Drill Press

The material for this handout has been adapted from Chapter 59 (pages 394-402) of Wood: Technologyand Process, by John L. Feirer, Mission Hills, California: Glencoe/Macmillan, 1987.

After studying this section, you will be able to:• List those safety precautions that must be followed in operating a drill press.• Identify the cutting tools that can be used in the drill press.• Identify the adjustments that can be made on a drill press.• Demonstrate the proper operation of a drill press.

LOOK FOR THESE TERMS

drill press machine spur bit solid center auger bitexpansive bit mortising attachment spade bitfly cutter multispur machine bit spur machine bitForstner bit plug cutter twist drillhole saw sanding drum

The drill press is used primarily for drillingand boring holes. With proper speeds, it canalso be used for shaping, routing, carving,sanding, and mortising. Fig. D-1. The size ofthe machine is determined by the largestdiameter stock that can be drilled through thecenter. If the distance from the column to thecenter of the table is 8 inches, then the size ofthe drill press is 16 inches. Machines equippedwith step pulleys usually have four speeds of470, 780, 1,300, and 1,950 RPM. Fig. D-2.Machines with variable speed pulleys canoperate at any speed from 450 to 4,700 RPM.Fig. D-3. The higher speeds are needed for suchoperations as routing and shaping.

SAFETY

In operating a drill press, observe thefollowing precautions:• Use a drill or bit with a straight shank -

never a square one.• Check the speed. Use a slow speed for large

holes and a faster speed for smaller holes.On a step pulley machine, change the speedwith the switch off. On a variable speedmachine, change the speed with the machineoperating.

• Keep your hair and loose clothing awayfrom all moving parts.

• Place the drill or bit in the chuck straightand tighten it securely.

• Always remove the chuck key beforestarting the machine.

• When making the setup, make sure the bit ordrill will not mar the vise or table. Place apiece of scrap stock under the work to bedrilled.

• Clamp round stock in a V-block beforedrilling.

• Keep your fingers at least 4 inches (100mm) away from the rotating tool.

• Remove chips and shavings with a brush orstick of wood-never your fingers.

• Feed the drill or bit smoothly into theworkpiece. When the hole is deep,withdraw it often to clear the shavings. Fig.D-4.

• Check the setup carefully before doingspecial operations such as routing orshaping.

D-6 Cutting tools used on the drill press. A. SolidCenter Auger Bit; B. Space Bit; C. Spur machine bit;D. Multispur machine bit; E. Forstner bit; F. Expansivebit; G. Countersink; H. Twist drill.

CUTTING TOOLS

The following cutting tools are used in the drillpress:• Twist drills are available in sizes from 1/16

inch to 1/2 inch by 64ths. Some twist drillsets all have 1/2-inch shanks so they can beused in portable electric drills. Twist drillsare available in metric, number and lettersizes. Fig. D-5.

• Spade bits come in diameters from 1/4 inch to1 1/2 inch. They are fast-cutting tools thatleave a rather rough hole.

• Spur machine bits are the ideal tool for drillingwood. They come in sizes from 1/8 inch to1/2 inch by 16ths. The sharp brad point letsyou place the hole exactly where you wantit. The sharp cutting spurs make a cleanhole in wood.

• Multispur machine bits cut a perfectly roundflat-bottomed hole.

• Plug cutters are used for cutting crossgrainand end-grain plugs and dowels up to 3inches long. They come in common sizes of3/8, 1/2, 5/8, 3/4, and 1 inch. The smallersizes match the diameter of dowel rods.

• Twist drills with an adjustable countersinkattachment are used for installing flat headscrews. They do the same job as the screw-mate drill and countersink. Solid centerauger bits with straight shanks can be usedfor boring larger holes.

• Expansive bits are adjustable to differentdiameters. When using this tool, make surethe workpiece is fastened securely withclamps.

• Fly cutter, sometimes called a circle cutter,can be adjusted to cut holes from 1 inch to 4inches.

• Hole saws come in sizes up to 3 1/2 inches.Saws of several different diameters can fitthe same mandrel.

• Forstner bits are used to cut flat-bottom holes,even through knots, end grain, and veneer.

ADJUSTMENTS

The following adjustments are made on a drillpress:• Speed. Speed is adjusted by either changing

the belt on the pulleys or by turning thehandle on the front of the variable speedcontrol. Before changing speeds on a beltand pulley machine, first make sure thepower is disconnected. Then raise the coverover the pulleys. To adjust to the fastestspeed (for holes under 1/4 inch (6 mm))place the belt in the top position with thebelt on the largest pulley on the motor(driving pulley) and on the smallest pulleyon the spindle (driven pulley). Fig. D-6.

• Installing a drill or bit. Place a piece of scrapwood on the table. Use the key to open thechuck slightly larger than the shank of the

tool. Hold the tool in the chuck, makingsure it is straight. Then tighten securelywith the key. A common mistake is not tohave enough pressure on the tool shank. Ifthis happens, after drilling begins, the toolitself begins rotating in the chuck instead ofcutting the hole. Fig. D-7.

• Adjusting the table. Release the tablelockingclamp. Raise the table so that the spacebetween the top of the workpiece and thepoint of the tool is about 1/2 inch (12 mm).Tighten the clamp.

