Drilling bobbins
At a recent Club evening a member constructing his first clock and having to make lantern pinions asked how to drill the bobbin with a No 61 drill without risking breakage or wander of such a delicate drill.
Experienced clockmakers will know that the hole to be drilled is started or spotted with the drill protruding about 1/8in from the holding device. Those using open-ended collets in their drilling spindle will have no trouble accommodating the length of the drill shank but those using a Jacobs chuck should know that the back of the chuck and the taper on which it is mounted are normally soft enough to be drilled; mine has a 1/8in blind hole to accommodate these small drill shanks.
John Feeley, UK
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