[CAUT] hammer line

[Alan McCoy]

Mark,

This discussion began with the hammer line being altered for better tone. I
didn't make any adjustment for the weight change. No doubt there is a
noticeable change in weight felt at the key. That'll have to wait for the
next time I'm at the piano.

Alan


> From: Mark Cramer <cramer at brandonu.ca>
> Reply-To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org>
> Date: Tue, 19 Feb 2008 16:57:04 -0600
> To: 'College and University Technicians' <caut at ptg.org>
> Subject: Re: [CAUT] hammer line
> 
> Hi Ric,
> 
> I think what he means, is if you add 3mm (for instance) to the bore of
> hammers at some point along your strike line, the bulk of the hammer's mass
> (the big felt part) is now further from the pivot point.
> 
> This has to affect MOI. As my good friend Stan Kroeker suggests, when you
> move the weight up or down on an old metronome, it certainly seems to have a
> measurable (predictable) effect on the speed.
> 
> The same would be true for curving the line by moving hammers further/closer
> to the center-pin.
> 
> So, while I'm enjoying the exchange of good methods for measuring strike
> weight, sorting, thinning shanks etc., I'm struggling with the concept of
> sorting shanks over .1 gram difference, distributed who-knows-where along
> it's length, but moving a 4-10g hammer in/out by several mm and not
> accounting for it. (!?)
> 
> If I've missed this in the discussion, please (anyone) feel free to "tune me
> in," either on, or off-list.
> 
> I'm in favor of the pursuit, but just need to know that we are aware of and
> dealing with "all" the variables.
> 
> BTW Ric, thanks for the spreadsheet, it's a good working tool!
> 
> Best regards,
> Mark Cramer,
> Brandon University
> 
> 
> 
> -----Original Message-----
> From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of
> Richard Brekne
> Sent: February 15, 2008 3:25 PM
> To: caut at ptg.org
> Subject: [CAUT] hammer line11
> 
> 
> Now this is an interesting concept.  How does altering the bore length
> to match string height variances move the mass farther out on the arc...
> and how does this in turn add up to a more serious problem then the at
> least two biggies I can see it corrects ?
> 
> Cheers
> RicB
> 
> 
>     So, if the strike line you set "by-ear" ends up being a little
>     crooked, and
>     uneven string height is the culprit, why not vary the bore-length?
> 
> 
>     A wise and valued supplier who I turn to for pre-hungs when things get
>     "bizzy," will not do this for me. His claim being that moving mass
>     further
>     in/out on the arc will have more detriment than anything I'm trying to
>     correct.
> 
>      
> 
>