2026-04-03

Last modified: 2026-04-03 11:06:48

Keyboard Glockenspiel

OK, I'm committing to building the thing now.

So I need to print all 23 keys, which is 9 black keys and 14 white keys.

The white keys (to match the toy piano) go: "GABCDEFGABCDEF", so I need 2 copies of each letter.

And then I need:

• 23x 6mm steel balls
• 46x 2mm diameter 12mm long pins
• 46x 3mm diameter 30mm long (?) pins
• 2mm thick sticky-back felt strip
• 23x tone bars made from the 2mm by 12mm steel strips
• wood for the case

The 3mm diameter pins need to stick up from the case floor by some distance comfortably greater than 12mm and any amount less than 20mm. So I guess for example drill the holes 12mm deep so that they stick out by 18mm and we're golden.

I've gone for stainless steel dowel pins. I kind of wanted the brass aesthetic but stainless was easier to find and I don't actually care that much.

I may be able to make a start on the tone bars later. I was originally hoping to cut them oversize and then use the CNC machine to trim them exactly to length, but I actually think that will be too much hassle. What I should do instead is cut them to the right length, ding them and test for tone, and then drill them by hand. I think that will be faster. The hole locations will be less precise but should be fine. If I set up a stop on the pillar drill table then I can at least centre them in the bars.

So what does the case want to look like? Oh, annoyingly my smooth key adjacencies are B/C and E/F, so having a G at the left-hand edge and F at the right means I either need a special G and F to make a smooth edge, or the case needs a step in the edge, or I ought to put a C or F at the left-hand edge and B or E at the right.

Having C on the left is apparently typical, but then it won't match the toy piano, which is the only instrument I currently know how to play, and it would make sense to make them both act the same.

Go C on the left. Learning the new layout is temporary but an ugly case is forever. This does mean that some of my existing repertoire will need transposing.

OK, how about going from F at the bottom (one key lower than toy piano) up to B at the top (two keys higher). So it becomes only a little wider, but still spans the full range of the toy piano and keeps the straight-ish keys at the edges?

So that gives 31 keys in total instead of 23.

Bar lengths would be:

• F4-B6: 172mm to 72mm
• F5-B7: 122mm to 51mm

I think go for F4-B6, because 51mm is looking too short.

The case needs to have:

• bottom piece for balance pin and front rail pin to sit in, and keys to bottom out on
• some sort of bar to hold the keys down
• adjustable back rail to actuate the hammer lever
• support the tone bars above the hammers
• maybe box in the sides to protect the mechanisms of the end keys?

We need adjustment in the height of each individual tone bar, the height of the back rail at both ends, and maybe some trivial adjustment in the height of the bar that holds the keys down