Weigh your wood!

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BlackLotus
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Weigh your wood!

Post by BlackLotus » Wed Jan 16, 2008 10:55 am

Before you put blade (or potato peeler) to the wood, stick it on a good scale.

I bought two kits from the same store (sitting right next to each other). They look identical but one set of wood felt a little heavier. I put each half on a scale and found the first box to contain pieces that weighed in at 14.68g and 14.25g. The next box contained pieces that weighed in at 8.11g and 8.69g. I was so surprised by the large difference that I weighed each piece again just to verify.

Guess which pieces we are going to use. I may buy a couple more kits just to see if one weight is a fluke or if they really vary this much in density.



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Pinewood Daddy
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Re: Weigh your wood!

Post by Pinewood Daddy » Wed Jan 16, 2008 11:06 am

I think you were off a decimal point in your numbers.

I've seen blocks from 80g to 160g. The lightest ones are more like balsa wood and have less structural strength. We use blocks weighing 100g to 110g.

Look for straight grain also. If your drill axle holes, funky grain will push the drill off line. Vertical grain is best, drilling straight through the growth rings.



BlackLotus
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Re: Weigh your wood!

Post by BlackLotus » Wed Jan 16, 2008 11:26 am

Pinewood,

I stand by my numbers and I am curious as to why I would want to drill axle holes in a space derby rocket :shock: . I am also really hoping it is balsa wood. That works better for the space derby. :P

I should have titled my post better to ensure everyone realized I was talking about the space derby. This section of the site does not seem to get much traffic.



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Pinewood Daddy
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Re: Weigh your wood!

Post by Pinewood Daddy » Wed Jan 16, 2008 11:53 am

DUH!!! I didn't notice the forum your post was in! I use the Statistics link to show all new posts. Sorry.



Jthompson
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Re: Weigh your wood!

Post by Jthompson » Sun Feb 10, 2008 10:08 pm

I measured 12 blocks of balsa from various kits and found vast differences ranging from 7.5 g to 21.3 g. The average was 12.8 g and the standard deviation was 4.3 g. Lighter is better.


John Thompson
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BlackLotus
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Re: Weigh your wood!

Post by BlackLotus » Mon Feb 11, 2008 9:25 pm

The lightest we found, after five kits, turned out to be the very first kit I picked up at 8.11g and 8.69g. The heaviest kit is 19.18g and 19.25g. HUGE difference building between these two kits.



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