Stradella button stuck down...

[Rosie C]

I was practicing today on my Hohner Concerto when the C fundamental button on the stradella became stuck.

The button itself can wobble within the hole, and when I play the reed doesn't sound. When I play the C on the contra row the note sounds as expected.

All very mysterious. I'm thinking something is sticking in the metal rod mechanism. I can contact them seller but just wondering if there's any easy fix I can try?

 

[Ben-jammin]

If the seller is an accordion shop I would contact them. It sounds like shaft the button is on somehow got under the levers it actuates. It might not be difficult for you to correct it but I would be worried it will be a chronic reoccurring problem and they may have a solution for it.

 

[Rosie C]

Yes it is, but they're closed for the next week, though I will give them a call when they re-open.

Meanwhile I've found I can lift the button (a pencil with a bit of double sided tape on the end) then when I press the C on the contra row it's pulled back down again, so yes it's like the rod is somehow mislocated

 

[JKJ]

I know nothing about the bass mechanism in the Hohner Concerto but a stuck button on my Hohner Verdi III was an easy fix - the bass machine came out easily in two sections, buttons, mechanisms and all, and smoothing the hole did the trick. It was a simple catch but the button still sounded the reed, continuously while stuck.

Based on what very little I’ve learned about the bass mechanisms the fact that the reed doesn’t sound seems like a more serious problem such as a bent or broken connection. If the bass machine doesn’t come apart in modules as in the Verdi I understand disassembling it can be a major effort to disassemble without creating a mass of confusion. If I didn’t have a trusted repair person handy I would probably first remove the cover and look for an obvious mechanical problem. Finding one might suggest a fix.

I’m hoping someone with experience with that specific accordion and/or bass machines in general will have far better insight and more encouraging suggestions.

Best of luck with the fix. I am still rank beginner working hard at learning the stradella side but certainly seems handicapped without that button functioning!

JKJ

 

[Rosie C]

Yes, much of what we play is in the key of G so I do need the C fundamental.

Thanks for your other comments!

Playing with the buttons on the fundamental and contra row, it seems they are interconnected. Not all in the same way but for each pair of notes pressing one of them makes them other button drop down.

 

[debra]

It is what we call a "jumped pin". The piston has a pin on the side that pushes a lever (part of a catorcetto) to open the right pallet.
When either the piston or the lever is slightly out of alignment the pin may jump over the lever and then the button is free to fall down (as it did).
It's a simple fix, but alas the way the bass mechanism is set up when you open up the bass compartment (by removing the plate that's under the bass belt) the first 4 rows deep in the mechanism are all for the chords, and the piston with the jumped pin is on the 5th level down. It can be fixed without removing the first four rows of buttons (or part thereof in the center) but it's a bit tricky. When you shine a flashlight into the mechanism you may be able to see where the problem is. Then it's "only" a matter of being able to reach it.

 

[Rosie C]

when you open up the bass compartment (by removing the plate that's under the bass belt) the first 4 rows deep in the mechanism are all for the chords, and the piston with the jumped pin is on the 5th level down.

Thanks for your very helpful reply Paul. This is not encouraging, but at least I can access the mechanism without removing the bellows and can take a look. Have you any hints on how to remove the plate?

 

[Ben-jammin]

Paul will likely know how specifically that panel comes off on your model. If you unscrew the bass strap there might be screws under holding it on, on other accordions the rubber “feet” have screws that need removed. Old Scandallis had a clever latch you pressed to remove. Usually when I have a problem like this I excercise properly functioning adjacent buttons to watch and really understand how it’s supposed to work before getting in there with a tool to try to correct things.

 

[Rosie C]

Thanks Ben. I've found a reasonably local accordion repairer. If I can remove the cover I can do a video call with him with a view to visiting his workshop. That's as far as I'll go, but he's offered to have me watch and learn how to repair it... "teach a woman to fish!"

 

[debra]

Thanks for your very helpful reply Paul. This is not encouraging, but at least I can access the mechanism without removing the bellows and can take a look. Have you any hints on how to remove the plate?

With virtually every accordion you can either unscrew screws in or next to the feet and when you don't see any screws you can unscrew the feet themselves. Some accordions have an additional small screw near where the black plate meets the white one with the button holes, to keep the plate more firmly down there.

