[pianotech] Carbon Fiber Lever (was Hammer Technique: was Q & ARoundtable)

[Ron Nossaman]

On 2/6/2011 11:37 AM, Kurt Baxter wrote:
> Tom:
>
> Your points about light weight (as of value apart from any stiffness
> attributes) and easily interchangeable heads are valid. Not
> understanding the engineering behind it, I assume the CF tube alone must
> make some significant stiffness gain, and how much is then lost due to
> the threaded joint is clearly a question wanting for data, not opinion,
> mine or anyone else's.

The moment of inertia (calculating stiffness for bending calculations) 
is higher for material volume used in tubing than for solid rod. So for 
a given quantity of material, tubing will be much stiffer than solid 
rod. Steve uses a really big tube, which makes a really stiff lever. So 
he gets a huge stiffness to weight ratio.

I don't have an opinion on the head joint that you'd be interested in.


> And: http://www.tuningpindriver.com/
>
> Isn't there a case for patent infringement here?

I don't know. The patent specifies aluminum tubing, and that's what the 
original release was made of. Carbon fiber came later. How many years of 
profit will it take in legal fees to test it?
Ron N