AN E-BOOK ABOUT MODEL AIRCRAFT

THIS NEEDS AN INDEX
Engine Cleaner
The next time you are at the hobby shop open a can of Z-BEST engine cleaner take a small sniff (i said small sniff) this stuff is rank a can costs approx.-5 to 6 bucks. Then go to your local auto paint store find a can of aircraft paint remover take a sniff (remember A small sniff) same o same o.A quart costs about 10 bucks approx.8 times as much. If your really cheap sell some to your friends, then the rest will be FREE.
Submit ed by gwag@mindspring.com

Locating Engine Mounting Holes
Engine thrust angle can be affected by small errors in the location of the mounting holes. To ensure the mounting holes are properly located on the engine mount, the most important task is marking the holes to match the engine case lugs. One good way to mark these holes is with a machine screw of just the right size to pass through the hole in the mounting lug. Cut the screw so it is just a few thousandths of and inch longer than the thickness of the lug, and, cut it on an angle so there is a sharp edge which extends just through the lug. Now, use two small pieces of double sided tape to hold the engine temporarily in place while you rotate the cutoff screw in
each of the four mounting lug holes. This will leave a mark which is the exact diameter of, and in the proper location for, the mounting screws. The next part is to get a true center mark for this mounting hole. If you have an automatic center punch, you may be aware that some of them come with replaceable tips. Buy an extra tip or two and grind them so they just fit through the mounting lugs and use them to center punch the holes.

THROTTLE ADJUSTMENT

The object of the throttle set up is to have a full throttle setting without straining the linkage and at the same
have a good range of idle adjustments with the trim lever, including shutting down the engine with the trim.
Most transmitters have the capability to achieve this without a problem.
Keep in mind that if the throttle does not stick, it is very easy to move the arm with little or no resistance.
A small cable in a plastic housing is usually adequate to do the job and still be flexible enough to absorb
any binding that may occur thru the full range of controls.
If you still have some binding at full throttle you might want to use something similar to the illustration using
A DuBro post with a spring between the post and the Ni-Rod or linkage you are using. This is referred to as
a Servo Saver.

You can also adjust linkage throw by off centering the arm on your servo as shown in Figure 2.
For those that have metal arms on the carburetors , you can fiddle with the arm to get more or less throw as
shown above.
The general adjusting procedure:

1) Set throttle trim to center.

2) Connect linkage on servo and throttle arms, adjust clevises so that full throttle on the transmitter just gives
full wide open at the carb.
3) On the transmitter, bring the throttle stick back towards idle. (a) If the carb closes completely before you reach idle, you'll need less throw; (b) if the carb is still open more than 1/32nd of an inch, you'll probably need more throw; (c) if the carb is open about 1/32" and you're able to completely close it with the trim, you should be pretty close.

4) Run the engine, make further adjustments if necessary.

Assuming adjustment for total travel is necessary , the first thing to try is going to a different hole on the servo arm. If travel is too great, go in closer to the servo for less throw; if travel isn't enough, shift out a hole on the servo arm.
There are some servos ( Hi-Tech ) for one that offer a servo arm which has finely adjustable length, and thus adjustable throw.
If it was easy .. anyone could do it on the first try.

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VELOCITY METER
Take your propeller balancer and attach a 11 x 8 prop. Hold the balancer in the wind to achieve the maximum propeller RPM. Measure the RPM with your tachometer. Divide that RPM reading by 100 and the resulting number will be within 2 MPH of the existing wind velocity.

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