Electrical failures

It is important to always use good-quality equipment. Today, manufacturers usually list the components they recommend for their specific airframe. These can include heavy-duty switches, redundant battery systems, voltage regulators, and so forth. This is a good place to start but if you have any doubts, seek the advice of other experienced giant-scale enthusiasts.

Generally, I think it’s best to use electrical accessories from the same manufacturer of your radio system so everything is consistent throughout your aircraft. Dual battery packs are preferred to power the receiver with two separate switches and heavy-duty servo extensions throughout the entire airframe. For those that prefer 4.8V or 6V (4 or 5-cell) Ni-Cd or NiMH batteries, a voltage regulator is not needed. Newer LiPo and lithium ion packs require the use of a voltage regulator for power. Using higher amounts of voltage to power a servo will increase the overall torque, if the servo is designed for higher voltages. Using higher voltages with servos intended for 4.8V can lead to servo damage and failure. Always check the specifications for your electrical components and follow the factory-recommended settings.

Also, when it comes to airborne battery packs, you should always charge, cycle and/or balance them properly for maximum performance and lifespan. It is also important to routinely check all the electrical connectors and monitor battery voltage between flights including the engine’s ignition battery. Engine vibration can take a toll on the aircraft, and can lead to electrical components becoming disconnected or fail.

Over the years, I’ve had situations arise where either a battery, or a voltage regulator failed. As voltage begins to decrease, you’ll find that the aircraft’s response is becoming rather sluggish in the air. Should this happen to you, decrease throttle and prepare for an emergency landing. Keep control surface corrections at a bare minimum and once safely on the ground, check your battery voltages. It is not uncommon for one of the two battery packs in a redundant setup to fail. Don’t push a bad situation.

Wing failure and flutter

While building a giant-scale model, it’s important to follow proper build practices to ensure a structurally sound aircraft. Wing panels have to withstand the forces that act upon it during any given flight so don’t take shortcuts with wing construction. Ensure the spars are installed properly. If the plans show the use of shear webbing that connect the upper and lower spars, ensure that the balsa grain is in the proper direction. For the best strength, the grain should be in an orientation that is perpendicular to the spar and not running span-wise. Since giant ARFs have become so popular, I think it is very important to really check out all the critical areas within the wing, and the airframe. If you feel an area on an aircraft appears questionable, don’t be afraid to reinforce that area. Spending a few extra hours reinforcing a spar, a servo mount, or any other area can save a lot of grief down the road.

One summer, while pulling out of a vertical down-line, I experienced “wing flutter” on an all-composite aircraft. The wingtips began to flutter which resulted in stripping out both aileron servos in flight. One servo was locked at full deflection! Immediately, I throttled back and the aircraft began to roll. I was able to stabilize the aircraft while it was in a constant roll and applied the inputs to perform a 180-degree rolling circle to bring the model to the outer edge of the runway. Decreasing altitude with throttle management and various rudder and elevator corrections, I waited for the airplane to be in an upright position and forced it onto the ground. Post flight inspection showed that the wing’s trailing edge and the ailerons’ leading edges had de-laminated in flight. A crack was also evident on the wing at the end of the wing tube. Surprisingly, the fuselage and the tail were in perfect condition! It was difficult to predict this type of failure as the entire aircraft had a full-composite fiberglass, Kevlar, and carbon-fiber airframe. The important thing is to keep flying the plane and don’t just give up.

Two receiver switches and a minimum of two flight batteries to power the receiver are mandatory for all giant-scale models as in the event that one component stops functioning, the aircraft will have power the pilot will be able to land the model safely.

Control direction

Far too many pilots have lost their models as a result of having the control surfaces reversed. To prevent this, perform a control surface check before takeoff. Check the direction of each control surface and from behind the aircraft. Don’t perform the check with your plane inverted on a stand. It’s too easy to get confused about what’s up and what’s down. If you sent your radio system in for service, perform a ground check for all your planes using that transmitter to ensure no settings have been accidentally changed.

Finding reversed controls once in the air is a bad thing. Only an experienced pilot can react quick enough and apply the control inputs needed to safely return the aircraft back to the runway. As a tip, let’s say you notice the ailerons are reversed after takeoff. It is crucial to switch to using only throttle, rudder, and elevator to get the airplane back on the ground if it is too difficult to use reversed ailerons inputs.

Using twist-tie clamps from Sullivan Products is the most effective way to keep fuel lines from coming loose while an aircraft is in the air.

