Assembling the hammers

This page describes how to assemble the hammer.

All hammers are identical for the different notes.

Parts needed:

Tools needed:

  • A 3d printer
  • Screwdriver
  • Pliers
  • Knife and / or files to clean up the 3d printed parts.

Clean up all the parts to remove any artefacts from the printing.

Push the HammerHead onto the end of the HammerBlockAndShank. This should be a relatively loose fit.

Lie the HammerHead and the HammerBlockAndShank on a table top, and attach the HammerShankEndCap to the end using a 2.5 mm x 8 mm countersunk self tapping screw. As you tighten the screw, keep the two flat faces against the table top so as to keep the flat faces parallel. Be careful not to over tighten this screw. It only needs to be tight enough to stop the HammerHead from spinning around and falling off.

Being very careful to keep their orientation the same in both ends, push two magnets into the holes in the HammerBlock. The magnets each have a north and a south pole. When you push the magnets in, you need to make sure that the north pole of one magnet and the south pole of the other face outwards. If you have two north poles or two south poles facing out, then the forces generated when the coil is energised will be in opposite directions, and the hammer won’t move. The easiest way to achieve this is to stack the magnets end to end, and push the hammer once onto the top of the stack and once on the bottom of the stack. Do not push the hammer twice onto the same end of the stack.

Create a pivot by cutting a 23 mm long piece of 3 mm wide 3d printing filament. Use a pair of pliers to slightly flatten the pivot in the middle. This will make the pivot a tight fit on the hub. Push the pivot through the pivot hole in the hammer head so that an equal length of filament sticks out either side. Note that although it may be tempting to use a piece of filament you have lying around after a printer jam up, or the last few centimetres of a reel, avoid this. You want the filament to be as straight and smooth as possible. If the pivot is not straight, it won’t turn. If the filament is not smooth, you may hear grinding noises as the rough two faces of the pivot slide against each other.