes this with extra sanding in that area.

 

[Disco Stu]

Is there a good way to drill axels if you don't have a drill press?

you can use a regular drill and this tool: http://www.maximum-velocity.com/pro-body.htmHowever, IMO the most important step is to drill the axle holes precisely. Without a drill press that is VERY difficult.

BTW, you'll need a #44 drill bit.

That's what we use and it comes with the correct drill bit. Easiest if you drill prior to any cutting.

 

[Disco Stu]

Thanks, Disco. How did little Stu do at Districts?

I think I mentioned previously that my boys are out of Scouts. However, this season several boys came by to use my shop and get some tips. I did no work on their cars other than cutting the blocks on the table or band saw. That is just too dangerous of a process for little guys. And without exception, every boy who came by took either 1st or 2nd at their Pack, and placed in the top 3 at Districts. They were pretty pumped.

Nice. Our district races are this weekend.

 

[17seconds]

Great thread with tons of good info. A couple of questions if I may....

1. Our front right wheel is the raised wheel. Do we want the car to steer slightly right or left? It is currently steering right (toward the direction of the raised wheel.).

2. It looks like we should have the wheels a credit card width away from the car body. I'm assuming that means the center of the wheel where the axle goes through? That appears to be closer to the car body than the actual part of the wheel that contacts the ground.

3. Related to the above, would we want all 4 wheels spaced the same amount from the body? Do you want one closer and the others a bit farther away so only one wheel is making contact with the rail?

Thanks for the help in advance.

1. Right2. Correct

3. Ideally the front dominant wheel (front left in your case) should be inset roughly 1/16". That keeps the left rear wheel off the rail. My son accomplishes this with extra sanding in that area.

I think you have to be careful with #3 though. I shaved off about 1/16" with a jigsaw and obviously things worked out well but I was really worried when I saw that the track rail is almost exactly the width of the pinewood block. It would be good to make sure there's a hair more space between the body and the hub on that wheel so it isn't too tight.

 

[Brony]

We had ours this past Saturday. My only goals were for the girls to participate in the making of the car to the point where they were a little uncomfortable and to field a competitive car that didn't cost an arm and a leg. We were successful on both of these. :thumbsup: The girls (5 & 7) did a little sawing on test wood with a coping saw, did some Dremel-ing and sanding and did all of the painting and the design. Since none of us had been to one of these events before, we simply did our best, but didn't know how serious other girls/dads would be taking it.

I did a lot of the work and frankly most of the work involved was fixing what I screwed up along the way. For instance, I wound up soldering the fishing weights since they stuck out too far under the car on one of them. Tips on here were useful, but I really needed someone with some good tools who'd done this before. I didn't see any tungsten putty at our event but probably 1/3 of the cars used stick on weights.

Results - heats were run as 3 cars at a time and then winners ran against winners, etc. you kept racing til you lost 3 races. Each of our cars won 1 or 2 races and the girls got a kick out of that which was nice to see.

The cars

Older girl

Younger girl

Thanks for people's help on here. (though I really wish someone had told me why to drill axle holes. Now it makes sense after screwing with that axle slot )

 

[Disco Stu]

District races were Saturday. Stu Jr got first in his den, second overall. The second place kid from last year edged him out this time.

Same story at Districts this year. Won his den fairly easily, then lost to the same kid again in the finals.

We improved a little over last year. They improved a lot. That thing was flying down the stretch.

 

[sho nuff]

Ill get a pick of the car up soon...

LIttle Nuff dominated his den and pack again this year with nobody beating him...though, the last heat was extremely close.

Districts today were a different story. Thought his car was set up pretty well going into it...but man there were some fast cars out there today.

They did it all based on time this year...much faster than last year's elimination rounds based on a points system on a 3 lane track.

4 runs...drop your slowest and just run the one round. He ended up something like 29th out of 70 or so. Though, they said after the top 10, the next group he was in was extremely tight time wise.

He had fun and did finish in all 4 positions in the heats he ran in which was good to have him see his car run and win a heat (also his best heat by far time wise)

 

[shuke]

Let's do this.

 

[Polish Hammer]

Just came back in here to get a refresher. Have two boys doing it this year. The older son who did well last year now says he just wants a fast car and doesn't care about looks. We'll see...

 

[The Commish]

for next year

Shoulda known the FFA would have something on this

 

[17seconds]

We're about halfway done. Shape has been cut and first paint job done. We used a band saw at a scout leader's house and my son was a bit scared but did help with the cut. He painted it red/white/black and we are looking for some good stickers to add.

Now I'll get in there and make it fast, then we'll finish up the decoration.

