Show us something that you MADE...

[Trixie]

I'd add :to the above tips- weight- to the rear and as high as reasonably possible. The track start is elevated. The higher the weight, the greater the potential energy= greater terminal speed, all other things being equal.

I helped my son make a rail, similar to the gold one pictured, with a lead rear spoiler. met all specs and won easily. Just be careful it doesn't tend to wheelie.

Also, if you don't have a lathe, a drill press or even a hand drill (properly secured) will do fine to hold the nails for polishing.

[Slimie]

Thank you both, already looking forward to next years Cub Scout race!

-Simon

[Anglewood]

Those guys pretty much covered it. The main key is reducing friction as much as possible while taking advantage of gravity by maximizing weight (and placement).

-Connor

[Fast_Boy_Slim]

Originally Posted by Anglewood

Each year my school does a Pinewood Derby as an 8th grade project. Every 8th grader is given a kit and about a month (with deadlines) to build a car. Along the way we work in various 8th grade standards and the kids all build their own cars along the way. One fun part is that as a teacher, I get to build a new car each year to compete in the "teacher race." This is my submission from this year. The body shape is based on the 1931 Miller V-16 race car. I ended up winning the teacher class for the second year in a row by employing a number of speed tricks that I have learned over the years.



-Connor

What a great tradition. We have nothing like that in the UK. Where do you start with stuff like this do all the kids get given some wheels and a hunk of wood or do you have to source it all? Do the girls build cars too as there are plenty of competitive Dads with daughters too

[thisflatearth]

http://www.maximum-velocity.com/kits.htm

[Slimie]

Originally Posted by Fast_Boy_Slim

What a great tradition. We have nothing like that in the UK. Where do you start with stuff like this do all the kids get given some wheels and a hunk of wood or do you have to source it all? Do the girls build cars too as there are plenty of competitive Dads with daughters too

Our local Cubs do it every year (East Devon), that's why I'm looking for tips!

They supply a block of pine, four wheels and pins to hold them and the rest is up to you.

-Simon

[mjydrafter]

Originally Posted by Fast_Boy_Slim

What a great tradition. We have nothing like that in the UK. Where do you start with stuff like this do all the kids get given some wheels and a hunk of wood or do you have to source it all? Do the girls build cars too as there are plenty of competitive Dads with daughters too

Just to add to the above our pack gives each boy a car, and then parents can buy one ($10 IIRC).

The pack we were in did something really cool and invited the girl scouts to our derby. So the GS each made their own cars as well.



Does the UK have Hobby Lobby? I've seen cars and all kinds of extras there. Cars, stickers, wheels, little dudes (drivers), fake engines, you name it.

Other than the wheels, everything else would be pretty easy to recreate on the cheap. Just need some pine wood blocks and nails.

[Slimie]

Originally Posted by mjydrafter

Just to add to the above our pack gives each boy a car, and then parents can buy one ($10 IIRC).

The pack we were in did something really cool and invited the girl scouts to our derby. So the GS each made their own cars as well.



Does the UK have Hobby Lobby? I've seen cars and all kinds of extras there. Cars, stickers, wheels, little dudes (drivers), fake engines, you name it.

Other than the wheels, everything else would be pretty easy to recreate on the cheap. Just need some pine wood blocks and nails.

Our local Cubs sell the components to raise funds, my daughter is a Cub she didn't fit in any of the more girly groups!

We came almost last in the event this year, mostly because I followed the rules and let her do most of the work.

Next year will be different

Hobby Lobby, what's that?

-Simon

[ADK]

Dads doing all the work and using these speed cheats ruins the event for the kids. there should be a supervised build where the kids do their own work and an open class for the cheater specials.

[Anglewood]

Originally Posted by thisflatearth

http://www.maximum-velocity.com/kits.htm

That's a great site for speed tips (I've used their basic speed kit before). The specific kit we use can be found here:

http://www.pinewoodderbycars.com/

The kit is only $3.45, and my fellow science teachers and I applied for a grant to supply kits to all of our 8th grade students. The work is all up to them and they can get very creative. I of course am available to help cut out and paint cars, but I encourage them to get as much help at home as they can. Here is a pic of the finalists from my five 8th grade classes:



-Connor

[Pablo83]

I love the Back to the Future Delorean.

Originally Posted by Anglewood

That's a great site for speed tips (I've used their basic speed kit before). The specific kit we use can be found here:

http://www.pinewoodderbycars.com/

The kit is only $3.45, and my fellow science teachers and I applied for a grant to supply kits to all of our 8th grade students. The work is all up to them and they can get very creative. I of course am available to help cut out and paint cars, but I encourage them to get as much help at home as they can. Here is a pic of the finalists from my five 8th grade classes:



-Connor

[rob feature]

Projectile motion project for physics 111





This thing's been loads of fun. We built this to hurl anything from paintballs to smaller snowballs, but it can be scaled easily with a few tweaks. As of presentation time we were throwing paintballs 100 meters at about 30 meters/second with a 10 kilogram counterweight. The hook should hold around 40 kilograms, giving us a bit more punch. Might have to try the snowballs this weekend

[beyondhelp]

Originally Posted by rob feature

Projectile motion project for physics 111





This thing's been loads of fun. We built this to hurl anything from paintballs to smaller snowballs, but it can be scaled easily with a few tweaks. As of presentation time we were throwing paintballs 100 meters at about 30 meters/second with a 10 kilogram counterweight. The hook should hold around 40 kilograms, giving us a bit more punch. Might have to try the snowballs this weekend

That's excellent. My daughter and I built a rubberband powered catapault for school a while ago. Wish i had pix, it was a beast. They never specified a limit to the number of rubber bands or power of the device. With a little twisting of about 50 wide rubber bands, the limit became the 3/8" allthread pivot and the 1" dowel for the arm. We built the base out of 2x4's and set it up so she could stand on the ends to anchor it while arming it. initial tests with golf balls yielded similar results to yours. *and some odd looks from the neighbors. We reduced the power considerably before taking it to school.

[rob feature]

Originally Posted by beyondhelp

That's excellent. My daughter and I built a rubberband powered catapault for school a while ago. Wish i had pix, it was a beast. They never specified a limit to the number of rubber bands or power of the device. With a little twisting of about 50 wide rubber bands, the limit became the 3/8" allthread pivot and the 1" dowel for the arm. We built the base out of 2x4's and set it up so she could stand on the ends to anchor it while arming it. initial tests with golf balls yielded similar results to yours. *and some odd looks from the neighbors. We reduced the power considerably before taking it to school.

Yeah, golf balls are on the list for sure. Our test range made that a little dangerous, but wide open spaces aren't far away. Think they'd give me shit at the driving range?

[2bold2getold]

I Made Daughter's Birthday Present.