 

[Rosie C]

Thanks to everyone who posted here, also to Roger at https://www.jollyrogeraccordions.co.uk/ who has gave me so much help in diagnosing the problem before I drove to his workshop that we've almost fixed it!

Photo 1: there were two small slotted screws under the bass strap
Photo 2: we removed the panel and had a sinking feeling at the apparent complexity of the bass machine
Photo 3: I operated the fundamental buttons one at a time and looked for differences - the piston for C had dropped down
Photo 4: I drew everything upside down, but you get the idea. All the fundamental pistons we could easily see have a good contact with the little connecting rod. But the C piston has a slight bow and only just connects with the rod - a little sideways movement and it will slip off

It's back together and working - but I'm sure it will go again. I did try bending the piston but there's not really enough room to work.

 

[debra]

...
Photo 4: I drew everything upside down, but you get the idea. All the fundamental pistons we could easily see have a good contact with the little connecting rod. But the C piston has a slight bow and only just connects with the rod - a little sideways movement and it will slip off

It's back together and working - but I'm sure it will go again. I did try bending the piston but there's not really enough room to work.

If you cannot easily correct the slight bend in the piston you may be able to push the end of the lever it has to push a bit sideways.

 

[Rosie C]

If you cannot easily correct the slight bend in the piston you may be able to push the end of the lever it has to push a bit sideways.

Thanks! I'll give that a go tomorrow when I have some daylight.

 

[JKJ]

Photo 2: we removed the panel and had a sinking feeling at the apparent complexity of the bass machine
… the C piston has a slight bow and only just connects with the rod - a little sideways movement and it will slip off

It's back together and working - but I'm sure it will go again. I did try bending the piston but there's not really enough room to work.

Excellent start! Isn’t the thing amazing and wonderfully complex! Someone described the bass machine as an incredible complex mechanical computer, and think of how many years ago this technology was developed. The inside of my accordion reminded me vaguely of the complexity of the technology in a player piano I rebuilt decades ago - technology invented over 100 years ago. And we think we’re so clever today!

I don’t know where you and others could find them but I keep a drawer full of special tools just for working in sometimes very tight places. A few years ago someone from the hospital had taken a box of surgical tools to a local metals recycling place. This place is unusual since the will let you pick through things and only charge scrap prices based on weight.

The tools were stainless steel, titanium, etc., some with gold plating on working ends. The haul contained a variety of gripping tools (hemostats, tiny pliers, special long-reach grabbing tools), cutting tools such as long tiny scalpels and scissors (one with tiny blades intended for eye surgery), small hammering rods, and much more. Some tools are bent and shaped in unusual ways, often perfect to reach that impossible spot. There were so many tools I gave away a bunch, some to a veterinarian friend, and kept what I imagined might be useful some day. And they have been - just last week I was working deep inside a tight electronic control box and had just what I needed to grip and bend and reassemble.

Someone interested in delicate repairs might make contact with a local hospital and see if they also throw away used surgical tools. (All are sterilized, BTW)

I also make special tools as needed. For bending small metal parts for adjustment sometimes just a simple steel rod with a slots cut into the sides or ends can do the trick - sometimes use two tools at once, one to stabilize to prevent incidental damage and the other to apply the force in the right place. If you could use tools like that to work on your accordion and don’t have a way to make them perhaps a local “tinkering” friend has the resources and knowhow. I and some friends keep metal-working tools (mill, lathes and such) as well as welding equipment. If I can’t fix it my buddy Joe prob can! Mostly we like to work on small things but being able to repair big equipment too is useful around the farm! And it’s all good fun.

(I too am fortunate to have an expert accordion repair person, this one local, willing to take the time to teach me to diagnose and make adjustments and repairs. AND give me accordion lessons and encouragement! We spent some time today on fingering for stradella scales and techniques for “walking bass“. SO much to learn, so little time…)

JKJ

 

[tcabot]

but he's offered to have me watch and learn how to repair it...

This reminded me of a sign that a local car mechanic used to have in his shop that went along the lines of
- £50 Oil change
- £70 Oil change while you stand and watch
- £150 Oil change while you watch and tell me how to do my job.

 

[Rosie C]

This reminded me of a sign that a local car mechanic used to have in his shop that went along the lines of
- £50 Oil change
- £70 Oil change while you stand and watch
- £150 Oil change while you watch and tell me how to do my job.

I've seen similar signs! But Roger seems a very decent chap and saved me a four hour round-trip