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Tips / help with tuning a Wurly 112

Started by dandan, July 19, 2016, 03:17:18 PM

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dandan

Attempting to tune my 1956 112.  Having a hard time with the lower register because the dampeners get in the way of getting at the tine screws.  I figured out that you can prop up the dampeners with lengths of coffee stir stick, but still I've damaged three of the felt dampeners just accessing screws. 

The harp was corroded just enough - and looks like its never been tuned before - that getting the tine screws undone was a chore.  The screws have bolt heads that are so shallow that i almost stripped a few of them. So I actually pulled the harp out to loosen all the screws. Unfortunately i couldnt think of a way to tune all the tines on the harp before sticking it back in.  The amplified sound seems necessary. .

I know there is a reason not to just put a dab of solder on the back of a tine... But I'm not sure why that is.  It seems like it would be easy to fix if i did end up pulling a tine and a quick fix that might save me a few dampener felts. Any tips?

DocWurly

#1
I'm just about to do the same thing.  I've installed a new reed bar into a 112 I worked on a couple of years ago.

This time around I think I'm actually going to do the arduous thing of unscrewing all the damper arms for better access to the screws.

Are you using a vertical 5/16" socket wrench?  You must be using a horizontal one if you are hitting the old felts. I'm not sure I'd loosen those screws with anything but a vertical one, and in that case you wouldn't be tearing off those felts if you left the damper arms on.  What you _would_ be doing is twisting the damper arms to the side a little bit, if you aren't removing them.

I _think_ that's what I did, last time around, and I didn't break any of those arms.  Did I?  Oy.  But...your mileage might vary and that would be a drag.  I am not going to tempt fate this time around, so the arms are coming off.  You need a short screwdriver to do so.

If a screw is stuck, I apply straight jaw vise grips horizontally to the wrench for extra torque.  (My wrench therefore has a chewed up handle.)  I don't generally use the vise grip method to _tighten_ screws, though--I popped the head off a 120 screw that way and extracting the screw was a nightmare.

Be aware of those washers!!  They are separate from the screws on this model!  It's an entirely different screw than on all later models.

The washers have an up and down side.  You will be able to tell which is which from the markings the head will have left.  It is crucial to reinstall the washers the same side up as before, or the reeds won't ring out.

The other crazy thing about the washers is that, because they are loose, their positioning has a major effect on the pitch of the reed.  You must be conscious of their front-back and side to side positioning when you tighten the reed.  You can actually use this weirdness to affect the reed's pitch...it gives much more leeway that pushing the reed front to back. (But not only _can_ you use it....you _must_ be aware of it or you won't be able to understand why the screw's pitch seems to be changing in ways that are out of sync with your filing).

My other nightmarish memory of tuning this is that the pitch of the reeds would change and sharpen by up to 10 cents, a couple of days after tuning.  It was as if the reed screw was slackening a bit, after having been set free for the first time in decades.  That treble sustain bar system also affects the pitch of the reeds.  I wrote about this on the board in the past, I think....






DocWurly

I believe you will also find that, unlike the reed screws on any model from 1966 on (the 200's and the 140B's), these reeds will go _down_ in pitch slightly as the screws tighten.  If so, it's probably because the washer becomes concave upwards as the head tightens on it, so the flexing area of the reed increases slightly. Perhaps, in fact, the washer relaxes slightly after a day or so, which is why the pitch goes up again.

On the reed bar I am about to tune, the whole reed bar is sharp by 5 cents to 15 cents.  It sounds decently in tune to itself.  I suspect that the sharpness is due to a relaxing of the screws and washers over 60 years. 

DocWurly

Ahhh.....remembered knowledge!

The original orientation of these reeds is with the solder tip facing down.  On all but the bass reeds, there is a very abrupt, sharper thick-to-thin taper where the reed is ground to thinner.  If the reeds are facing in their correct "down" orientation, the positioning of the washer does NOT affect pitch significantly.  It's only a factor if the reed is facing up.  For whatever reason, perhaps easy to explain.  It may be, as well, that the front-to-back slide of the reeds on the reed bar is much less dramatic as a pitch factor when the reeds face down.

Jezza

I'm a few months too late, but for what it's worth: I removed my reed bar for tuning, propped it up near my piano, and ran a wire back to the amp so it would still make noise. I need them to record together nicely and I could just tap the reeds with a screwdriver to hear them, so that worked well for me.

Tuning with a soldering iron and metal file is a pain in the ass. I can't imagine also doing it with the reed bar and dampers in place.
- Jezza

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