I'm posting this two years after this video was made. I wanted to leave a bread crumb for anyone who is doing their research for the big race. The tips in this video are very good for building a fast car. All things being equal (i.e., you don't have any superstar cars in your Pack) you will have a top car with these tips, and it won't take you a year to build as they are fairly easy to implement. Good luck!
Thank you for the kind comment. As mentioned in the video's description, we made a second video showing a step-by-step example of how to implement these tips.
Hi John, I'm not sure why my post isn't on here. I love your videos and had a few questions as I am in crunch time to help my grandson build his car. 1) my pack requires 4.5" between axles, so do I cut the car shorter, or leave the excess in the front or back what do you recommend? 2) I need 3'8" clearance underneath and they don't allow weights underneath unless the car is hollowed out or it's shape creates an arch where you can put weights, which means in a 3/8 " car all the weights have to be on top. I don't understand how you determine the balance point using a ruler. If I buy a flat metal ruler at home depot can you walk/talk me through that? I think that is key in knowing how to put all these weights on top of this car. I tried looking at the pictures of your cars but none of them show weights except the two up front. If I use the cube tungsten weights I would have a wall of weights sitting on top, is that right or am I misunderstanding weight placement. I'm sorry I am new to all of this but would really appreciate any and all help/clarification you can provide. Thank you,
Thanks for the kind words. I'm working on a follow-up video showing step-by-step how to make a car that implements all of the tips from the first video.
Well done video! I like the NASA engineer video too. Interested to see the different views from rail riding to straight. You didn’t mention anything about negative camber on the rear wheels for less tread friction. Do you do canted axles in the rear?
Thank you for your comments. Canted wheels and rail riding seem to be commonly mentioned techniques, but we haven't tried them. I feel they are less important than the other points in our video. Both techniques seem to add one type of friction in order to reduce another type, so it's difficult for me to judge the net gain. And based on our results, they aren't necessary for winning our Pack's race (at least for now!).
That is correct, but there is a caveat. If the car is balanced on a very thin ruler, then the car may never stop wobbling, even if it is on the balance point. We use a metal ruler that is about 1/16 inch thick so there is a flat (but narrow) edge on which the car can rest.
Thank you for making such an awesome video! No annoying background music, no long, drawn out intro. Clear and to the point!
Thank you for the kind words. I don't like rambling videos either!
Thanks for the vid, I thought about narrowing the wheels, should have less friction but not sure of the outcome yet.
I'm posting this two years after this video was made. I wanted to leave a bread crumb for anyone who is doing their research for the big race. The tips in this video are very good for building a fast car. All things being equal (i.e., you don't have any superstar cars in your Pack) you will have a top car with these tips, and it won't take you a year to build as they are fairly easy to implement. Good luck!
Thank you for the kind comment. As mentioned in the video's description, we made a second video showing a step-by-step example of how to implement these tips.
Hi John, I'm not sure why my post isn't on here. I love your videos and had a few questions as I am in crunch time to help my grandson build his car. 1) my pack requires 4.5" between axles, so do I cut the car shorter, or leave the excess in the front or back what do you recommend? 2) I need 3'8" clearance underneath and they don't allow weights underneath unless the car is hollowed out or it's shape creates an arch where you can put weights, which means in a 3/8 " car all the weights have to be on top. I don't understand how you determine the balance point using a ruler. If I buy a flat metal ruler at home depot can you walk/talk me through that? I think that is key in knowing how to put all these weights on top of this car. I tried looking at the pictures of your cars but none of them show weights except the two up front. If I use the cube tungsten weights I would have a wall of weights sitting on top, is that right or am I misunderstanding weight placement. I'm sorry I am new to all of this but would really appreciate any and all help/clarification you can provide. Thank you,
I made two videos that are similar. I posted answers to your questions with the other video: ua-cam.com/video/fOamVOSvimk/v-deo.html
Great video. Make more please. 😊
Thanks for the kind words. I'm working on a follow-up video showing step-by-step how to make a car that implements all of the tips from the first video.
Well done video! I like the NASA engineer video too. Interested to see the different views from rail riding to straight.
You didn’t mention anything about negative camber on the rear wheels for less tread friction. Do you do canted axles in the rear?
Thank you for your comments. Canted wheels and rail riding seem to be commonly mentioned techniques, but we haven't tried them. I feel they are less important than the other points in our video. Both techniques seem to add one type of friction in order to reduce another type, so it's difficult for me to judge the net gain. And based on our results, they aren't necessary for winning our Pack's race (at least for now!).
underated
Does balance point mean I place the weight temporarily and adjust it so the car balances without wobbling front or back?
That is correct, but there is a caveat. If the car is balanced on a very thin ruler, then the car may never stop wobbling, even if it is on the balance point. We use a metal ruler that is about 1/16 inch thick so there is a flat (but narrow) edge on which the car can rest.
Hello my friend. Nice to see your clip.
First even though I’m like 7 months late
Congratulations!
The science of how to make the fastest pinewood derby car.
☺
Mark rober engineer