Pinewood Derby 2025

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  • leehljp
    The Full Monte
    • Dec 2002
    • 8552
    • Tunica, MS
    • BT3000/3100

    #16
    Are you able to look at other people cars and inspect them - to see if there are clues as to the difference in speed?

    Are you allowed to add ceramic or other wax coatings to the axle? or graphite or similar?

    You got my curiosity up.
    Hank Lee

    Experience is what you get when you don't get what you wanted!

    Comment

    • LCHIEN
      Super Moderator
      • Dec 2002
      • 21459
      • Katy, TX, USA.
      • BT3000 vintage 1999

      #17
      Here were the "family" entries, you could view them:


      But they were more or less sequestered after checkin (weighing and checking dimensions) which makes sense so that they can't be altered or tampered with.
      So no, I didn't handle or inspect the other cars.
      There are rules but except for the weight and dimensions, I don't think they were strictly checked.
      Specifically, concerning wheels and axles, you are supposed to use the provided wheels and nails from the BSA kits. With no modifications other than mild sanding smoothing and polishing.
      no bearings. Only dry lube like graphite.
      a lot of people sneak in prepolished grooved axles but as I noted of three I tried, all three looked much worse than the ones I polished in years before. A speed trick is to lathe the official wheels taking off material on the inside leaving the outside unattended but losing half the rotating mass. Expensive to buy. I haven't tried that. Then there's magical lubes, I haven't tried. So someone is beating my legal cars i don't know what they are using.
      Last edited by LCHIEN; 01-28-2025, 06:38 PM.
      Loring in Katy, TX USA
      If your only tool is a hammer, you tend to treat all problems as if they were nails.
      BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questions

      Comment

      • leehljp
        The Full Monte
        • Dec 2002
        • 8552
        • Tunica, MS
        • BT3000/3100

        #18
        about 4 or 5 years ago, I was looking for a good "protectant" polish (polish isn't the right word) for our cars to help keep bugs off. I ran into a compound that was developed by a military supply company for aircraft to do similar. it was expensive (about $40 for 16 oz. I think). I ordered it and used it about twice and then it came up missing. It did super and it was super slick. The closest I can find now is "graphene" spray in Amazon: https://www.amazon.com/s?k=graphene+coating&crid=3CJS0Y5NB7SWB&sprefix=gr aphene+%2Caps%2C137&ref=nb_sb_ss_ts-doa-p_2_9

        I was curious if that or something similar could be applied to the axle and inside the hub of the wheels. Are the inside the wheel hub burnished? BTW, I remember what you said about your wife preventing a build up of new tools after retirement, but a lathe with the right accessories sure is handy in many situations. I use my wood lathe for drilling often and on rare occasions tapping a precision hole. that lathe is good for burnishing and of course removing the extra weight inside the wheels.
        Last edited by leehljp; 01-29-2025, 07:54 AM.
        Hank Lee

        Experience is what you get when you don't get what you wanted!

        Comment

        • LCHIEN
          Super Moderator
          • Dec 2002
          • 21459
          • Katy, TX, USA.
          • BT3000 vintage 1999

          #19


          I chuck up the nails in an old 1960's K-mart drill with a variable speed Variac I have mounted (usually used for winding fishing line onto my numerous fishing reels) and we polish the nails with varying (usually 400, 600 and two higher grits we used to use for polishing the ends of fiber optic connectors).
          I also take a triangular file to the underside of the nail head. There will be various burrs and flashing and I try and make it a bit conical to reduce the friction area in contact with the wheel hub.
          For all purposes this is the same as a small lathe.

          I also have a wheel mandrel for mounting the wheels in the chuck. Typically I try and deburr the wheels but the molds are pretty clean and round so I just run some 400 grit gently over them.


          Where can I get some fine lathing tools for trimming saft plastic at low speeds?
          Loring in Katy, TX USA
          If your only tool is a hammer, you tend to treat all problems as if they were nails.
          BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questions

          Comment

          • leehljp
            The Full Monte
            • Dec 2002
            • 8552
            • Tunica, MS
            • BT3000/3100

            #20
            "Where can I get some fine lathing tools for trimming saft plastic at low speeds?"

            Pen turning chisels would be best in my opinion - or at least would be the tools of my choice. Pen turning chisels are mostly just short lathe chisels but the same basic size handles and short shafts.

            Look at these: https://www.amazon.com/s?k=hand+carving+tools&crid=H1FJNP060VMR&sprefix=H and+Carving+%2Caps%2C161&ref=nb_sb_ss_mvt-t7-ranker_1_13
            I would NOT use these (above) because the different size carving knives do not have enough mass and hand holding material or gripping area.

            Pen Turning chisels (shorter than normal bowl turning chisels) still have enough mass and enough hand hold material that the trimming at slow speed will not jerk it out of your hand.
            https://www.amazon.com/s?k=pen+turning+tools&crid=3EX6Q2Y85KKR6&sprefix=p en+turning+%2Caps%2C209&ref=nb_sb_ss_mvt-t7-ranker_3_12

            I personally am used to HSS chisels and sharpening them to razor sharpness, however carbide insert tools/chisels will do almost as well.
            Last edited by leehljp; 01-31-2025, 05:40 PM.
            Hank Lee

            Experience is what you get when you don't get what you wanted!

            Comment

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