Helical Cutterhead
There are many cutterhead designs
that carry the helical label, including
simple straight blades broken into
segments and dispersed around the
cutterhead cylinder. However,
despite the name, they retain many
of the liabilities of the long blade
designs. While designing the PJ-
882HH 8" Parallelogram Jointer we
wanted to incorporate the
performance of a true segmented,
shear-cutting helical head.
The PJ-882HH 8" Parallelogram
Jointer helical cutterhead is so
effective because its carbide inserts are arranged in spiral-shaped rows. The inserts have a 4”
radius ground into them and are mounted so they approach the wood at a 14-degree angle. That
creates a true shear cut that eliminates much of the impact and the resulting fiber disturbance
other cutterhead designs deliver to the wood.
The helical cutterhead (left) uses individual solid carbide cutters, each with
four cutting edges that can be “indexed” four times should the first edge
become dull. We include five extra carbide cutters, screws and two drivers
with the PJ-882HH. One driver is placed in a screw to hold the head steady
while the other driver loosens the screw at the cutter to be replaced or
indexed.
The helical cutterhead cuts so efficiently that it dramatically reduces the noise made when
cutting wood. In fact, it is so quiet, new PJ-882HH 8" Parallelogram Jointer users often think it is
not cutting wood at all, until they see the results. The shearing effect of the helical cutterhead
produces a remarkably smooth surface on even heavily figured wood.
The helical cutterhead inserts are precisely machined from solid
high-grade carbide, each with four identical cutting edges. If an
edge eventually goes dull, you simply index it to the next cutting
edge! Each insert has a marking at one edge that makes indexing
all or any number of them the same way very easy, though
needing to do that is unlikely.
Because the inserts themselves and the seats into which they fit
are so precisely machined, there is no adjustment or “fitting”
necessary. Indexing or replacing an insert takes just seconds.
Simply loosen its retaining screw, turn the insert to its new
position and tighten the screw.
The durability of the carbide combined with the low impact, shear cutting action mean the inserts
have an extremely long life, far exceeding that of straight blades. The potential life span of these
carbide inserts means that many PJ-882HH 8" Parallelogram Jointer users may go years before
having to index them. Should a hidden piece of metal be encountered and actually damage a few
of the carbide inserts only the ones actually contacting the metal need to be indexed or replaced.
The solid carbide cutters in the
helical head last far longer than
straight knives, but just in case, we
provide extra cutters, screws and
drivers to install them
