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place by a cam lever, as are many aluminum tool guides and back-to-back bench clamps. Some routers even use a cam lever to "lock in" the bit depth. How It Works. A cam lever rotates around a pin called a cross dowel. The lower drawing at left shows how the pivot point on the wide, rounded part of the cam lever is a little off-center (called an eccentric cam). When the lever is "up," the cam doesn't apply any pressure. However, as you push the lever down, it begins exerting downward force to lock your jig or fixture down tight. And the further you push the lever down, the more pressure you're going to get. Quick Release. And what's so nice about these clamps is the pressure is released immediately when the lever is flipped back up. It's much easier and quicker to flip a lever than turn a knob. Cam levers are especially useful as a time-saver when used with a slot or T-track. You just flip up the lever, slide the part where you want it, and simply push the lever back down to lock it into place. I've replaced all the knobs on my stop blocks and fences with cam levers because the quick-release feature is a real time-saver. WORKING WITH CAM LEVERS When you buy cam levers, you'll get the lever along with a threaded cross dowel (For sources, see page 51). You simply insert the cross dowel into the lever so that the threaded hole is between the lever's "wings." The hole will take either a 5/i6"-18 or a W-20 bolt or threaded rod, depending on the size of cam lever you bought. These are the two most popular sizes for cam levers. You can see different styles in the box on the far right of the next page. Bolts and Rods. You can use a flange, hex, or stove bolt, or threaded rod to anchor your cam lever, depending on your application. The bolt or rod should extend above the hole to give the cross This versatile accessory packs a load of holding power. CAM ACTION PRESSURE When making a shop jig, many woodworkers turn to various types of knobs to make the jig adjustable. But there's another option that may not be so obvious — cam levers. Cam levers, also known as quick-release levers, can make working with jigs and fixtures quick and easy, especially when you're doing repetitive work. You've probably used cam levers without realizing it. Most table saw fences are locked into PRESSURE OFF OFF-CENTER CAM 10 ShopNotes No. 83 |
