[CAUT] practice rail

[Ron Nossaman]

Fred Sturm wrote:
>     A customer has asked me to install a practice rail (muffler felt). I 
> haven't done this retrofit before. I see Jansen has one. Are there 
> others? Any advice, comments?

The easiest way I've found is this. Get a 6' length of 
aluminum bar stock, about 1/8"x1/2", a short length of about 
1/8"x3/4" steel or aluminum (or a 3/4" length of 1" angle), 
and an automotive choke cable. Measure and bend the ends so it 
will fit into the piano. Trim the ends as necessary, and drill 
holes for the pivots. You can drill a series of spaced holes 
for the cable wire so you can find the most workable leverage 
ratio by trial and error after everything else is in. The nice 
thing about aluminum is that you can dogleg it around the bass 
overstring offset to keep the felt as close to the string as 
possible. Put whatever padding you want on the action 
brackets. Install the felt, trim to the right length (depth), 
and locate the pivot points with icepicks, or small nails 
acting as temporaries. For the pivots, the damper lifter 
hanger pins (fluted on one end) driven into the side of the 
case work great, and the punching won't fall off the pin and 
roll under the piano like it does when the pin is in the 
muffler rail arms. Adjust the spread of the arms so it doesn't 
slop around. Make a bracket for the choke cable, mounted under 
the bass end of the keybed. Fit the cable in the bracket and 
determine the length of  wrap needed. Pull the wire, cut the 
wrap, and push the wire back in. The wrap can be held to the 
case side by a couple of Dampp-Chaser wire clips, or simply 
three 1" sheet metal screws, two on one side, and one in 
between on the opposite side. Push the choke knob all the way 
in, prop the muffler rail up to clear the hammers, and make a 
right angle bend in the wire (toward the treble), a little 
above the hole where you think you'll want it. Another right 
angle bend, about 1/4" past the first, making a "Z", gives you 
a connection to the rail. Take the rail out, tip the treble 
end up, feed the wire into the appropriate hole in the bass 
end, and reinstall the rail. That's it. If the choke cable 
won't hold the rail up, kink it gently until it will.
Ron N