GrnEydDvl
10+ year member
Registered User
Me and Saywhat? played this game during the design of my first box. The rods take up very little volume relative to net vol of the box. I know everyone understands and assumes this but lemme show you some real numbers.
Let's assume you have a 35w x 15t x 15l net internal box. So that is 7875 cu inches or ~4.56 cu ft.
If you use two 1.5 inch dowels to support the box (one up and down, one front to back) that will take up (.75^2)x(3.14) x (15) = 26.5 cu inches of space for each. Or 53 cu inches or .03 cu ft for both. For you less than mathematically inclined folks, that is 3 hundredths of a cubic foot to increase the structural integrity of your box considerably.
And this is using 1.5 inch rods, which I think are pretty excessive but I haven't dealt with anything larger than about 4.5 cubic feet net. Bigger boxes may require larger supports but I normally use 1/2 - 3/4 inch dowels. In our example, if we used 3/4 inch rods they would take up 6.6 cubic inches each, or ~13 cubic inches / .0038 cu ft for both. Considerably less volume than 1.5 inch rods but I doubt either will affect tuning noticeably. Maybe someone with a calculator can let us know how it changes tuning.
Another tip is to cross internal rods so they touch each other and bind them together. This further strengthens the support they provide. You can bind them with wood glue or twine or a zip-tie.
Let's assume you have a 35w x 15t x 15l net internal box. So that is 7875 cu inches or ~4.56 cu ft.
If you use two 1.5 inch dowels to support the box (one up and down, one front to back) that will take up (.75^2)x(3.14) x (15) = 26.5 cu inches of space for each. Or 53 cu inches or .03 cu ft for both. For you less than mathematically inclined folks, that is 3 hundredths of a cubic foot to increase the structural integrity of your box considerably.
And this is using 1.5 inch rods, which I think are pretty excessive but I haven't dealt with anything larger than about 4.5 cubic feet net. Bigger boxes may require larger supports but I normally use 1/2 - 3/4 inch dowels. In our example, if we used 3/4 inch rods they would take up 6.6 cubic inches each, or ~13 cubic inches / .0038 cu ft for both. Considerably less volume than 1.5 inch rods but I doubt either will affect tuning noticeably. Maybe someone with a calculator can let us know how it changes tuning.
Another tip is to cross internal rods so they touch each other and bind them together. This further strengthens the support they provide. You can bind them with wood glue or twine or a zip-tie.
