2026-07-19

Last modified: 2026-07-19 13:36:25

Keyboard Glockenspiel

I've printed all of the remaining hammers and have super-glued a bunch of the ball bearings on to them:

These are glued using a drop of medium-viscosity super glue, I used it quite sparingly so won't be surprised if some of them come off, I can just re-glue them as and when that happens.

I've also glued the black keytops on, using Stormsure flexible repair adhesive. I haven't used this before, I chose it over superglue because I don't want white marks around the edges of the join. Again I was quite sparing with it but the joint for the keytops is basically only loaded in compression so the glue doesn't even have to do anything really.

Alright, first tune! Mary Had a Little Lamb: https://www.youtube.com/watch?v=R_7Fbg969f4

You can hear one of the ball bearings come unglued during the video.

The keys don't always come back up on their own, and the activation force is about "4x M6 nuts", which I weighed at 12 grams, so it wants about 4x as much activation force, which I can achieve by adding counterweight to the backs of the keys. I'll work out roughly how much to add, do that to all of them, and then if any keys still seem wrong I can adjust them individually.

I think all of the tone bars are "off by one", which means all of the tone bar holders want to be ever so slightly longer? Unsure, I may try putting all the bars in the correct places and see if any of them fit. I need to change the tone bar holders anyway to add a groove for an o-ring to stop them falling off, so no big deal if I need to reprint them all. I am thinking I will make the peg oval-shaped, so it constrains the bars left/right much more than forwards/backwards. That way it stops them hitting their neighbours but doesn't bind up if the length is slightly wrong. And the groove for the o-ring will be a circular groove that only cuts into the sides.

Regarding the rattling, there are a few sources:

• the tone bars are not held down by o-rings, I think this is the main one
• the top surface is not screwed down
• the key return is not damped, I need to put a strip of foam there

It seems like the key bottoming when you press it makes a bit of a clunk, not sure what I can do about that, it is already damped by foam.