Definitely going with a rail rider and lifted wheel again this year. I don't think the car will be as fast as what we did before because it is not a speed shape. Son did a boxy design with a lot of wood in the front. Not much volume to put weight in the back. Center of balance will be a good 2" in front of back wheel. Currently at about 4.5oz, need to add some 1/4 oz more lead and then the patented screw with washers for the final weight.

We smoked the pack last year and got 3rd in the district (versus 15 pack winners) so I think we'll still bring it.

 

[Polish Hammer]

Which wheel gets lifted and how again? Do the other three just go straight?

 

[17seconds]

Which wheel gets lifted and how again? Do the other three just go straight?

Pick a front wheel to lift, I like doing the left one. There's a couple of ways to lift it. Best way is to drill a new hole 1/16" above the existing slot. You need exactly a #44 drill bit though, which you can get at Ace Hardware. You could also lift the wheel by simply bending it up a little once it is nailed into the existing slot.

The other 3 wheels go straight unless you want to build a rail rider. A rail rider is biased to drift in the direction of the lifted wheel so the non-lifting front wheel hugs the rail all the way down the track. This method is faster than going dead straight because no track or car is perfectly straight for the length of the run and in reality it will bounce back and forth, losing energy. Better to bias it to hug the rail and stay in that position all the way down. Again, it should be the active front wheel hugging the rail so the lifted wheel doesn't touch anything and therefore adds 0 resistance to the run. You test the drift on a board - I have a 5ft long 2x6 board that I setup as a ramp and get the car to drift left about 2" from the top to the bottom of the board. Have a center mark at the top of the board and at the bottom a center mark and some marks 1", 2" from center.

People get it to drift by bending the nails with a special tool, I just use pliers but you have to be careful you don't scuff the nails which can cause resistance. Oh and if you really want to be anal, spin all 4 wheels on your nails before you put them on and make the lifted wheel the one which spins the shortest amount of time.

 

[DerbyDad]

Oh the good ol' days of Pinewood Derby.

 

[Polish Hammer]

Thanks for the tips! Both of my boys got first place in in their den. In the finals the younger one took 7th (first time doing it) and my older son got 2nd. By rights he should have had 1st, but had a bad last run. He was running an equivalent speed of 206+ pretty much all day (low of 205.8 and high of 207) and on the last one started his car with a wheel on the rail...ran a 202-something and in the end he lost by .01 seconds on average. (Inadvertently built his as a rail rider, but it worked, I guess.)

On to districts!

 

[dnurk]

Such great info in this thread. I did want to share one hard learned lesson for future scout parents.

Last year was our first derby and I followed most of the advice in this thread. Unfortunately the car sucked and was by far the slowest in the entire tribe. Upon investigation we got too aggressive with sanding the axles and took off too much metal. They were mirror bright and smooth but the wheels had way too much wobble because of the decreased axle diameter.

This year we used super fine wet sandpaper and went slow. Took off just enough to remove the factory marks on the shaft and nail head. Went with all 4 wheels on the ground and got the weight way back in the car. Balance point was just 1/2" in front of the rear axle. We did drill new axle holes as well.

He took first in his den and first overall this year...not losing a single heat. 4 run average in the finals was 227.44 mph. He went from tears last year to cheers from his friends this year.

Thanks to everyone in this thread for the knowledge share.

 

[The Commish]

It's that time of year again!

Race is in two weeks.  We've done most of what's suggested in this thread.  Letting my son roll on his own (outside of the precision cutting for axles)...this year they have a sibling division and I'm working with his little sister, showing him "how to" on her car and letting him do his own.  We'll see how it goes.

 

[Ignoratio Elenchi]

 

 

[Peter Lemonjello]

Don't know if this has been shared, but it helped me as a newbie 4 years ago. Plus you can then go down the rabbit hole of all his other cool videos. Science behind car design

 

[The Commish]

I can reduce his list down to three.

1.  Three wheels on the track, aligned to "rail ride"

2.  Wheels tilted up to ride on the edges and graphite each wheel

3.  Weight placed in the back of the car as close to the back axle as possible erring to just in front of the axle if no behind

 

[Ignoratio Elenchi]

I can reduce his list down to three.

1.  Three wheels on the track, aligned to "rail ride"

2.  Wheels tilted up to ride on the edges and graphite each wheel

3.  Weight placed in the back of the car as close to the back axle as possible erring to just in front of the axle if no behind

Had our first ever race this past weekend, waited too long to start on the car and wish I'd read some of the tips online ahead of time.  Already thinking about improvements for next year.  Pretty sure it would've been against our pack's rules to have a wheel not touching the track, but otherwise all we did was cut a rough wedge shape, stick a bunch of weights on top above the rear axle, and squirt some graphite into the wheels.  Took 4th out of 14 in the Tiger Den which was tough (top 3 got sweet trophies) but otherwise was pleasantly surprised.  

