Here is a picture of the 'lab' and the sophisticated test equipment. A foam block with cm internals marked on it. The board clamped across the middle with a plank of wood and the bag weighing scales used to lift the tip of the board.
The scales are marked in kg but to get Newtons you just multiply by 9.8.
|Testing the point load flex in the carefully controlled test environment in our car port!|
|Testing a 132x41cm full carbon Crazy Fly Raptor|
Here's the rest results for my first board and the predicted values. Drum roll please.........
Not too bad I have to say. I think the 20kg prediction /measured gap may be a confluence of experimental errors but at least the figure is in the ball park and if its within 10% then I think that is great given that there would be a large number of in situ effects that aren't taken into account in the model.
Most importantly the model can be used to determine the relative affects of different parameters and now I have a benchmark from my first board to have a real sense of what that stiffness feels like.
|Centre and tip flex profiles (blue and pink respectively)|
A valuable addition to Board Off will be some more granularity around the laminate properties given that there is so many permutations and combinations of lay-ups that possible.