Iding Basics

USING THE CORRECT COMBINATION

Making More Holes

of drill speed and feed (the pressure you apply) is important to drill a hole efficiently. If the speed is too slow, you're wasting time. And using too high a speed for the material ' can overheat—and dull— :•' . .• . the drill. When using a pneumatic (air) drill, calculating its speed is impractical, but with practice you'll be able to determine the correct feed and speed. If your drill bit is straight and sharp and if your speed and feed are correct, you'll get a well-formed spiral chip. Aluminum is a relatively soft material, so you don't have to push too h a r d to drill a hole. But if you're drilling in corrosion-resistant steel, you'll have to increase the feed (pressure) and lower the drill's speed. This follows the general rules of drilling holes: • Small Drill—High Speed & Light Pressure • Big Drill—Low Speed & High Pressure • Hard Material—Lower Speed & Higher Pressure 100

APRIL 2001

Part I: Drilling techniques -,

RONALD STERKENBURG

fust as a two-handed grip improves your accuracy with a pistol, it will also improve your drilling accuracy.

hole is dimensionally accurate and has a good finish. Lubricants do not prevent the drill bit from overheating. And if you are drilling a deep hole, withdraw the drill periodically to relieve chip packing. There are a number of different drill lubricants, but Boelube works well with aluminum castings and corrosion-resistant steel, and it's available from many aviation hardware suppliers.

Drill Lubrication You don't need to lubricate your drill if you're putting holes in sheet aluminum, but if you're drilling an aluminum casting or hard materials like corrosion-resistant steel, lubrication will give you benefits. Besides helping to remove chips and prolong drill life, lubricants ensure that the

Boelube lubricant has benefits when drilling aluminum casting or corrosion-resistant steel.

Holding the Drill If you're using a pistol-grip drill, your holes will generally be larger than the drill size because you can't hold it

dead still, and how much the drill will wobble depends, in part, on how you hold the drill. Just as a two-handed grip improves your accuracy with a pistol, it will also improve your drilling accuracy. Whether you're left- or righthanded, point your index (trigger) finger on the barrel pointing forward and pull the trigger with your second finger. Steady the drill with your other hand, making the "V for victory" sign with your index and middle fingers to keep them safely out of the way. To control the drill speed accurately, I squeeze my hand rather than pull the trigger. The main advantage of this drilling technique is that the pushing force is in line with the drill's rotational centerline. And by bracing the grip with your other hand, it's easier to keep the drill from cutting through the material too far too fast, allowing the drill chuck to hit—and damage—the surface._________

A ruler, square and an ultra-fine point marker are used to draw lines on the material where it will be drilled.

The recommended two-handed grip will improve your drilling accuracy.

Hole Layout

Drilling holes in material at predetermined positions requires a careful layout, and drawing lines on the material is the easiest way to accomplish this. To draw the lines accu-

rately, you'll need a combination square, a ruler, and a marker (an ultra-fine point Sharpie is an excellent choice). If you don't want to mark directly on the material, you can apply masking tape over the material and mark on the tape. The advantages of the tape are that it reduces the chances of "drill walking" and it prevents scratches and nicks. After you lay out where the holes

factoryfive.com

At Factory Five Racing we're serious about engineering excellence. Maybe that's why our cars have so completely dominated the component car industry for the lastfive years running.

$10,990 Complete AH you need to huild your car ix the running gear from a late model Mustang 5.0 and our pkg. The FFR chassis is engineered specifically to uxe these tough Ford drivetrain components.

The unique combination of modern running gear and classic design delivers world class performance that dominates at the track, yet is reliable and comfortable on the street.

©

To find out more, or to receive our free detailed information package, please call 508-291-3443. You can also visit our website at www.factoiyfive.com.

