CBA treble button issue

[CC_PDX]

I'm about to take one of my boxes apart to tweak this minor issue. One of my treble key pairs feels like it "catches" or hangs slightly, causing it to require more force than the others to press down. It plays fine, but the result is that it is more of a jarring "pop" on/off feel vs. the smooth even response on the others. It feels like a mechanical issue/ever so slight misalignment so will let you know what I find--anyone have any guesses or suggestions on what might be causing it.

Also, anything else I should do while I have it open?

Thanks.

 

[losthobos]

Also check that it's not 2 pallets rubbing together under the grill rather than the button end that's causing the sticking feeling...

 

[debra]

Also check that it's not 2 pallets rubbing together under the grill rather than the button end that's causing the sticking feeling...

That's good advice because that is a common cause for a note "catching". The pallet may be rubbing against another pallet but also on some stud for the register mechanism. Button keyboards can also often be inspected by looking underneath (removing a plate under the keyboard), unlike piano keyboards that offer no access to the underside. (The cause of a key not moving smoothly on a PA is often under the keys, but not on a CBA.)

 

[CC_PDX]

Thanks all. I figured it out. The pallets were not rubbing or catching. It was impacting two adjacent buttons C1 and Eb1. The stickiness was felt in both the 1st row and the 4th row repeats, but the actual catching was on the 4th row -- the opening in the wooden for the button to travel was a little small / too close to the bottom of the button. I came in from below the keybed with a little oval needle file between the rods, I was able to widen those openings a mm or so and let it travel freely.

 

[debra]

Thanks all. I figured it out. The pallets were not rubbing or catching. It was impacting two adjacent buttons C1 and Eb1. The stickiness was felt in both the 1st row and the 4th row repeats, but the actual catching was on the 4th row -- the opening in the wooden for the button to travel was a little small / too close to the bottom of the button. I came in from below the keybed with a little oval needle file between the rods, I was able to widen those openings a mm or so and let it travel freely.

Good "catch"! Sounds like a minor button (top) displacement. Luckily easy to find without any disassembly. Glad you figured it out.