2024-05-30

Last modified: 2024-05-30 12:00:04

• Music box
• Machine building

Music box

I have this music box from a box of biscuits Lucy got for Christmas.

The plan is to make a replacement cylinder that plays different music.

To start with I just want to make a cylinder that hooks up to the mechanism and rotates, then make it pluck a few notes, then work out what notes they are and program an actual tune.

Here's a cylinder model that will plug into the drive gear, and has a helix around the outside of half of it:

So if it works, it will be silent for half a rotation, and then play a "scale" (?) for the other half, plucking each note one by one.

First iteration:

It hooks up to the drive gear perfectly, but it is slightly too long for the plastic support to go in, and slightly too short to be supported directly by the metal bearing thing.

And it looks like the helix doesn't quite stick out far enough to pluck the notes properly.

Second iteration fits properly, and seems to work OK:

So next questions are:

1. how long does one revolution take?
2. what note do I get off each string?
3. what tune do I want to play?

The first 2 notes (2 lowest frequencies) are not available with the cylinder as I have it. I could get one more if necessary, but easier if I can get away without using it. The last one will probably be too much trouble.

Machine building

I've filed down the filler in the holes:

Worked pretty well.

Next step is epoxying inserts into the right-hand upright.

Need to take the template off at 4pm. Then after the epoxy is set I can see if I can bolt up the gantry! Then see about fitting motor brackets.