Factory Five Racing, inc. factoryfive.com

Call 508-291-3443 forFree Brochure Mustang and Cobra are registered trademarks. Factory Five Racing, Inc. is not connected to the holders of these marks. 4I300DOI

Factory Five Racing, Inc. 18 Kendrick Road Wanham, MA 02571

For more information, visit SPORT AVIATION on the Web at www.eaa.org

Sport Aviation

101

EAA SportAir Workshops

Building Basics

Training For Aircraft Builders And Restorers

are supposed to be, creating them is the next step in the process. If you're working on a flat surface, you can use a center punch to keep the drill from walking away from where the hole is supposed to be.

^

The Leader in ReLreiiliontil /Million

You Can Build It

Let Us Teach You How. EAA SportAir Workshops travel the country to offer

training near you!

An anvil or metal plate is used for

UP.

California Colorado Florida Georgia Maryland

' Ohio Oklahoma Pennsylvania Pennsylvan Texas Washington Washingto

Minnesota New Hampshire North Carolina

Washington Washingto D.C.

Wisconsin

SportAir Workshops Offered; • Introduction To Aircraft Building

• Fabric Covering

•What's Involved In Building An Airplane

• Composite Construction

•TIG Welding

• Finishing And Spray Painting

• Gas Welding • Sheet Metal

• Sheet Metal Forming • Electrical Systems, Wiring And Avionics

l-800-WORKSHOP 1-800-967-5746 [email protected] www.sportair.com 102

• Engine Installation

APRIL 2001

•Test Flying Your Project • Kit Specific Workshops: Lancair Assembly Vans RV Series Assembly Velocity Assembly

backup material that will be punched.

When using a center punch, make sure you back up the material with a metal plate or anvil. If you don't, the punch could dimple the material and possibly destroy it. Place the point of the center punch on the crossed lines you laid out

and hit it with a hammer to create a

punch mark. (If you can see your mark from the reverse side of the material, you're hitting too hard.) Many people prefer the automatic center punch to the traditional punch and hammer. If you're one of them, make sure its tip is properly ground to 120 to 135 degrees. Many automatic center punches are actually prick punches, and they make a smaller mark than a center punch.

The drill should be perpendicular to the material to prevent the bit from walking.

The World's Best Selling Floats

• Rugged • Lightweight • Safe • Shock Absorbing • Dependable • Proven

Twin or Monohull Once you've center punched your holes, place the tip of the drill in the punch mark and slowly start drilling. If the drill walks out of the hole, it means the drill is not perpendicular to the material. Stop drilling and correct your hand position. If you're drilling on a curved surface, lay out the hole locations (preferably using the tape method). Then place the drill point at the center of the crossed lines, perpendicular to the surface, and turn the drill a few turns by hand. (Hold the drill motor steady while turning your left hand clockwise.) This creates a small indent that prevents drill walking. ,>.,.;

and your aircraft.

FULL ITU5 Info kit $8 US, with video $16 US.

20% DISCOUNT in

$25 US for overseas. 333 - 7400 Wilson Avenue,

N. America & 15% outside N. America

Delta, B.C., Canada V4G 1E5

ON ALL FLOATS

Tel: (604)940-9378 Fax: (604) 940-9566

I- APR 30,

:-mail: [email protected]

www.full-lotui.cojn

SAFARI

Two Place Helicopter Kit

Phone: I (807) 222-2474

Website: vfww.acehelicopter.com Info Pack & video $36 USD j

Start drilling slowly and check after a few revolutions if your drill is in the center; if not you could walk the hole a little by pointing the drill in the direction it should go and drilling slowly until the drill is properly lined up. For holes 3/16 inch and larger, drill a pilot hole with a smaller drill. Select a drill size equal to the width of the chisel edge of the final drill size. If you're drilling hard materials, like corrosion-resistant steel or titanium, lay out the hole locations and center punch them (and don't forget to back up the material before punching the holes). Then drill pilot holes using a #40 or #30 drill (preferably a cobalt-vanadium—Co Van—bit) and a drill lubricant (like Boelube). Finally, enlarge the holes to the desired size with a drill or reamer. Remember, in hard material you need to drill slower and press harder. Sport Aviation

103

Features

Pricing

Canadian Home Ruturs Inc.

On a curved surface, hand starting the drill will create a small indent which will prevent mishaps.