After you notice a problem with how your gasser operates, its best to remove the carburetor and ensure that no debris is found. Shown here is the carburetor on a Desert Aircraft 120cc engine.

Engine Failure

Gasoline engines have a strong reputation of being reliable. However, proper setup is key for the engine to perform properly. Always ensure the throttle linkage is firmly secured and that the throttle travel volume is similar between the high and the low throttle setting. A reliable idle and a smooth transition to maximum power is also mandatory.

A variety of synthetic oils exist today that have a recommended mix ratio of 100:1. It is extremely important to precisely measure the oil and gasoline quantities. Always go through the proper engine break-in process and if an engine is not performing as desired, don’t attempt to fly the aircraft. Also use fresh fuel and high-quality fuel filters to ensure that debris does not find its way to the carburetor. While all giant-scale gasoline engines will exhibit some level of vibration, excessive vibration is typically caused by an unbalanced propeller or an engine that is inadequately secured. Always check the engine is properly mounting bolts and that the firewall is properly glued in place.

When an engine abruptly quits, you have to react quickly. Get the nose down relation to the horizon and keep the airspeed at a moderate setting to avoid a tip stall. Speed is important! Occasionally, the engine will quit when the aircraft is too far from the runway or too low to the ground. If this occurs, quickly observe the surroundings to find an area that is flat and safe for the model. Don’t try to stretch the approach! Attempt to land the aircraft in that area with a minimal flight speed as it contacts the ground. For a giant aerobatic model, flaring the aircraft at a 20-degree angle of attack before it touches the ground will help minimize any damage.

When an engine failure does occur, like the left engine on this twin, a pilot must be prepared to execute an emergency landing without hesitation. (Photo by David Hart)

Always perform a visual inspection on certain critical areas, like the elevator joiner on this beautiful aircraft. Typically, stress cracks will appear before a given area fails completely.

Despite the fact that structural failures can occur at any time, a pilot must always react with safety as the most important concern. Always keep the aircraft away from the crowd and make every last effort to land the aircraft. (Photo by David Hart)

Final thoughts

As an RC pilot, you must always be ready for the unexpected, as a failure can occur at any point during the flight. Try to figure out what’s wrong, make your decisions quickly and maintain airspeed. The best way to avoid problems in the air is to set up your airplane and its equipment properly while still on the workbench. BY JOHN GLEZELLIS

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SMOOTH THAT OLD IRON

Have you ever noticed the slick surface on a new covering iron after you first pull it out of the box? The iron seems to float on top of the plastic covering, giving you a beautiful finish. However, after time goes by and the iron gets a little older, the smooth Teflon feel on the surface just goes away. Here is a simple way to rejuvenate that old iron. When the iron is cool, add a little baby powder to the surface and rub it in with your fingers. This will give the contact area a new surface that will glide much more easily over your covering. You can reapply powder as needed to keep the iron gliding smooth.

PAPER TOWEL SHIM

I always have a problem with getting the socket-head bolts into those hard-to-reach spaces. Even though the socket-head bolts do hold on better than a Philips or screwdriver head, they tend to let the bolt fall off just before you can get it started. That’s where this trick is really going to save your day! Add a little piece of paper towel to the end of the ball driver and press it into the socket head of the bolt. You will find that this holds better than a magnetic head driver.

RECYCLE THAT OLD BIKE

Many bicycle spokes have the same thread size as a standard-size airplane pushrod, which means you could have 25 to 50 pushrods from an old bicycle wheel. First remove the tire and inner rim tape to get to the spokes. Now just cut the spoke near the center hub and slide it out. Cut it to length when needed. Many of the newer spokes are made of aluminum and are very light.

AILERON ALIGNMENT JIG

When setting up the aileron linkage, it is helpful to have a third hand holding the aileron in the center position. The next best thing is to make this simple alignment jig out of a clothespin and two pieces of balsa. Just put the two pieces of balsa above and below the aileron centered on the gap between the aileron and wing trailing edge. Attach the clothespin to hold the aileron in place. The soft balsa will help prevent the clothespin from marking the surface. Just be sure to remove it before operating the servo when testing the throws..

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1 Charged Battery ID
If you have a bunch of battery packs you use over and over, knowing which ones are charged and which are not can get confusing. An easy way to identify packs is to place a small ID sticker on the packs after you charge them. Once you’ve used the pack for a flight, peel the sticker off so you’ll know it’s in need of a recharge.

2 Propeller Safety Tips
To prevent accidents, full-size aircraft are equipped with propellers that have brightly colored tips. Do the same with your model airplane propellers. Mask off the tips and spray on some bright yellow or white to make the prop tips more visible while it’s spinning. The finger you save might be your own!
 
