Actually I was talking Tiger and Wolf and older. I would not trust any of the scouts in his troops to use a band saw or any power saw. If you were using power saws by before age 10 more power to you but no thank you.
I make the cuts and I do the drilling. The rest is his work. I teach the entire time. I watch over him as he is painting too.
The point is originally it was to teach scouts to whittle, and actually think on how to make something, not ask their fathers to make the cars for them.
Shame on all of you fathers.
Whittle? Well that belongs to a bygone day. Also how many 6 years old whittle? That is how early they start the pinewood derbies.
Well my husband did, and whittled his derby entry, and my brother did, and whittled his derby entry. They were both in the scouts in the 60s. Back in the day 5-6 was when you tended to get your first pocket knife. How else do you learn to whittle and knife safety?
mrAru gave the hint of using a very dense wood, makes it easier to make it look all swooshy and race car like [his terms … he channels an inner kid now and again] and still get it in under the weight limit.
This won’t work. Extra weight on the wheels does in fact create extra drag - but so does the production of lift (the drag from which is known as induced drag). And even mediocre wheels are going to be better than what results from changing the aerodynamics.
At a guess, mediocre wheels/bearings have a 20:1 ratio of weight to drag (good ones - e.g. train wheels on a steel track - can exceed 500:1). To achieve even 5:1 with a “lifting body” type design for a pinewood derby racer would be commendable.
My son’s pack got around the problem by having a separate adults’ division. All the dads got to get out their own resentments over their own dads taking all the fun out of it for them that way. The winner, btw, was a guy who bought a kit right at the meeting that night, screwed some washers onto the top of the bare block, marked his name on it with a Sharpie, and went from there.
I agree with all the comments about forgetting who Scouting is for - and the answer isn’t the parents. For those who don’t forget, and support their kids’ efforts to make their cars rather than taking over, they’ll find their kids keeping and treasuring their cars into adulthood. I still have mine, for instance - it’s a reminder of a time when I learned how to make something and accomplish something for the first time. I would have hated to have that experience hijacked by anyone, even my own Dad.
It is.
Inertia is exactly proportional to mass, so you can’t gain or lose anything there by adjusting the car’s weight.
But unless the racetrack is in a vacuum you always want the car as heavy as possible. This is because air imposes a drag force (proportional to the square of the velocity) that at any given speed is the same for both a light and a heavy car (assuming they have the same shape). And an equal force will always produce more effect (in this case, more deceleration) on an object with smaller mass.
Another way to state this: at any speed above zero, the net acceleration (effect of force due to gravity minus effect of all forms of drag) of the heavy car is greater than that of the lighter car.
Inertia comes into it in the runout after the ramp section. All cars will fall at the same rate (see Galileo and Newton for an explanation), but when they level out, the heaviest car will have the most kinetic energy, and will decelerate less due to friction. A heavier car will also track straighter and will lose less energy into banging off the track guides. So yes, max it out.
True only if you add “in a vacuum”.
As far as learning to whittle goes, I learned first on bars of soap, then sticks for roasting wieners and making smores, and eventually neckerchif slides (get a block of wood maybe two inches long, drill a half-inch or three-quarter-inch hole down the length of it, and carve a design into it with your genuine Swiss Army Knife (accept no lesser substitutes:D).
When I did pinewood derbies, my dad did most of the actual hands on work, but I did most of the designing (he was giving me feedback on whether he thought it was a good idea or not), and at the end of it all, I did the painting. It was a lot of fun, and got me started on a lot of the related skills and thinking process (also, I got to see my dad melt lead in a pot on the stove, which was pretty danged neat to see). I maintain that Cub Scouts should be a team effort, the dad and the son spending quality time together and the son learning valuable skills. It’s when he hits Boy Scouts that it becomes more about what he can do on his own working with the other Scouts.
My kids crossed over or quit before I could make a test car, but here’s how I think that the effects rank in order of importance.[ul][li]Weight–this is a given; light cars don’t win and may not finish the race. The car should weight just over five ounces, and you should be able to reduce the weight to 5.00 ounces as weighed by the judges scale.[/li][li]Wheels–The nails need to be machined and polished until they shine, It also helps to smooth and true the outside of each wheel in a lathe. The wheels currently supplied in the BSA kit are better than the ones from a couple of years ago. There are also people on the net who custom turn aftermarket wheels and axles and who also custom finish the BSA wheels. No matter what your rules say, you can find a custom wheel that will be allowed and will run truer than anything that most of us can make. IMHO, the wheels supplied with the Pine Car brand kits run from bad to useless.[/li]Make sure that the wheels are aligned and that the car tracks straight on a hard flat floor. Do not paint any part of the body that comes in contact with the wheel. Use regular black graphite to lube your axles unless your pack or district requires that you use the white stuff (some people use oils made for high vacuum environments, but they usually aren’t allowed. Besides, they’re a little too exotic for me.) Load your wheel with graphite at home, then spin it by hand for several minutes. Each wheel should keep spinning for 15-20 seconds after you spin it.
