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Can one of you brainiacs explain this to me in Texican terms


jsharrwick
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It's the scale.  We have a lot of scales in our lab.  Some of the poor quality ones will do this.  The difference between the two is likely outside of the scales capability.

 

Try again putting it on on the same exact spot.

I bought that scale for the pack years ago.  It is much better than the one we had.  Do you know if it is a decent scale?  It seems very accurate and very sensitive.  If you lean on the table, the scale will change.

 

I have considered building a cradle for the cars so they sit on they scale the same way each time and then zeroing the scale with the cradle installed.

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Scales aren't cheap.  I'm sure the one you have is fine.

 

I suggest placing the car on the scale the same way each time. 

As I recall that one was hundreds of dollars and very precise.  Also bought the 500g calibration weight for it.  It is just very very sensitive and you are correct that one must put the item to be weighed on the scale the same way each time.

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As I recall that one was hundreds of dollars and very precise.  Also bought the 500g calibration weight for it.  It is just very very sensitive and you are correct that one must put the item to be weighed on the scale the same way each time.

 

Sounds like a pretty good scale balance.  For the calibration weight, did it also come with a glove and is it stored in a box?  You should not touch the weight with your skin, you will increase the weight of the weight over time.

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What did your car weigh in as a block of wood? I just weighed our block and tires to be 4.95oz.. I'm thinking I might need to add a little weight when we are done cutting them today and after the sanding. 

Did not weigh just the block, but that sounds about right.

 

We removed the majority of the wood so that we could add the weight right where we wanted it, which is just in front of the rear axle slot.

 

If you are going to concentrate on one thing, it is filing / polishing the axles, do not forget to polish the back of the axle head, and using lots of graphite in the wheel hubs and on the axle.

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What are we talking about here?  5/1000 of a ounce?  Surely you aren't concerned about a reading difference of 0.005 oz.  In my experience, that much variability would be expected in such an uncontrolled measurement as described here.

It is funny, but the boys all want to be as close to 5 ounces as possible.  And the scale is so accurate that lots of boys and dads spend quite a bit of time adding and subtracting minute amounts of weight.

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What are we talking about here?  5/1000 of a ounce?  Surely you aren't concerned about a reading difference of 0.005 oz.  In my experience, that much variability would be expected in such an uncontrolled measurement as described here.

 

Ya that's like 31/100000 of a pound or 1.41748e-7 of a metric ton.  Who cares?

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Ya that's like 31/100000 of a pound or 1.41748e-7 of a metric ton.  Who cares?

Boys do.  Since it was important to Ryan, we made it happen.  Fun with a purpose.  He learned some new skills and he paid attention to detail, instead of just settling for close enough.  

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We can only do so much.  However, if you would care to provide us with a more accurate balance, we would gladly accept it.

 

WoKzoo has several antique scales I'm sure she'd let you borrow.  I doubt any of them are more accurate that +- 1/2 a pound (at best).

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Boys do.  Since it was important to Ryan, we made it happen.  Fun with a purpose.  He learned some new skills and he paid attention to detail, instead of just settling for close enough.  

 

I won the overall pinewood derby my last year as a cub scout, having taken second overall (to my brother) the prior year.  My first year, I think my misshapen car finished in the lower rankings.

 

I got a big trophy for winning, it was pretty cool.  We had a scale.

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I won the overall pinewood derby my last year as a cub scout, having taken second overall (to my brother) the prior year.  My first year, I think my misshapen car finished in the lower rankings.

 

I got a big trophy for winning, it was pretty cool.  We had a scale.

See, it matters!  You remember this.  We are making memories and hopefully building character at the same time.  

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See, it matters!  You remember this.  We are making memories and hopefully building character at the same time.  

 

The memories are cool, as are the lessons learned.  I learned very basics of car assembly, a bit about sportsmanship, a little about perceived unfair advantages (when I lost), aerodynamics, graphite, weight distribution, and taking a longer view of things (when I won).  It was nice to see cause and effect in play.

 

I did not have under-inflated tires.

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