ORIGINAL: balsaworks
ORIGINAL: Remby
Weigh everything now, never used to. Really helps keep the weight down, no question.
True words.
A good scale is indispensable if you want to grade your balsa, and build stronger, lighter planes. Nowadays there are incredibly cheap and accurate electronic scales that will weigh fractions of grams.
It pays off to play with the balsa bits in your hands, and bend them in various directions to get a feel for the stiffness. It’s easy to compare the stiffness of sticks and sheets of same size by bending in your hands. Sheet stiffness can be measured by holding the sheet on end on a scale and pushing down until the sheet buckles. Once it buckles the reading will be more or less constant and it will give an indication of the stiffness of that sheet.
The density of balsa can vary wildly not just between trees, but also within a block, or a sheet.
A strong lamp is helpful to check for hard and soft streaks in balsa sheets.
The photo below shows a 1/16th sheet with a calculated density of 7 lb/cu.ft. The more translucent areas are probably 5-6 lb, and the darkest streaks on the right side could well be over 12 lb.
It´s entirely possible to take an 8 lb, 1/8” x 4” x 36” sheet , slice up 30 sticks, and get sticks that vary from 6 lb to 12 lb with not a single one at 8 lb.