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Choosing the best Drill Press

best1The majority of severe woodworkers as well as DIYers will certainly inform you that the best drill press is essential to get. The drill press is just an extremely useful device to get within the device shed, workshop, or even garage area. It really is meant for a handheld drill press however offers more precision as well as power. There are various kinds of drill squeezes accessible on sale at the present. To assist you find the correct drill press for your requirements, we now have outlined a few of the aspects you should think about.

Which kind of Drill Press?

Very first, you just have to choose whether you require a bench top drill press or even ground standing. In case you are liable to utilize it for big tasks and enjoying the floor area accessible, the ground version will certainly match you much better. The bench top is compact and lighter in weight compared to ground version, and can manage the majority of DO-IT-YOURSELF work along with simplicity.

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Energy:

The power of the drill press generates calculated Hp. This can be an extremely important element that is thought the best drill press for your requirements. In case you are likely to utilize it for lightweight DIY function just, you most likely only require the one-half horsepower -1/2 horsepower electric motor. Larger work will need a larger electric motor.

Dimension:

Whenever buying for the drill press you will certainly remember that, they tend to be outlined because eight inch, ten-inch, twelve inch and thus on. This is the size of the drill press as well as decides the size associated with the item you can function. The size of the drill press is really calculated through the “throat capacity” This is the range between the column and the middle of the chuck. The drill press having a five-inch throat capability will certainly drill the hole in the middle of the ten-inch size disc and it is known as ten-inch drill press. Quite simply the size of the drill press may be the range between center from the chuck and also the column, occasions 2. Make certain the drill press you purchase is not too young for your requirements.

Velocity:

Whenever using wooden a higher spindle velocity is needed, whilst dealing with stainless steel needs a reduced spindle velocity. In case you will be dealing with each component, make certain the velocity is adjustable on the drill press you purchase. The majority of drill squeeze nowadays possess five or even more velocity configurations.

Spindle:

The particular spindle journey is what lengths the spindle should go straight down in a single sweep. This can additionally figure out the depth associated with a hole which can be drilled along with 1 proceed. A great suggestion would be to appear for the drill press along with a flexible depth quit. This can assist to make sure that you drill holes in some accurate depth each time.

The Worktable:

It is very important have the ability to change the worktable on the drill press. Make certain the particular worktable can transform down and up as well as a tilt towards the edges. This can be a requirement whenever drilling in numerous perspectives.

Reliability as well as Precision:

Among the advantages of the drill press is it enables you in order to drill precisely as well as accurate. A few versions get precision one stage further along with laser guiding techniques. This can be an excellent function besides making the holes super easy.

Guarantee:

In no way, purchase a power device with a guarantee. Make certain you reach minimum annually guarantee on your own buy. Using the info in this post as well as reading through drill press testimonials, you can select a drill press, which fits your unique requirements.

Greatest Price:

For the most powerful price from the drill press, you have to select your own device smartly. You do not need to overspend on the drill press in case you will not utilize it which regularly. In case you had been likely to utilize it on a normal foundation for all sorts of drilling, after that it might be a good idea to purchase a good drill press that may make penalties.

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Towering timber: four easy techniques for modeling tall trees

 The lush, tree-covered terrain found in numerous regions across North America has been a source of inspiration for the scenery added to countless model railroads. Although modelers are drawn to create such scenes, many find their efforts fall short of looking like a forest. Why?

One of the most common reasons they don’t see the forest is for the lack of trees. Most modelers simply don’t install enough trees to represent heavily wooded regions. Real forests are filled with a multitude of trees and vegetation that continue to grow and replenish the landscape over the course of many years. Like most model railroaders, I’m not quite willing to spend as much time and effort to create an entire forest as Mother Nature spends.

