Air Hammer

[Joseph Garrett]

Terry,
Really sounds good. However, the torque readings are a bit high, according
to the "Chart" I've been using for these many years. I originally got it out
of the PTJ and have it attached to the back of my "work sheet/String scale
analysis sheet" clip board. According to the chart: "75 ip to 125 ip = firm
tuning range. Excellant tunability for the tuner with above average hammer
technique." "125ip to 165 ip = tight pins. Special techniques and high skill
level required to do a fine tuning in this range".
I don't remember who wrote the chart, but as it was way back around the Don
Galt time, I suspect it was Don Galt.
In practical application, I have found that the range of 110 ip to 130 ip is
what I like and try to achieve. Of course, it does depend on the type of pin
block material you use. As I use Delignet, these readings are the best,
IMHO. For Standard Type pin block material, I have found that higher
readings, say 140 ip to 150 ip,  were a bit better.
It is my opinion, that most rebuilders tend to pin a bit tighter than I like
or is necessary. Methinks the "accu-twist" guys had a bit to do with this.
:-)
Along with the torque chart, I have incorporated the tuning pin/drill size
chart, (both European and American) and wire size(s) chart, (Euro/Amer). If
anyone would like one of these charts, please contact me and I'll send it
"snail mail".
Regards,
Joe Garrett, R.P.T.
----- Original Message -----
From: "Farrell" <mfarrel2@tampabay.rr.com>
To: <pianotech@ptg.org>
Sent: Tuesday, May 01, 2001 2:47 PM
Subject: Air Hammer


> Just tried out my Danair Palm Nailer #RN-16-8 for the first time driving
> three tuning pins into a pinblock. Holy cow cookies! That thing is slicker
> than you-know-what!
>
> Often as I drove a tuning pin by hand (with manual hammer) into a bare
> pinblock, I could see the damage I did to the top of the hole as the pin
> wiggled back and forth with each blow (hey, I'm a newbie!). I'm sure it
> continued throughout the driving process. The couple pianos I have
restrung,
> resulted in acceptable (for me - I had low expectations), but far from
> perfectly uniform tuning pin torque.
>
> The three pins I drove into a bare pinblock resulted in 160 in-lbs. torque
> for each one. Not 150, not 170, but all three were like exactly 160
in-lbs.
> of torque. I had never done that before. Oh, boy, this has made my day. I
> can hardly wait until after I finish restringing and start
chipping/tuning.
> Clearly, I am expecting fabulous results.
>
> Thank you Del Fandrich and Roger Jolly (and anyone else that participated
in
> that thread - I know there were a few) - I recall that both of you use an
> air powered hammer, and one of you recommended the Danair specifically.
Man,
> you just drive those puppies straight down. I am just absolutely amazed at
> what a difference it makes! Fast, easy, and NO tuning pin wiggling.
>
> What do you use as a guide for tuning pin driving depth control? On my
bare
> test holes, I used an one-inch-thick piece of hard maple with a 5/16-inch
> hole drilled in it. I placed the maple guide over the tuning pin hole,
> inserted the tuning pin, and drove it with the Palm Nailer until it would
go
> no further. That worked perfect - for a bare block. Now I need to figure
out
> what to use when I am driving the pin through the plate into the block.
What
> does anyone use? Something hard to physically stop the Palm Nailer from
> going any further - or do you tape a stick or something to the thingee
that
> goes over the top of the tuning pin and just watch until it touches the
> plate or whatever?
>
> Can we adapt this thing for bridge pins - or just way too much horsepower?
>
> Terry Farrell
> Piano Tuning & Service
> Tampa, Florida
> mfarrel2@tampabay.rr.com
>