ARTICLES & REVIEWS
Ripping Long Boards On The Tablesaw
by Barb Siddiqui & Richard Jones
Ripping Long Boards On The Tablesaw
By Barb Siddiqui
For a smooth, secure cut when ripping a long workpiece, both infeed and outfeed support are important. If using a single-roller stand at the outfeed end, be certain it is set perpendicular to the blade so it doesn't carry the board at an angle away from the fence and line of cut. Roller balls on a stand, or use of a dedicated outfeed table, are more reliable options. Before you begin, check the board for irregularities such as loose knots, cupping, or any possible metal. Prepare one straight reference edge to run against a fence.
Featherboards are useful to put pressure on the workpiece immediately ahead of the blade, which will assure the work is consistently in line for the cut. This can be done with one's left hand but you have to consciously anchor that hand on the tabletop and allow the piece to slide along fingers and thumb, being certain not to move forward with the wood into the blade. A splinter will quickly distract you, so featherboards are safer.
Some workpieces are too wide to be guided by a featherboard in the miter slot. A few alternatives then are either using your hand to guide it as mentioned, some sort of sled setup to fully guide the work, or attaching a guide strip to the underside that can run against the far edge of the tablesaw.
For normal rip cuts, however, the safest method is to use a half-fence so the workpiece has no chance to bind between the uplifting back teeth of the blade and a tightly set fence line. Shop made half-fences can be as simple as a straight 2x4 attached to a regular fence, or arranged in an L-shape like the one pictured. What they all have in common is, they end at or before mid-blade. This lessens the danger of kickback by allowing for any contortion in the wood that might make it open up slightly (or greatly) after passing through the sawblade.
The L-shaped designed half-fence, attached with small knobs to T-slots in an auxiliary fence, works well because it allows the width of your hand, with a shoe-style push stick, to hold down the final end of the cut securely and safely. A homemade crown guard, as presented by Tage Frid in his 'Tage Frid Teaches Woodworking, Bk. 1, Joinery' (see Wood Central book review pages,) keeps chips from flying in the operator's face, assures some control in case of any problems, and allows passage of the operator's hands without impeding the cut, along with good visibility.
A well-aligned splitter is a must. A splitter attached to a crown guard is a convenience. Zero-clearance inserts are also an advantage in not letting small pieces fall through around the blade.
The half-fence pictured was made to attach with a 1/16" clearance above the tablesaw top, so dust would not clog against it and impair the cut. An alternative would be to make a 1/16"x1/8" rabbet on the edge facing the cutting action, and have the half-fence lay flush to the tabletop. This is needed more for multiple ripping than for the action of ripping a single board. You could always take a dust brush and clear any sawdust away, but that is just one more step to remember for each procedure.
One advantage to using this L-shaped setup is, you can rip boards right down to 1/2" strips if necessary, and not waste material by not having room to pass it by the blade safely.
Make long, shoe-style push sticks in different thicknesses, 3/4", 1/2", or 1/4", so you are ready for whatever is needed. The shoe-style is superior to a birds-mouth style for this job, because it holds the work flat to the tabletop.
If cutting thin material, you may want to rig an auxiliary fence with a cut-out shelf that allows passage of an edge of the material under the fence, assisting in holding it down to the table. Vertical featherboards attached on the fence can also put pressure downward, but their use would require a straight, regularly attached half-fence, not the L-shaped arrangement shown. Cutting laminate or 1/4" thick plywood would not require a half-fence at all.
One factor in the safety of long rip cuts is to consider ahead of time where your on/off switch is for the machinery. An operator usually stands to the left of the blade, out of the 'kick-back zone,' when using a tablesaw. Too many machines are made with the on/off switch on the right side, far out of reach. Some people rewire them, moving the switch to the left. Some people set up a knee board so it can be hit while their hands are full of troubled wood, and others fabricate an extension bar to the left, accessible where the operator stands, so the machine can be turned off easily. Whatever your method, decide it ahead of time, know where that button is, and know how you're going to reach it.
There is a great deal of controversy over blade height when ripping. Personally, I've tried to use a sawblade 1/4" above the workpiece, and I prefer to use a tablesaw blade at or near full height, well protected by an unobstructing guard.
With a reliable splitter and guard, infeed and outfeed support, the right pressure from featherboards and a good push stick, ripping long boards can become as routine as any other tablesaw operation. The general rule with any machinery is, if what you are about to do 'feels' unsafe or wrong in any way, stop what you are doing, think through the procedure, and either change it or find another way to do it. Safety is always the responsibility of the individual woodworker.
Ripping On the Tablesaw
By Richard Jones
Because I have a European background and training in furniture making, and familiarity with European woodworking machinery, Barb asked me to run my eye over her article describing her wood ripping techniques and table saw set up to act as a counterpoint to her findings, techniques, and suggestions. She discussed important safety topics, and offered good tips.
