Instruction Manual
Section Five
I. SHARPENING STANDARD TAPS UP TO 1 INCH DIAMETER
A. Equipment and Accessories required (see Figure 53A):
B947 Tap Grinding Fixture; B641C
9
/
16
inch collet (STANDARD 5C — STAND
ARD EQUIPMENT); B647B Bushings to fit taps No. 7 & 8, 9 & 10. 11 & 12.
and sizes
¼
inch,
5
/
16
inch,
⅜
inch,
7
/
16
inch,
½
inch.
9
/
16
inch,
⅝,
inch (STANDARD
EQUIPMENT); B647B Bushing to fit taps No. 0 to 6 (AVAILABLE ACCES
SORY); B947C Six Lift Cams for R. H. Thread Taps (STANDARD EQUIP
MENT) listed by flute range and tap rise; F3947CL Six Lift Cams for L. H.
Thread Taps 'AVAILABLE ACCESSORY); B947D Two, Three, and Four Flute
Index Discs (STANDARD EQUIPMENT); B947D Five and Six Flute Index
Discs (AVAILABLE ACCESSORY); B651C800 .800 inch Collet for 1 inch
taps (AVAILABLE ACCESSORY); B647F Bushings for B641C800 Collet, to
fit
11
/
16
inch,
¾
inch, and
⅞
inch size taps (AVAILABLE ACCESSORY)
B. Mount the B947 Fixture on the left end of the grinder table as shown in
Photo 53. (INDEX NUMBERS ARE FROM FIGURE 53A.) Mount a 6 inch
straight wheel (80 GRIT) and wheel guard as shown
C. Swivel the tap grinder fixture base Swivel (No. 9 ) , and thus the spindle, to
the desired chamfer angle. Angles required for 2, 4, 6, and 8 thread chamfers
are approximately 17 degrees, 9 degrees, 6 degrees, and 4 degrees respectively
for standard chamfer taps.
D. Select the Index Disc for the tap size with the correct number of lifts on the
Index Disc to correspond to the number of flutes on the tap Insert into the
fixture as described in step E below.
E. Installation of the Index Disc (SEE THE INDEX NUMBERS IN FIGURE 22)
1 Unscrew the Collet Draw Tube and Handwheel from the Collet (NUMBERS
5, 20, and 4) and remove the Collet Adapter (No. 12), from the Spindle
(No. 18).
2. Remove the B947T Thrust Collar (No. 19) and B947Y Coil (No. 21) by
releasing Socket Set Screw (No. 23).
3. Pull out the Collet Adapter Assembly (No. 12) from the front end of
the fixture.
4 Remove the keyed Index Disc (No. 14) and install the one with the correct
number of index lobs,
5. If a different Lift Cam is needed, proceed to step F. If no different Cam
is needed, omit step F and install the Collet Adapter Assembly again into
the spindle in reverse order. Proceed to step G and following steps.
F. Selection and Installation of the Cam:
1. The Cam should be selected according to tap size. All Cams are stamped
indicating the number of flutes and the tap size each will serve In addi
tion to standard equipment cams for right-hand threaded taps, Cams are
available for left-hand threaded taps.
2. Install the Cam into the Spindle Assembly:
(a) Unlock the Spindle Housing by releasing the Hex Socket Cap Screw
(No. 25).
(b) Pull the spindle forward from the Housing to expose the Cam.
—71—