Key Upstop Rail and Post Installation 2024-10

This is a trial. A better process is yet to be developed with advice from colleagues and professionals.

Firstly, the post and block are installed. Ream the existing old hole through keyframe so the post body can slide in snuggly. Note that there are two brass nuts on the post. The upstop rail is fastened between them. 

If possible, on a few pianos, check how much the posts are sticking over key tops. 14 mm is the average this time. With the 14 mm protrusion and keys at the ideal height, decide the length of the post. The post shall go into the guide hole just drilled, but not protruding the bottom of keyframe. 

Mark where to cut the posts, saw off the extra length. After sawing, the posts are not at the exact same length. It is ok.

On the base blocks, draw diagonal lines across to determine the block center.  Clamp the block firmly in a vice on a drill press, drill through the center with a bit for the post threads. Thread in the posts.

Make sure all posts have the same protrusion over key sticks as measured before - 14mm. Tape the bottom of the guide holes so the keyframe won't be glued on anything. Smear woodglue on the bottom of the base blocks and in the guide holes. Glue down the base blocks.

Here comes the upstop rail. The stock Reyburn mailed to us is longer than the keyframe. On the bass side, place one end of the rail flush to the edge, mark where the screw hole is on the rail. On the treble end, mark the screw hole location and the end of rail. Also mark where the posts go in.

Use a square to transfer marks onto the surface of the rail.  Mark the center. Measure the rail screw and post body width, select drill bits slightly larger than the widths. Note that the width of the screws and posts are different. Different bits are needed.

On a drill press, drill the pilot holes. Make sure the screws and posts can go through freely.

Counterbore for the nuts on both sides on the rail. The nuts don't have to be flush to the rail surface. They can stay a little higher. Cut the rail to length.

Install the the rail on the keyframe to see if it fits. Then felt the bottom of the rail. Trim the felt flush.

For the nuts and screws, a punch is used to open the slots for a clean look.

Don't forget to check if the keys are rubbing on the posts. If they are, mark the location of the post on the keysticks and modify on a drum sander.

Pivot the keys back and forth to see if any key is rubbing on either gliderstuds or upstop rail posts. Modify if necessary. Now the rail can be put away till the action regulation is finished.