Update on 1924 Guerrini restore

[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
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.

[ike milligan]

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
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.

What looks like is happening, aside from the usual issues with keys
changing shape over many decades, is that when I ran the new spindle
through the bed, supposing to track the old spindle holes, it came out
the other side a little off center.

Then when I place the reamed key into the key bed., it usually fits
pretty well until I run the spindle through it. Then it sometimes rubs
enough on one side (to my left) to cause a problem. As I did start on
the end where the spindle came out a bit off, the problem could get less
as I approach the other end. I can force the .002" feeler on the left
side, and once I slowly start shaving the key, I can use the feeler to
detect wide places that need more attention. Once I have treated the
key, it seems to track nicely with no detectable sideways play in the
groove at all. When I use any sandpaper, I then go over that with a
flat razor blade to smooth it out, as the sandpaper raises the grain.
Once I have about a .0015" clearance it is no problem. Also the opposite
side of the key behind the spindle hole has to be shaved a little. I am
not through with the first octave yet.

I can't see enough sideways space on either side of the keys to cause a
problem. They are tight on the spindle with no kind of wobble, and what
looks to be very little room on either side.

[ike milligan]

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
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