LEAD...and TUNGSTEN!

CAUTION: Although lead is not easily absorbed through the skin it is still a toxic material and handling precautions should be noted. Always wash your hands after use. Clean up afterwards and never use around food or place on surfaces where food is prepared. "And, keep your fingers out of your mouth". That said...

Lets begin by clearing up what I'm sure is just a typo by some of my esteemed colleagues in the derby industry. Tungsten is not heavier than Lead and Lead is not heavier than Zinc. Even a pound of Feathers weigh the same as a pound of Lead. The difference is DENSITY and VOLUME. More accurately stated - The greater the density of a material, the less volume is required to obtain the same weight.

1 ounce of Tungsten displaces 1.47 cc (19.3 g/cc)
1 ounce of Lead displaces 2.50 cc (11.35 g/cc)

Now, lets get back to business..

Lead has about twice the density of the lead substitute (zinc) sold by others as weights for pinewood derby cars.

Even better...TUNGSTEN (W) has greater density than lead. This is not only a non-toxic alternative to lead, but it's also 1.7 times more dense. That means you can cram more weight into a smaller area.

Using weighting material with greater density let you pack you mass into a smaller volume giving you more room for creativity in body styling and shaping. Concentrating your Center of Mass (CM) over a smaller area has definite advantages in how you distribute your weight to make the best use of your potential energy.

Check out my NEW WinDerby Lead Free Tungsten Putty.

The perfect way to make those last minute tweaks and CM adjustments.

OPTIMIZE YOUR CM - The farther back you can move the Center of Mass (CM), or balance point, the faster your car will go. Each 1cm (.394") that you can move the CM from the center towards the rear will reduce your time by about .0014 seconds. To put this into perspective, this equates to approximately .6cm (.236") at the finish line!. THAT'S HUGE IN A CLOSE RACE! But use this knowledge with caution. If your CM is too far back, your front end will wobble and bounce SERVERELY SLOWING YOUR CAR! Experiment and find the optimum CM for your car design.

Arm Yourself with Knowledge - The Physics of pinewood derby

Let's keep all this weight stuff in perspective. Kinetic energy is 1/2 Mv2, so the car with more mass M must also have a slower velocity v for energy to stay constant. A fraction of a gram doesn't make a huge difference at the finish line but one gram can easily mean the difference between winning and losing because of the high accuracy of race timing devices. If you do the math, 1 gram (0.03 oz) can still makes about 1/8" difference at the finish line and some race timers measure 10 times closer than this. So, if you are really sloppy with your weight management and go in with a 4 oz car, you can be behind over ½ car length or 4" at the finish line.

So, what is the actual importance of optimizing weight?

a) It is about the same importance as friction control (lubrication)
b) It is about the same importance as air drag control (streamlining)
c) The person inspecting your car (weighing) thinks it is a lot more important (like Aristotle-Lecture 1) and he is the judge.
d) Its a lot easier to get maximum weight, compared to optimizing a) or b).

Keep in mind - the weight of your car is just 1 more piece of a puzzle that has many interdependent pieces.



Domain Reseller

gEvery object with mass that can be affected by gravity has Potential Energy PEg = mgh. If your derby car is in a position to be affected by gravity (resting at the start pin), it has gravitational potential energy. Once the car is in motion it has velocity and the Potential Energy is converted to Kinetic Energy KE = (1/2)mv2, which is the energy of motion. There is a direct relation between gravitational potential energy and the height of an object; the higher that an object raised above the the ground, the greater the gravitational potential energy.


LEAD

CUT LEAD WIRE (aprox. 3.7oz)

This is the same lead wire as shown above. We've cut it into 3 sections so that it fits nicely into our pre-drilled bodies.

CAUTION: Although lead is not easily absorbed through the skin it is still a toxic material and handling precautions should be noted. Always wash your hands after use. Clean up afterwards and never use around food or place on surfaces where food is prepared. "And, keep your finger out of your mouth". Click here to view MSDS

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Item #H19q

 

 

 


$2.00


LEAD WIRE (aprox. 4 oz)

Here is the easy way to add the main weight to your Pinewood racer! 3/8" lead wire, about 5.75" long and approximately 4 oz. in weight. More than enough for one car. Cut with wire snips or a hack saw, drill a hole and insert. Easy. Fill the opening with wood putty. This is an industrial product, not available in retail stores. Looks like a worm!

CAUTION: Although lead is not easily absorbed through the skin it is still a toxic material and handling precautions should be noted. Always wash your hands after use. Clean up afterwards and never use around food or place on surfaces where food is prepared. "And, keep your finger out of your mouth". Click here to view MSDS

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Item #H16
s

"New Size!"

