On Thu, 3 Nov 2005 22:56:02 -0600, "Deborah Kelly"
spent a bit of time in the archives, but didn't find what I was
looking for. but this is close:
and this is good for general reading:
some good reading about saw safety:
although it's in british rather than proper 'ol amurican english...
here's a website that has a pretty good picture:
of what Unisaw A100 (keeter) is describing:
From: Unisaw A100
The following presumes you have a right tilting Delta
Unisaw. Please make the necessary adjustments for your make
of saw, insert thickness and blade tilt direction.
How To Make A Zero Clearance Insert With Splitter:
1) Go to Home Depot/Lowes and give an eye up to the stack
of 1/2" MDF.
2) Find a sheet that hasn't been dinged by the fork lift
tines during the twice weekly Warehouse Rodeo and Jousting
3) Wrestle the sheet off and onto one of the (insert color
here) flat carts.
4) Wheel it back to the nice man at the Safety Speed-Cut
5) Instruct him to make cross cuts at about 32". You may
choose to use another size(s). Exercise this option now.
6) Load the cut sheets back onto the cart, stand in line,
let everyone know how peeved you are that you are being made
to stand in line, make an ass of yourself and then pay the
nice people at the check out.
7) When back at the shop set aside one piece for a table
saw sled to be built later. Set another aside for future
projects or jigs and fixtures.
8) With the last piece begin ripping the sheet into pieces
1/16"ish wider than your table saw blade insert.
9) Cross cut the pieces 1/16"ish longer than your insert.
10) Make a template. Here's where people usually chime in
to just use your present insert to make the new inserts. I
prefer to make a template for reasons that will be made
11) Start with your OEM insert and trace a line around it
onto one of the MDF blanks.
12) Band saw (jig saw) the rounded ends off.
13) Go back to Home Depot/Lowes and buy some 3M (Scotch)
No. 4011 Exterior Mounting Tape. It has a proper amount of
tackiness but isn't so think that the template/item being
cut will shift thus spoiling the cut.
14) Double face tape the MDF to the OEM insert with
4-pieces of tape 1" long. Press together using hand
15) Load router table with router bit having a bearing on
top. Raise bit until the cutter is a red cubic hair or so
above the thickness of the MDF.
16) Run the MDF/OEM insert sandwich into the bit and trim
off all edges and ends.
17) Go back to Home Depot/Lowes and purchase a box of 1/2-8
flat head Phillips sheet metal screws.
18) Using the OEM insert to locate, drill and countersink
the face of your template for four of these screws.
19) Insert screws so that points just peek out by 1/32"ish.
20) Using this template take another of the MDF blanks and
press the pointy end screw side onto the blank.
21) Rout off the excess as you did above with the template
and OEM insert.
22) Rinse and repeat until all blanks are routed.
23) Drill and countersink the face of the MDF insert for
leveling screws. Step 20 will have pre-located these for
you. Insert 1/2-8 flat head Phillips screws into freshly
drilled and countersunk holes so tips are just coming
24) Into the edge of each template drill and countersink a
hole for a 3/4" course thread drywall screw of other screw
of your choosing. Do the same with one screw on the end of
the MDF insert. Be sure to oversize this hole so the screw
does not split the MDF. This screw hole is not structural.
25) Insert screws into freshly drilled and countersunk
26) Place MDF insert into blade opening in table saw.
Check for fit. Adjust leveling screws so insert is flush
with the saw table. Adjust the edge screws in or out for
perfect snug fit.
26) Repeat the above with three blanks for every saw blade
you own, i.e., you have four blades then fit up twelve
27) Using your dado set place onto the saw arbor the two
28) Insert MDF insert into blade opening and park the saw
fence over it but to the wide side away from the line of the
dado set below.
29) Raise dado set until the cutters are just starting to
bulge through the face of the MDF insert.
30) Repeat until all inserts are done.
31) Replace dado cutters with your saw blade and repeat the
raising through though this time raise the blade as high as
it will go.
32) Carefully measure from the fence side face of the saw
blade to the fence side edge of the insert and set saw fence
at that setting.
33) Feed one of the inserts into the saw blade for 1 1/2".
Stop and with draw.
