Pinewood Derby today!


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We'll be racing in our 3rd pinewood derby today. Three years ago my sons car came in second. Last year we didn't do so well. This year he wanted the Batmobile. It was the most difficult car we have made, but I think it turned out pretty good for a dad that only has a jigsaw and sander to work with.

Last year his year older sister went to the race and was updet because she couldn't make a car with dad and race. Well this year we made her a crocodile car and I'm going to make sure she at least gets to run it down the track.

Pictures and racing updates later!

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Wow! I can't believe we did so well this year. My sons car was the fastest of the 35 cars there! I honestly have no idea what we did but I'll take it all day long! It even beat the thin little waffer cars that look like heck, but run the fastest . It must have been the weights in the back of the car. Look hard the "thrusters" are painted lead fishing weights I bought at Wal-Mart. I was going for looks, but I believe they accidentally turned into secret speed weapons!

Here is a picture of my two kids and their cars. Mackenzie was glad to have a "Crocodile car" this year and she got to enter the sibling race. Unfortunately her car didn't run very fast.

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Here is the competition:

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Here is my son receiving his trophy:

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Here is the "Batmobile" and the trophy

picture.php?albumid=440&pictureid=3366

All in all a great day at the races!

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Congratulations on the race.

You know the old joke about how the Boy Scout makes his first car, right? When he's 35 and has a son in the Scouts! :D

PWD is a great tradition where Dad throws son out of the workshop because he's messing with the table saw instead of working. Dad wants the car sanded so it will look the best and the kid wants to paint it no matter how bad it looks.

The keys to winning are these:

1) Alignment. Before touching the car, we made sure the car was square (most aren't). We square it up with the table saw. This makes sure the wheel rides on top of the axle and doesn't press against the car's side or the nail head. Once the car is cut and sanded, it becomes imperfect and impossible to square.

2) Weight. We drilled holes alternating (left side and right) near the bottom of the car. We then alternated round tungsten weight so that the car's balance is about an inch and a quarter in front of the back wheels. We puttied over and painted all but the very front hole in the car and we used lead fishing weights in it and just plugged it with a pencil eraser. At the official weigh in we could take the eraser out and add/remover tiny fishing weights to get it exactly to the weight allowed.

3) Axle preparation. We put the axles in a drill press and then used sandpapers alternating all the way to 800 wet sand. There are often burrs on the axles that hurt time. This gets the axles very very smooth.

4) Wheel preparation (depends on your rules). On the inside wheel hub where it touches the car, we coned that part so the least material touching the car. Also on the outside of the wheel you will see a die line on the hub where the nail head will sit. Sand that off, it provides uneven friction. We also took a pipe cleaner and put powered graphite on it and ran it through the inside of the wheel to reduce friction.

5) Paint. The very thing that probably added the most time to our car was to put a small round sticker over the area where the axles will be inserted into the car during the paint job. The reason being that most Testors or spray paint are sticky even when dry. So each revolution that the wheel makes against that paint just slows the car and can even cause alignment problems. Once the car is painted we took an exacto knife and cut around the edges of the sticker to free it without pulling off paint. Pull off the sticker and then rub the unpainted areas with powdered graphite several times to make them smooth as a baby's butt.

6) Graphite. Once the wheels are on and the car is done we squirted a few puffs of powdered graphite on the inside of each wheel where the axles go in. Once you put this in you need to roll the car on a flat surface maybe 5-10 times (say across a table). The first few times the wheels turn, time actually decreases but soon the excess falls out and then gets to where it is doing its job. This will last for the entire derby.

That's it. All legal according to the rules and some kids go for looks and don't care about speed. Others go for speed and don't care about looks. It's a good exercise in both engineering and perserverance...it takes some time to do all of this.

The fastest car one year was a car that wasn't touched. They ran the PWD blank and just made sure the weight was perfect and the axles/wheels prepped. It was funny.

New

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I won lots of trophies as a kid when I did it. Great idea for time with the dad! We cut sheet tin and hot glued them on for cool hub caps. It held a supply of graphite in the wheels. We bought black widow graphics for mine too. It got retired and then my brother used it and won too. His trophy was bigger and he did't even do anything! lol

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Newarcher, I did a few of those things. I sanded the axels a little because there were burrs on them. I didn't square it (don't quite get what is required to do that). When I placed the wheels on the first time one wheel was way off the ground. I lowered the axel and had to glue it to keep it in place so all the wheels were touching at the same time. I then added the weights to make sure it was just under the max weight. Not sure how it got so fast because I'm sure some dads did all that stuff you mentioned. I really just lucked out. You are right, no way could a 7-10 year old cut that block of wood. He picked the design, I used the power tools. He drilled a couple holes and used the power sander once so he could say (I helped with the power tools). He painted and applied the polyurithane. I attached the wheels and glued them in place. Next year will be our last race as my son will be a Weebelos. Makes me sad thinking about it.:(

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I won lots of trophies as a kid when I did it. Great idea for time with the dad! We cut sheet tin and hot glued them on for cool hub caps. It held a supply of graphite in the wheels. We bought black widow graphics for mine too. It got retired and then my brother used it and won too. His trophy was bigger and he did't even do anything! lol

That's a great idea, but I don't think they would allow your hubcap method today. I almost got disqualified for gluing the axels in place! I was told if we race at district I would have to remove the glue. If I remove the glue one wheel will fall off! LOL

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It's funny that you bring this up! I just finished two cars for my kids last weekend. They race them for Sunday school once a year apparently. The race is this Sunday...I'll try and get a few pics of our creations. It's way more work than I remember as a kid.LOL

Great tips New! I'll definately give them a try.

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That's a great idea, but I don't think they would allow your hubcap method today. I almost got disqualified for gluing the axels in place! I was told if we race at district I would have to remove the glue. If I remove the glue one wheel will fall off! LOL

Yea that's silly. Mine was more of a wedge and then we used lead pin weights to get it up to the weight limit. My car intentionally had only three wheels touching and one front wheel just barely off the surface. I think it was maybe to cut down on friction. I'm not sure. Also we sanded the wheels with very fine grit sand paper to get rid of any imperfections that made it less round. I remember the kit wheels I used had a single rib running down the center of the wheel. The wheel that was just off the surface had this sanded away. Setting the axles was the hardest part. My dad did that back then. We never sanded them though. It'd think it would create more friction with the plastic wheels.

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