If you are a regular visitor to the many
woodworking forums and newsgroups available online, you will
probably often see questions raised by newer woodworkers about
zero-clearance inserts for table saws. "How do I make them?" or
"Where can I buy one for xxxxx model saw". The question is
raised at least a few times per month on many forums. It is true
that making inserts is certainly the most economical way of
producing these inserts, and you can use offcuts or scrap pieces
to do this, however, it appears that not all our readers like
making them, have time to make them, or don't have the tools
needed to make them easily, so we decided we might try and
review some commercially available systems over the next few
months.
The first product we managed to get our hands on
is the Betterley Tru-Cut system. So let's take a closer look...
A zero clearance insert is a solid insert for
the table saw with a kerf cut into it by the blade. For a
standard 0 degree ZCI, you place and level your insert and
clamp it down before raising the saw blade up through the
insert. This cuts a clearance for the saw blade only, and the
rest of the insert provides the necessary support for your workpiece right up next to the blade on both sides, and front
and back too if you like. It also does away with that large,
nasty gap in your standard metal insert. The downside is that
you need to make a new insert for each angle you have your blade
set to, i.e. one for square cuts (0 degrees) another for
45 degree cuts and so on. It's a small price to pay for the
great benefits ZCIs offer. Another advantage is that it aids in
dust collection by pushing more dust below the blade to your
extraction system. If you need to cut veneers or thin material
for inlay or parquetry work, you must have a zero clearance
insert to achieve good and safe results.
|
Tru-Cut Model # |
Saw Description (fits
this model saw) |
| DR-110 |
Delta Right-Tilt Unisaw,
Contractor's Saw |
| DL-112 |
Delta Left-Tilt Unisaw |
| PL-212 |
Powermatic 66 |
| JR-310 |
Jet 10" Right Tilt Cabinet
Saw (XACTA), Contractor's Saw |
| JL-312 |
Jet 10" Left Tilt Cabinet
Saw (XACTA) |
| JS-314 |
Jet 10" Super Saw |
| WL-412 |
DeWalt DW746 |
| CL-512 |
Craftsman, Ridgid (3 3/4" x
14") |
The Tru-Cut system comprises two components.
The metal aluminum insert itself, and the replaceable phenolic kerf inserts.
The red aluminum insert is very solid and quite heavy. It is very
well machined to provide a flat top surface and relieved
to accept the blue phenolic kerf inserts. A number of tapped screw holes are
also machined to allow the user to level the insert with the
saw table, level the phenolic inserts with the aluminum insert
face and secure the phenolic to the aluminum insert itself.
Set up occurs in that same order. A bunch of leveling screws
are included to allow you to level every component of the
insert to ensure a flush surface on which your wood will run
over. It takes about 10 minutes to set your main leveling
screws and phenolic insert leveling screws, and in most cases,
this is a one off adjustment. The leveling screws have a bit
of red thread sealing tape around them that ensures a tight
fit and reduced chance of movement once they are inserted and
adjusted.
The blue phenolic inserts - the
replaceable component of the system - have six countersunk
holes for securing it to the insert. To swap the insert for a
new or different one, just release the screws, switch inserts
and secure back down. No need to make entirely separate zero
clearance inserts for each cutting task, although, admittedly,
it does takes longer to change out a phenolic
insert as opposed to a whole shop-made insert for a particular
task. The underside of the inserts have a relief cut in them
that will allow you to make the initial kerf cut without the
need to use a smaller blade for clearance, or perform other
procedures to make the initial kerf clearance before you can
set the ZCI insert down flat and flush with your table (see
photo). This is very handy and saves a lot of time when making
the initial cut through the insert. You will still need to
clamp the whole insert down to the table when making this
initial cut however, the design simply takes out a few steps
to get started, and these steps can be time consuming, so
there are benefits to the system in that department.
On the edge of one side of the aluminum insert
are two small spring-loaded ball plungers. When the aluminum
insert is in your table saw, these ball plungers are pushed in
slightly and help keep the insert firm in place, reduce insert
vibration when the saw is in use, and prevent lateral movement
of the insert which can result in oversized kerf cuts through
your phenolic plate. Its a great design and I only wished my
standard inserts had the same feature instead of the crummy
rubber spacer I battled with for a long time! No such problem
now.
The solid aluminum also ensures the insert will not warp, bend
or twist under load and remains flat with the table. Sometimes
hardwood inserts can bow and twist over time. This is one
problem the metal insert plates are able to avoid.
In Use
So with the inserts all set up, the initial kerf cut made,
the Tru-cut insert system is ready to go. I have made inserts
for standard 0 degree cuts (square cuts), 45 degree cuts and
some for the dado set at the most common thicknesses - 1/4"
for drawers, and 3/4" for shelf dados etc.
If you have not used a ZCI before, the results
you see will be quite noticeable. You can expect less chipping
and splintering on the underside of the cut as the wood is
supported right up against the blade. We cut ply, chipboard
and melamine with very little noticeable chipout on the
underside using a standard 40 tooth combination blade.
There
is no chance of small offcuts or slithers of wood falling down
next to the blade, and reduced chance of wood twisting,
bending, or hitting the back edge of the insert, as is
sometimes possible with standard large gap inserts. If you use
the GRR-Ripper table saw accessory or regularly rip thin
strips of wood on the table saw, a zero clearance insert is a
must have item. It will improve safety and quality of cut.
There is a relief milled in the back end of
the aluminum plate to accept your standard saw guard fitting
that comes with your saw. I have left the guard out of the
photos supplied here for clarity only, but the guard did fit
fine. You could also fit the MJ Splitter by Microjig if you
only plan to raise the blade a small way above the table, but
you cannot use a 10" blade at full height and accommodate the
splitter because of the relief cut in the rear of the plate
leaves no where to secure your MJ splitter down. Other drop-in
splitters may also work if they secure by the same mechanism
and have the same clearance as the standard splitter/guard
that shipped with your saw.
You can remove the
ZCI from the saw by using the milled finger hole at the left
front edge of the insert. Lifting it straight up allows it to
be removed relatively easy. Getting the insert back in takes a
little longer as it is a relatively tight fit, but it will be
secure in the slot.
Conclusion
Replacement phenolic inserts come in packs of two and retail
for around $17.99 per pack. The Tru-Cut insert itself retails
for around US$79.99 and comes with 1 phenolic insert to get
you going. Realistically, you will want to buy the Tru-Cut
insert and at least one pack of replaceable phenolic inserts
to get started (this gives you three phenolic inserts to start
with). This will cost you just under US$98 (prices as at
5/5/05) which is a bit of an outlay for a table saw insert.
There is no doubt you could make your own much cheaper, but as
mentioned above, some people don't wish to make their own for
many reasons, so the Tru-Cut system may be an option for them.
So, if you are prepared to invest the money in
the system, you will get quite a solid product. It will be
easier to make various inserts to use for your table saw, but
switching them will take longer than dropping in a full size
shop-made insert. You can buy full size phenolic inserts for
various model saws at about US$15-$20 each, so I guess in the
long run, you are only paying half as much per phenolic insert
when used with the Betterley Tru-Cut system, so if you choose
to buy your ZCIs instead of making them, there are dollars to
be saved over time with the Tru-Cut system, especially as a
single ZCI eventually gets chewed up a little and needs
replacing over time.
The Betterley Tru-Cut Insert System is quite a
good product if you own one of the table saw models that the
inserts are made for. And I guess, that if you have read this
far into the review, you may be the type of person that
doesn't like to make their own inserts anyway, so the Tru-Cut
system is worth weighing up against other ZCI solutions
available on the market.
