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Q1 Plans Chapter 3 Page 3-1

Quickie Plans EZE Tech

CHAPTER 3

EDUCATION

DON'T SKIP THIS SECTION. Every hour you spend in this preparation section will save you five when you really start building your aircraft.

GENERAL

In this section you won’t build any part of your airplane. What you will do is learn how to build your airplane the right way. This construction technique is radically different from anything you’ve done before (including building boats, surfboards, airplanes, and gocarts), and you should assume there is only one correct way to do it. We’ve discovered lots and lots of wrong ways of doing things and have written the plans to keep you from repeating our mistakes. We insist that you do things our way. If you have a better idea, suggest it to us, we’ll test, and if it really is a better idea we’ll publish details in the QUICKIE NEWSLETTER

This section will teach you all of the techniques required to build your airplane, show you what special tools you need and how to use them. The educational samples that you will build in this section are designed to give you experience and confidence in all of the techniques that you will use in the construction of your airplane. The steps in construction of each sample are arranged in sequence (as are the steps in construction of the actual aircraft parts) and you should follow the sequence without skipping any steps. You will learn the basic glass layup technique used throughout the aircraft, special corner treatments, foam shaping, cutting, and joining methods. A summary of these techniques is provided on yellow paper for you to tack up on your shop wall.

TOOLS

There are certain tools which are necessary to complete the aircraft. Three lists of tools are provided here. The first is the absolute bare minimum required, sacrificing efficiency; the second is a recommended list for the best compromise of cost and work efficiency; the third is a list for the “Cadillac” of shops where ease of construction is more important than money. The non-common items are stocked by the Quickie distributors.

  1. Basic Required Tools

    Common Household Butcher Knife
    Coping Saw
    1/4" Drive Socket Set
    Small Open End Wrenches
    Sandpaper 36-grit carborundum Aloxite Fastcut (50 sheets), also 220-grit and 320-grit wet or dry silicon carbide (20 sheets each)
    Pliers
    1" putty knife
    Hacksaw
    Blade & phillips screwdriver
    Box of single-edge razor blades
    24" carpenter's square
    Felt Marking Pens
    3-ft straightedge
    100 eight-oz paper cups (Lily 8SN1)
    50 3-oz paper cups (unwaxed)
    12-ft decimal steel tape (Stanley 461-112)
    1/4" drill with #30, #32, #10, 1/4" and #12 bits
    #10-32 & 1/8" NPT TAPS
    Roll of grey duct tape
    1" paint brushes (25)
    6" plastic or rubber squeegee
    Scissors
    Wire Brush
    Pop Rivet Puller
    Homemade balance for ratioing epoxy
    Wall thermometer 50 to 100° F
    1/4" hand drill

  2. Recommended Tools (in addition to those above.)

    Dremel-type miniature high-speed hand grinder with saw and router bits.
    6” to 9” disc-type hand sander
    Set of 1/4”, 1/2” & 1” chisels (wood)
    Small set of X-Acto knives
    Stipple rollers
    1/2”-dia 100° counter sink (piloted)
    6” machinist steel ruler
    X-Acto ragor saw
    Box of wood tongue depressors to mix epoxy
    6 ft straightedge
    Cheap holesaw set or flycutter
    3/8" variable-speed hand drill
    12" long drill bits - #10 & 1/4"
    Hand broom/brush
    Large commercial 12" scissors (Wiss #20W)
    Sabersaw
    Bench-mounted belt sander
    Stanley surform plane
    Square & half round file
    Several 6" C-clamps
    Vacuum cleaner (shop type)
    10" 18 tooth/inch handsaw (see sketch)
    Quickie handsaw


    Approx 150 lb of small weights *

    * Weights are used to hold various parts down while epoxy cures. They’re bear in 5 to 15—lb pieces. The items in the photo work great. We got them for 5¢/lb at a local scrap yard. Sand filled milk cartons also work well.
    Quickie Weights
  3. For the First Class Shop (in addition to those above)

    Drill Press
    18-inch bandsaw
    Vernier Caliper
    Epoxy ratio pump (Michael Engineering Dispenser)
    90° drill adapter
    Air compressor with blow nozzle
    Orbital Sander
    3/8" & 1/2" spotface

  4. Items Used Only Occasionally & Can Be Borrowed

    Nicopress sleeve tool
    1 dozen 1/8" Clecos
    Hotwire voltage control




The following tools are ones you make:

Sanding Blocks

These are required in many areas during construction and for finishing. You may also use a “soft block,” which is a block of the blue styrofoam wrapped with sandpaper.


