Pinewood Derby Car/Physics Question
#31
BTW, There is a great deal of set up given in this book and you will find the car to be VERY FRADGLE after you get tuned properly. When you get to the race DO NOT LEAVE THE CAR UNATTENDED ON A BENCH EVEN FOR A SECOND. We made that mistake and one of the moms came over and picked up the car and started spinning the wheels and general handling it roughly. The next run the car was all over the track and ran a much slower time then the other 3 runs. Lucky the car in the other lane was not such a good car and so my grandson won that round. After that round He was able to get it back close to where it was but not quite, still good enough to win!
#32
Watch "Down and Derby" http://en.wikipedia.org/wiki/Down_and_Derby
with Your son and as many of the troop/friends as You can gather. That is the perfect intro, all the other advice is great. 3 wheels, alignment(yes, really),also axle angle is extremely important and where You end up depends on Your belief, ie axle down, wheels end up floating on axle, bumping on body, floating back to axle, axle up, opposite is true with them touching the outer axle nub more often, axle 90= wheel float mostly on axle with bump occuring at both body and or metal, all this is particularly important in the 3 wheel car,polished axles, weight rear bias,sanded wheels(take debur a bit extreme), let kid design basic car and go with it using as many of the above as possible within the designers limitations.
Make sure to watch the film, it will give You a classic memory on top of the memory. Good times, enjoy!
with Your son and as many of the troop/friends as You can gather. That is the perfect intro, all the other advice is great. 3 wheels, alignment(yes, really),also axle angle is extremely important and where You end up depends on Your belief, ie axle down, wheels end up floating on axle, bumping on body, floating back to axle, axle up, opposite is true with them touching the outer axle nub more often, axle 90= wheel float mostly on axle with bump occuring at both body and or metal, all this is particularly important in the 3 wheel car,polished axles, weight rear bias,sanded wheels(take debur a bit extreme), let kid design basic car and go with it using as many of the above as possible within the designers limitations.
Make sure to watch the film, it will give You a classic memory on top of the memory. Good times, enjoy!
Last edited by Glen; 01-21-2009 at 08:58 PM.
#33
Instructor
Join Date: Feb 2004
Location: Orlando (Mickey World)
Posts: 220
Likes: 0
Received 0 Likes
on
0 Posts
Others are very correct. It's all in the wheels, axles, friction, and ALIGNMENT. After assembly, find yourselves a very shallow ramp, put a long piece of tape down the center from one end to the other, and let the car roll down the line. You want a very straight roll. The PW tracks have center rails almost as wide as the wheel track, the the wheels will rub all the way down if it doesn't track exactly straight, Work with the axles until it will roll straight all by itself.
#34
Addict
Rennlist Member
Rennlist Member
Thread Starter
Wow, I never expected this wealth of information. Luckily the race is not until the 31st so I have time to review the books and movies and read/reread this thread. Thanks a million guys.
#36
Advanced
I sincerely do not mean to thread jack, but what a perfect time to introduce myself and join in the discussion about the Pinewood Derby. First, let me introduce myself, some of you may know me as SWATDoc on "other" forums. However, I have decreased my involvement with our SWAT team and shifted from being an active member to more of a Emergency Medical resource. This is a direct consequence of additional responsibilities acquired in my advancement of my career and my desire to remain involved with my family. Hence I am changing my user name to reflect where I am in my life. I have three young sons that keep me very busy with their electric jeep, 4 wheeler, a Karting passion, and of course the Pinewood Derby (among many other things). I am forever indebted to the law enforcement officers who I have come to know, I value their friendship, and look forward to spending time with them in a much less hostile environment. I have lurked here to this point, but now plan to contribute to the best of my abilities. It's nice to see so many familiar characters along with new enthusiasts.
As a child, I was a past Pinewood Derby Champion, most in part to an overzealous cousin who essentially designed and fabricated some of the most outrageous cars imaginable. Ultimately, it was this that got me disqualified because it was very obvious that I had not made the cars by myself and was only the face/driver for a very talented craftsman. In the end we dominated and I had no problem walking away with the DQ, because we all knew who the real winner was "me" and my cousin...we laughed about the whole ordeal and it taught me a lot about egos and being humble when absolutely trouncing fathers who thought they had built/brought a car that would be competitive. Do not be fooled, there are many of life's lessons which can be learned through the process of design (drawings), development (Dremel tooling, sanding, painting, etc.), and track day performance (car care, schedules, and podium experiences). Even if the child is not the brains behind the team, it is ultimately all about teamwork if presented in the right manner. I will try to find some of the old photos but it was a very long time ago (like 35 years). Many of the same tactics described here were employed by our team, including axle/wheel work and very small frontal surface area (we modeled ours after F1 cars of the era).
Good luck to all, and please remember to allow your children to participate in whatever manner that they can....it will be remembered and one day they too will rise to the occasion to absolutely devastate the competition!
As a child, I was a past Pinewood Derby Champion, most in part to an overzealous cousin who essentially designed and fabricated some of the most outrageous cars imaginable. Ultimately, it was this that got me disqualified because it was very obvious that I had not made the cars by myself and was only the face/driver for a very talented craftsman. In the end we dominated and I had no problem walking away with the DQ, because we all knew who the real winner was "me" and my cousin...we laughed about the whole ordeal and it taught me a lot about egos and being humble when absolutely trouncing fathers who thought they had built/brought a car that would be competitive. Do not be fooled, there are many of life's lessons which can be learned through the process of design (drawings), development (Dremel tooling, sanding, painting, etc.), and track day performance (car care, schedules, and podium experiences). Even if the child is not the brains behind the team, it is ultimately all about teamwork if presented in the right manner. I will try to find some of the old photos but it was a very long time ago (like 35 years). Many of the same tactics described here were employed by our team, including axle/wheel work and very small frontal surface area (we modeled ours after F1 cars of the era).
Good luck to all, and please remember to allow your children to participate in whatever manner that they can....it will be remembered and one day they too will rise to the occasion to absolutely devastate the competition!
#38
As mentioned rolling friction is a large concern on these cars. When my son was involved in building them the fastest cars at the events were running on 3 wheels not 4. They were balanced in such a way that one of the front wheels (the axle was also pinned a bit higher on one side) was not touching. Don't know what kind of tech inspection they go through now a days.
Good luck.