Over the last couple of days, I have been distracted by a potential project. I want to build a 16″ span model – but lighter than I normally do (I want to hit 12 grams w/o rubber as opposed to 20 grams w/o rubber).
I got to thinking about wood selection. If I built with some 7 lb wood (1/16″ square) that would be lighter than I normally do. Good idea – I’ve built Peanuts like this, why not go to Dime/Embryo size with similar wood. Actually, I’ve done it before with my Indoor Dimers and Embryos, so the practice matches the theory.
Then I had another thought – I have some 6 lb 3/32″ wood – maybe that would be near the same weight but (hopefully) a little stronger due to the increased cross-sectional area. Hmmm – yeah, that might work!
I did a similar thought process years ago regarding building lighter for Peanuts (I thought I had it online in my How-To section and was going to link it here, but, it is not there ***), but hadn’t really thought about that relevance on today’s project.
I got out my handy-dandy Excel spreadsheet and did some involved, round-about calculations that cleared my mind – and I realized there was a much simpler method of calculation.
This is a screen capture from my CAD program to illustrate the correction to my wrong-thinking. The image on the left is a square 1/16″x 1/16″ – like you were using 1/16″ square wood. The image on the right is a square 3/32″x3/32″ – like 3/32″ square wood.
Now notice that the small square had 4 units of area in it and the large square has 9 units in it. A piece of 3/32″ square has 2.25 TIMES MORE WOOD than a piece of 1/16″ square. How does that apply to my problem? you can look at it in two ways:
1 – if I used 7 lb 1/16″ square wood to build with, to get a piece of 3/32″ that weighed less, I would need 3 lb wood.
2 – conversely, if I used 6 lb 3/32″ wood, I could build with anything less than 13.5 lb 1/16″ and it would be lighter.
For my project, I don’t want to build out of 13.5 lb wood – I’ll stick with 7 or even 8 lb 1/16″ sticks!
*** – my previous article had to do with building Peanuts out of 1/20″ square rather than 1/16″ square. Using the same density wood would realize a similarly significant weight savings. Of course, finding 1/20″ wood of light density is a challenge.