jack slap rail

ozboz · Post by **ozboz** » 29 Mar 2007, 02:04

Hi, i am regulating a Herrburger-Brooks upright action on a Spencer piano 1930s could anyone please advise on jack slap rail to jack notch settings and any regulation specs specific to this older piano .

Post by **Barrie Heaton** » 29 Mar 2007, 18:33

Key height is 65mm from keybed to lip, Blow 47mm, DOT (dip) 10mm, Checking 15mm, damper lift 1/3, Slap rail the should be 2 -3 mm play from the jack to the slap when the hammer is in Check, less than that and you can get bobbling hammers, more that that and its not coming in to play

Barrie,

ozboz · Post by **ozboz** » 02 Apr 2007, 19:21

many thanks. i am assuming let of to be 3mm , also the damper slap rail on the piano some how had come of and is missing felt which i have replaced, how close should it be to the damper wires . many many thanks to a wonderful service you provide .cheers oliver

Post by **Barrie Heaton** » 02 Apr 2007, 20:43

Sorry Yes 3mm
On the damper slap you are looking a 4mm gap when the note is at play any less you will have problems with touch. The damper slap rail is not as critical on an upright as a grand if the gap is set too big but if too small it will give you problems. It may have been removed because it was warped

Barrie,