Although my reluctance makes sense, it presented me with a bit of a challenge–I model a narrow gauge, logging railroad operation in the Pacific Northwest. One option would have been to model a completely logged out area with nothing but stumps. However, my On3 railroad is set in the Cascade Mountains of Oregon during the 1920s, prior to any major deforestation efforts. This meant I’d have to make a lot of large trees. “Large” is no exaggeration. Even a mid-sized 100-foot-tall and 4-foot-wide tree ends up being more than 24″ tall with a 1″ trunk diameter in O scale!

In the instructions that follow, you’ll see the variety of methods I used to assemble a realistic forest of mature trees. The examples depicted are shown in O scale, but the techniques can be adapted to create trees for smaller scales too.

Towering timber technique 1 Balsa block

1 Form trunk. Starting with a 2″ x 3″ block of balsa about 24″ long (for O), use a sharp knife to carefully trim away a long, narrow piece to form into a tree trunk. A single block of balsa should yield two or three tree trunks.

2 Add texture. Once you’re satisfied with the general shape, use a wood rasp to give the trunk texture that simulates rough, peeling bark. Also, carve a few indentations into the base of the trunk to create the illusion of roots.

3 Drill holes. Use a pin vise to drill holes for the first two limbs about one third of the way up the tree and 180 degrees apart. Add more pairs of holes by rotating the trunk 90 degrees and moving up the tree 1″ each time.

4 Color the trunk. Tree trunk colors vary from brown to gray. Commercial stains are available, or use a few drops of black and brown leather dye mixed into rubbing alcohol. Brush the stain on the trunk and allow the wood to dry.

5 Add tree limbs. Use sprigs of caspia to represent tree limbs. Caspia is a dried flower you can often purchase at arts and crafts stores. Place a dab of carpenter’s wood glue into each hole before inserting the caspia branch.

6 Spray and sprinkle. When the tree limbs are securely fixed, cover the branches with an inexpensive hair spray (unscented) or spray adhesive before sprinkling on various shades of Woodland Scenic ground foam.

Towering timber technique 2 Furnace filter foliage

1 Form a balsa trunk. This tree-making method starts by carving the same style of tree trunk previously explained in technique no. 1. For this technique, however, you won’t need to drill holes to attach limbs.

2 Furnace-filter foliage. When pulled into tufts, furnace filter material can be used to form trees branches. Skewer the thin tufts onto the trunk, using slightly smaller, more closely spaced pieces at the top. White glue holds them in place.

3 Add ground foam for color and texture. Once the filter branches are fixed to the trunk, apply hair spray or spray adhesive over them and sprinkle on various shades of green ground foam to finish the tree.

Towering timber technique 3 Plastic Branches

Branches from kits. For extremely tall trees, 3 feet high (or taller), start with trunks and add plastic branches from Woodland Scenics Realistic Tree kits, either TK1101 or TK1102. Use a pair of pliers to bend the flat, plastic limbs into natural shapes, and then glue them onto the trunk.

I used small pieces of furnace filter to finish off the tops of these tall trees, then covered all the limbs and branches with the same Woodland Scenics clump foliage and ground foam I used on the other trees.

For trees this large, drive a nail with its head cut off halfway into the base of the tree trunk. The nail will improve its stability when you plant the tree in the scenery using hot glue.

Towering timber technique 4 Wire and rope

1 Into hot water. First, put a 1/2″ length of hemp or fiber rope into boiling water. Remove the rope when it begins to straighten, and then hang it up to dry. Add weight to the end of the rope to keep it from recoiling.

2 Trimming the line. When the rope is dry, cut pieces of various lengths. For O scale, start with a 6″ length and then cut each subsequent piece shorter by 1″. For HO, start with 3″ lengths. Use a fine-tooth comb to separate the rope pieces.

3 Add wire. Cut two lengths of no. 14 wire and twist them together at one end. Find the longest pieces of rope and place them between the two wires. Add shorter pieces as you work to the top. Epoxy the rope to the wire.

4 Twist the tree. When the epoxy sets, trim the rope pieces to the shape of the tree. Now place the twisted end of the wires into a vise and the other end into an electric drill. Run the drill slowly to twist the two wires together, which will cause the rope pieces to fan out.