3 Small Parts Sticker
When building (or repairing) a model, it is sometimes hard to place a wooden part properly inside a narrow fuselage. An easy way to do this is to use a sharp awl as a “part sticker.” Now, simply add glue to the part, stick it with the “part sticker” and guide it into position.

4 Emergency Screwdriver
It never fails that whenever you need a specific tool for the job, you’ll find that tool anywhere but where you need it. If you find yourself in need of a common, straight-blade screwdriver, you can always take a modeling blade and place it backwards in its handle. The exposed part of the blade can now be used to tighten that screw.

5 Throw-away Epoxy Mixing Pad
While mixing epoxy, use a pad of Post-It notes for the mixing surface. Then after applying the adhesive to the model, simply throw the used note away and you’re ready to mix some more adhesive. No clean up required.

6 Easy Control Surface Alignment

When you install and adjust your pushrods, it is better and easier to do if you lock your control surfaces in their neutral positions. Use a pair of coffee mixing sticks and a couple of clamping clothespins to keep the surfaces from moving.

7 Easy Clevis Keepers
If a clevis were to pop off one of your model’s control horns, you could lose control and crash. A simple and cheap way to prevent this from happening is to add a clevis keeper. Simply slice a thin section from some model fuel tubing and slip it over the clevis. It will act like an O-ring and keep the clevis securely in place without binding.

8 Handy Clamp
There are a hundred tasks in modeling during which you simply need a third hand. Soldering connectors to wire leads is a good example. In a pinch, you can use a pair of pliers with its handles wrapped with a rubber band. The pliers are heavy enough to act as a steady base and the rubber band provides enough clamping force to hold delicate items without damaging them.

9 Simple Building Board
You don’t need a complete building bench or table to build model airplanes; just use a straight piece of pine board. But to make it easier to insert pins to hold the wood parts in place while the glue dries, get some cheap Peel-n-Stick cork sheeting from a hardware store or a convenience shop and stick them to the building board. Place your plans on top and protect it with some clear kitchen wrap or wax paper. Should the cork get damaged or you get some glue on it, simply peel the cork away and replace it with a new piece.

10 Sheet Separator
If you build from plans or kits, you have to cover your model. Often, it is very difficult to separate the covering film from its backing sheet so you can iron it into place. The easiest way to do this is to apply strips of masking tape to each side and use them as pull tabs to separate the two thin layers of plastic.

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Getting Started
Gas engines are fairly easy to operate. If you can operate garden equipment and chainsaws, there’s no reason you can’t properly set up and run an RC gasser. Your basic gasoline engine operates using the “fire triangle” principal, meaning it needs air, fuel, and heat to run. Take any one of these away and it will not run. These three fire elements are brought together using the engine’s ignition system, carburetor, and spark plug. I like to install a new engine on a test stand and adjust it before bolting it onto my airplane. It is then much easier to work out the linkages, fuel line attachments, test various propellers and set the top end for maximum power using a tachometer.

This Zenoah G45 is an older model engine that uses a magneto setup. It’s a workhorse that requires very little maintenance.

The new breed of smaller gasoline engines, like this RCGF Stinger 10cc side-exhaust powerplant from Legend Hobby, come equipped with electronic ignition systems.

Engine types
Gas engines use either a magneto spark system or an electronic ignition system. Engines that use a magneto setup are a little heavier, but very easy to use and require almost no maintenance. There is no battery required for a magneto, but you do have to install a grounding kill switch to turn the engine off and prevent it from accidentally starting. If you have a helper, always have them carefully handle your airplane and show them where the off switch is. Newer engines with electronic ignition systems are a bit lighter, but they require a separate battery pack and a power switch to operate the engine.

Always have a friend help you start your engine. Securing the model’s tail prevents it from moving forward when the engine fires up.

A gas fuel tank with a pickup and vent line, T-fitting for the engine supply line, and a fuel filter.

Startup
When you fire up your engine, the airplane can move forward, so always have a friend secure your airplane before you start the engine. Position the propeller blades (in relation to the magneto magnets or the electronic ignition’s triggering module) as the engine manual suggests. When you swing the propeller through compression, the spark plug should fire. If the blade position is off, it can make starting the engine more difficult. For increased safety, use a proper size electric starter instead of hand-propping the engine. But if you do hand-start it, use a glove or chicken stick.

