Discussion:
Update reposted repairing 1924 Guerrini
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ike milligan
2015-05-18 18:43:53 UTC
Permalink
On this same thread I will post a link to p.5 and more pictures, which
is not on the server yet.
The main issue is that when I put the larger diameter spindle, the keys
have less play, i.e. "wobble", than they did with the smaller one, and
the very close tolerance in the key bed means that on the larger spindle
some of them are off center diagonally just a tiny smidgen, and can rub
on the grooves in the key bed. The maple keys and the walnut key bed are
"rock hard" now after the wood is about at least 100 years old.
I was using a .002" blade from a feeler gauge to decide where to shave a
key that no longer fit. With the larger spindle, there is no way the
key **meant to say the keys are not quite settling because the spindle
is off a fraction.**
can settle by itself without some help. Also had to remove any paper
shims that were left on the keys. To get the last one I worked on to
fit, I had to use some medium grit sandpaper and then smooth the cut
with a razor blade, which you will see.
After I get all the keys into the key bed and test out the accordion, I
might have to loosen them up just a bit, but that would be a delicate
process not to be overdone. the few I have in there already seem to work
fine.
There will also be a couple of other operations described when all the
keys are in.
The link to page 5 will be posted here on this thread.
I haven't got the whole page 5 ready yet. Some notes:

If a key is warped, the key top will be too close on one side and a
wider gap on the other side, and might even rub.
When I try to straighten a warped key, First I remove the plastic key
top and the spring. I run water over the wood key and heat it while
moving it uniformly over an alcohol flame. When the key is hot, (it may
scorch just a little) I hold it in two hands and bend it to straighten
it. The ends are not to hot to hold. I hold it in the new position a few
moments until it acheives the desired shape.

Putting the straightened key back in the key bed, with the spindle
installed, I sand the old glue off the key, and then put the glue on the
key top, placing the plastic key, lined up the way it needs to be
vis-a-vis the adjacent keys. Pressing down on the key top while placing
something under the end of the key to hold it up, makes it bond to the glue.

When Page 5 is ready, the keys will be back in the key bed and there
will be some photos with captions.

Meanwhile for the photos and captions we have now
http://accordionville.com
ike milligan
2015-05-19 04:23:47 UTC
Permalink
Post by ike milligan
On this same thread I will post a link to p.5 and more pictures, which
is not on the server yet.
The main issue is that when I put the larger diameter spindle, the keys
have less play, i.e. "wobble", than they did with the smaller one, and
the very close tolerance in the key bed means that on the larger spindle
some of them are off center diagonally just a tiny smidgen, and can rub
on the grooves in the key bed. The maple keys and the walnut key bed are
"rock hard" now after the wood is about at least 100 years old.
I was using a .002" blade from a feeler gauge to decide where to shave a
key that no longer fit. With the larger spindle, there is no way the
key **meant to say the keys are not quite settling because the spindle
is off a fraction.**
can settle by itself without some help. Also had to remove any paper
shims that were left on the keys. To get the last one I worked on to
fit, I had to use some medium grit sandpaper and then smooth the cut
with a razor blade, which you will see.
After I get all the keys into the key bed and test out the accordion, I
might have to loosen them up just a bit, but that would be a delicate
process not to be overdone. the few I have in there already seem to work
fine.
There will also be a couple of other operations described when all the
keys are in.
The link to page 5 will be posted here on this thread.
If a key is warped, the key top will be too close on one side and a
wider gap on the other side, and might even rub.
When I try to straighten a warped key, First I remove the plastic key
top and the spring. I run water over the wood key and heat it while
moving it uniformly over an alcohol flame. When the key is hot, (it may
scorch just a little) I hold it in two hands and bend it to straighten
it. The ends are not to hot to hold. I hold it in the new position a few
moments until it acheives the desired shape.
Putting the straightened key back in the key bed, with the spindle
installed, I sand the old glue off the key, and then put the glue on the
key top, placing the plastic key, lined up the way it needs to be
vis-a-vis the adjacent keys. Pressing down on the key top while placing
something under the end of the key to hold it up, makes it bond to the glue.
When Page 5 is ready, the keys will be back in the key bed and there
will be some photos with captions.
Meanwhile for the photos and captions we have now
http://accordionville.com
To avoid some of these problems, use a brand new perfectly straight
spindle, not a used pretty straight one, like I recycled.

Also when sharpening a spindle to run through the key bed, grind the
point on 4 sides symmetrically on the bench grinder, not with an
off-center point.

It looks like taking off a few thousandths of an inch on the side of any
key rubbing the side of the channel, is all it is going to take,
hopefully. Right now it still does not look like a loose keyboard. So
far nothing wobbles, and the clearances are within acceptable parameters.
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