5 Add foliage. This photo shows the results of twisting the wires and rope. Spray paint the tree brown or gray. While the paint is still wet, sprinkle the tree with shades of green ground foam. You can use the wire at the bottom to plant the tree on the layout.

6 Growing taller trees. Wire trees can be made taller by combining them with a balsa trunk. Drill a hole in the top of the wooden trunk and then insert the wire tree base. Use hot glue to fix the two parts together, then finish the tree using one of the first three techniques.

Can’t see the forest for the trees? One look at this scene on Lou Ullian’s On3 logging railroad and you’ll see the natural-looking results of several tree-making techniques.

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Transform a table into a deer cleaning station

BUTCHERING A DEER used to be a chore that turned my basement into a mess and sent me limping up the steps with a backache. This DIY butchering table has made my meat cutting a more pleasant experience. It’s cheap, easy to store and clean, large enough for two people to work at together, and raised to a spine-pleasing height. Before butchering, clean the table with a 50-50 mix of bleach and water, and rinse it with distilled water.

Start with a sturdy, 6-foot-long, polyethylene-topped folding utility table, available at most hardware stores–I picked mine up at Lowe’s ($60; lowes.com).

Drill holes in one right-hand corner (lefties would use the left-hand edge) to accept the mounting bolts from a Cabela’s No. 32 manual meat grinder ($90; cabelas.com). It chews through 5 pounds of venison a minute, and cranking the handle makes me feel a little old-school (this despite my bloodstained iPod earbuds).

Fill a small vessel with hot soapy water for cleaning your Knives.

Spread out a pair of thin, flexible cutting boards in front of you to protect the edge on your knives.

Place up to three large pans or bowls on the table: One for meat trimmings that will be tossed, one for chunks of meat that will be ground for burger, and a third for the finished cuts of meat destined for the freezer.

Raise the 29-inch-high table to a height that is comfortable for you: Cut a length of 2-inch-diameter PVC pipe into four pieces, each about 12 inches long; adjust the length of the pieces as necessary. Slip a piece over each table leg.

Start with a sturdy, 6-foot-long, polyethylene-topped folding utility table, available at most hardware stores–I picked mine up at Lowe’s ($60; lowes.com).

Drill holes in one right-hand corner (lefties would use the left-hand edge) to accept the mounting bolts from a Cabela’s No. 32 manual meat grinder ($90; cabelas.com). It chews through 5 pounds of venison a minute, and cranking the handle makes me feel a little old-school (this despite my bloodstained iPod earbuds).

Fill a small vessel with hot soapy water for cleaning your Knives.

Spread out a pair of thin, flexible cutting boards in front of you to protect the edge on your knives.

Place up to three large pans or bowls on the table: One for meat trimmings that will be tossed, one for chunks of meat that will be ground for burger, and a third for the finished cuts of meat destined for the freezer.

Raise the 29-inch-high table to a height that is comfortable for you: Cut a length of 2-inch-diameter PVC pipe into four pieces, each about 12 inches long; adjust the length of the pieces as necessary. Slip a piece over each table leg.

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Stallside Med Tray

Here’s how to turn a bread pan into a handy medication tray-for very little dough.

OVERVIEW

This project is easy and inexpensive. You’ll simply mount two tablecloth clamps-those used to secure a tablecloth onto a picnic table-onto a bread-loaf pan.

BEFORE YOU BEGIN

* If you have several horses, make one tray for each stall to keep their medications separate.

* When your horse is inside his stall, keep his feed door closed at all times, so he can’t reach the medications.

* When he’s outside his stall, tie him so he can’t reach his tray or any others. Ask your barnmates to do the same with their horses.

stallside* Keep all equine medications out of reach of children.

* When your barn is exceedingly hot or cold, store the medications elsewhere to retain their effectiveness. (Check the medications’ labels for appropriate temperature ranges.)

