Vertical Hitch Pins, was [CAUT] duplex position

[Ron Nossaman]

> I'd think it would be just as easy to say that most if not all 
> plates can easily withstand the pressures of vertical hitches with the 
> strings "riding high." Maybe someone knows if this was really a design 
> consideration at Baldwin. Del?


Like anything, it depends, and as usual, no one has proposed 
mindless replacement of standard hitches with vertical without 
some intelligent consideration behind it - as it's being 
argued against.

This has all been covered before, and is in the archives.

First: With the plate and bridge heights accurately set so the 
strings are in a more reasonable 2-4mm height range on the 
hitches, or even up to the height of the aliquot the vertical 
hitch replaced, rather than the 10+ that seems to be assumed, 
there isn't a huge lot of added torque on the plate.

Second: If you rearrange the hitch pattern so they aren't in 
the original "break here" straight line perforation pattern, 
you considerably decrease the likelihood of breaking anything. 
See photos.

Third: If you keep the hitches as far from the plate edge as 
is feasible, you add further safety factor.

Fourth: If you have a minimum allowable plate thickness, like, 
say, 11mm, you won't be installing these things where it's 
dangerous to do so.

Fifth: If you only drill your pilot holes a couple of 
thousandths of an inch undersized for roll pins, rather than 
ten, you can drive the pins in easily with a small light 
hammer rather than mauling the plate with a sledge to install 
them.

Sixth: If you set the string height at 4mm on the pins as you 
string it, you'll have some positive bearing when you pull the 
thing up to pitch the first time. You did, after all, 
determine beforehand where the bridge would end up under 
bearing load and set the plate height accordingly, right? 
Remember, you're in (or are) a small rebuilding shop where 
you're responsible for doing your own thinking, not in a large 
factory where you're going through the same narrow operation 
infinitely on autopilot without verification that the 
prerequisites to your current operation have been met by 
someone else. So if you pull the soundboard up off the rim, 
it's safe to blame personal stupidity rather than the vertical 
hitches.

Yes, there is still a chance of plate breakage, just as there 
is when you restring a piano with no modifications whatsoever. 
If it's a big concern, don't install vertical hitches. 
Vertical hitches in the bass alone can improve bass response 
with a shorter than optimal back scale, and most bass hitch 
risers are heavy enough to take almost anything you could do 
to them.

Ron N
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