Quickie Sanding Boards

Alot of elbow grease is saved if you replace the sandpaper often.

Long Straightedge

This is not absolutely required, but is quite handy when jigging or checking the straightness of flying surfaces. it is merely a 6-ft or 8—ft lx3 or 1x4 piece of lumber that is hand-selected to be “eyeball straight.” You can get it one of two ways: (1) Order it from Aircraft Spruce or Wicks - they plane them perfect from dry lumber. (2) Sort through the lumber (dry fir or redwood) at your local lumber yard until you find one that looks straight when you eyeball it from one end. Mark it and hang it on the wall so it doesn’t end up as part of a shelf!

Epoxy Balance

Devices which automatically ratio the correct amount of resin and hardener and dispense it with the pull of a lever are available from VariEZE distributors for approximately $130. These save time and epoxy. You can ratio the epoxy the way we did in building N7EZ and N4EZ by building the following simple balance; Cut out the 5-step instructions and glue to your balance - don’t skip steps! Follow each step exactly every time you mix epoxy.


Quickie Balance On Next Page

Quickie Balance Instructions

Q1 Plans Chapter 3 Page 3-2

Epoxy Balance Plans



Hot Wire Cutter

You will need a hot wire cutter to carve all the foam cores for the canard, fin, and wings. Refer to the sketch.

Hot Wire Cutter

The Variable Voltage control can be obtained from a Quickie distributor, or you can substitute any controllable power supply to include the 14 to 20-volt range with at least 4 amp capability. An alternative is to borrow two 12-V battery chargers or auto batteries and lash up the following device. The “A” blocks represent either a battery or a 12—V DC battery charger with 4-amp capability.

Cheap Variable Voltage Controller

The cutter should be used only on the blue or white styrofoam. A hazardous gas is emitted if you try to cut urethane.

You can substitute .02S nicrome wire which can be run at a lower current (about 2 amp) but nicrome wire is difficult to find. Adjust the current to obtain a wire temperature which will allow the wire to cut the foam at a rate of one inch every four to six seconds when pulled with a light load (Less than 1/2 pound) This can be checked with a small scrap of foam. if temperature is correct, foam will have

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Q1 Plans Chapter 3 Page 3-4

UNI cloth has 95% of the glass volume woven parallel to the selvage giving exceptional strength in that direction and very little at right angles to it.

BID is generally used as pieces which are cut at a 45—degree angle to the selvage and are laid into contours with very little effort. BID is often applied at 45-degree orientation to obtain a desired torsional or sheer stiffness. UND is used in areas where the primary loads are in one direction, and maximum efficiency is required, such as the wing skins and spar caps.

Multiple layers of glass cloth are laminated together to form the aircratt structure. Each layer of cloth is called a ply and this term will be used throughout the plans.

Marking and cutting the plies of glass cloth is a job that you will repeat at often in the construction of your Quickie. Glass cloth should be stored, marked, and cut in a clean area with clean hands and clean tools. Glass contaminated with dirt, grease, or epoxy should not be used. A clean, smooth surface is needed for marking and cutting. The area used for storing and cutting glass cloth should be separated from the aircraft assembly area because it will be exposed to foam dust, epoxy, and other things which can contaminate the cloth. You will need a good sharp pair of scissors, a felt—tipped marker, a fairly straight board, and a tape measure for marking and cutting. The small amount of ink from marking and numbering plies has no detrimental effects on the glass cloth.