PROCEDURE

Step 1. Determine where to drill holes into each clamp. Using the measuring tape and pen, measure and mark a point 1/2″ in from the end of the clamp’s straight section, centered edge to edge. (See illustration, above.) Then measure and mark a second point 1/2″ in from the other end of the straight section. Repeat this step for the other clamp.

Step 2. Drill holes in each clamp where you made your marks. First, lay the scrap piece of lumber on your workbench to protect it from drill marks and to provide a smooth, supportive drilling surface. Next, lay one clamp on the board, straight section down, pen marks up. Drill a hole in the center of each mark you made in Step 1. Repeat this step for the other clamp.

Step 3. Determine where to drill the holes in the pan. Place one clamp 2″ in from one end of the pan’s long side, then place the clamp’s top bend just beneath the pan’s lip. Run the pen’s tip through the clamp’s holes, making two corresponding holes on the pan. Repeat this step on the pan’s other end.

Step 4. Lay the pan on its side so the pen marks face up. Drill four holes in the pan where you made your marks.

Step 5. Mount the clamps onto the pan. Align the holes in one clamp over the holes on one end of the pan. Thread a screw through the pan’s top hole, from the outside in, and hand-tighten with a nut. Then hold the nut with one hand and finish tightening the screw with the screwdriver. Repeat this step for the three other screws.

YOU’LL NEED

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* 2 stainless-steel tablecloth clamps

* Measuring tape.

* Felt-tipped pen

* Scrap lumber (about 1″ x 4″ x 6″)

* Power drill with 1/8″ bit

* Standard-size, nonrust bread-loaf pan

* 4 machine screws and corresponding nuts (1/4″)

* Screwdriver

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The modeler’s dream workbench

Most model railroaders use the basic tools I described in the June issue. Now let’s take a look at the tools you can add to make that basic assortment into a dream workbench. The combination of tools that’s right for you depends on your personal interests and the materials you like to use. If painting and weathering are your favorites, then airbrushes and a compressor will be of interest.

Before we look at specialized tools, however, let’s talk about what the dream workbench itself might look like. Over the past 45 years, my workbenches have ranged from a door laid across a pair of sawhorses to an ancient oak desk. The size of the bench won’t affect the quality of your modeling, but good organization and efficient use of space will certainly contribute to a dream workshop.

The dream workbench

A few years ago, my wife and I bought a townhouse for our retirement. I added a finished railroad room in the basement and designed my dream workbench to fit in one corner, as shown in the photo.

My new workbench has an L-shaped work surface, a three-drawer pedestal under one end, and a tall storage cabinet at the opposite end. Since I do a lot of airbrushing, I included a small spray booth with an exhaust duct to the outside. My compressor is tucked under the bench, and an airbrush holder is attached to the tall cabinet.

My motor tool has a flexible shaft, so it’s hung (out of sight) from a substantial hook driven into the ceiling over the bench. I also have a Unimat, a convertible power tool that can be used as a lathe, drill press, or milling machine. It sits near the left end of the bench within easy reach. An old office desk chair on wheels allows me to shift easily from one work area to another.

Along the back of the bench I’ve lined up my machinist’s tool chest and parts drawers, also within easy reach. I use the drawers to hold parts, adhesives, and tools. The tall storage cabinet contains longer items like stripwood, rail, and other building materials, as well as my unbuilt kits. Small hooks in the door keep cords, airbrush hoses, and other tools handy.

This workbench serves my needs, but don’t be afraid to adapt my ideas to fit your combination of tools and materials.

Next, we’ll look at some of the specialized tools that you may find useful to enhance the enjoyment of your own dream workshop.

Taps and dies

In the early days of the hobby, locomotives were made mostly of metal. Machine screws were commonly used to assemble the models, but it was up to the modeler to drill and tap the holes.

