Accurate tapping
As any lathe owner will know, accurate tapping is simple using the tailstock chuck. Problems arise when we need to tap a hole in a large plate or irregular
shaped object that will not fit in the lathe. Particularly, ensuring the tap in the tap holder is dead true (90 degrees) to the workpiece when starting to
cut the thread. A simple solution is to use a drill press. First, observe the usual safety rules: most importantly isolate the power supply.
Fit the tap in the chuck, then set up the workpiece in a machine vice, set the position of the vice relative to the tap and secure to the drill press
table. Unlock the table and raise until the tap locates in the hole and turn the chuck by hand until the thread has started to be cut. Leaving the table
unlocked and supported with one hand it is a simple matter to turn the chuck with the other hand until the thread is finished.
I have easily tapped material from 1mm up to 8mm with taps as small as 10 BA using this method and most importantly it is 100 per cent accurate
every time>
Alan Coppen, UK
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