Ripping operations on the table saw can be fraught with danger if safety issues are underplayed, ignored, or you are unaware of potential causes of accidents. Without using a power feeder, the safest method for ripping jobs but an item well outside most amateurs armory of tools, strategies can be taken to reduce the chances of mishaps such as kickback and to prevent fingers, etc, making contact with the saw blade.
The half fence, or short set rip fence described by Barb is surely inspired by the normal ripping technique and fence setup taught to trainees in the UK and is the norm in Europe: European rip fences typically have a straight extrusion of aluminium easily adjusted fore and aft and locked in place in the body of the fence-The Delta Unifence in the US is of this pattern, and the style can also be seen on European imports to the US such as Felder, Altendorf, Casolin, Laguna, etc.. For ripping purposes the front end of the fence is set long enough to hold the wood being cut against the blade only to a point just beyond where the front downward chopping teeth finish the cut.
All that I would add to Barbs suggested pattern is to make the 'sub-fence' she described a convenient width, e.g., if you make it 4" wide and you want to rip a piece to 6" then it's easy to calculate and set the main fence to 10". Similarly, if you make a tall fence to facilitate ripping thick stock, make it a convenient 2" wide for example, or if you use metric use numbers like 30mm, 50mm, etc.. I notice that Beisemeyer(sp?) make a clamp device with a short length of melamine faced particle board attached that fits over their fence. The device is used as a length stop for cross cutting operations. A couple of these devices might be a good beginning for a home made short set rip fence.
A long fence, such as the full length style favoured in the US, I believe can increase the likelihood of kickback. Take a piece of wood being ripped where internal stresses are released and the kerf open up after the cut. Here, the piece being dimensioned [on the right of the blade] will attempt to bow away from the blade but is prevented from doing so by the long fence. The piece is forced tighter against the sawblade. This bending, if powerful enough, can cause the wood to make firm contact with those all important up-cutting rear rising teeth of the blade where probably 90% of kickbacks come from. If the saw is being operated without either a splitter (or riving knife) and no upper (crown) guard, the likelihood of kickback occurring increases. The short fence allows the piece to bend away from the blade freely.
Naturally if released internal stresses result in the kerf closing after the cut, the wood will pinch on the blade, again a likely cause of kickback, and a splitter or riving knife and over-blade guarding goes a long way to ameliorating this dangerous situation.
Referring to Barbs point on blade height preference, one reason for the blade being set low, particularly on European style saws with riving knife and crown guard encasing the teeth, is so that fingers can't easily be slipped between the crown guard and the top face of the wood- see later images. Another reason for a low set blade is to reduce spelch [blowout, US term?] on the
underside of the cut-more important with veneered board materials, than with rough ripping of solid stock.
Because of my European training and background I tend to use table saws in a different manner to most Americans, and this discussion touches on some of those differences. I do use the typical European short set rip fence for ripping, but I seldom use the feather boards or other hold downs described by Barb. In ripping rough sawn material the stuff is seldom of consistent thickness and width, so hold downs are either too tight, or too loose, and I was taught how to rip without them.
To rip I take the stance illustrated below. My right hand is at the back of the piece. My left hand also holds the wood down and against the fence, and moves forward with the cut. When my left hand is within about 6" of the blade, I lift it off and move it back toward the rear of the plank, and push again, or grab a push stick to give the sideways and downward force. The cut is completed as in the image on the right with push sticks to keep my hands away from the blade. As can be seen from the images, I have a preference for the dog-legged birds mouth style of push stick. I've always been reluctant to pass my hand alongside the blade, which the shoe type push stick generally forces you to do, but I prefer the shoe push stick to no push stick at all! If a helper is to hand, it's a good idea to set him or her up with a hammer and a few wedges to drive into the kerf after the cut-see left image.
I don't use a table saw for dadoing and moulding operations-I never have because those operations have not been a regular part of British hand fed sawing techniques for decades. But if I did use a saw this way I see definite benefits to incorporating hold downs, feather boards, etc., to reduce the chance of kickback and playing a role in keeping fingers away from the exposed unguarded blade. In these operations, the wooden parts are normally machined and squared to known dimensions, so the guards etc., can be set and left until the operation is complete.
A few final points. As can be seen from the images above, I use an outfeed table on my saw in preference to rollers. I like the inertia and friction that a flat table has, meaning that a piece of wood resting on it stays put. Rollers are an attractive option, and used correctly they can add a great deal to safety in support. One issue to bear in mind with rollers is that what can roll one way can quite easily roll the other way-maybe your helper mistakenly gently nudges a piece of wood back in the general direction of the rear of the sawblade. If it is picked up by the rear up-cutting teeth, the piece could easily turn into a projectile. Lastly, picking the right blade for the job helps
no end. Ripping solid wood is always best accomplished with dedicated flat top grind (FT) rip blades. Every other type of blade is a lesser compromise for this operation, although all of us make this compromise from time to time.
(The two pictures above first appeared in the August 1999 edition of Woodshop News in my article, "Catching The Rip With Big Sliders." Photography is by Black Star/Tom Callins.)
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Barb Siddiqui & Richard Jones
© 2003 by
Barb Siddiqui & Richard Jones
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