Author: Bob Aberle
Edition: Model Aviation - 2015/04
Page Numbers: 85,86
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Electrical wire capacity

Q608

You commented a while back about the current-carrying capacity of the various connectors used for electric-powered flight. As you stated, "overloaded" connectors can sometimes heat up to the point of melting. Keeping this in mind, what about the wire used with these connectors? Are there any guidelines for the current-carrying capacity of the wires?

A608: Connector construction, as well as wire diameter, is very important to the safe and efficient operation of an electric-powered system. Since my last mention of electrical connectors, I found an excellent website offered by the ICARE sailplane company (listed in the Sources section).

What concerns me is that some RTF electric-powered model aircraft employ ESCs that use small-gauge wire that can't take the load. The result is that the connectors on the ESC and the wire can't handle the electric load. To help correct this type of problem, I've found several useful sources. One is the RBE Electronics website, which contains charts showing wire gauge with equivalent wire diameter and the current rating for the various wire diameters used in electric-powered flight. With an internet search you'll find many similar references.

A bit of advice: if your ESC wiring gets hot from an overload (too much current), move to the next larger-capacity ESC. Make sure your interconnecting wiring is at least the capacity of the wiring used on your ESC.

For sources of electrical wiring, Summit Aerospace advertises widely in model magazines and its website contains a lot of wire information. The company sells wire for RC use in cut packages or by the foot.

Some wire is stamped or marked with the wire gauge, but in many cases—especially with smaller-diameter wire—there are no markings. When you purchase new wire, place it in small bags and mark the gauge number with a felt-tipped marker.

BP Hobbies and Radical RC are two other suppliers of wire for RC use (see Sources).

Piper PA-11 Cub Special

Q609: This may be the wrong column for this question, but here goes anyway. I've heard that there is a little-known variation of the Piper J-3 Cub called the Piper PA-11 Cub Special. Can you supply me with some contact information and possibly a photo?

A609: This airplane is dear to my heart. I took my first flying lessons in the late 1950s in a Piper PA-11 Cub Special. It is basically a Piper J-3 Cub but with a fully cowled-in engine; the J-3 had exposed engine cylinder heads. The PA-11 was produced after World War II and was a contemporary of the popular Aeronca 7AC Champion.

What made the PA-11 stand out was its color scheme variation: the Aeronca was yellow and orange, while the PA-11 was yellow and blue. I built and published a small Stand-Off Scale version of the PA-11 that appeared in the December 2004 RC MicroFlight newsletter published by Air Age Media. My version had only 130 square inches of wing area and weighed just 5.4 ounces.

I recently decided to build a Carl Goldberg Models anniversary edition of the Piper J-3 Cub with a 76-inch wingspan and 744 square inches of wing area. To make this airplane into a PA-11, I purchased a scale cowl from Fiberglass Specialties in Searcy, Arkansas (see Sources). The cowl cost $36, including shipping; it is well made and fits perfectly. I also purchased a set of excellent plans for a small PA-11 on floats from noted scale modeler Bill Schmidt of Bel Aire, Kansas (contact in Sources).

Aircraft Museum Guide

Q610: I remember your series called "Bob Aberle on the Museum Trail" that appeared in 1989 and 1990 in Flying Models magazine. Your articles have inspired me to go on an aviation museum tour this coming summer. Are there any listings of the various museums throughout the country?

A610: I recently came across a book titled Guide to Over 900 Aircraft Museums, USA and Canada. It is available in paperback or on CD. The paperback version is $27 plus postage; the CD is $18 plus postage. This is a detailed and accurate guide and should be just what you want. See the website listed in Sources.

SOURCES:

Transcribed from original scans by AI. Minor OCR errors may remain.