Next I ream the bore to the final shape. Reamers are scraping tools made from steel bar. The steel is turned down to the desired shape of the bore on a metal lathe. The edges are sharpened and the reamer is used in the woodlathe at low speed. The cylinder is now mounted on the woodlathe between centres and as much wood as possible is removed from the outside.
Lumps have to be left for key mounts and an allowance has to be made for shrinkage.
The Waiting This is the bit the customer hates. But it is a vital investment in the stability of the instrument. Because wood shrinks as it dries, all sorts of stresses are present in seasoned timber. When you drill out the hole for the bore, the remaining timber starts to move again. It takes a long time for these stresses to work their way out - a break of three to four months is the least one should wait before continuing.