Taps are hardened steel tools that cut screw threads into drilled holes. A tap wrench holds the tap securely, as shown in the photo. A tap also comes in handy to rework screw holes where the thread has gotten worn or stripped. I also use taps to cut new, slightly larger threads when I replace metric screws in my brass models. For these replacements, I use similar-size American screws that have a Unified Fine (UNF) thread that’s easier to obtain in the United States. Modelers in other countries may want to use metric sizes.

A die is also a hardened steel threading tool, but it cuts outside threads on a piece of rod. It can be used to make long screws that are handy for holding heavy parts together.

To handle most potential modeling situations, you’ll need the following taps and die sizes on your workbench:

* UNF thread tap sizes 00-90, 0-80, 1-72, and 2-56

* Metric taps in 1.0mm and 2.0mm sizes, including both coarse- and fine-thread versions of each size

* UNF dies in thread sizes 00-90, 0-80, 1-72, and 2-56

In addition, a suitable tap wrench and a die stock are necessary to hold these cutting tools square and apply leverage as you cut the threads. Use care to avoid forcing these tools as you use them.

Cleaning materials

Before any model can be painted it must be clean and free of dirt, grease, and oil. There are two ways to prepare a model for painting.

Stripping removes all of the old paint from a model’s surfaces so that new paint will adhere. Two kinds of paint stripper are available. For most plastic models, use 91 percent isopropyl alcohol (sold in drugstores). For metal, use paint strippers that are available at hobby shops. Disassemble the model and put the parts to be stripped into a plastic refrigerator-storage container. Pour the alcohol over the parts, put on the cover, and allow them to sit for 2 or 3 days. Remove the parts and work off any loose paint with a small, stiff paintbrush. Finally, wash the parts with warm water and a mild detergent, and let them dry.

Be sure to read and follow the instructions when using the commercial strippers since prolonged exposure to the chemicals can damage some models.

A second method uses an ultrasonic cleaner, special detergents, and solvents to clean metal parts. Use a cleaning solution that’s compatible with the items you want to clean (check the manufacturer’s instructions) and turn on the cleaner. The ultrasonic vibrations will work with the solution to loosen and remove the old paint and grease in a few minutes. Then rinse and air dry the parts.

High-heat soldering equipment

As our modeling skills grow, the lightweight soldering tools useful in wiring may not provide enough heat for larger projects. There are two other sources of concentrated heat that should do the job.

* Resistance soldering creates the necessary heat by passing a low-voltage and high-amperage electrical current through the parts to be soldered. For example, to repair a loose handrail on an imported brass model, I attach the ground lead of a resistance-soldering unit to the locomotive. Then I touch the second lead to the handrail and turn the power on. As the current flows, the loose joint quickly heats because it’s the point of highest resistance in the circuit. I add a very small amount of solder, and as soon as it flows into the joint, I turn off the power and hold the handrail steady until the solder cools.

The secret of resistance soldering is that only the point of contact between the parts gets hot, because that’s where the resistance is highest. While resistance soldering works fine for small parts, its concentrated heat doesn’t work as well to solder large parts.

* Micro torches. Several micro torches are available that burn either propane or butane. Small torches are about the size of a ballpoint pen, while others are larger and often include trigger-activated ignitors for one-hand operation. These torches produce a small, pointed flame with a working temperature between 2,300 and 3,000 degrees.

The high temperature delivered to a small work area is ideal for soldering brass detail castings of all sizes onto brass cars or locomotives. However, the high heat must be used with caution–it’s possible to melt small brass detail parts and wire at these temperatures.

Unlike a large soldering gun, whose point is always coated with solder that can accidentally flow onto the casting, the torch flame applies only heat. You feed solder into the joint separately so you can control the amount applied for a neat, strong joint.

Airbrushes

An airbrush is the best tool for spray painting model railroad equipment and structures. From basic color application to fine weathering, the airbrush produces a professional appearance in a fraction of the time required for brush painting. Airbrushes are specified as being either single- or double-action, depending on their control methods.