34) Set up porty planer and begin planing stock to a
thickness that matches the kerf made in the last step.
Note: Don't presume that you only need to plane the wood to
the advertised blade kerf unless your saw has zero run out.
35) Cut and fit the freshly planed stock into the kerf.
Let it stick out a minimum of 1/4" plus the thickness of
whatever material you expect to be cutting, i.e., for 3/4"
material you will want this to stand 1".
36) Glue freshly trimmed, freshly planed stock into kerf
slot in the MDF insert. When dry, insert MDF insert into
saw blade opening and rip a piece of wood. Check to see
that there is no gap between the wood and the freshly glued,
freshly trimmed, freshly planed stock.
37) Repeat until all inserts for all inserts are done.
38) Set aside balance of insert blanks to be used at a
later date or for when you set up for dado cutting.
39) Post your horrible experience at Home Depot/Lowes on
rec.woodorking and make an ass of yourself.
A splitter, as well as a riving knife, is intended to do one
thing - keep the kerf from closing and making contact
with the teeth at the back of the blade coming up out
of the saw table top, being lifted up off the table and
into the teeth near the top of the blade. From there
the speed of the part goes to about 150 mph and the
direction can be anyone's guess.
A splitter typically is close to the back of the blade
WHEN THE BLADE IS SET TO ITS MAXIMUM HEIGHT.
But as the blade is lowered, the distance between the
spliiter and the rear teeth increases. When cutting
1/2" - 3/4" stock, which are what most of us
typically are working with, there can be several
inches between the splitter and the rear teeth. In
that situation, the splitter isn't doing what it's
supposed to do at the beginning of the cut.
As for "anti-kickback pawls" they're typically
more of a PITA and less of a "safety device".
There are several types of kickback and causes.
If you understand what does what you can take
the steps you deem necessary to minimize
So here's some info that should give you a
good start on what you need to know about
the causes of kickback. Some are obvious
and some aren't. A cupped, twisted or
bowed piece of wood can be far more
dangerous than no splitter or riving knife.
(for the regulars, sorry about posting the
url again - but if it prevents one injury ...)
It is my understanding that many European machines come with riving
knives that raise and lower with the blade to retain optimal spacing.
The guard is a separate entity. But the difference in name is more of
a regional 'he says - she says' difference than a physical one.
And if the pawls are not sharp enough to dig into the wood, or strong
enough to restrain the piece against 3 HP of throbbing Baldor, they
are useless anyway.
More thorough information on these facts should probably be given
emphasis in a new machine's instruction manual, rather than on some
outdated, dysfunctional OEM splitter. It's Christmas time - lot's of
new table saws and lots of new owners... We don't want to kill off
any of next years tool shoppers...
Simply meeting some UL/CSA standard as to the existence of a blade
guard doesn't equate into a useable OR well designed feature. What it
DOES indicate is that MFG's designed some minimal, crappy contraption
that was needed to barely pass spec 20 years ago, and hasn't put one
iota of though into it since.
Let's take a poll - how many people here like OR use the guard that
with their saw? A show of hands, please...
Mine is removed ONLY for non through cuts. My BT3000 came with riving
knife and blade guard. I've had case hardened wood clamp the riving
knife which was about 3/16" from spinning teeth hard enough to stop
forward movement. It is curved matching 10 blade shape.
The purpose of the riving knife is explained on my web site.
Please look at Circular Sawbench Safety - Riving Knife.
The 'tongue' might be a splitter, a less effecive device that can allow too
great a gap between itself and the up-running teeth.
Jeff Gorman, West Yorkshire, UK
email : Username is amgron
yep, riving knives are better than splitters.
however, there are a large number of very fine old tablesaws in north
america for which riving knives are not an option. on my 40 year old
powermatic it's not a matter of what can be purchased commercially-
there really is no way to mount one.
a homemade splitter is better than no splitter, and really does go a
long way to prevent kickback.
FYI, I have a set of shop made zero clearance throat plates for
various configurations. Rather than worrying about placing and
removing the splitter I swap out a throat plate with a splitter glued
in (1/8 strip of maple) and one without. Doesn't take long at all.
But lookinig over the site at
http://www.homestead.com/ValRoseWoodWorks/Splitter.html I think I am
going to rethink what I do.
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