Try FULL LOTUS'floats

just one* In rough water. No other float offers so much protection for you

Ask About our Silver, Gold 4 Platinum . Purchase Groupings

• Lycoming Engine

- Gear & Shall Driven - Dual Controls • 4130 Chromoly Steel

DUAL STE

SCI-S4/6

ality ru

foil ince 1974 Dual Music Inputs • All/Crew/ISO

• Small 2.5" x 1" • Easy Retrofit for SPA-400/600 • 5-Year Warranty

FULL SERVICE WEB SITE!!! sigtronics.com/sa • Full Product Line • Technical Information • Accessories • Installation Instructions

Fast E-mail Response

Gel Ear Seals Full Flex Boom Noise Cancelling Mic 5-Year Warranty Sjigtronics .when it counts!

949 N. Cataract Avenue # D • San Dimas, California 91773 (909) 305-9399 • FAX (909) 305-9499 • www.sigtronics.com/sa For more information, visit SPORT AVIATION on the Web at www.eaa.org

Custom Instrument Panels www.Avionikits.Corn (888) 833-KITS TOHF™

You Install! Drill Pressing WI/IONICS SYSTEMS Tailwind Field

[email protected]

14974 Merritt Farm Lane Leesburg, VA 20176

Experienced in Lancair, Glastar, RV, Pulsar, Velocity, Kitfox, and others. Panels designed and built to suit your needs. Call or E-Mail for information. References available.

Aural Warnings Accurate and Affordable No Ugly Probes or Moving Parts True full range AOA Instrument Lightweight and Easy to Install Landing Gear Warning Option Patent Pending

Proprietary Software Systems QfiO Iris Cirnlfi

Fast, Reliable, Hi-Te

-WeicW Starters e Industry's Standard.

"Shipped to aircraft manufacturers worldwide on new engines. Fully Guaranteed and Dependable.

For Continental Series Engines 0-300D & E

IO/TSI0360 0/IO-470

Twice the Spin... Half the Weight!

For Lycoming Engines A. HT Model 10.4 Ibs. light

5.8 Ibs. light

i

For Franklin Series Engines

B. LS Model 7.8 Ibs. light

(PZL)4A , 6A4, 6A

_____

8.0 Ibs. light

NO BENDIX DRIVE

C. PM Model 7.8 Ibs. light

www.skytecair.com • 1-800-476-7896 • 817-573-2250 P.O.

Building Basics

Box 1024, Granbury, TX 76048 • FAX 817-573-2252

For more information, visit SPORT AVIATION on the Web at www.eaa.org

Found in most shops, the drill press offers many advantages, with variable speed and perfectly straight holes leading the list. When using a drill press, make sure that you clamp your work securely to the drill press table—and keep your hands away from your work while drilling. Failure to do this could result in serious injuries if the bit grabs the material and starts spinning it around. If you need to drill large holes, drill pilot holes first. And don't forget to remove the drill chuck key before starting the press. Leaving it in is a common mistake that has happened to many of us. It will send the chuck flying through the shop.

Making Big Holes There are situations that need holes larger than a drill bit or reamer can create, like when we're cutting holes for instruments, and a number of tools can do the job. The most common is the hole saw. Available in many sizes, it works with your drill. A spot facer also works with your d r i l l . You drill a pilot hole that matches the size of the spot facer's pilot, put the pilot in the hole, and slowly start drilling. When using a spot facer, back up the material with a piece of wood to prevent damage to the hole when the spot facer breaks through the material. Wobbling the drill a little will improve the action of the spot facer. An instrument cutter (chassis punch) is another tool that makes instrument-sized holes. First you drill a 3/8-inch hole, insert the threaded piece, and turn the cutter clockwise till snug. Use a wrench to turn the bolt clockwise. This action creates a clean-cut hole, and the tools are available in different sizes. An alternative way to use the chassis punch is to put the threaded piece in the vise and turn the cutter clockwise till snug. Rotating your work by hand clockwise will result in a clean-cut hole. 104

APRIL 2001