by: Paul Goodwin
I hope to (soon) find the time to write an article descibing how to design and build an iceboat plank.
In the meantime I felt it was a good idea to pass along a plank design spreadsheet that was put together by John Bushey. This spreadsheet calculates the stresses on a plank and estimates the bend properties based on a three-piece plank design (core with top and bottom skins). You enter all the design parameters such as core and skin thickness, wood modulus (stiffness), plank width and length, etc.
The only parameter that can be hard to find is the wood modulus, so a few have been added to the spreadsheet to get you started. This is the only real gray area, and actual wood modulus can vary widely from the published numbers.
To use the spreadsheet, you enter the parameters in blue, and it calculates the numbers in red (deflection and stress). To use the spreadsheet you will need to have Microsoft Excel (or another spreadhseet that can import Excel files).