In each step the size, type, and fiber orientation of each ply is given. Take the list to your glass cutting table, roll out a length of the appropriate cloth, straighten the selvage, mark all of the plies, and cut them.

Now is a good time to stop reading long enough to go and cut a square ply of BID and see how easy it is to change its ahape by pulling and pushing on the edges as shown in the sketches. Cut a square with the fibers running at 45° and pull on the edges to shape the piece.


Shaping a BID Square

It helps if you make fairly straight cuts but don’t worry if your cut is within 1/2 inch of your mark. As you cut BID it may change shape, just as the square ply that you are experimenting with does when you pull on one edge. Plies that distort when cut are easily put back into shape by pulling on an edge. Rolling or folding cut plies will help keep them clean and make it easier to maintain their shape. If several plies are called for, it may help to number them before cutting. Save your clean scraps and make an effort to use them for smaller plies. If the cloth is spotted with epoxy, throw it away.

When cutting long strips or large pieces of 45° BID, always roll or fold it so it keeps its shape when handled. When it’s applied it can be set on one end of the part and rolled onto it. If you pick up each end, it will distort and not fit the part properly.

The fiber orientation called for in each materials list is important and shouldn’t be ignored. UNI is characterized by the major fiber bundles running parallel to the selvage and being much larger than the small cross fibers which run at right angles to the selvage. In BID the cross fibers are the same size as those running parallel to the selvage, giving BID an even “checker board” appearance. BID is commonly used for piles cut at 45° to the selvage. Your tailor would call this a "bias" cut. The 45° cut makes it easy to work wrinkles out of a ply locally, without having to chase it to the far edge. The 45° cut also makes it possible to make a ply slightly longer than originally cut by pulling on the ends or wider by puiling the sides. The 45° orientation isn’t critical; you don’t need to measure it. Your eyeball of a rough diagonal (45° ± 10 ) is adequate when either cutting or laying up the cloth.

Epoxy

In recent years the term “epoxy” has become a household word. Unfortunately “epoxy” is a general term for a vast number of specialized resin/hardener systems, the same as “aluminum” is a general term for a whole family of specialized metal alloys. Just as the “aluminum” in the spar of a high performance aircraft is vastly different from the “aluminum” pots and pans in your kitchen, the “epoxy” in your Quickie is vastly different from the hardware store variety.

Epoxy is the adhesive matrix that keeps the plies of load-carrying glass cloth together. Epoxy alone is weak and heavy. It is important to use it properly so that the full benefits of its adhesive capability are obtained without unnecessary weight. A large portion of your education in composite structural work will be spent learning how to get the full strength of an epoxy/glass mixture with the minimum weight. This section will discuss the terminology and techniques for working with epoxy resin and its hardener.

An “epoxy system” is made up of a resin and a hardener tailored to produce a variety of physical and working properties, The mixing of resin with its hardener causes a chemical reaction called curing, which changes the two liquids into a solid. Different epoxy systems produce a wide variety of solids ranging from extremely hard to very flexible, Epoxy systems also vary greatly in their working properties, some are very thick, slow pouring liquids and others are like water. Some epoxy systems allow hours of working time and others harden almost as fast as they are mixed. A single type of resin is sometimes used with a variety of hardeners to obtain a number of different characteristics. In short, there is no universal epoxy system; each has its own specfic purpose and while it may be the best for one application, it could be the worst possible in another use.

The RAE-type epoxy systems used in the construction of your Quickie are tailored for the best combination of workability and strength, as well as to protect the foam core from heat damage and solvent attack. These systems are also low in toxicity (SPI-2) to minimize epoxy rash. These epoxies are not similar to the common types normally marketed for fiberglass laminating. Three different systems are used in the Quickie, for three different types of work: a slow curing system, a fast curing system, and a 5-minute system. The very fast curing (5-min) system is used much like clecos are used in sheet metal construction (or clamps in woodwork) for temporary positioning. Five-minute is also used in some areas where high strength is not required, but where a fast cure will aid assembly.

