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Thread: Cub Scout Pinewood derby loss

  1. #101
    Join Date
    May 2003
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    Sorry magic, im not out to score any points with anybody,(I thought you could tell that already ) i just hate it when the laws of physics get twisted and other people actually might believe in them, Go back and read post 79, Evan even highlighted Pn's reply and incorrectly replied to it,,,
    Stuff it Boomer. You need to go back and study your grade school physics.
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  2. #102
    Join Date
    May 2006
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    Evan, Im sorry, I didnt mean to make you upset, (At least not this upset) I was only handleing this with the same kind of tenacity that you do when you know you are right,

    One needs only to look into the archives to find out how many times iv asked you for advice when i dont know the answer and you always have a helpful sugestion, there is also NOBODY on this board who could ramble on like you do about almost anything under the sun and for the most part be right on the money, You are in my opinion the single biggest credit to this board and although You/ like me/ dont cut anybody any slack you also take the time to help people more than anybody else and my intentions were not to get on the bad side of you.....


    so for what its worth, sorry.

  3. #103
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    May 2003
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    Apology accepted. I should not have lost my temper. My fault.
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  4. #104
    Join Date
    Dec 2009
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    Stevens Point, WI
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    Just finished carving out my own car with my son and daughter for our local race coming up. This is our second year. Didn't feel it was warthy of its own thread so I used this one out of the 3 pinewood threads started here because it looks to have the most history.

    I used a die grinder with a burr bit to carve out most of mine and then some sanding. I have it in its base/sealer paint now so I can start painting final colors. I wish I would have added strips of wood to the sides so I could have fenders/covered wheels. I think it might look a bit goofy with wheels sticking out. Just wanted to share.





    Son and daughter, daughter wants/is in the middle of stripes.

    Andy

  5. #105
    Join Date
    May 2016
    Location
    Michigan
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    Nice work,
    How long has this been going in USA?

    I formed the opinion that this is about the most expensive way to go racing.
    Because the only winners are the youngest in a large family!.
    By the time I figured out how to get up anywhere near the winners, the boys were grown out of it!
    https://app.box.com/s/57451a658617b048ea10
    https://app.box.com/s/eb28ed3bec0492a87c8f

  6. #106
    Join Date
    Apr 2014
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    What'd you figure out? I saw one post on a woodworking group that said that friction is everything.

  7. #107
    Join Date
    May 2016
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    Michigan
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    Quote Originally Posted by Puckdropper View Post
    What'd you figure out? I saw one post on a woodworking group that said that friction is everything.
    I forget most of it now.
    See the photo of the track. The wheels run in grooves. there is clearance in the grooves.
    I thought the first item was to constrain the wheels to minimize contact with the outer wall.
    As I recall the most promising runs were when we put slight positive camber and pushed the nails in.
    After that, the finer details can be approached.
    I think the winners' fathers had time to replicate the track at home and try adjustments but i never got that far.

  8. #108
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    Dec 2009
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    Stevens Point, WI
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    Yes it seems to be mostly about the friction loss. Camber wheels, polished axles, polished wheel hubs, alignment, and graphite. Last year I just raced the block of wood how it came out of the box and just stuck my time into the axles and wheels. I only lost to the pack leader. My son watched me build mine and used my tricks on his own, he took home 3rd over all. This year I figured I better carve mine so the other grown ups don't feel so bad when they lose.



    Andy

  9. #109
    Join Date
    Dec 2008
    Location
    Kendal, On
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    That's awesome. I can't wait to get into this stuff with my kids.

    And to wombat who said this is the most expensive way to go racing.....ha ha. Wait until they actually GO racing . I used to think motorcycle racing was expensive. After talking to a bunch of car guys (both drag and road courses), Now I think it's about the cheapest way to go actually (and most fun).

    Nice looking car Andy.

  10. #110
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    Mar 2005
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    Toronto
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    I remember reducing friction was the big part of it, that and maximizing the weight. I made a balance and weights calculated based on density and dimensions, parental overkill perhaps but getting to 4.99999 oz seemed the key and it worked out well. Now that cub is in Vet school lol

    rekindling thoughts on the subject, the idea of a moveable weight would be (I think) a big win. Where a stationary weight is, front back etc, matters not. Its potential energy is how much vertical fall it has. But what about a ball bearing at the end of the car that on movement would be triggered to roll forward to the front....that would increase the vertical for that portion of the weight. Build the lightest car possible with all the weight a ball bearing that moves from back to front
    Last edited by Mcgyver; 02-09-2017 at 11:46 AM.
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