Author Topic: Clavinet new replacement bushings - stuck keys - binding  (Read 150 times)

Offline JDB3

  • Pre-Piano
  • *
  • Posts: 9
    • View Profile
Clavinet new replacement bushings - stuck keys - binding
« on: May 22, 2021, 12:30:13 PM »
There's an old thread about how new replacement bushings can create a binding against the inside of Clav keys resulting in stuck keys, sluggish response etc. Two of the solutions were to ease the key width by inserting a flat blade screwdriver in the metal gap where the bushing will rest and gently spread the gap until best fit is achieved and another by shaving the sides of the bushing with an Exacto knife.

I can't say I recommend either of these. Attempting to spread the flexible and quite strong metal core of the key will likely result in cracking the plastic not matter how careful you are (Me raising my hand here...) and as with any flexible metal, you'll need to overspread slightly as the metal will close back some small amount - and shaving the sides of the bushing with a razor knife results in uneven over-cutting (a lot in my case) which negates the purpose of the bushing (sideways control) and also makes me extremely insane in about 15 minutes.

Both of these methods are in-exact and don't provide enough control for best effort sizing - the goal would be near zero side to side wobble and still allow the key to drop with gravity when no spring is attached.

A better solution I've found is to cut a narrow 1/2 inch wide x 4 or 5 inch long piece of 220 grit sandpaper and lightly sand both sides of the bushing until best fit and drop is achieved. VERY LITTLE sanding is required! about 5-12 passes on each side depending on the variables of key metal width, corrosion, paint/glue residue on the bushing support etc.

I'd also recommend buying an extra set of bushings as you will over-sand the first dozen bushings but then you'll be so pleased with the perfect fit you've made on the next dozen, you won't be able to stand that first octave you started with.

The insanity factor isn't any worse than pushing hammer tips into their socket and squeezing needle nose pliers over and over and ov....