Impact hammers was RE: Tuning Hammers.....How Many?

Dean Reyburn dlr@reyburn.com
Tue, 20 Sep 2005 13:57:37 +0900


Hi Terry,
The reduction in weight in our impact hammers is mainly from the  
introduction of
a titanium shaft and head. Most of the weight in the hammer is in the  
brass or
bronze weight at the end, and that is as small as we can make it and  
still be a
reasonable length and effective.

We're converting to a titanium extension (the part that attaches to  
the tuning tip)
for our higher end M300 model, that should reduce the weight by  
another ounce or so.
Current models have stainless steel extensions.

The Titanium has another small advantage for the head and extension,  
it has a warmer
feel since it does not absorb heat as well as steel (which also makes  
it hard to
machine).

The Titanium shaft in our M200 and M300 not only reduces the weight  
but makes the
shaft a little more stiff. With less bending it channels a little  
more of the impact
into the  tuning pin. This is similar to why titanium works a bit  
better for a
standard tuning hammer also. Less bending gives a slightly more  
positive feel. It
feels as if you have more consistent, direct control of the pin with  
less effort.

We use the smallest brass/bronze weight (7 ounce) which is effective  
at a reasonable
length, ours will work for about 99% of tuners and pianos. We have a  
slightly larger
weight available for $25 if you want two weights (or free trade or if  
specified).
The heavier weight (8 ounces) gives about 25% more thrust since all  
the weight is
added at the end. The smaller standard 7 ounce weight works much  
better for fine
tuning IMO, and works fine for all the pianos I've pitch raised. But  
I know from
feedback that there are some pianos out there with super-tight pins  
which benefit
from the heavier weight.

The standard tuning pin thread we use fits Schaff, Watanabe and most  
Hale tips.

We've had trouble meeting demand since the impact head is difficult  
to machine for
a small shop. This production problem is just about behind us since  
we have a larger
machine shop with a computerized (CNC) machine making just heads.  
These new parts
are due to to be delivered very soon.

You can modify an older Mahaffey or Bowman/Renner hammer to be  
similar weight as ours,
it needs to be a 7 ounce weight at 8.75 inches from center of head  
swivel to center
of weight. On some models you simply need to cut off about 1/4 to 1/3  
of the weight
at the top. A few of Francis' Mahaffey's impact hammers I've seen are  
(imo) way too
long to work easily (some as much as 2-3" too long) but most are in  
what I'd consider
the right range. Francis' hammers were the original impact hammer to  
my knowledge,
and were well made, but varied widely in length and weight size.

If your distance is greater that 8.75" you can get by with less  
weight, but the
longer the the tool is, the more unwieldy (and bendy) the shaft gets.  
And the longer
it is the more likely it is to hit the piano or customer's wall. We  
are using what we
think is the optimal weighting discovered from a lot of empirical  
testing (aka trial
and error in the field).

Hope that's helpful,

-Dean

http://www.reyburn.com/cyberhammer.html

On Sep 18, 2005, at 1:06 AM, Farrell wrote:

> That's also supposed to be one of the main features of the new  
> Reyburn impact lever - minimal weight (for an impact lever anyway)  
> - supposedly significantly less weight than others - their deluxe  
> model weighs 428 grams, 15.1 ounces total weight,  and has USA/ 
> Japan tuning thread/tip (titanium alloy shank and head, stainless  
> steel extension, bronze weight).
>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  RPS, Inc.              contact: <http://www.reyburn.com/contact.html>
  Dean Reyburn, RPT
  2695 Indian Lakes Road            web page: <http://www.reyburn.com/>
  Cedar Springs, Michigan, 49319 USA
  Sales & support: 1-888-SOFT-440 (or 616-696-1002)   Fax: 616-696-8121



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