Pinewood Derby Rules

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Speedster
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Pinewood Derby Rules

Post by Speedster » Thu Oct 18, 2012 7:51 am

2012 Commodore Perry District
Official Pinewood Derby Car Rules

All cars must be made this Scouting year, and be made from the Official Cub Scout Pinewood Derby Kit !!
ONLY BSA STORE BOUGHT CARS ARE ELIGIBLE. NO TARGET STORE CARS.

1. Length: Overall car length shall not exceed 7 inches

2. Width: Overall car width shall not exceed 2 3/4 inches.
Minimum width between inside edge of wheels is 1 3/4 inches.

3. Height: Overall car height shall not exceed 2 1/2 inches.
Bottom clearance between car and track is 3/8 inches.

4. Weight: Car weight shall not exceed 5 oz. Car may be hollowed out and weight filled up to the maximum weight. All weight must be securely built into or attached on to the car body. No movable weighting will be allowed.

5. Wheel Bearings: Washers, bushing, or bearings of any kind ARE NOT ALLOWED.

6. Axles: You must use the nail axles provided in the official kit. Light sanding/polishing of axles to remove burrs is permissible. NO machining/grooving of axles is allowed. Axles MUST be inserted in to the pre-made slots only. The axles and slots must be entirely visible. The nails may not be inserted at an angle. Axles and wheels shall be positioned squarely to the car block and ALL FOUR wheels must make contact with the track at all times. NOTE: Any Car suspect of using illegal axles WILL be automatically disqualified.

7. Wheels: Must be Official "B.S.A. Pinewood Derby" as supplied in kit or colored B.S.A. replacements purchased thru the B.S.A. The wheels may NOT be tapered, rounded, or grooved. The outside portion of the wheel may be lightly sanded to true the wheel and remove mold marks, however, the tread mark (beaded or dotted edge) on the outer edge of the wheel must still show to prove that it is an Official B.S.A. wheel kit. (Note: New B.S.A. wheels do NOT have mold marks on the tread surface.) No wheel covers or hubcaps will be allowed. NO paint, stickers or appliqué' anywhere on wheels will be allowed. NOTE: Any Car suspect of using illegal wheels WILL be automatically disqualified.

8. Lubricants: Only powdered lubricants (i.e. Black Graphite or White Teflon) are allowed. NO Liquid lubricants of any kind are permissible. Lubricants shall be applied to the axles and wheel hubs ONLY. No lubricant on the wheel faces or tread will be allowed. Lubricant shall NOT fall off car with a light tap on a solid surface. Excess lubricant will not be allowed.

9. Springs: NO SPRINGS of any type are allowed.

10. Details: Details such as steering wheels, drivers, roll bars, fenders, etc, are OK as long as they do not exceed the overall dimension specifications listed above, and are Securely Fastened to the car.

11. Attachments: The car must be free wheeling. No starting Devices, i.e. Rubber bands, motors etc. will be allowed.

12. Starting Line: No car may protrude past the starting line for any reason. If any part of the car goes past the starting line before the gate is dropped, it will be disqualified. NOTE: Most starting gates make contact with the car at the "front, center" point, and with a tolerance of 3/4 inch, side to side.

Does anyone have rules that are more restrictive?



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Re: Pinewood Derby Rules

Post by Rukkian » Thu Oct 18, 2012 8:10 am

12. Starting Line: No car may protrude past the starting line for any reason. If any part of the car goes past the starting line before the gate is dropped, it will be disqualified. NOTE: Most starting gates make contact with the car at the "front, center" point, and with a tolerance of 3/4 inch, side to side.
This needs to be edited, and you missed a "not".

As for more restrictive, there are plenty that are, but I try to provide a framework to races competitive while still allowing some openings for people that want to try new things the ability to do so.

From my personal experience after dealing with both, I have found that dry lubricants are an issue and if possible should be avoided. They make a mess. This year in our pack, we are actually buying 1 bottle of krytox by the pack for the whole pack to use at workshops, and at the derby, and suggesting that people not use graphite (and now allowing it in the building).



Speedster
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Re: Pinewood Derby Rules

Post by Speedster » Thu Oct 18, 2012 8:55 am

I tried to copy the rules word for word. Where did I miss a "not"?



Rukkian
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Re: Pinewood Derby Rules

Post by Rukkian » Thu Oct 18, 2012 9:12 am

Nevermind, it was me that missed something. Apparently I need more coffee this morning!