• Setting the depth gauge or stop. This deviceon the side of the drill press controls how farthe cutting tool can move. If you wish todrill a hole only partway through a piece ofwood, draw a line on the side indicating thisdepth. Pull down on the handle until thepoint of the tool is at this line. Then move

the two adjusting nuts that limit the drillingto this point.

GENERAL PROCEDURES

1 . Select the correct bit or drill and fasten itsecurely in the chuck. Caution: Alwaysremove the key before turning on thepower.

2 . Make sure the proper layout has been madeand that the position of the hole is wellmarked.

3. Make sure the drill or bit is free to gothrough the table opening in the drillpresstable. Also, place a piece of scrap woodunder the material. This will help preventsplintering when the drill goes through theunderside of the work.

4. Adjust the drill press for the correct cuttingspeed. The speed should vary with the typeof bit, the size, the kind of wood, and thedepth of the hole. In general, the smallerthe cutting tool and the softer the wood, thehigher the speed. Select the approximatespeed. Then use good judgement whenfeeding the tool into the material. If thetool smokes, reduce the speed and the feed.

5. Clamp the work securely when necessary,especially when using larger drilling andboring tools, hole cutters, and similarcutting devices. Clamping is a must if thetool has only one cutting edge, such as ahole cutter. Fig. D-8.

DRILLING SMALL HOLES IN FLATSTOCK

To drill or bore a hole that is 1/4 inch orsmaller, use a twist drill. Locate the center ofthe hole and mark it with a center punch orscratch awl. Place it on the table over a piece ofscrap wood. Turn on the power and slowlymove the point of the bit into the stock. Holdthe stock firmly and apply even pressure to thehandle. If the stock is hardwood or the hole isdeep, back up the bit once or twice to removethe chips before finishing the hole. Always borethrough the hole and into the scrap wood.

D-6 The belt in top position produces thehighest speed , in the lowest position theslowest speed is attained. Some drillpresses have three step cone pulleys givinggreater speed selection choice.

CUTTING MEDIUM-SIZED HOLES INFLAT STOCK

Holes from 1/4 inch to 11/4 inch can be cut with avariety of drilling and boring tools. Forexample, a twist drill, auger bit, Forstner bit, orspade bit could be used. Figs. D-9 and D-10.There are two methods for boring a throughhole. The simplest is to place a piece of scrapwood under the hole so that the tool will cutthrough the stock and into the scrap piece. Thiskeeps the underside from splintering. Thesecond method is to cut until the point of the bitshows through the stock, then drill from theother side. To bore a hole to a specific depth,adjust the depth stop with the power off. Bringthe cutting tool down to the side of the workwhere the depth is marked. Then set the depthstop.

BORING LARGE HOLES IN FLATSTOCK

Holes larger than 1 1/4 inch are best cut with ahole saw or a circle cutter. Make sure that thework is firmly clamped, especially when using ahole cutter, since any tool with a single pointtends to rotate the work.

OTHER DRILLING OPERATIONS

Holes can be drilled or bored in round stock byholding the workpiece in a V-block. Fig. D-11.To drill or bore holes at an angle adjust the tableto the right or left to the correct angle. Fig. D-12. Countersinking is necessary when installingflat head screws. Fig D-13.

MORTISING

If much furniture construction is done, amortising attachment should be available. Thisgreatly simplifies cutting a mortise-and-tenonjoint. A mortising attachment consists of ahollow, square mortising chisel in which anauger bit revolves. The chisel itself is ground toa sharp point at each corner. These points enterthe wood just after the revolving bit. They cutthe square opening after the bit has removed

most of the stock. On most mortisingattachments, the chisel is fastened to the quill ofthe drill press and a straight-shank auger bitfastened in the chuck. The chisel should be thesame width as the width of the mortise to be cut.A fence should be attached to the table to guidethe stock. Fig. D-14.

SHAPING

For shaping, a spindle speed of 4,700 RPM isneeded. This speed can be attained by using thevariable-speed pulley or a high-speed motor. Itis also necessary to have a special adapter thatwill hold the shaper cutter. Fig. D-15. Thisadapter can be attached to the spindle of the drillpress. Then an inexpensive set of shaper cutterswill enable you to construct setups that will cuta variety of shapes. Never use a shaper cutter ina chuck. Select the shaper cutter for theparticular shape you want to make.

The depth of the cut can be controlled byplacing a collar of the correct diameter justabove or below the cutter or by using a fence.Fasten the cutter and collar to the specialadapter. Raise the table to the correct positionand lock it in place. Make a trial cut in a pieceof scrap stock of the same thickness as thefinished piece. In using a shaper attachment,

force the wood into the cutter very slowly.Sometimes it is a good idea to cut the design topartial depth and then go over it again. If thedesign is cut on three or four edges, finish theends first and then the sides. If the trial cut issatisfactory, cut the edge. Fig. D-16.

ROUTING

A routing tool is fastened in a special routerattachment. The spindle speed must be about5,000 RPM. Various types of routing such asgrooves, slots, and irregular openings can bedone on the drill press. Fig. D-17.

SANDING

Sanding drums are available in several sizesthat can be used in the drill press to do edgesanding. Manufacturers supply sanding sleevesin grits and sizes to fit the drums. Fig. D-18.