Scratch Building, Aircraft Design, 3D/CAD If you are starting/building a project from scratch or want to discuss design, CAD or even share 3D design images this is the place. Q&A's.

contest balsa

Reply
Old 12-09-2004, 05:07 PM
  #1
WILDMAN 420
Thread Starter
 
Join Date: Dec 2003
Location: Owen Sound, ON, CANADA
Posts: 128
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default contest balsa

I was wondering if anyone can tell me the weights of contest balsa sheets, ie. 1/6X3X36 inch and so on? MOst places around here won't grade it, and when i ask for it they say, well you can come and sort through it, so i am wondering what it should weigh to be contest grade? i have a digital scale to take with me. I am going to scratch build (sorry, Plans Build for the purists) a 1/3 scale stearman, aI want to keep it as light as possible(don't we all) Thanks for any help.
WILDMAN 420 is offline  
Reply With Quote
Old 12-09-2004, 06:00 PM
  #2
fritzke
 
Join Date: Jan 2002
Location: Crystal, MN
Posts: 1,290
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: contest balsa

Lookie here:
[link=http://skyhooks.ca/basheet.htm#anchor407734]Balsa Sheet Weights, Size by Density Chart[/link]
Dave
PS Contest wood is in the 4-6 LB per cubic foot range. But it MUST still have a "Grain" or it is punky junk.
A 1/16 x 3 x 36 sheet is .0039 cubic feet of balsa!
fritzke is offline  
Reply With Quote
Old 12-09-2004, 06:15 PM
  #3
BMatthews
Moderator
 
BMatthews's Avatar
 
Join Date: Oct 2002
Location: Chilliwack, BC, CANADA
Posts: 12,279
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: contest balsa

Unfortunetly it's hard to judge the stringiness of the grain until you buy the sheet, cut off a small strip and break it. If it breaks clean across with little or no sign of fibrous content then use it for non structural uses like thicker wing ribs or small lightly stressed parts. If it breaks with lots of fibers evident then it's good stuff and can be used for most anything where the weight is suitable. Just a little 1/4 wide by 1 inch long sample is enough. And watch out for this feature changing a lot over the width of a sheet. It can and does frequently happen.
BMatthews is offline  
Reply With Quote
Old 12-09-2004, 09:39 PM
  #4
Mike James
 
Mike James's Avatar
 
Join Date: Jan 2002
Location: Anchorage, AK
Posts: 2,565
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: contest balsa

The weight of any material, including balsa, ply, and foam is .009259 X Density, per cubic inch.


For example, a 4 inch X 36 inch sheet (144 square inches) of 1/16th balsa, (.0625 inches thick) at 6 pound density, is:
(144 X .009259 X 6) X .0625 = .49 ounces

I have some (free) info on my site, if you want to predict other structural weights, at http://homepage.mac.com/mikejames/rc...rediction.html
Mike James is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 08:23 AM.