Curious if anyone has insights on this, I was convinced that weight was a critical component.  One of the other dads (also a first-timer) cut way too much off the block and/or didn't add enough weights, the car ended up coming in at like 3.7 oz at the weigh-in.  Was pretty worried that the car wouldn't even make it to the end of the track.  Took 2nd out of the den.  What gives?

 

[The Commish]

Had our first ever race this past weekend, waited too long to start on the car and wish I'd read some of the tips online ahead of time.  Already thinking about improvements for next year.  Pretty sure it would've been against our pack's rules to have a wheel not touching the track, but otherwise all we did was cut a rough wedge shape, stick a bunch of weights on top above the rear axle, and squirt some graphite into the wheels.  Took 4th out of 14 in the Tiger Den which was tough (top 3 got sweet trophies) but otherwise was pleasantly surprised.  

Curious if anyone has insights on this, I was convinced that weight was a critical component.  One of the other dads (also a first-timer) cut way too much off the block and/or didn't add enough weights, the car ended up coming in at like 3.7 oz at the weigh-in.  Was pretty worried that the car wouldn't even make it to the end of the track.  Took 2nd out of the den.  What gives?

The other cars must not have been all that good. In my experience if you can avoid wheel shimmy and keep it as straight as possible you have a shot. Keep friction at a minimum. I'd be shocked if they had issue with a wheel not touching. 

 

[Big League Chew]

I won 1st place in 88 and 2nd place in 89

AMA

 

[shuke]

While I enjoyed the time with my son, after 5 years I’m so glad I don’t have to #### with this anymore. 

 

[IrishTwinkie]

Had our first ever race this past weekend, waited too long to start on the car and wish I'd read some of the tips online ahead of time.  Already thinking about improvements for next year.  Pretty sure it would've been against our pack's rules to have a wheel not touching the track, but otherwise all we did was cut a rough wedge shape, stick a bunch of weights on top above the rear axle, and squirt some graphite into the wheels.  Took 4th out of 14 in the Tiger Den which was tough (top 3 got sweet trophies) but otherwise was pleasantly surprised.  

Curious if anyone has insights on this, I was convinced that weight was a critical component.  One of the other dads (also a first-timer) cut way too much off the block and/or didn't add enough weights, the car ended up coming in at like 3.7 oz at the weigh-in.  Was pretty worried that the car wouldn't even make it to the end of the track.  Took 2nd out of the den.  What gives?

This is applied physics. Potential energy converted to kinetic energy. You need the weight as high up on the track as possible, with the caveat that too high makes the car jump when it hits the sections of the different tracks. You want the center of balance some where around an inch in front on the rear wheel. I'd be surprised if the light car even finished. When I was helping run pitcrews for the PWD, I would have been strongly recommending that they weight the car closer to the allowed 5.

For my cars, I'd often hollow the underside just to get more weight higher on the track. Higher on track means more potential energy. (ie time for gravity to work on it)

The wheel touching thing is just to prevent the rotational energy of the 4th wheel spins to reduce the max kinetic energy possible. Some folks allow it, others don't. In my experience it is hard to monitor. 

Keeping the car aligned helps. Bouncing into the rail steals energy. 

In the end the PWD is supposed to be about fun. If your and son and you had fun building the car together and racing... then its a win, no matter what place the car took in a race. That kind of win is better than any trophy. My son is now an Eagle Scout but helps regularly in his old pack. He is close to aging out. Wants to build a car for the old timers race next year. To me, that's better than what ever trophy he won years ago.

PS: Sweet trophies are a sin in my book. It puts the incentive on the wrong thing. My pack used to use trophies made by the Webelos. Wooden blocks and plywood. As a result, more kids made the car. I noticed a correlation between sweet trophies and clearly adult built cars

 

[AhrnCityPahnder]

Gonna go ahead and dot this thread, think it's in my future soon.  

 

[Dan Lambskin]

Will be my 3rd year doing this, now will have 2 kids doing it.  Oldest has always been more concerned about looks (shark car with a huge dorsal fin and a Nyan cat car) but then gets disappointed when his car sucks 

Well see what  we end up with this year.  I'm sure I could do the Googles and end up with some awesome cookie cutter wedge car but I just don't really care that much.  

 

[SWC]

brohans for anyone who has a kid sad because there car did not win you tell them hey little brohan the go fast guys miss stopping to pick up the gals and when you are cruisin on friday night you will be the guy with a papershaker under your arm while the fast guys are stuck polishing their trophy take that to the bank bromigos 

 

[Ignoratio Elenchi]

I'd be surprised if the light car even finished.

We both were, too, that's why I'm wondering if it's possible that the conventional wisdom is wrong somehow.  I would've assumed that a car that was 20%+ lighter than everyone else would be doomed, no matter how bad the competition might be.