As an epoxy system cures, it generates heat and in some areas, the heat buildup of a medium or fast curing epoxy system is unacceptable. Where this is a potential problem, a slow curing system is used. Slow cure epoxy is always used with styrofoam, where heat can melt the foam away and ruin the joint. In other

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Q1 Plans Chapter 3 Page 3-3

smooth hairy surface. A cratered surface means too much heat. If the wire is too cold, the cutter will have to be forced hard, causing the wire to lag. Lag should not exceed 1/2 inch over the top and bottom of the wing and not over 1/8 inch around the leading edge. If the wire is too hot, it will burn away too much foam, making the part too small and will result in ruts in the foam if the wire is inadvertently stopped during cutting. The wire should be tightened until the wire starts to yield. Check this by tightening the wire while plunking it listening to the sound. The pitch will increase until the wire yields.

Jig Table

You will need a table to jig and build the wings and canard, It should he at least 2ft by 10 ft. Any larger than 4 ft by 12 ft will just get in the way. Use a little care in making a flat, untwisted surface. The following is s sketch of the one we made and it works fine. The box design makes it stiff in torsion. Set it up with the top 35 to 39 inches above the floor. Don’t get carried away with surface finish, since you are going to be gluing blocks to it with Bondo and chiseling them off several times.


Quickie Jig Table

 

 

MATERIALS

The materials, processes, and terminology used in the construction of your Quickie are new to homebuilding. This section is devoted to familiarizing you with the language, materials, and techniques used in these plans. This information is basic to the construction of your airplane. You should study this section and be sure that you underetand all of it before continuing.

There are five basic materials you will be working with. fiberglass cloth, epoxy, microspheres, flox, and foam. Each material, its properties, and uses will be discussed in detail. Basic processes using these materials will also be discussed.

Glass

The most basic structural material in your Quickie is glass cloth. Glass cloth is available commercially in hundreds of different weights, weaves, strengths, and working properties. The use of glass in aircraft structures, particularly structural sandwich composites, is a recent development. Very few of the commercially available glass cloth types are compatible with aircraft requirements for high strength and light weight. Even fewer are suitable for the handlayup techniques developed by RAF for the homebuilder. The glass cloth used in the VariEze has been specifically selected for the optimum combination of workability, strength, and weight.

The glass cloth in your VariEze carries primary loads, and its correct application is of vital importance. Even though doing your glass work correctly is important, this doesn’t mean that it is difficult; in fact it’s VariEze!


Quickie Fiberglass Types

Two types of glass cloth are used, a bi-directional cloth (RA5277BID). and a unidirectional cloth (RA5177UND). (Use the full part number for ordering your cloth, but for simplicity the plans will use only the BID or UNI designations.) BID cloth has half of the fibers woven parallel to the selvage edge of the cloth and the other half at right angles to the selvage, giving the cloth the sane strength in both directions. The selvage is the woven edge of a bolt of fabric as shown in the accompanying sketch.


Quickie Fiberglass Selvage Edge

Q1 Plans Chapter 3 Page 3-5

areas where heat buildup isn’t a problem and a faster cure is desirable, a fast curing system is used. Both the fast and slow cure epoxies will cure to a firm structure at room temperature within one day. Complete cure takes 14 days.

The RAF epoxy systems are called RAES (for slow curing), RAEF (fast curing), and 5-MIN. Both the RAES and RAEF hardener use the same RAE resin.


Mixing Epoxy Resin

Note: If working conditions are hot (85° to 90°F), RAES can be used where RAEF is called out. While this practice is allowable, the best results are obtained working between 70 and 80°F with the specified epoxy.

