Larry Renger (AMA--L9246) campaigned his own-design 1/2A hollow log racer in the Knights of the Round Circle 1/2A Proto Hollow Log Races. It is in the spirit and tradition of the Scientific-Musciano hollow log designs. With these, you could get practically any type of airplane you wanted, so long as it was 18” wingspan and had a partially hollowed balsa block fuselage, all for $3.95. At least, that was what was advertised in the magazines for a couple of decades. Larry’s Zippiee design is a bit more refined. Elliptical surfaces all around, internal bellcrank, very streamlined fuselage for maximum racing speed, and short landing gear to reduce drag. According to Larry, that short gear might well have been the plane’s downfall, as discussed later.
This particular design in my opinion is easily the most beautiful of the genre, with only the Golden Hawk coming close. As such, it was well worth it to me to do a bit of work to restore some of its original beauty. It had been thru a pretty bad crash or two. I believe Larry said it torque-rolled on takeoff and came in on him, perhaps because of the lack of propeller ground clearance.
Here is what we started with. The fuselage had been epoxied back together, maybe to make another try during the contest? The rudder and aft fuse didn’t quite line up and needed some work. The outboard wingtip was lost. Perhaps it was windy that day, and it blew off the field and into the grass? Follow along and see how things turned out.
Figure 1. The first picture I took of the Zippiee repairs. Here, I have already stripped off the engine, then cleaned off the plane to get rid of any oil and dirt. A template of the intact wing was made from my favorite template material—a Corn Chex box. Don’t use high-sugar cereral box cardboard because then the planes always come out heavy! The piece of balsa has been scientifically selected for the exact proper density for the new wingtip. Actually, it is what was left over from making a couple of new biplane wings barely visible under the sanding block at the top of the picture. But those are part of a different rebuild story!