Single-action airbrushes provide variable control of only the air flow. The width of the spray or quantity of paint is adjusted by turning the cone in the nozzle. This type of airbrush is excellent for big projects such as structures or large scale rolling stock.

Double-action airbrushes offer a two-way control, as shown in the sketch. The vertical movement controls the air supply while a horizontal pulling motion controls the quantity of paint. This kind of airbrush is excellent for painting small details and weathering.

Most veteran modelers own and use both types of airbrushes.

For more information, see Cody Grivno’s article, “Basics of airbrushing,” in the April 2006 issue of Model Railroader.

Airbrush accessories

Use a natural-color light source to ensure that the color of the paint you’re using matches the prototype. While true natural light is sunlight, a fluorescent fixture with full-spectrum lamps is the best (and most expensive) substitute. A less-expensive solution is to use one warm and one cool lamp to produce a close approximation.

A small compressor provides the air pressure that’s needed to make an airbrush operate. Many compressors are available, but I chose a basic mid-priced unit with an adjustable regulator valve that delivers the required pressure without a lot of unnecessary extras.

The pressure hose and connectors usually come with the airbrush. Be sure to use a moisture trap in the air line. If a power switch isn’t included, it’s a good idea to install one so you can shut down the compressor to change colors, unclog the nozzle, or switch models.

A spray booth is necessary to protect your health by drawing paint solvents and pigments out of the workshop. You may be working with water-based paints, but it’s still a bad idea to inhale dried pigments floating in the air.

A sealed fan at the back of my booth sucks the atomized paint through a filter and exhausts the fumes through a flexible dryer hose to the outside. A straight metal duct with a single bend is preferable.

For information on building a spray booth, see “The Paint Shop spray booth,” by Andy Sperandeo and Gordon Odegard, in MR’s January 1988 issue.

You also need to use a two-stage respirator mask capable of filtering out paint particles and organic solvent vapors. These masks are available from hobby dealers or hardware stores. Modelers spraying organic solvent paints also need to use nitrile rubber gloves and safety goggles. Note that latex rubber gloves are porous to organic solvents and don’t protect the skin from them.

Specialized tools

Many tools are available to make specific jobs easier, while others enhance accurate mechanical work. Specialty tools are often designed to efficiently handle repetitive jobs. All three of the following tools address specific modeling problems. They’re all manufactured by North West Short Line (NWSL).

The Puller is designed to remove pressed-on wheels from an axle without damage. The photo shows how this tool holds the wheel squarely while a T-handled screw forces the axle through the wheel.

The Quarterer is a jig that’s used to check the alignment of steam locomotive crankpins and position them for reassembly. Ordinarily, the crankpins are a precise 90 degrees apart with the right side leading (90 degrees ahead of the left). If a set of drivers is out of quarter, the rods will bind. Requartering by hand is a tricky business, but this tool makes it simpler, and once the driver has been corrected, smooth operation will be restored.

The Bender is a brake for bending light metals to any angle up to 90 degrees. It eliminates the trial-and-error of bending parts by hand or using a pair of long-nose pliers. It also helps make multiple repetitive bends.

Benchtop power tools

Three benchtop tools are invaluable additions to a modeler’s dream workshop.

* A modeler’s drill press allows you to drill precision holes of any size in brass, plastic, or wood. A drill press is more stable than drilling by hand. This stability is especially useful with very small, easy-to-break bits in the nos. 60 (.040″) to 80 (.0135″) range.

* A milling machine uses a rotating cutting tool, set vertically or at an angle, to cut grooves, slots, and a variety of shapes in heavy gauge (1/16″ or thicker) brass, nickel silver, or aluminum. Shaping parts like fluted steam engine side rods or main frames are typical projects for a milling machine.

* A lathe rotates a horizontal piece of metal, hard plastic, or wood against a cutting tool that removes material to produce cylindrical shapes of any length. These parts range in size from a small metal whistle to an entire boiler. In wood, it’s possible to turn circular structures like a lighthouse or all sorts of storage tanks.