The working and strength characteristics of an epoxy system are dependent on the resin, the hardener, and on the amount of each in a given mixture. Epoxy systems are engineered for a specific ratio of resin and hardener. It is quite important that the proper mixture be obtained. An accurate balance or ratio pump must be used to accomplish this. A drawing of an inexpensive ratio balance is included in these plans. The mix ratio accuracy is particularly important with RAEF & RAES. The 5-MIN can be adequately ratioed by merely pouring a blob of part A in a cup and adding a blob of part B that looks the same volume before mixing. Never eyeball estimate RAEF or RAES, always carefully use the balance or pump.

Epoxy resin and hardener are mixed in small batches, usually 6 ounces or less, even in the largest layup. The reason for small batches is that, in large batches, as the hardening reaction progresses, heat is generated which speeds the reaction, which causes even more heat, which speeds up in a fast reaction called an exotherm. An exotherm will cause the cup of epoxy to get hot and begin to thicken rapidly. If this occurs, throw it away and mix a new batch. The small volume batch avoids the exotherm. For a large layup, you will mix many small batches rather than a few large ones. With this method you can spend many hours on a large lay-up using epoxy that has a working life of only a few minutes. If the epoxy is spread thin as in a layup its curing heat will quickly dissipate and it will remain only a few degrees above room temperature. However, in a thick buildup or cup, the low surface area to mass ratio will cause the epoxy to retain its heat, increasing its temperature. This results in a faster cure causing more heat. This unstable reaction is called an exotherm. Exotherm tesperatures can easily exceed the maximum allowable for foam (200°F) and damage the foam-to-glass bond. This is why the slow epoxy system is used in joining foam cores as exotherm is impossible as long as epoxy joint thickness is less than 1/8”.

Unwaxed paper cups are used for mixing and ratioing resin and hardener. Convenient 8-oz cups for resin are available from RAF distributors. The hardener cups are the 3-oz unwaxed bathroom paper cups available at any grocery store. Don’t use waxed cups; the wax will contaminate your epoxy.

If you are using the homebuilt balance, follow this procedure. Place the resin (8 oz) cup on the right cradle. The resin cup can be either a new clean cup, one with a little uncured epoxy left in the bottom, or a clean cup from a previous layup with hard epoxy in the bottom (smooth, nor lumpy). Now, take a clean 3-oz hardener cup - pour a splash of hardener into it then scrape the hardener back into the container. This gives the hardener a wet surface, so its remaining hardener will not be counted in the balancing. Now, place the wet hardener cup on the scale, check that it swings freely and balance it perfectly by moving the small weight. Epoxy is then poured into the 8 oz cup (6 oz or less). Hardener is then poured into the 3—oz cup at the other end of the balance until the arm is level. When resdy to mix, pour the hardener into the resin cup and mix completely. If you have the ratio pump, you simply put one cup under the spout, pump out the amount that you want and mix.

Mixing is done by stirring with a stick, being careful not to spill any. If you spill part of an unmixed cup, the ratio of resin and hardener may be inaccurate and it shouldn’t be used. Mix each cup for at least two minutes. You should spend 80% of your mixing time stirring the cup and 20% scraping the sides to assure complete mixing. Do not mix with a brush. The bristles can soak up the hardener, changing the ratio. Use a tongue depressor or wood stick.

The working temperature has a substantial effect on the pot life and cure time. Very hot conditions will cause the cure to speed up. In cold working conditions the cure will be delayed and if it is cold enough, epoxy may not cure at all. Working temperatures must be between 60° and 90°F. A range of 70 to 75°F is best. Be sure to get a wall thermometer (approx. $1.50 at any general store) to check the temperature of your work area. At 75°F, 5-mim must be used within four minutes, RAEF must be used within 20 minutes and RAES must be used within 50 minutes.

Cold epoxy results in increased time required to do a layup, since it takes longer to “wet” and to squeegee the cloth. A layup at 65° may take almost twice the time as st 75°F. On most layups (except for joining foam cores) its best to have 70 to 80°F room temperature and 80 to 90°F epoxy. Resin and hardener can be kept warmer than room temperature by keeping it in a cabinent with a small light bulb on. DO NOT store your resin or hardener on a cold floor if you plan to use it within the next several hours, if you let your shop get cold between

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