The Drill Press
With the proper drill bits, you can drill through all kinds of materials, including wood, metal, plastics and glass. Safety is rather basic for the drill press, as there is usually no reason to put your hands very close to the drill bit. So I’ll just highlight a few safety considerations aside from the obvious (like don’t put your hand under the drill bit!).
One of the first things you should do when you buy a drill press for woodworking is to buy some good quality brad-point drill bits. These bits have a centre point and outside spurs. The spurs cut the circumference of the hole ahead of the actual cutting part of the bit, so you get clean holes at the entry point. The centre point allows you to drill exactly where you want. Sometimes placing a small indent on the wood with an awl exactly where you want to drill is helpful, as you can feel the brad point engage with this mark.
Most people don’t realize that the regular twist drill bits you find in most stores are actually designed for drilling in metal, although they will certainly drill holes in wood too. But since the end of the bit is rounded, these bits don’t work as well in wood, particularly when using a hand-drill.
The biggest problem is that regular bits can skate around and enter the wood in the wrong place. Stick to a good quality bradpoint bit for the best accuracy. Also, many people like to line up the brad point with the mark they have placed on the wood and then turn on the machine. What they may not realize is that the vibration caused by the motor will often shift the workpiece slightly before you start drilling. One way to deal with this is to clamp the workpiece to the drill press table before turning the machine on. But this can take a lot of time, especially if you are drilling a lot of holes. My preferred method is to turn the machine on first and line up the drill bit with your mark as you bring the lever down. The speed of the drill bit will make most of the bit’s tip invisible, except for the brad point. So just lower the bit until it is almost touching the wood, and then readjust the workpiece as necessary and drill away. Because your eyes can’t line up the mark both side-to-side and back-to-front at the same time, there is no way to know if you are lined up properly until the bit is just above the workpiece.
There are two major issues regarding the quality of the holes you drill (aside from using good quality drill bits): break-out and burning.
Break-out: Most good drill bits will leave a reasonably clean entry to the hole. But if you are drilling right through the wood, you will get some nasty torn fibres on the exit side. Sometimes this “break-out” can travel half an inch or more across the exit side surface, particularly with veneered stock. What happens is that the sheer force of pulling the drill press lever down breaks the bottom of the hole out before the drill bit has a chance to cut the wood fibres cleanly.
The best solution is to use a backer board to support the bottom of the hole. Be sure to use a board that is consistent in thickness so that you don’t affect the 90- degree angle of the hole. I like to use a piece of scrap plywood. The goal is to drill through your workpiece and just 1/8” or so into the backer board. Then you won’t get any break-out. If you are drilling many holes, just clamp the backer board to the drill press table and drill away.
Burning: This common problem, caused by running the drill press too fast, causes burning of the wood. This will result in a blackened hole and burned wood does not hold glue properly. Also, if you heat the drill bit to the point of turning the metal blue, then it has lost its temper and can’t even be properly sharpened without removing all of the blue metal. Chances are that a new drill bit will be cheaper than correcting the problem.
What you have to remember is something called rim speed. The larger the drill bit is, the higher the speed of the outer surface of the drill bit. The outside of the drill bit travels farther than the centre of the bit, even though the drill press is running at a set speed. This means that the outside of the bit is travelling much faster than the centre of the bit, since speed equals distance over time. It also means that the larger the diameter of the drill bit, the faster it is travelling at the outside of the bit.
So you must run your drill press at a slower speed as the drill bit diameter increases. Run only the smallest drill bits at full speed (usually about 3000 rpm).
When you get to large bits, like a 3” diameter forstner bit, you should be running at the slowest speed you have (250 rpms or less). If you see smoke or burning of the wood, slow down your speed and watch your quality improve.
Next issue Hendrik gives three tips on using your router.