AMT 4121 - Advanced Jointing and Cutterhead Maintenance; Knife Whettering and Cutterhead Repairs

DIRECTION OF GRAIN
Avoid feeding work into the jo inte r against the grain
as show in Fig. 11. The r es ult will be c hippe d and
splintered edges.
CORRECT FHD·WITH THf GRAIN
Fig. 12
BEVELING
To c ut a bevel, lock the fence at the required angle
and run the work across the knives while keeping it
firmly against the fence and tables. Several passes
may be necessary to arri ve al the desired result.
When the angle is small, there is l ittle difference
whether the fence is tilted to the right or left. Ho w-
ever, at greater angles approaching 45 degrees, it is
increasingly difficult to hold the work properly when
the fence is tilted to the right. The advantage of the
double'lilting fence is appre ci ated under such con-
ditions.
When tilted to the left, the fence forms a V-shape
with the tables, and the work is easily pressed into
the pocket while passing il across the knives. If the
bevel is laid out on the piece in such direction that
Ihis involves cutting against the grain, it will be
better to lilt Ihe fence 10 the right.
TAPER CUTS
One of the most useful joinler operations is c uttin g
an edge to a laper. The method can be used on a
wide variety of work. Tapered legs of furniture are a
common example.
Instead of laying the piece on the front table, lower
the forward end of the work onto the rear table. Do
this very carefully, as Ihe piece will span the knives,
and they will take a "bite" from the work with a ten-
dency 10 kick back unless the piece is firmly held .
N
ow push Ihe work forward as in ordinary jointing.
The effect is to plane off all Ihe slack in front of the
k nives, to increase depth , leaving a tapered surface.
The ridg e le ft by the knives when starti ng the taper
may be removed by laking a very light cu t according
to the regular method for jOinting, with the front
table ra ised to its usual position.
Pr actice is required in th is operation, and the begin·
ner is advised to make trial c uls on waste materia l.
Taper cuts over part of the length and a number of
other special operations ca n easily be done by the
experienced craftsman.
B
WRONG FHO ·AGA.INSr THE GRA.ING
Fig. 11
Feed with the grain as in Fig . 12 to obtain a smooth
surface.
CUTTERHEAD MAINTENANCE AND REPAIRS
After considerable use, Ihe knives will become dull
and it will not be possible to do accurate work.
Unless badly damaged by running into metal or other
hard material , they may be sharpened as follows:
WHETTING KNIVES
DISCONNECT THE MACHINE FROM POWER
SOURCE. Use a fine carborundum stone; cover it
partly with paper as indicated in Fig. 13 to avoid
marking the table. Lay the stone on the lront table,
lower the table and turn the culterhead forward until
the Slone lies flal on the bevel of the knife , as shown.
Hold the culterhead from turning , and whet the
bevelled edge of the knife, stroking lengthwise by
sliding the stone back and forth across the table . 00
the same amount of whetting on each of the three
blades.
OILsrONE p"'RrLV
WHETTING ~NIV~S
Fig . 13
CUTTERHEAD REPAIRS
The entire cutter head assembly may be removed for
cl eaning, bearing or blade repl acement or any other
cutterhead maintenan ce procedures. To remove it ,
lower both feed tables to clear the c ulterhead . Re-
move the bearing retaining stud hex nuts (Part No .
17 ) and remove the entire culterhead assembly , with
bearings , studs and bearing housings. When reo
installing the assembly, be sure the machined
curved seats of the base casting are free of dirt, dust,
grease, etc. to obtain a good tight fit.