A dowel drill guide is an essential tool in any woodworker's shop. It enables the woodworker to make dowel joints accurately. Properly coordinated, uniform dowel holes aid in the accurate assembly of woodworking projects. The dowel drill guide has pre-set allowances and guide markers that allow for common dowel and wood sizes.
How It Works
Dowel drilling guides are hand-held devices with small clamps that attach the guide to the wood. Used correctly, they guarantee proper dowel alignment by forcing the tool's operator to hold the drill at a perfect 90-degree angle to the wood's surface.
The "guide," is actually an interchangeable sleeve about one inch long. It's held in place by a small clamp usually operated by a wing nut. The guide will accommodate different sizes of sleeves to fit any size of drill bit. The operator first chooses his dowel size, the compatible drill bit, then the sleeve that fits the drill bit. The sleeve can also be moved up and down on the side of the device to accommodate different thicknesses of wood, with pre-set centre marks for 3/4-inch, 1-inch and 1 1/4-inch thicknesses, the most popular settings.
The operator first clamps the proper size sleeve into the device, then, after marking the dowel location on both pieces of wood, clamps the device on the wood, seating the sleeve against the wood's surface. The operator then inserts the hand-held drill, with the correct bit installed, into the sleeve and drills the hole, bottoming out the drill chuck on the sleeve to achieve uniform depth.
Drilling dowel holes by hand without the aid of a drilling guide is nearly impossible. Even the best woodworker cannot hold a drill straight. Even when it appears straight, the drill will invariably angle off in a slightly different direction without the aid of a drilling guide.
There are several different configurations of dowel drilling guides. Some of them are free standing, with a large, round base that is heavy enough to hold a drill in place. This type is used for flat surface dowel placement, but is not recommended for the ends or sides of wood. Another guide configuration attaches to the drill itself. Two beams about 12 inches long that are joined at the top characterise these types of guides. The drill slides up and down between the two guides. Other drilling guides resemble a revolver, with different chamber sleeves that turn in a circle. The chamber is rotated to receive the right size drill bit, then the guide is clamped to the wood.
The most basic drill guide can be purchased for about £9. It will include a single guide sleeve that you buy according to your needs. It will have some plastic parts and be somewhat fragile. The more expensive drill mounted dowel guides will run about £71 (as of June 2010), featuring solid metal construction, many different sleeves and attachments, and will last for years.