What speed does Balsa shread at?

[Karl]

Is there a certain speed that balsa fins seem to shread at? I made some adjustments to my ' Mach Buster ' and it hits 631fps and the fins are only laminated with paper... The thickness with the paper is 4.05mm

Karl

 

[SwingWing]

There isn't any one number. It is affected by things like span, thickness, grain direction, sweep and area. Long span, thin fins will shread much sooner (lower speed) than shorter span, thicker fins.

 

[vjp]

What swingwing said! But, provided your grain is oriented properly, the fins are laminated well, and you've glued them on straight with a decent glue and with good fillets, they should be fine. 631 fps is only about .6 mach (430 mph), anyway, and even plain balsa fins are fine at this speed.

 

[teflonrocketry1]

Buy the software and find out:

https://www.aerorocket.com/finsim.html

Bruce S. Levison, NAR #69055