After turning the workpiece to the correct dimensions, increasingly finer grades of abrasive paper can be applied to provide a smooth finish that’s ready for painting.

Convertible tools offer a way to combine all three benchtop machine tools into a single unit if space is at a premium. MicroLux or Sherline are two of the best known current manufacturers.

Unimat has sold convertible machine tools for many years. The firm’s present line can be seen on the Internet at www.thecooltool. com. A Unimat can be set up as a lathe or as a drill press, see below. With the addition of a milling table (sold as an accessory), it can also be used as a milling machine. I bought a Unimat in 1954, and it sits on one end of my workbench ready for my next project.

Handheld power tools

Small, portable power tools can speed up construction projects. Make sure all of the power tools you use are properly grounded, and treat battery-operated tools as if they’re always live.

A small, handheld electric rotary tool fitted with a variety of steel cutters, abrasive wheels, and cut-off disks is a must for a wide variety of tasks. The popular Dremel Moto-Tool is a typical example. Adding a variable-speed foot control and a flexible shaft make fine work easier because they take the motor’s weight and speed control out of your hands.

Remember to use proper safety glasses anytime you’re working with a power tool.

RELATED ARTICLE: Where to get modeling tools.

Your local hobby shop. This gives you a chance to look at each tool before you buy it.

Mail order. These suppliers can be easily located by checking the ads in Model Railroader. Two of the largest mail order firms are Micro-Mark at 340 Snyder Avenue, Berkeley Heights, NJ 07922-1595, www. micromark.com; and William K. Walthers Inc., 5601 W. Florist Ave., Milwaukee, WI 53218-1622, www.walthers.com.

Internet. Many tool distributors have their own Web sites, which is a good way to locate specialized tools.

Hobby shows. Most hobby shows include vendors who carry tools. As with the local hobby shop, this gives you a chance to look before you purchase, even though you won’t be able to get the ongoing advice that your local hobby dealer can provide.

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Drill practice

DRILLS ARE WIDELY USED TOOLS, FROM THE small hand drill to the bench or floor mounted drill press, all the way to large radial arm drills. The cutting tool employed by the drill is the drill bit. While most people think only in terms of cutting round holes, drill bits and fixtures can be obtained that cut squares, pentagons, hexagons, and octagons. In some cases, drills are used to enlarge holes that already exist. Specialized “step” drills can also produce two diameters or more at the same time. The drill bit is secured by a chuck, a collet, or a taper.

Drill motors or drill presses are often variable speed tools so that the cutting speed can be matched to the hardness of material being processed. The common round drill bit has two cutting edges or lips and a flute that spirals away from each cutting edge to remove chips. The cutting edges are joined in the center at the tip of the drill forming the dead center. While the dead center provides strength, it reduces the cutting ability, particularly for a larger drill bit. This effect is compensated by first drilling a smaller “pilot” hole to remove the material from the center of the hole. Accuracy in drilling can be further improved by first marking the hole center with a punched indentation. Lubricants should also be applied to the bit when cutting large holes or thick metals.

When drilling, the workpiece, the drill or both must rotate in order to create a hole. In situations where both the tool and the workpiece rotate, the rotation is in opposite directions.

img02There are four types of equipment commonly used for drilling holes. Hand drills and lathes are generally used when only a few holes are needed. A drill press, or CNC (computer numeric control) machine are normally used in industrial applications where many holes need to be drilled and greater accuracy and consistency are required.
FAIHANDDRILLHand drills are portable and are generally used for home repair or shop maintenance. Typically, hand drills are used when only a few holes need to be drilled, or the part is too large or awkward to be mounted in a machine. The drill bit is held in a chuck and either rotated by hand, electric power, battery, or compressed air.