To prevent debris from clogging your engine, place filters in your fuel container’s pickup line and between the fuel tank and your engine.

Prop care
Always balance your propellers, and if you ever nose over your airplane, check the prop tips for damage. Use the size and pitch recommended for your engine and test-fly using that propeller before trying a different size. After the first few test flights, recheck the prop bolt(s) for tightness. It is always a good idea to do this before your first flight of the day.

Fuel
Regardless of your type or size of gas engine, always use clean, filtered fuel. Install a filter in your fuel container’s pickup line as well as between your engine and the fuel tank. If you use a T-fitting in the engine supply line and a fuel dot for filling and draining your tank, place another filter between the dot and the T-fitting.

It is also very important to properly mix your fuel using the engine manufacturer’s recommended ratio for gasoline and oil. For the first couple of tanks of fuel, use a ratio of 30:1 to 40:1; after that, use 50:1 or whatever the recommendation is. Some more expensive synthetic oils have superior protection qualities and can be used up to a 100:1 mixture, but I have only used regular 2-stroke oil available at most garden supply and hardware stores with excellent results.
FAST FACT
There are 128 ounces in a gallon. For a 30:1 mix ratio, add 4.2 ounces of oil to 1 gallon of gas. For a 50:1 ratio, add 2.56 ounces of oil.

Test Rig
The best arrangement I have found for running gas engines is a simple wood box structure. I make the base from thick plywood or pine with a face (where the engine is attached) that’s the same thickness as the model’s firewall. The face is supported with plywood side pieces glued and screwed together. I then install the engine and screw the structure to a picnic table. I use all the same RC hardware used in my airplane and I install the fuel tank and engine ignition system inside the box. I use a throttle servo and linkage controlled with my transmitter and a receiver or an electronic “servo driver” and battery to adjust the throttle. Getting to know your engine using a test rig is a lot better than trying to figure things out before your first flight at the flying field.

After sorting everything out on the test rig, I then install the engine on my airplane and test run the engine once more with the engine cowl removed. This way I can check the model’s linkage setup, fuel line runs, and the tank’s plumbing for proper function. If it all checks out, you can button it all up, install the cowl, and head to the flying field. You’ll impress all your friends with how easily your engine fires up.

A simple, sturdy box makes a great test rig for setting up gas engines. Notice the throttle servo and linkage used.

After setting up your engine on a test rig, you can install it on your airplane and test run the engine again before installing the engine cowl.

Spark plugs come in different sizes and ratings. Be sure to use the type and size recommended by the engine’s manufacturer.

Big and impressive multi-cylinder radial engines are very popular. Most are 4-strokes but they use the same basic setups and procedures to operate. Most use a single carburetor to feed all of the cylinders.

Hand-starting is the norm for most giant-scale modelers. If you do hand-prop your engine, be sure to wear a heavy leather glove for increased finger protection.

Spark Plugs
The spark plug is the heart of the gasoline engine. It used to be very important to use resistor-type plugs to help prevent radio interference that was common with 27 and 72MHz radios. With modern 2.4GHz radio systems this is no longer an issue, but you should use the spark plug recommended for and supplied with the engine. It is also a good idea to check to make sure the spark gap is within specs according to the instructions. Should the gap be too narrow or too wide, it can affect the performance of the engine. A good average setting is between 0.02 and 0.03 inch. Spark gap gauges are readily available at auto part stores and small engine shops.

Needle Settings
When the engine has started, allow it to warm up a minute or two, advance the throttle slowly to full power, and note the response. If the engine sags, loads up and dies, it’s too rich. Lean the low-end needle about 1/8 turn clockwise, and try again. If, however, the engine makes a hollow burbling sound and dies, then the mixture is too lean. Open the needle slightly counterclockwise.

Next, adjust the high-end needle until the rpm peaks out and back off the needle, decreasing rpm by 200 to 300. All engines unload during flight, so don’t try to get every single rev out of your engine on the ground running static. Once you have the high-end needle set, check the low-end setting again, since adjusting either needle can affect previous setting adjustments you’ve made. What you are looking for is a smooth, slightly delayed transition to full throttle and then solid performance without the engine overheating.

Running Radials
Some of the bigger RC giant scale models are now being powered by big 4-stroke, multi-cylinder radial engines. These round engines are very popular but are also affected by engine temperatures. With enclosed engine cowlings, it is advisable to add baffles between the cylinders to channel the incoming airflow directed through the cylinders’ cooling fins. This setup helps you to maintain the recommended rule of using “two times the cooling air exit area relative to the air inlet area.” It is a small detail but very important for a properly running engine. In operation, use the starting procedures (and the fuel mix ratio) recommended by the manufacturer.

