Plate bolts/screws

[Ron Nossaman]

> Thanks Terry and Ron. You have to wonder what is going on behind the 
> plate is the wood faulty or did they drill the hole to big. And why was 
> this not fixed at the factory?  I have been checking plate bolts/screws 
> for some time and am surprised at what I find. I don't think many 
> technicians check them.
> 
> Jack Houweling

I rarely check them, except for Yamaha service bonds, which 
are very few these days, or for some perceived problem. I very 
often found loose plate screws in the verticals, and an 
occasional one or two in the plate webbing in grands, or 
perimeter bolts in the GH models. Not in the better models, 
naturally, because of the two piece plate bolt. It's about got 
to be sloppy fit. When pianos roll off an assembly line one 
every 16 seconds (figuratively speaking) screw pilots have to 
be big enough that someone can punch the screw in near 
instantly with an air tool, 3500 a day, without having excess 
torque slowing him down.

Still, I think it's better than the late Aeolian product I 
tuned last week. They lubed the plate screws in these objects 
(they ain't pianos) with something that soaked in and made 
every tuning pin within two inches of a plate lag oily jumpy 
loose. As far as I'm concerned, loose plate screws trump loose 
lubricated tuning pins 200:1. Some folks can produce pianos 
with both tight, but apparently not everyone.
Ron N