Cradling was: Epoxy Reinforcing of Action Parts

[Roger Jolly]

Hi Bill,
              A better solution than bending the jack centre's, it to twist 
the balancier post and put a dab of CA glue around the glue joint. I have 
long since come to the conclusion that rubbing jacks is caused by the 
balancier post twisting with humidity changes. No risk of broken parts, and 
no slowing of the jack.
Hope the tip helps.
Regards Roger


At 11:08 PM 3/29/2003 -0500, you wrote:
>>At 2:25 AM -0700 3/29/03, Dave Nereson wrote:
>>Bending pins to center the jack in the rep. lever hole (other 
>>alternatives are  to install a new jack and hope it's straight, or plug 
>>the center pin hole with ??? and re-drill it, which I've never tried.  Or 
>>put in a whole new wippen).  Yes, center pin.  By vertical, I think he 
>>means centered in the window, as opposed to the jack rubbing on the 
>>wippen because of a jack center pin hole drilled crooked (or jack 
>>warpage, or sloppy bushing).
>
>Thanks, Dave, for a great job of answering Terry's questions. You were 
>right on the mark. (Including the humor about the air nailer. It was a 
>pre-emptive joke. I figured somebody would suggest I was tapping the tops 
>of the jacks too hard, so I tossed in a wisecrack about  the air nailer 
>alot of us are stringing with now.)
>
>When you rap the top of the jack (firmly supporting the body of the rep 
>underneath the jack's pinning), the top nudges over because that rap has 
>actually bent the jack's CP. The beech of these parts is so brittle that, 
>the normally minor force required to bend the pin shears the jack instead 
>of pending the pin. To center the jack in the rep lever's window, the jack 
>pin still needs a slight bend. In this case I'll have to bend the pin 
>before pinning the parts together.
>
>I didn't have a whole lot of time Thursday evening to perfect this trick 
>of bending the pin outside of the parts, something I heard from Bill 
>Garlick. But I was inserting the pin into the parts so there was equal 
>amounts extending from each side. I then nipped a mm. off the flat end 
>with the flush cutters, for a reference line (vertical). With a tiny pair 
>of needle-nose, I put a modest bend in the pin (similar to what you'd find 
>if you pulled the pin out of a cradled jack and asked it to roll on a flat 
>surface) at a distance from that nipped end equal to the width of the 
>bushed wood which the jack will slip  in between. I next inserted the pin 
>until the the nipped end was flush to the wood. Now it is possible by 
>rotating the pin (and its bend just outside the bushing) to lean the jack 
>to centered.
>
>Too big a bend, and you have a badly binding pin, off-centered to its 
>bushing. Thursday evening, I was making my bends "in the beech", and it 
>was hard to control to get the required amount of bending without binding. 
>I think I'll try doing the pin bending with the pin in the jaws of a 
>machinist vice. There's probably not more than a dozen which require bending.
>
>What this means for the durability of the parts under normal playing 
>circumstances, I don't know.
>
>At 2:25 AM -0700 3/29/03, Dave Nereson wrote:
>>I would go for all new jacks.
>
>Schaff is the only catalog selling jacks separately. The reps and jacks 
>are a good match for the Tokiwa universal reps with a tall heel. I asked 
>somebody at Schaff to  send me three of the "Chickering jacks" if they at 
>all matched the shape of the jacks on the Tokiwa reps, and they didn't. 
>I've run out the the old Steinway jacks which pulled me through the first 
>six I fractured trying to cradle. (You undo the mortise&tenon joint with 
>vinegar, scrape the old glue out of the joint, with a razor blade put a 
>14º bevel in the front surface of the fly (vertical) where the tender 
>butts against it, and reglue. The only modification is that the angle 
>between the fly and tender goes from 90º to 104º.)
>
>It's a little late in the game for new jacks (even if they were 
>available). I'd go for an entire set of new reps. But the proposal was 18 
>months ago, and it took the church 12 months to get the grant approved. 
>The church may have to scrape together the money for new reps some year, 
>but not this one.
>
>At 2:25 AM -0700 3/29/03, Dave Nereson wrote:
>>  Beech is pretty darn dense stuff. You will not be able to "impregnate" 
>> beech with epoxy.
>
>It may have been dense 100 years ago, but now it's down around the 
>toughness of cherry. Oh, the things you add to the list of stuff to watch 
>for, which you wish was already on that list!
>
>Bill Ballard RPT
>NH Chapter, P.T.G.
>
>"May you work on interesting pianos."
>     ...........Ancient Chinese Proverb
>+++++++++++++++++++++
>
>
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