Keyboard: Easing keys

The balance pin holes and mortises are all a little snug at present and the keys need to move as freely as possible without actually being loose, so all the mortises and holes need to be eased to reduce friction.

I used this tapered reamer, which reaches a diameter of 3/32" (matching the balance pins) roughly at its midpoint:


A reamer is a cutting tool and I have previously stated that it isn't a good idea to cut material away when easing keys, in case one goes too far and needs to undo the adjustment. I tried to press the reamer into the balance pin hole from below without twisting it, which would bring the cutting flutes into play. To ease the mortise portion, I put each key onto the leftmost balance pin of the key frame (as shown above) and worked it up and down firmly, letting the pin burnish the mortise sides.

What I'm aiming for is to be able to lift each key straight up on the balance pin and have it slide back down on its own when released. That strikes a good balance between looseness and tightness.