r u magnetically balanced?

[Richard Brekne]

Ok... I can see I should clarify my last.

The thing is that magnets can be applied very easily and in a variety of 
ways to provide a lifting force. But just like assist springs this 
lifting force remains more or less a constant (depending on how you deal 
with the magnet of course).

My system is quite workable, yet I still have the problem of finding a 
really eloquent solution for mounting the key magnets so that they are 
both adjustable and easy to fold out of the way so to adjust capstans. 
This approach tho uses much smaller magnets then the MBA or SMBA does 
and therefore avoids the problems of magnetic fields interfering with 
each other. It also is installed in line with the leverage system 
instead of as an outside force applied to the system. Tho I am unsure 
still as to whether or not there is a real advantage to that.

Velos other invention along these lines is similiar in that it is also 
an inline installation, being comprised of a magnet on the hammershank 
opposing a mate installed on the top of the repetition lever.

The main benifit I can see for my own idea is that you can feasably 
exert far more uplift on the top action without changing the coupleing 
between the hammer whippen and the key. This sets it apart from all the 
other assist schemes.

The flip side of that is that the actions touchweight characteristics 
are largely determined by the mass of the system, and by the physical 
leverages used. Assist mechanisims do not change that. So at this point 
I am leaning towards thinking that any <<adjustability>> is best left at 
very small levels... say 2-3 grams for evening out static balance weight.

If that turns out to be correct, then the adjustable whippens really can 
do the job as well as anything, and are probably the cheapest way of 
going about it.

That only goes for a system where the total affect of the assist 
mechanism is confined to just a few grams lifting weight however.

If you want the assist mechanism to do the statics job that say 15 grams 
of Frontweight does... then you are in another ballpark and I lean 
towards magnets as a better solution then springs.

But then I am not a subscriber to the extreme low key mass school of 
action balancing thought. I believe that pianists mostly prefer actions 
that have fair amounts, tho not extreme by any means, of lead as counter 
balancing to medium heavy hammer weights combined with about a 5.8-6.0 
standard action ratio.

That said... pianists suprise me all the time, and I see at least one 
other action configuration that appears to be acceptable... high ratio, 
medium heavy hammers, no key leads and very strong assist mechanims.

So it depends on what you want to do really. Magnets have a lot of 
potential if their use is explored thorougly enough and if we drop some 
of our prejudices about non traditional solutions.

I could go on.. but this is long winded enough I suppose.. :)

Chers
RicB


Piannaman@aol.com wrote:

> In a message dated 2/29/04 2:22:35 PM Pacific Standard Time, 
> antares@euronet.nl writes:
> 
> 
>> The invention was done by a Mr Velo, a retired Philips engineer.
>> I was once a believer in assist springs and I in fact have a grand
>> piano here at home with assist springs which one can regulate, but I no
>> longer believe in them because they have their problems.
>> The magnets are in fact the ultimate solution.
>> Richard Brekne knows very much about these and was so very friendly to
>> let us all share his gratis knowledge.
>>
>>
>>
>> friendly greetings
>> from
>> André Oorebeek
>>
>> Amsterdam -
> 
> 
> 
> Hi Andre(and Richard),
> 
> Wasn't Richard working primarily with whippen/capstan magnets?  Magnets 
> appear to be the wave of the future in piano action/key systems.   
> 
> Seiler uprights used them on hammer shanks for awhile as a way to 
> accelerate the hammer return(or was it the hammer stroke....:-).  I 
> don't know if they still use that technology.  
> 
> Dave S.
> 
> Dave Stahl