Bottom line
Gasoline engines, if properly installed and taken care of, are the most user-friendly power systems available. They are easy to start, fuel efficient, and reliable. After you’ve set up your carburetor, you usually won’t have to readjust it for an entire flying season. And remember it’s no secret: a properly running engine will greatly extend your RC airplane’s lifespan!

TROUBLESHOOTING CHECK LIST

If you have difficulty starting and obtaining a smooth transition from idle to full power, here are some common items to check off your troubleshooting list.

– Does your engine fire up, burn off the prime and then die?
Check your fuel draw. Make sure the fuel lines are not pinched, kinked, blocked or have any pinholes. Make sure your engine is properly set up. Is your fuel tank installed upside-down? It happens to the best of us. When you flip the prop (with the choke closed), the carburetor should draw fuel and you should be able to see it move in the fuel lines toward the carburetor.

– The carburetor doesn’t draw fuel.
Check the needle valves for proper settings. Make sure the carburetor is tightly fastened to the engine and is not leaking air. Check the carburetor’s internal fuel intake screen filter and make sure it is clean. It is under the carburetor’s top cap (the one held in place with a single screw). If it’s dirty, remove it and flush it with fresh gas or replace it. Finally, check that the engine head/cylinder case is tightly fastened to the engine case and that the gasket is undamaged. Even a small air leak here can affect compression and prevent the engine from starting.

– There’s no spark.
Make sure your kill (grounding) switch is in the correct (run) position. If you are using an electronic ignition, make sure the battery is fully charged and the wiring to the timing sensor is properly connected.

– An engine that has been running well loses compression.
Check for a stuck or broken piston ring. If this happens during flight, perform an emergency landing as soon as you can. Don’t turn the engine over by hand as this can easily score or gouge the piston sleeve. Carefully check for internal damage. If you don’t feel comfortable doing it yourself, send the engine out for inspection and repair.

By Gerry Yarrish

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A SHARP IDEA
Most model airplanes use dowels to secure the leading edge of the wing to the fuselage, and for easy installation, the nose of the dowel should be slightly tapered. Many modelers use sandpaper and a sanding block to make the taper. Next time, take the dowel and insert it into an electric or mechanical pencil sharpener. After a few seconds in the sharpener, the dowel will have a crisp, clean, even taper. A little sanding will create a smooth finish.

IN TOO DEEP
If you cut hinge slots using a hobby knife, you know that making slots of the correct depth is a hit-or-miss operation. Here’s a solution: Using a straightedge or a tape measure, lay the knife-blade point to the depth required (the blade must be parallel with the straightedge), and use a permanent-ink marker or some tape to create a line straight across the blade where it enters the wood. The line on the blade indicates when it’s at the correct depth.

NOW YOU SEE IT; NOW YOU DON’T
Most cowls require cutouts for the air vents and motor and speed-control access. To make the cutouts accurately, you need to measure and mark them properly. Ballpoint pens and pencils don’t write well on smooth, painted surfaces, and lines made by regular markers are difficult, if not impossible, to erase. A solution is to use dry-erase markers—the ones used in boardrooms across the country. Dry-erase markers, like regular markers, will leave a line on smooth surfaces, but when you’ve finished making the cutouts, you can simply use a rag to wipe off any remaining ink.

HANGING AROUND
We all know the kind of tangled mess that wall chargers can become if they aren’t kept orderly. Go to your local home-improvement store, and buy a few of the inserts that go into duplex outlet boxes. Attach them to a cabinet door or other out-of-the-way place, and voila!—you’ve got an easy, tangle-free way to hang your chargers for storage.

SERVO EXTENSION HOLDER

At one time or another, most of us have had to fish for a servo extension wire that slipped back inside the wing; but there is a solution. Cut a 3/16-inch hole in the bottom of the red plug from an old bottle of epoxy. Across the hole, cut a slot that’s just wide enough to squeeze the connector at the end of your servo extension through. Trim the access hole in the wing to fit the plug, and you’ll never have to go fishing again. This trick also works well for hold-down bolts.

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Simple Crush Plate

Purchase Lucite at the hardware store and pick up a 1 1/4-inch hole cutter.  Use the hold cutter to cut out some Lucite 1 1/4-inch disks. Then use a drill press to cut out a 1/4-inch hole in the center of the disk. This large Lucite disk can be used with the wing retention bolt and it will not crush the trailing edge of the wing. Because the disk is transparent, it will be hardly visible when installed.