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FatSebastian
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Re: Pinewood Derby Rules

Post by FatSebastian » Thu Oct 18, 2012 9:22 am

Speedster wrote:2012 Commodore Perry District Official Pinewood Derby Car Rules
Available here as PDF which includes an "Acceptable Wheels diagram".



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Darin McGrew
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Re: Pinewood Derby Rules

Post by Darin McGrew » Thu Oct 18, 2012 12:13 pm

Rukkian wrote:From my personal experience after dealing with both, I have found that dry lubricants are an issue and if possible should be avoided. They make a mess. This year in our pack, we are actually buying 1 bottle of krytox by the pack for the whole pack to use at workshops, and at the derby, and suggesting that people not use graphite (and now allowing it in the building).
We've been doing that for a few years now. I have 3 bottles of Krytox 100 that should last us several more years. (We have 3 bottles so 3 people can be applying lube at the same time, not because we use that much lube in any given year.)

Anyway, on to my observations about the rules...
The nails may not be inserted at an angle.
Really? If the kid inserts the nails into the original slots, then it's almost guaranteed that the nails are inserted at an angle. This rule and the "four on the floor" rule are bad rules because they make it a lot harder for a struggling team to make a legal car.

Plus, there's no indication of how precise the 90° angle must be. If our axles are at a 90.04° angle, is that close enough?
No lubricant on the wheel faces or tread will be allowed.
My experience with powdered lubricants (primarily graphite) is that they get everywhere, including the wheel faces and tread. You may as well disqualify everyone and cancel the event.
Most starting gates make contact with the car at the "front, center" point, and with a tolerance of 3/4 inch, side to side.
How high is the starting gate? Does the central contact point on the car need to be at axle height? Can it be a little higher than that, to allow for designs with rounded noses? Can it be at the top of the block, to allow for bathtubs, boats, and similar designs?

We addressed this issue by making our starting gate "pins" out of 1in-wide aluminum bars, which were cut long enough for cars where the nose is at the very top of the block.



Speedster
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Re: Pinewood Derby Rules

Post by Speedster » Thu Oct 18, 2012 1:08 pm

OK Darin, I know you're kidding on a couple of those. Alcohol will clean the wheels and the inspectors are looking for a flagrant violation on angled wheels. I didn't know the inspectors personally last race but they seemed like really nice guys. Your last one is a concern. We have 2 aluminum tracks at District, a Best track and a Freedom track. The 8 fastest cars in each grade will run on both of them. I don't know the measurements of their starting pins. There was no problem starting last year. I agree, a track needs to be able to handle every legal car. We'll see what happens in 2013.



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Re: Pinewood Derby Rules

Post by Rukkian » Thu Oct 18, 2012 2:09 pm

I guess my question is, why have the rule of 4 on the floor? It has been shown time and again that it is tough (especially with the slots) to actually get 4 on the floor. There are numerous posts about people putting their first car together and not being able to get all 4 door, and wondering if that is all right. The ones that will push it could easily get a 3 wheel car past inspection if you are only looking for blatent raising, and then you are left only punishing honest people.

I know this has had some debate over the years, but after having worked with both types of rules, I try to stay on the less it more rules, allowing for creativity, and hard work to seperate the good cars from the bad.

If you are worried that some will just do the car for the kid, make a parents race. You will still get some that want their kids to win at all costs, and this rule will not help that, all it does it make it tougher for the ones that will struggle to put a car together in the first place.

As for the alcohol, sure it can get it off, but in my experience, you will always get some cars with it on the wheels/body accidentally.



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Re: Pinewood Derby Rules

Post by Darin McGrew » Thu Oct 18, 2012 2:32 pm

Yeah, the issue with lube on the tread and sidewalls isn't terribly serious, because you can clean the tread and sidewalls. But I recall when we still used graphite, and we'd have cars with grey fingerprints all over them, and occasionally we'd have a grey car that had started as some other color until the team building it decided to hide the grey fingerprints by applying graphite to the entire car. Worrying about graphite on the tread and sidewalls of the wheels seems trivial in comparison.

But I sincerely believe that "four on the floor" and "axles must be square" rules are bad rules because they make it a lot harder for struggling teams to just build the car. Combining them is even worse because adjusting an axle to get all four wheels on the floor will angle the axle, and adjusting an axle so it is square will raise one of the wheels. It's an over-constrained system unless you get all four axles in exactly the right spot to begin with, which struggling teams aren't going to do.

