Woodworker's Journal fall-2009, страница 10

A chuck's three jaws seat on the flat part of DeWalt's Pilot Point bits, so the bit can't slip.

QNo matter what kind of portable drill I use or solutions I try, I can't seem to get keyless chucks tight. The drill bit slips inside the chuck whenever it meets a certain amount of resistance. Is there some secret to securing the drill bit inside the keyless chuck? Some sort of temporary adhesive or slip-resistant coating that I should use? Looking forward to any solutions you might have.

Alexander Bove Chestnut Hill, Massachusetts

A Although I know of no "miracle coatings" that prevent bit slippage, I can think of several things to minimize the problem. Since keyless chucks with smooth plastic outer shells are difficult to grasp and tighten, you can improve your grip and increase bit-tightening torque by wearing gloves with anti-slip coated palms. To improve your chuck's hold on larger-diameter twist bits, try using flat-ground-shank bits (see photo, above).

It's also important to consider your technique: Are you applying

Aligning wood banding to plywood is one good use for biscuits, but they're not ideal for high shear-strength applications.

too much pressure as you drill, causing the bit to slip? Try a little less downward force, especially when the bit is just about to break through the underside of the material. This is most important when boring through thin sheet metal. When drilling thick materials, such as wood or plastic, make sure to pull the bit out occasionally, to clear chips that can create enough resistance to hang the bit up.

— Sandor Nagyszalanczy

QI recently had to repair an exterior wood storm door and thought it was a perfect excuse to try a biscuit joiner. I disassembled the door and found that it was held together with hardwood dowels. After replacing the dowels, I was wondering if there is any rule of thumb as to when to use dowels or biscuits.

Tom Chadwick Glen Rock, New Jersey

A Are you trying to reinforce the joint or simply align the parts? Because of the deep penetration you can get with long dowels, they'll provide more joint shear strength than biscuits. My primary application for biscuits is as alignment aids. However, dowels can be much fussier to work with. You can't beat the side-to-side adjustability and ease of installation with biscuits.

A second consideration is the size of the parts you're assembling. Even the #0 biscuit — the smallest conventional size — needs a slot about 2" long. This won't work on a face frame with 1¹/2^M-wide rails. The more recent face frame biscuits, and other specialty sizes, can help solve

this problem, provided you've got a machine that can cut the smaller slots they require.

— George Vondriska

QWhy is there always a little bit of "play" in a retractable tape measure's end hook? Arthur Mendel Richmond, California

v-X

Tip movement allows for the thickness of the metal hook.

A Those moveable hooks seem a little odd until you consider that the hook has a thickness. If you're pulling the tape to measure off a board's end, the hook's thickness doesn't matter — it's situated on the other side of "zero" and opposite of what you're measuring. But, if you push the tape into a corner, the thickness of the hook would add to the sum of your measurement if it didn't move. Every "inside" measurement would be off by the hook's thickness. So, a hook is designed to move the same distance as its thickness to account for both inside and outside measurements. To keep it accurate, remember your shop teacher's advice ... don't let it slam home.

— Chris Marshall

10 Reader Questions, Answered