Bob McDonald balsa wood weight chart

[Airacobra]

I was told by some that there is a balsa wood weight chart available. I was told this was completed by Bob McDonald. Does anybody have the chart that they would be willing to post on here. Thanks, Keith

[George Truett]

These?

[Airacobra]

Thank You George, but what I am looking for is the weight of a sheet of balsa 1/8" X 3" x 36" for exapmle should weigh and how that calculates out to 4Lb wood or what. Maybe it was in Stunt News at one time and I have to search those.

[Airacobra]

You got it George, my fault for not looking deeper into the response. THANK YOU!

[pmackenzie]

There is a chart here. But when using any chart be sure to correct for variations in width, thickness and length! Not all wood is the size that the label says.

http://www.go-cl.se/balsa.html

[BYU]

I was told by some that there is a balsa wood weight chart available. I was told this was completed by Bob McDonald. Does anybody have the chart that they would be willing to post on here. Thanks, Keith

You might want to try out this handy tool as well

http://nclra.org/Programs/BalsaDensity.php

1/8 x 4 x 36 =19 grams for 4 lb stock

More easily obtainable in my experience is 24 gram which is 5lb density

[Fredvon4]

very top of any page on this site in  the middle....click n play with that calculator

[Brett Buck]

Multiply the thicknessxwidthxlength, divide by 1728 (gets the volume in cubic feet)
weigh it in ounces, divide by 16 to get it in lbs. If you measure grams, divide by 453 (grams in a pound)

Density is the mass divided by the volume

     You can use this to make your own charts, it that is what you want.

    The biggest issue was noted above - the actual size is not necessarily what is marked. Most of the "1/16" I have gotten in recent years is much thicker than that, , averaging around .070" vice .0625". You might think, who cares, that's only .0075". But, it's also 12%, and if you use the marked thickness from a chart, it's off by 12% (and looks heavier).

   About 10 years ago, everyone was complaining about their "Contest Balsa" coming out around 6.5-7 lbs/cu ft. Using the marked dimensions, I got something very similar. However, I also found it was averaging 0.072", which means it was well in specification.

    I would also note that .079 = 2mm. So, given that it is usually cut in foreign countries, they may be shorting people on 2 mm balsa, instead of giving us a bonus on 1/16".

     Brett

[Sean McEntee]

Multiply the thicknessxwidthxlength, divide by 1728 (gets the volume in cubic feet)
weigh it in ounces, divide by 16 to get it in lbs. If you measure grams, divide by 453 (grams in a pound)

Density is the mass divided by the volume

     You can use this to make your own charts, it that is what you want.

    The biggest issue was noted above - the actual size is not necessarily what is marked. Most of the "1/16" I have gotten in recent years is much thicker than that, , averaging around .070" vice .0625". You might think, who cares, that's only .0075". But, it's also 12%, and if you use the marked thickness from a chart, it's off by 12% (and looks heavier).

   About 10 years ago, everyone was complaining about their "Contest Balsa" coming out around 6.5-7 lbs/cu ft. Using the marked dimensions, I got something very similar. However, I also found it was averaging 0.072", which means it was well in specification.

    I would also note that .079 = 2mm. So, given that it is usually cut in foreign countries, they may be shorting people on 2 mm balsa, instead of giving us a bonus on 1/16".

     Brett

     Sage advise!

     I keep a small scale in my car (I always get some sideways looks when my car is randomly searched when going on post  ) and have the NCLRA density calculator saved on my phone.  About once a month, I make the rounds to all of the Hobby Lobbys and Michaels' in town, and sift through their balsa shelves.  I've got to the point that I can pick out contest grade wood by feel with about 80% accuracy, and then weigh it to make sure.  For some strange reason, Hobby Lobby's 1/4"x3x36 sheets are often with in the 4-7 lb/sq. in. range. 

     Like someone else mentioned, make a small "cheat sheet" of min and max weights for each cut, from 1/16 to maybe 1/4, in 3 and 4 inch widths and keep it in your car or wallet or something.  Like the old man said, "good wood is where you can get it", so its worth it to sort through places that carry balsa.  It can be a bit time consuming, but a couple sheets here, a block or two there, and one can get a good stockpile pretty quickly.

[Abi]

These?

Thank you for posting these! These files were created by Steve Yampolski who used actual volume/density calculations in the original. My copy didn't have the formulas. Yours has the formulas preserved!