Unfortunately, it is not easy to remove the jig for inspecting the result, as one
could with the "Reliance" so it is necessary to remove the drill from the jig. First,
check that the cutting edge is straight to prove that you have sharpened the drill
with the correct angle. If that is satisfactory, then check the chisel angle with
the gauge. It is likely that when first using the jig that you will find that an
adjustment to the projection will be needed. Remember, more if the chisel angle is
too great and less if too small. Repeat the process until a satisfactory result is
achieved, at which time you can check the clearance angle against a similar size
new drill just to be doubly sure as you may consider a little more clearance is required
even if the chisel angle appears OK. With that done, make a note of the drill's diameter
and the projection used, for future reference.
My advice would be to arm your self with a few drills of varying sizes and set about
sharpening these making a note of the projection used as above. Keep the results
for future reference and as the values are not crucial you can use these to interpolate
for drill sizes between, adding to your records as more sizes of drills are sharpened.
Users of the "Reliance" did for many years achieve this just visually so reasonable
results can clearly be achieved using the method. However, I believe greater accurately
is worth aiming for, especially as it is necessary to remove the drill for inspection
with the jig being used. In this case, I feel the simple attachment shown in Photographs
10 & 11 to control rotation to be all but essential and therefore worth making. The
photographs should make the method of using it clear and whilst in theory it will
work with any drill the length of the vee in which the drill rests is of a length
that will prevent it working much below a 5mm diameter drill. Incidentally, the jig
is stated as working with drills from 3 to 18mm diameter.
One point about its use that I will mention is that the two arms should be parallel
when secured onto the drill. Again, precision is not called for, visually should
be sufficiently accurate, perhaps measure with a rule for larger drills.
For greater detail on sharpening standard drills, frequently known as jobber drills,
and also dimensions for the 180 degree setting assembly, see my book Tool and Cutter
Sharpening in the Workshop Practice Series. The book also covers such subjects as
drills specifically for drilling brass and aluminium. Point thinning is also covered
which reduces the length of the chisel, especially beneficial when using larger drill
sizes on smaller machines.