Hammer Boring Question - Mehlin Grand

[Newton Hunt]

Hi David,

> It's not my math, is it?

Well, if it isn't your math then something is wrong.

If the hammers are original check that they may be hung at an angle
different than 90 degrees to the shank.  Mason & Hamlins are all hung
at 89 degrees instead of 90 (strike point moved toward player).

First I would express it this way: String height 8.1875", pin height
6.6875', bore at 1.5".  It is not practical to measure to a ten
thousandth but hundredths are easy and desirable.

> the hammers being replaced measure 1 15/16", almost 1/2" longer

The difference between 1.9375" and 1.5" is 0.5625".  This much
difference is NOT acceptable.  You will not be able to regulate the
action properly and you will be loosing considerable tone because the
hammer is not striking the string at 90 degrees to the molding.  You
will have a severe under striking problem.

When ordering a set of hammers or boring them myself I measure the
heights of the string at each section end and at each end of the
action.  I bore the hammers for each section and once I had a set
bored to reflect a difference of 3/8" from one end to the other of a
bass section.  Angles of bore are measured from the stretcher at each
section end BUT the bass is bored at half the angle of the bass
strings to permit proper passing of the hammers.  

Based upon one section being bored at 1.5" I would add less than
0.050" to the bore distance for filing in the future.  Never more than
that.  If you approach 0.125" you will not be able to get the hammers
off the rest cushions.  Even .030" is sufficient.

I prefer to bore my own hammers so if there is an error it is my error
and not someone else's.

I once bore the middle section hammers at the opposite angle and did
not notice this until I started to hang them.  These hammers were
tapered and shaped.  Fortunately there was enough molding left so I
could plug, rebore and reshape the tails without loosing too much
wood.  I also prefer to shape the tail myself so I can get the radius
_I_ want and not what I gotten from some back shops.

David, these hammers are not appropriate for this piano and you should
send them back and get ones that are.

Good to see you name again.

		Newton