Cheap And Easy Wheel Chocks

A quick way to keep your plane in one spot is to use these wheel chocks made from 1/2-inch PVC pipe. You can vary the length of the side pieces to accommodate different sizes of wheels. Before gluing the final pieces, fill the assembly parts with sand.  You can make several of these for about $4 or $5 and a few minutes of your time.

Looking Good
Protect your aircraft’s cover scheme! Before you fuel it up, apply a thin coat of clear dope to the trim surfaces. This will also keep the trim from coming loose when you clean your aircraft.

Custom fit for your wing
Looking for a less expensive, effective and truly custom wing bag? Try Reflectix foil insulation that can be found at any hardware store. It is like bubble wrap with Mylar on both sides and comes on a roll.  Start by laying your wing on half of it and fold it over the top. Then, cut off the excess but leave a few inches around and a little extra for a fold over flap. Use a regular stapler, spaced as close as you can, to seal up the edges. You can staple the edges with the wing inside to give it a sung fit. Add handles made out of flat nylon cording purchased at a fabric store.

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This is a typical control horn and base. The horn is one-inch long and has a base 3/4 in. square. Use those dimensions to draw a horn of any shape you desire. If you already have an adequate store-bought horn, it will save you from designing your own. Draw the base using the dimensions shown. The slot in the center fits over the base of the horn, so be sure to make it the proper length and width.

Lay the paper pattern you designed, or an actual horn, on the credit card and trace around it with a fine-point pen. If the card has been handled, you may have to scrub it with soap and water before the pen will work.

Use the same procedure to draw the bases. Two bases are used with each horn, so the eight bases on a card will accommodate four horns.

Cut the horns and bases from the card. A #11 blade works very well, as does a pair of sharp scissors. Use sandpaper to smooth the edges.

Your custom horn and its bases are now ready for mounting on your airplane’s control surfaces.

Epoxy a base plate to the horn. Set it aside to dry.

Determine where on a control surface you want to place the horn and cut a slit through the foam wide enough so the horn can be inserted. Put a little epoxy on the horn and base plate and slide it in the slot. Next, apply epoxy to another base plate, slip it over the protruding horn on the opposite side of the foam. Snug it tight to the foam’s surface and use a clamp to hold everything in place until the glue dries.

These are the credit card servo mounts. Cut a 3/4 in. strip from the card and mark the center. Measure 1/4 in. on each side of the center mark to create the space between the servos.

Now you can determine the length of your servos and add 1/16 in. to that measurement. For example, Hitec’s HS-81 servos are 1 3/16 in. long. Add 1/16 in. to that measurement and measure that length (1 3/16 in. plus 1/16 in.) outward from each of the 1/4 in. marks. Mark that distance on the card. Most micro servos are about 1/2 in. wide (you might want to measure the servos you plan to use). Measure 1/2 in. from the card’s edge and draw a horizontal line.

You now have two 1 1/4 in. x 1/2 in. rectangles marked on the card. Use a blade or scissors to remove those rectangles. Place the servos in the rectangular openings on the mount and mark and drill 1/16 in. holes for the servo screws. Cut another 3/4 in. strip from the credit card and use the completed mount as a template to carve and drill the second mount for the other side of the foam.

Select the site for the servos on your airplane and use one mount as a template to cut servo holes in the side of the aircraft. Glue a mount to the side of the plane so it surrounds three sides of the newly cut holes. Put a servo in the mount and screw the mounting screws through the servo, card mount and foam until 1/16 in. of the screw protrudes from the foam. Attach the second servo.

Add glue to the remaining mount and place it on the opposite side around the two servos, so its holes lie on the protruding screw tips. Hold the mount in place and tighten the screws. Use a side cutter or file to remove the sharp tips of the four screws that stick out from the mount.

That’s it! No more trips to the hobby shop—you can now make your own horns and mounts!

BY JACK JOSEPH

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A good landing starts out with a good landing traffic pattern. Start your landing pattern by entering the crosswind leg and then turn into the downwind leg. Turn into the base leg, start your descent and then set up your final approach. All your turns should be 90 degrees.

In a crosswind landing, you should set up a crab heading angle that produces a straight tracking path. The stronger the crosswind, the larger the crab angle needs to be.

A smooth and consistant approach angle is also very important. Use throttle to control the descent rate and keep the wings level. Aim for an imaginary spot just above the runway, and cross the end of the runway at an altitude of about 10 to 15 feet.

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