Here are a few tips from the Model Airplane News vault—enjoy! If you have some tips of your own you’d like to share, please send them to MAN@airage.com. You could win a free one-year membership to The Hangar—our membership site with archives and more.
Here’s a simple way to make holes through balsa in tight spots. Just bend the tip of a soldering gun to 90 degrees, and burn the holes you want in the balsa. Having water and/or a wet rag on hand is highly recommended.
SIMPLE ENGINE ADJUSTMENTS
Many of us have had a cowl that fit so tightly that to make engine adjustments with the cowl on, we needed a needle-valve extension. And what a hassle it was to have to remove that extension every time we needed to remove the cowl! One way around this is to slot the top of the needle valve using a hacksaw or a Dremel tool. Then, all you have to do is drill a hole in the cowl to match the position of the needle valve and insert a flat-blade screwdriver into the slot to adjust your engine.
When installing certain components in his latest airplane, this reader had to make a variety of recesses in the balsa structure. The cuts to make the recess must not go through the balsa, so he devised a knife with a depth gauge. He wanted it to be easy to adjust for balsa of differing thicknesses. He came up with a simple, cost-saving cutter made out of a control horn and a new X-Acto blade. The blade depth is easy to adjust, and once he has the right depth for the wood he’s working on, he simply tightens the screws for a snug fit. The blade is held very tightly between the backplate and the bottom of the control horn.
ZIP-TIE WRAP PUSHROD KEEPER
While putting together a new foamie, this reader realized that he had forgotten to pick up micro pushrod keeper at the hobby shop. Not wanting to make a 45-minute trip back for a $1.50 part, he scanned his workbench for an alternative. He found a plastic zip-tie, cut all except 1/2 inch off the strap and drilled a hole in the remaining stub about 1/4 inch from the cut end. He carefully drilled a hole thought the tie’s square end. The tricky part was drilling the hole parallel to the strap and keeping it near the top of the square. Then he used a sharp X-Acto blade to slot and notch the holes as shown, and his new micro pushrod keeper was ready to use.
Getting your wing-mounting bolts started in the fuselage blind nut can be frustrating, especially if the wing has a belly pan. Here’s how to make starting the bolts much easier. First, cut a length of 1/4-inch-diameter hard-wood dowel and drill a clearance hole in the center for the screw. Next, cut a cone-shaped recess in one end with a router bit fitted to a drill press. Cut the cone end off the dowel, and use thick CA or epoxy to glue it directly over the blind nut. The wing bolt is now easily started as it follows the cone to the blind nut. You may need to use a larger-diameter dowel if you use nylon wing nuts.
To properly isolate servos from vibration, the servo case should not contact the die-cut plywood servo tray. If the servos are mounted in a cramped place, it’s difficult to locate and accurately mark the servo-screw mounting holes. To ensure adequate clearance, wrap the servo’s case with several layers of tape to get a tight fit in the tray, and mark the hole locations. Now you can drill the holes, remove the tape, and permanently install the servos.
Easy Servo Replacement
The next time you need to replace a servo that has its lead routed through equipment and bulkheads, try this: tie a string to the servo’s plug before you remove the servo. You can now use the string to pull the new servo plug through the same path as the old one.
Everyone seems to have some old 5- and 30-minute epoxy lying around that has become thick and difficult to squeeze out of the bottle. Place it in a microwave for a few seconds–longer, if needed. The epoxy will become thin and easy to mix while still retaining its strength. [Editor’s note: “seconds” is the operative word here, and I wouldn’t recommend doing this in front of your family members who also use the microwave. Better yet, maybe just buy some new epoxy? -Debra]