The Myth of the Left Tilt Saw - Canadian Woodworking Magazine

Machinery Details: Take a closer look at a trend in one of woodworking’s most popular machines, and prepare to be surprised.

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The Myth of the Left Tilt Saw



Photos by Rob Brown; Lead Photo – Courtesy of General

The Powermatic 66, the holy grail of table saws in the USA up until a few years ago (now discontinued), was only available in left-tilt. This was Powermatic’s flagship saw for over 40 years. Delta’s Unisaw, released in 1939, was only available in right-tilt until the late 1980s when Delta released a left-tilt saw to compete with the PM66. I expect the right- and left-tilt Unisaws of old will both be discontinued with the release of Delta’s new left-tilt-only version Unisaw. General released the model 350 table saw in 1966 and it wasn’t until July 2001 that they released the left-tilt model 650. General was rapidly expanding into the USA and needed a saw to compete with the PM66. The new kid on the block, Sawstop, has released three left-tilt table saws and I understand they have no intention to make a right-tilt version.

I believe the shift to left-tilt saws has been magazine/advertiser-driven. Articles on scary safety problems with right-tilt saws ignore the realities how people actually use table saws and miss out on some key points about how saws work.

Let’s look at the key arguments:
 
Motor cover on left vs. right. The motor cover is on the right of a right-tilt table saw and on the left of a left-tilt table saw. You could argue on a right-tilt it is hard to gain access to the motor. Or, you could argue, on a left-tilt it is harder to mount a sliding table. Left-tilt allows you to have a full cabinet of drawers under your side extension table. Advantage: Even
 
Location of tilt wheel. On a right-tilt, the bevel wheel is on the left. On a left-tilt, it is on the right, so you can turn it with your right hand. Advantage: Left-tilt


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Tilt Wheel – Since the tilt wheel of a right-tilt saw is on the left it makes it slightly more difficult for a right-handed person to use.

Arbor nut handedness. On a right-tilt, the nut is left-handed. On a left-tilt, it is right-handed. Advantage: Left-tilt


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Nut Handedness – With a right-tilt saw (shown) the nut is manipulated with the left hand, a slight disadvantage for most people. (Photo by Tom Morton)

Ripping material greater than 12" wide. If you are using a right-tilt table saw, the second bevel rip will leave the bevel of the first rip wanting to go “under” the rip fence. On a right-tilt table saw, you can move the fence to the left side of the blade for cutting parts 12" or less. Most table saws have a rip capacity of 12" to the left of the blade. On a left-tilt table saw you can rip work pieces up to the full capacity of the fence on the right-hand side of the blade. Advantage: Left-tilt


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Bevelling Wide Pieces – With a right-tilt saw you can move the fence to the left of the blade to make perfect cuts up to about 12" wide but no wider.

Tear-out on bevel cuts. On a right-tilt table saw, the “point” of the cut is at the bottom where tear-out is more likely. On a left-tilt saw, the “point” is on top where tear-out is less likely. This is reversed when using a sliding table. Advantage: Left-tilt


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Tear-out – While bevelling with a right-tilt saw you will often have to cut with the good side down, which increases the chance of tear-out.

Kickback while bevel ripping. On a right-tilt saw, your material is trapped between/underneath the blade and the fence. Any “movement” in the wood will increase the friction between the material and the blade, increasing the likelihood of kickback. On a left-tilt, the material is between/above the blade and the fence. Any “movement” of the material and it simply rides up on top of the blade. Advantage: Left-tilt


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Kickback – Because the angled blade of a right-tilt saw traps the work piece between itself and the fence with nowhere to go any internal stress that’s released when the work piece is machined may cause the blade to bind, causing kickback to occur.

Cursor accuracy. On a right-tilt saw, you align the fence to the arbor flange. It does not matter if you use a full kerf blade, a 3/32" blade or a 22mm dado, the fence cursor is always accurate. On a left-tilt saw, the fence cannot be aligned to the arbor flange. Advantage: Heavily Right-tilt


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Cursor Accuracy – The largest advantage when using a right-tilt table saw is that no matter what type of blade you’re working with the cursor will always be dead on. This is the overriding reason Eisan favors a right-tilt saw. (Photo by Tom Morton)

If you regularly rip a lot of pieces greater than 12", a left-tilt saw may be your best choice. The alternative is to rip square and bevel on your router table.

I believe the safety of left-tilts is exaggerated and used mostly to sell magazines and saws. I could see if you take a dressed 4' long, 12" wide board and want to rip a bevel in the middle of it, you could have potential kickback. But whether it is a left or a right-tilt, you will end up with two pretzels if there’s that much internal stress in the board. It would have been much better to rough dimension the board to 7" wide before dressing. You will then be removing so little wood on your bevel rip (left or right-tilt), you won’t be relieving any more internal stresses and distorting the board. When you bevel-rip the edge of this 7" board on a right-tilt, the board will be trapped under the blade and you will get a nice crisp cut. On a left-tilt, the board bounces on top of the blade requiring some sort of feather board near the blade to hold the board down. This potential kickback issue is virtually eliminated with sheet goods due to their uniformity.

The thing that every article I have ever read glosses over is cursor accuracy. On a right-tilt saw the cursor is accurate no matter what blade or dado size you put on your saw. On a left-tilt saw, once you zero your fence with a full-kerf blade, you have to subtract 1/32" from your fence scale when you use a thin kerf blade or reset your cursor. With a 22mm dado, you have to add 0.74114" to your cursor reading.

I believe that, in the real world, the hypothetical safety benefit of bevel-ripping wide solid wood boards on a left-tilt saw is of far less importance than the cursor accuracy of a right-tilt. I also believe that if you are uncomfortable performing new operations on any machine you shouldn’t do them.




DAVID EISAN
David Eisan