Dismiss Notice
Welcome to
Pinewood Derby Online, a forum for questions and discussions about everyone's favorite gravity powered racers!
CLICK HERE to register as a member today for full access to the forum, it's fast, simple, and absolutely free!

Why is rail running faster?

Discussion in 'General Pinewood Derby Discussion' started by oxford, Mar 23, 2015.

  1. bracketracer

    bracketracer PWD Royalty Pro Racer

    Messages:
    1,768
    Likes Received:
    151
    Trophy Points:
    63
    Gender:
    Male
    Location:
    STL
    Wow! Straight for the kneecaps eh Scott?

    I wonder how many newbs are sniffing their wheels tonight, trying to detect the slight odor.......
     
  2. BlewBYu

    BlewBYu Council Champion

    Messages:
    224
    Likes Received:
    1
    Trophy Points:
    16
    I am a newbie as well as a high school teacher. The result: I have a keen sense of sarcasm! Fortunately for me, no sniffing of wheels!
     
  3. oxford

    oxford Pinewood Ninja

    Messages:
    47
    Likes Received:
    0
    Trophy Points:
    6
    i always thought it was the phase inhibitor effect
     
  4. Fumbles

    Fumbles Workshop Leader

    Messages:
    168
    Likes Received:
    0
    Trophy Points:
    16
    This would explain why my car smokes while going down the track. I used to think it was because it was going fast but now I know it due to the campfire inside my DFW bore.
     
  5. letmrun

    letmrun Pack Champion

    Messages:
    18
    Likes Received:
    0
    Trophy Points:
    1
    While I am new here, and responding late, something smells a little off in DD4H's explanation. By just looking at the wheels and without a molecular analysis, the wheels look to be made of polypropylene. Polypropylene has a fairly high specific heat and would therefore act more like an insulator rather than a conductor of heat. This would allow for a slower more controlled release of heat from the wheel bore area as opposed to transferring it from the friction at the rail (wrong direction). DD4H is correct in saying there is a thermoduplicotic rxn. It is specifically an exothermic reaction, not an endothermic one, hence the generation of heat. The reaction is started by the initial generation of heat produced from wheel friction. The reaction is accelerated as the volatile solvents in the oil are released into the space surrounding the wheel bore. The volatile solvents most likely involved in the reaction are ethane (a 2 carbon compound), butane (4 carbons), and hexane (6 carbons). They likely combine in some fashion to form the 8 carbon compound octane. For example 2 butanes combine or 1 ethane and 1 hexane combine. This would result in dinuleoplatlet or trinucleoplatlet formation of the compound, not mononucleoplatlet as stated. Octane as most know is used in race cars to slow the rate of chemical combustion. In this case it probably decreases the rate at which the oil breaks down. Extra canting of the wheels is usually beneficial to allow excess octane to bleed off (the detected odor) thereby keeping internal axle pressures from getting to high. Sorry for the long and technical response.
     
  6. Crash Enburn

    Crash Enburn PWD Royalty

    Messages:
    1,228
    Likes Received:
    78
    Trophy Points:
    48
    Gender:
    Male
    Location:
    Albuquerque, NM
    Wait... So "thermoduplicoctic" is an actual thing?

    [​IMG]
     
  7. davet

    davet League Racer

    Messages:
    490
    Likes Received:
    33
    Trophy Points:
    28
    I don't know why it's faster but these guys here have proven it over, probably, hundreds of thousands of runs down the tracks over the years.

    I can't help but wonder, though, what the next, big break-through will be in pinewood derby design. Someone, somewhere is working in a dimly lit basement on a homemade track with a stopwatch after the kids have gone to bed with refining a flexible body, vibration dampening concepts, nano lubes, slippery paint, air propulsion of some type, or using a very exact airplane-wing profile to get slight lift to lessen the weight on the wheel/axle combo and the wheel/track combo.

    Whatever it is, I'm sure it will show up here after it's been proven in a race. [​IMG]
     
  8. down4derby

    down4derby League Racer Pro Racer National Champion

    Messages:
    420
    Likes Received:
    8
    Trophy Points:
    18

Share This Page