Key base repair tools

for balance beam pin holes on manual keyboard keys. Knocked out key bottom bores can be renewed exactly with this tool set and the wood patches. The prerequisite, however, is that it is a cylindrical bore behind the axle bore, otherwise the tool guide is missing.

By means of a basic drill equipped with 4 versch. interchangeable tenon sizes with depth stop and special replacement cross wood patches made of hardwood, this repair can be done quickly in 4 steps.

A taper countersink is used to drill out the knocked-out hole until the larger hole behind it is just cleared. Depending on the size of the hole found, the corresponding D=6.5/7.0/7.5/8.0 mm pin is inserted. The high-quality artificial drill is equipped with a depth stop, which is set according to the patching hole depth. The guide pin is now used to drill the hole for the replacement plate with an outer diameter of 20 mm and a small center hole in exactly the same position as before. Then the replacement plate is glued in place and, after drying, adjusted laterally to the width of the key. The balance beam pin bore can now still be adjusted to the axle pin size by reaming and the axle again engages in the key exactly at the previous position.

Together with the tool, 15 pieces of patching plates with an outer diameter of 20 mm and a thickness of approx. 7.5 mm are supplied. These are also available separately in a 10 piece package.