What is the real problem that your "four on the floor" and "axles must be square" rules are trying to address? Are crooked axles really a problem? Are wheels that don't touch the track really a problem?



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Re: Pinewood Derby Rules

Post by Speedster » Thu Oct 18, 2012 4:02 pm

I'm at a disadvantage. I'm sort of hated by the District Executive. Graphite and 4 on the floor came in 2 years ago when the aluminum tracks were brought in. The lady that use to run the derby became very ill and a whole new crew took over. The new crew did the graphite and 4 on the floor. I don't like it either, gentlemen, but unless the DE moves, we're stuck with what we have. I'm sure the intent of all the rules is to make the race fair for everyone. They're good people making poor decisions. I love the new aluminum tracks. We'll do the best we can. I truly hope no one has it worse than this.



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Re: Pinewood Derby Rules

Post by FatSebastian » Thu Oct 18, 2012 4:59 pm

Thanks for posting your rules, Speedster. Your "Super Restrictive" rules are not as bad as one might imagine, e.g., they still allow pre-drilling of slots.

Darin's comments speak to the fact that it isn't clear how the "no-angled-axles" rule is judged. It seems unlikely that axles could be inserted perfectly square without workshop machinery (like a drill press), which is probably not the intent of having such a rule. If the axles are of sufficient camber to lift the wheel tread, then a slip of paper can be used to feel if the tread is making full roadway contact. Only 2 degrees of camber will lift the tread enough to fail this test, which is not hard to do if you are a kid installing axles with a hammer as instructions often show. The rule that "ALL FOUR wheels must make contact with the track at all times" does not say that the tread contact must be flat.

The rule about nails being "positioned squarely" also suggests that there should be no toe; is the intent here to outlaw rail-riding? Again, it is not clear how this would be inspected; some kind of roll test might determine if the car has any directionality, but this seems overbearing. Arguably there is a gray area where a bent axle can still be inserted squarely, but can still have some toe and/or camber.
Darin McGrew wrote:Combining them is even worse because adjusting an axle to get all four wheels on the floor will angle the axle, and adjusting an axle so it is square will raise one of the wheels.
Darin said out loud what I was thinking. IMO these kinds of rules do not necessarily "level the playing field" because expert builders with tools and ability will be able to manage these constraints; meanwhile the project becomes unnecessarily harder for novices or teams lacking woodworking resources ("struggling teams" as Darin puts it). I suspect it takes much of the fun out of "just building" a simple car, especially the first time, which probably goes against the goals of the program.



Speedster
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Re: Pinewood Derby Rules

Post by Speedster » Thu Oct 18, 2012 5:22 pm

Your last line says it all, FS. Certain rules help the expert builder because he knows what to do and hurts the very ones they are meant to help. We'll do the best we can. Thanks for posting the rules with the pictures. That was very clever.



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Re: Pinewood Derby Rules

Post by *5 J's* » Fri Oct 19, 2012 5:58 am

For years I had been dealing with rules that I think we're written in an attempt to level the playing field but actually hurt the average builder. Fortunately, last year I had opportunity to update many of our rules.

One of the things I had noted was that the 4-on-the-floor ruled caused many dads to bust a sons car at check it. It tore my up to witness this for no good reason. A scout would "do his best" to install the axles into the slot - but the majority of times he will not get all four wheels to sit on the floor. So at inspection the inspector would note that all four wheels had to touch and in an attempt to get them to touch a dad would break a bit of wood from the axle slot such that axle could no longer be held into the slot - off to the workshop - superglue - etc, etc. Meanwhile, I knew we could build a car that would have all four on the floor at inspection, but at speed would lift on wheel. So was this rule leveling the playing field - certainly not. I used this information to affect a change in our rules.

I also really disliked graphite - due to the mess at home, the mess on the cars, and the mess on the track. And I knew oil is much easier to use and is much faster. Again, I sat down with leaders and used this information to change our rules.

anyway - I understand how had to is to change established rules - but seeing many cars get broke during inspection due to the 4-on-the-floor rule gave me the motivation try - and eventually succeed.



Speedster
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Re: Pinewood Derby Rules

Post by Speedster » Wed Oct 24, 2012 5:11 am

"but at speed would lift one wheel"
Is this something you are able to achieve intentionally?



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Re: Pinewood Derby Rules

Post by *5 J's* » Wed Oct 24, 2012 6:00 am

Speedster wrote:"but at speed would lift one wheel"
Is this something you are able to achieve intentionally?
yes.



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