A lathe is a machine that is normally used to turn or reduce the size of round or cylindrical parts. Lathes can also be used for drilling. In most lathes, only the workpiece rotates. The workpiece is held securely in the chuck. The drill is held in either the cross slide or tailstock and is fed into the rotating part to drill the hole.

The vertical drill press is the most commonly used piece of equipment in the industrial market. The drill is held in the rotating spindle and is fed into the workpiece by hand using the feed handle or by using the power feed accessory. The part is mounted solidly to the table using a vice, or clamps.

The CNC lathe or drill press is usually used for jig production drilling and machining. A computer is programmed to control the movements of the machine to produce greater accuracy and consistency. These are among the most sophisticated machines used today. When drilling with CNC machines, the workpiece, drill, or both may rotate.

Drill elements

A drill consists of three main parts: the shank, which is used to mount in a drilling machine; the body, which has grooves and edges that help in the cutting and removal of material; and the point, which is made up of cutting edges. The shank is the part of the drill which fits into a tool holder called a chuck, spindle holder or collet. There are four types of shanks — straight, straight with a tang, reduced, and taper with a tang (all taper shanks have a tang).
straight_taperStraight shanks are cylindrical and may have the same diameter or a smaller diameter than the cutting diameter of the drill. The shanks are usually soft so that the drill chuck can firmly grip the tool. Reduced shanks are produced so that larger diameter drills can be held in chucks on portable drills or holders that have a limited size range. The three most common reduced shank diameters are 1/4 in., 3/8 in., and 1/2 in.

The taper shank is conical (cone shaped) and thus suitable for fitting into the tapered hole of a machine spindle, driving sleeve or socket. On all taper shank drills, a “tang” is cut across the end of the shank. The tang helps remove the drill from the holder. It can be seen in a slot or opening when assembled in a taper shank holder or adapter. A drill drift key is inserted into the slot behind the tang and is hit with a hammer to knock out the drill. The tang is not used to rotate or drive the drill.

Occasionally, straight shank drills have a tang at the end of the shank. This is used with a special adapter known as a split sleeve driver to convert a straight shank drill into a taper shank drill for equipment that was designed to hold taper shanks.

The body is the part of the drill that falls between the point and the shank. The body is made up of the flutes, the land, and margin. Also, within the body of the drill is where the measurements for the flute length, helix angle and diameter are taken.

Flutes are grooves that run along the body of a drill. These flutes are either milled with a milling cutter or ground with a grinding wheel into the drill body. The purpose of the flutes is to carry cutting fluid to the point and to provide a path for the removal of the chips. Flute length is measured from behind the point of the drill to the end of the flute. The length, size, and depth of a flute determines how deep a hole can be drilled.

0_2011_06_11_132630The helix angle, or spiral angle, is the angle formed by the axis of the drill and the edge of the flute. The helix of the drill helps to lift the chips out of the hole. Angles range from around 20 deg., 30 deg. and 40 deg. Lower helix drills are for shallower holes and harder materials, and faster helix are for deeper holes and softer material.

The land is the part of the body between the flutes. This area provides drill strength. Widening the land for additional strength reduces space in the flutes for chips, so holes cannot be drilled as deep. Land widths are designed to be a balance between strength and adequate chip space.

The margin is the narrow raised portion of the land. It provides support and guidance of the drill into the hole. The remainder of the land is ground down or reduced in diameter, known as the cleared diameter or body clearance. The body clearance reduces the width of the land to prevent excessive rubbing and friction of the drill in the workpiece.

The diameter of a drill is measured behind the point of the drill across the top of the margins. The size of the hole produced by a drill will be slightly larger than its diameter.

The point is the part of the drill that cuts. It is the very end, cone-shaped tip, made up of the cutting lip, web, and chisel edge. The point angle is determined by measuring from cuffing lip to cuffing lip.

Tool tip

Drill bits must be kept sharp. Each cutting edge must have an equal opportunity to cut the metal for efficient cutting For general purpose applications the cutting edges of a drill should form an angle of 118 to 120 degrees.