Drill Doctor 750X - Manual (Page 8)

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Identifying Correctly Sharpened
Drill Bits (and what to do with
those that aren’t!)
Correctly Sharpened Bits
The entire surface from the
Cutting Edge to the Heel will
have a finely ground surface
without ridges or indenta-
tions. The Heel will always
be lower than the Cutting
Edge. The Chisel Edge will be
clean and straight.
Problem Cause
Chuck Jaws did not grip drill
bit properly in the aligning
process (Page 8).
Solution
Realign the bit by carefully
following steps 1 through 5
on Pages 8 to 10.
Problem
The Chisel Edge is
not clean or
straight.
Cause
The bit isn’t completely ground yet.
Solution
Continue sharpening the bit until
the chisel is clean and straight. If
the machine quits removing mate-
rial before the chisel is clean, re-
align and sharpen again. (Model
750X users can increase or
decrease MTO (material take-off)
to speed up this process.
Cutting Edge
Heel
Relief Angle
Problem Cause
Drill bit alignment.
Solution
Re-align the drill using the
Adjustable Alignment proce-
dure on page 19. To increase
relief, insert the alignment
guide on the chuck closer to
the (+) side of the alignment
port, then sharpen the bit.
Insuffecient (Negative)
relief or a slow cutting
drill bit.
Cause
Chuck too loose or too much
pressure when sharpening.
Solution
Use more torque when tight-
ening the Chuck or less pres-
sure when sharpening. Clean
the Chuck w/ compressed air
if the problem persists.
Bit backing out or
slipping out of the
jaws when you are
sharpening
Problem
Split Points
Split point drill bits prevent walk-around on the material
before they begin to cut.
This feature is described as self-centering. The need to
center punch is effectively eliminated. A standard drill bit
chisel point has to wear an area in the middle of the hole
to be drilled before the cutting edges will remove material.
Due to its additional cutting lips along the chisel edge, a
split point will begin cutting immediately. Up to 70% less
thrust (when compared to a non-split or conventional
point) is required to drill a hole with a split point.
Chisel Point
Cutting Edge
Heel
The Chisel Edge
is ground flat.
Incorrectly Sharpened Bits