Bronco pinewood derby.

[behemoth]

I am a committee member of the local packs pinewood derby committee. The parents are running a race themselves. So I am looking at the idea of a bronco car.

We found some leftover low melt point metal, boil it and it becomes a liquid to use for weight in the kids cars. The problem is we do not know what or were it came from or where to get more. Has anyone heard of this stuff it does not appear to be lead. The local OSHA parents want to know what it is before we expose the kids to it.

Last year I just melted tire weights but that is not good enough to toxic for them.

I was thinking the matchbox bronco was almost the correct scale for the wheels

 

[ransil]

Use lead just don't eat it.

 

[A4x4Junky]

I have no clue how much it costs or if it will do what you are asking, but I found this on an internet search.

http://en.wikipedia.org/wiki/Cerrobend

Anthony

 

[Clint]

Use lead just don't eat it.

X2. dont see what the problem would be with this at all. I used it for derby cars for a long time and nobody ever had a problem with it.

 

[SACHEM]

My dad carved out a hole in the bottom then filled it with a screw and washers. Also you have to use the wheels that came in the kit to be legal.

 

[chriscobbs]

Here are a couple Broncos....

http://www.earlybroncotoys.com/pinewood.html

 

[Bitch'nBronco]

you can get that stuff at the scout shop. My dad used shot (shot gun shot) and 5 min epoxy. He mixed the epoxy and then mixed the shot in with it. Worked great. Oh, and we hollowed out the cars first. Weight in the front above the axles worked best, and file down the burrs on the wheels. And if you look just below the nail heads they supply, they have burrs too. So file 'em down. Give 'em a nice coat of graphite and you should be good to go.

 

[behemoth]

weight to rear of car was found to be .45 seconds faster than weigh in the front to middle of the car. Very low profile and wheel base extended to the max. We have also milled new axle holes into the bodys at 5*-9* of caster. We have found that 6* seems to be optimal, with simmilar performance from 9*.

Axles trued, wheels trued, graphite baked onto axles. graphite wells in the body so that the wheel hub does not rub on paint.

There was an attempt at silly puddy in the nose to launch the car. It sticks to the start bar and when the start bar snapps down the car is pulled forward.

This is now illegal but it was successful.

There is one parent that is working within the limits of the rules. the top six cars were built at a clinic last year and were all within. .0015 sec of each other.

 

[br0nc0xrapt0r]

if you are concerned about lead poisoning just coat the lead with silicone or something.

 

[behemoth]

I was only set out to find the stuff as one of the committe members. Thank you all for the help, we think we have found what we were looking for. It still contains lead, but low enough an since we are not going to eat off of the cars it should not be a problem for the parents.

The car clinic results were given to me last year so I really can not say what is best. My sons car has the 6* castor and will run most of the weight in the rear. I am told this acts like a skateboarder pumping at the bottom of the half pipe. who knows.


I am also using straight wheel lead in his car. We shall see what the results are mid march.

thanks again.

 

[Fishbone]

My sons car has the 6* castor and will run most of the weight in the rear. I am told this acts like a skateboarder pumping at the bottom of the half pipe. who knows.


I am also using straight wheel lead in his car. We shall see what the results are mid march.

thanks again.

Since these run on gravity, the theory is the farther back the weight is the longer it stays on the slope, therefore you will have gravity working for you longer. Depending on your rules, you can also create a void on the inside of your wheel hub (Dremel with small burring bit works good). It will help hold more graphite, and reduce the surface area, reducing drag. I used to put a slight bevel in the outside of the hub too, where it contact the nail, same reason as above. I also used to hold one of the front wheels up about 10-20 thousands, so it had almost no weight on it. Making sure it tracks straight is another big thing.


I guess you didn't ask for all that, but these things are fun to make. It's all about the kids anyway, right.%) ;D My son is a Boy Scout now, I kind of miss the Pinewood Derby, in case it wasn't obvious.