NEW LOWER PRICE

$1.75


Tungsten & Wutty


h

10mm x 5mm

Lets do the math -
Pure Tungsten is 19.3 gm/cc
Volume of a cylinder = ¶r2h
3.14 x .5cm2 x .5cm = .392 cc
19.3 x.392 = 7.565 g

My tungsten is 99.99% Pure

Any variations in weight are due to cut length and diameter. NOT density.


GET THE LEAD OUT with
WinDerby TUNGSTEN ROD SEGMENTS - (the kit inclides 4 Tungsten segments for a total just over 1oz)

Tungsten is one of the most dense elements at 19.3g/cc. In it's pure form Tungsten is similar in density to Gold(Au). It is only surpassed in density by Rhenium(Re), Osmium(Os), Iridium(Ir), Platinum(Pt) and Neptunium(Np). This makes Tungsten perfect for high density weighting.

Tungsten is also non-toxic which make it a great alternative to lead when handling is an issue.

NEW SMALLER SIZE

I've made my tungsten available in small, easy to handle segments that weigh in at approximately 7.56g each (or about 4 pieces to an ounce). The obvious benefit is the ability to cram more mass into a smaller area. This has measurable benefits in both aerodynamics and on the placement of your CM for controlling how effectively you utilize your stored potential energy. My Tungsten segments are approximately 10mm(.394") in diameter by approximately 5mm (.197") in length. They will fit nicely in a "Y" Drill hole (.404").

IMPORTANT: Although Tungsten is non-toxic, it is NOT a toy for small children to play with. Always wash hands after use, keep away from food and your mouth. Click here to view MSDS

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Make it Thinner. Be a Winner

Item #H73

$5.95

Interesting side note - The origin of the symbol W is "wolfram", named after the tungsten mineral wolframite. A man named Peter Woulfe determined that tungsten was a new substance, but the element's name doesn't derive from his name. Rather, it comes from the Swedish wolf rahm or spumi lupi, which refers to the way the ore wolframite appears to devour tin during the smelting process. The de Elhuyar brothers (Fousto, left, and Juan Jose, right) found an acid in wolframite in 1783 that they subsequently reduced to the elemental metal with charcoal. - It's kind of cool where these things come from.



A 1oz ball of Wutty™ has about the same diameter as a penny!

The diameter of a penny is about 1.9cm. So, to find the density per cc we will caluculate the volume of the sphere -

V =(4/3)¶r3
V=1.33 x 3.14 x 0.857375
V=3.58cc

then divide the weight of the ball in grams (1 oz = 28.35g) by the volume (3.58cc) which equates to a density of -

28.35g/3.58cc or 7.9g/cc

you can also get the volume by measuring cc of displacement in water using a graduated cylinder.

A WinDerby Original
New Formula 2.0 Higher Density

TUNGSTEN PUTTY - (1 oz)
While solid tungsten is great for high density weighting it is not very practical for fine tuning and last minute tweaks. It's very difficult to shape or cut and you can pretty much forget about melting it down. It's melting point is 3410°C(6170°F).

That's where Wutty™ comes in.

It took awhile to get it right, but I think it was well worth it. My wife is just glad I'm out of the kitchen!This is the easy and safe way to add or subtract very small amounts of weight to your car. Wutty™ is my unique blend of Tungsten (W) and binder resulting in a Soft, Non-Hardening, Lead Free, Non-Toxic, putty-like material. Even after blending with my binder, Wutty™ is dense enough to easily make both fine and coarse weight adjustments with ease. You can even tweak you Center of Mass (CM) to optimize your performance based on varying track conditions. Simply pinch off small amounts, knead it with your fingers until sticky and add to your car. It can even be glued in place if necessary. TOP

 

Item #H74

$5.95

b ya weighting for..

NOTE: Wutty™ was created as a non-toxic, pliable alternative to lead putty. Turning pure tungsten into a putty involves the introduction of a binder which is, of course, less dense than pure tungsten. The density can be expected to be approximately 7.9g/cc.

IMPORTANT: Although my Wutty™ is made from non-toxic ingredients, it is NOT a toy for small children to play with. Always wash hands after use, keep away from food and your mouth. Click here to view MSDS


z

NEW

WinDerby TUNGSTEN WEIGHT KIT - (aprox. 4+ oz)

The TUNGSTEN WEIGHT KIT contains:

  • Approximately 3+ oz (12 pcs) of my Tungsten Segments
  • 1 oz of Tungsten Putty

Approximate total weight is 4 oz (-0% /+3%)

IMPORTANT: Although Tungsten(W) is non-toxic , it is NOT a toy for small children to play with. Always wash hands after use, keep away from food and your mouth. Click here to view MSDS

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The Weigh to Go...


Item #H75

$19.95



January 13, 2014


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