[li]Wheelbase–A longer wheelbase will bang into the track less. Redrill the holes for the axles so that the wheels are flush with the ends of the block (5-7/8" wheelbase.) It’s best to use a drill press so that the holes stay parallel and in line.[/li]
[li]Weight distribution–The weight needs to be at the back, with enough weight on the front wheels to keep them from lofting. I don’t think that this is to get the weight higher on the track as much as it is so that the car loses less potential energy when the front wheels hit the center rail.[/li]
[li]Make sure that the front of the car is clearly marked if you are racing an a districtwide derby, especially if you bothered to check the weight distribution or did the next thing:[/li]
[li]Front end design–All things being equal, a car may have a faster time if the front end is split with a spoiler high above the track, like this. The car will be free of the starting gate a split second faster.[/ul][/li]All of the above were determined by my sons. 
Seriously, they painted and did design and bodywork (It helped that our Pack had a parents class some years that couldn’t win.)
My son’s Cub Scout leader always gave the same speech every year when the kits were passed out to the boys at Christmas. (My son participated in four derbies.)
[paraphrased] “There are two extremes in building a Pinewood Derby car. One is where the father builds the car, and the Scout has little or no involvement. The other is where a Scout builds the car completely by himself, with little or no parent involvement.* Neither of these extremes are desirable. Instead, parents and Scouts should work together as a team. Scouts should be encouraged to do as much of the actual work as they can. Also, remember that Cub Scouts are not allowed to use power tools.”
*The reason that it was undesirable for a Scout to build a car solely by themselves is that you are talking about a boy between the ages of 6 and 10 trying to build a workable car out of block of wood, four plastic wheels, and four nails. You could always tell when a Scout built the car by themselves because they inevitably ended up a car with four wobbly wheels that was lucky to make it to the end of the track without a wheel falling off. When this happened, you also ended up with a very upset boy. Because it was impossible to prohibit parental involvement, it was thought to be better to actually encourage it, but with strict guidelines.
For parents who really wanted to build their own car, we also had an adult division that did not compete with the boys.
This was illegal in our local Boy Scout council. All Scout were required to use the official BSA pinewood debery materials sold in the kits. Substitute wheels were strictly prohibited, and would get a car disqualified if discovered. It was also considered to be cheating.
Robby, I have had the same experience. Also
Yes, just yes.
I feel compelled to mention that the whole reason Pinewood derby cars are made out of balsa wood is so that no power tools are required to make one. I know I carved mine myself in the late 80s. By honest to God whittling!
I find it a little bizarre that whittling seems too advanced for today’s cubscouts but not using dangerous power tools and a wind tunnel.
There’s nothing wrong with a parent and son building the car together (in fact, that’s probably ideal) but it’s strange that now we have to Formula 1 engineer these things lest junior walk away in tears at the Derby. Guess what? Every scout but one is going to lose the Pinewood Derby! Does it really matter what round they lose in?
My Pinewood derby in the 80s actually split all the cars into two categories: cars made by cubscouts and cars made by dads and cubscouts (read: dads). I won best paint job by a cubscout. (And yes, the car did look like a drunk monkey carved it.)
**They are not Balsa wood, they are pine. **This seems to be the breakdown here. They are not what they use to be.
I have this feeling that Pinewood Derby cars were always made of pine.
I just don’t know, I was never a scout, I am just the father of a current scout. But nowhere in the current instructions or the information in Boys Life does it suggest whittling or that kids should be using power saws. But it does strike me odd that pinewood derby cars were ever made from balsa.
If you haven’t guess it, I kind hate that a few people in this thread are trying to make us fathers feel bad about helping and teaching our sons when it was what is expected today by the scouts themselves and that they do not expect or want young kids using power tools or whittling.
There is a balsa wood rocket that the kids are suppose to whittle but they recommend a potato peeler for that one. Not a knife.
If they are cheap, white pine, they are closer to the balsa wood hardness end of the spectrum than the oak, mahogony end.
With some supervision IMO, depending on individual circumstances of course, having a cub scout whittle some pine down would not be unduly unsafe.
There are other drag forces that aren’t proportional to weight, besides air resistance. My gut feel is that rolling resistance is a bigger factor than air resistance in why you want the weight at the max limit.
