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Bass note sticking

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Mike K

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The E flat used in chords (C minor, F seventh, B major, etc) occasionally sticks. None of the other notes in the chord stick, and it happens not just with one button but with at least those three. It is not the E flat bass note but two octaves higher, at least that is what it appears to me. Curiously, it appears to not happen until after I have played for a while. Not sure how that can affect it but first 15 minutes maybe 30 minutes....no problem. Later I have issues but it does not do it every time.

This is a Giulietti with a full free bass, three rows mounted about the 120 bass stradella. I do not use the free bass much as I learned on a converter style and these rows are awkward to reach for me. I play the free bass on my other accordion. it does not appear that the free bass E flat sticks but since it is only occasional, I cannot be sure.

Any suggestions on what to try? I do not think it is a bent button. I have opened it up and looked but the left hand mechanics are confusing to say the least. I am not about to be brave enough to take them apart.

I did take apart a right hand on an accordion I bought for $20. Keys were all sticking. Cleaned it up and it works great. Rest of the accordion looked good when I got it. Just a student model. I figured it would be good for practicing repairs. The first and last key were a bear to get in and out but the rest of it went easy....Just time consuming cleaning the metal plate on each key to get off the rust causing it to stick. Guess just from lack of use, moisture and time.
 

JIM D.

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debra

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problems with the bass mechanics often require detective skills. last week I looked into a bass sticking problem on an almost new Piermaria and sure enough nothing appeared wrong when checking out the bass mechanism. Turns out the plate I removed to look at the mechanism was a bit bent (inwards) and pressed against the mechanism while playing... I bent the plate back and voila, problem solved. I haven't seen this problem before (or seen it mentioned anywhere) but of course Jim will have seen it all.
 

Mike K

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JIm, I did read the Accordion Revival on taking apart the bass section.....scared the crap out of me. Not quite ready to take that step. I will take some pictures. Tried dry teflon lubricant but probably did not spray it in right place since I do not know where the right place is. Pictures will be sort of limited as I am only taking off the back plate where the strap is located. Not brave enough to dismantle the whole thing.
 

Mike K

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Here are a few pictures. I removed all the bass reeds. I took a picture of the "felt" where that specific note opens and closes, not much you can see. it never stuck of course when I had it apart. Blew some air through it just to try to clean out anything that could be blocking it. Impossible to see the mechanism for that specific note from the other side. A few pictures from the back side (not inside the bellows). When I hit one chord.....lots of stuff moves. Have no idea where to spray.
 

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Mike K

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When I put it back together played fine for a while. Got through under paris skies several verses with no sticking. Played Libertango and crap....it was back.

One strange note, when I had the bass reeds off and set it upright to look at the back side, I heard something move. I found 3 washers sitting inside in the corner. No idea where they came from as it was the bellows side could have come from right or left hand mechanism. I removed them and saved them. Might have been on the screws holding the reed blocks down at one time is my best guess....three washers, three reed blocks. I never took them apart before and they were not on there today. Only got this accordion about a year ago. Was hoping that might have been the issue but does not seem that way.
 

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debra

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Did you check how much clearance there is between the plate you took off to take the pictures and the actual bass mechanism? You need to make sure that the plate cannot touch any part of the mechanism.
 

JIM D.

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Good call Paul :tup:
Seems I've taken for granted that Mike checked for a bent or warped bass panel.
And now Mike;
The pistons in your bass machine (some with 3 pins & some with 4) depress levers and a these levers can hang up on a inward bent bass plate.
Those washers you found may have been used before fastening your bass plate.
 

Mike K

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How do you check clearance? If the bass plate is on, I cannot see the pistons and pins. I could try loosening the screws that hold the bass plate and playing it that way to see if there is a difference. How would you "straighten" a bass plate?
 

Mike K

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I took those three washers plus one more and used them as spacers on the 4 screws holding the bass plate in. You can actually see the "edge" of the bass plate now when it is mounted on the accordion. The edge looks uniform so there is no significant warping along the edge. Cannot "see" any in the middle but no way to measure.

Still sticking. Just the one note.
 

debra

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Mike K post_id=55277 time=1518099572 user_id=1773 said:
I took those three washers plus one more and used them as spacers on the 4 screws holding the bass plate in. You can actually see the edge of the bass plate now when it is mounted on the accordion. The edge looks uniform so there is no significant warping along the edge. Cannot see any in the middle but no way to measure.

Still sticking. Just the one note.

Well, thats progress, really! It means that when the bass is sticking you can remove the bass plate without dislodging the stuck bass, so you can then peek inside while the bass is stuck and see where that is and what is holding it.
If removing the bass plate dislodges the stuck bass then it was the plate after all...
 

Mike K

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It does not stay stuck. It will be stuck for maybe 5 to 10 seconds while I am playing and then go away. By time, I take it apart it would not be stuck anymore. Even if it was stuck....afraid I do not really know what to look at. Impossible to see the actual mechanism that is opening the note, it is way in the back. The pins and levers in front I do not actually think are the problem.

When I have had it apart, I have not been able to make it stick, but as I said, it does not do it all the time and it usually disappears by itself. I can also make it close by hitting one of the buttons that uses that E flat a couple times.
 

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It can be quite difficult to see what is making a bass note play uncommanded, i would read accordion revival and look carefully at your bass mechanism under a bright light so that you can understand how it works.

Then if you operate the offending pallet with the reed block out and trace the path to the appropriate button you should be able to see all the points where something could be sticking
If you can get the pallet to stick then you can poke about with a length of bent wire to see what frees it, when you have located the problem you may need to get back here for recommended cures
You should not spray the whole mechanism with oil


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JIM D.

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Well your next step will be to observe the bell cranks (pipes) under the pistons.
These pipes rotate when a piston is depressed.
A pipe can open valves for bass and or chord when a piston is depressed.
It is not uncommon on an older box for a pipe to (at times) not rotate back (corrosion or old hardened lube) and leave a pallet open.
In this case you will need to remove the pistons, then remove the pipes for cleaning.
 

debra

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Maybe we could see something if the third picture (currently a very fuzzy out of focus picture of the bass mechanism) was redone, in focus, with no bass buttons pressed. In the fuzzy picture you can see that one note is active but it's too fuzzy to see what is pushing it open.
 

Mike K

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Hard to take a picture. Have to try doing it in daylight on a sunny day. Not many of those lately. Flash seems to screw up the shots.
 

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May have got lucky. I figured out which of these horizontal shafts was tied to the notes/chords giving me a problem. How it actually opens the valve for the E flat I cannot figure out, too much stuff in the way. I can see how the free bass buttons open the valve but not the chords.

Anyway, I loosened the screws that hold the clamps that hold the shafts. Then i scraped them a little with the end of a screwdriver. There was some white stuff on them, maybe a lubricant that was dried up. I then sprayed a little teflon lube on the ends. When I tightened the screws up for the clamps, I got them back to about the original tightness then backed off a quarter turn.

Put it back together and played it the longest I have been able to in months without a note sticking. So far....so good. Going to need a couple days or maybe weeks before I am confident it is fixed. Thanks for help/suggestions. I am sure I will be back with more problems. I did not realize I would have to be a repair tech in order to play the accordion again.
 

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Glenn

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Great news. I’ve been following this story with great interest. Better than the telly.


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debra

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Glad to hear the problem was resolved. Finding such problems is a difficult task, more like detective work than standard accordion maintenance skills.
 
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