Weaver Construction Log Page 7.
THIS PAGE UNDER CONSTRUCTION
Final Details and Test Report.
Since I plan on using the Weavers in small freeflight models, a neat little attached fuel tank seemed like a good idea. A great source of small, translucent tanks are various supermarket items that come with protective caps. These include certain brands of syrup and super-yuppie water bottles (a local ozzie brand of the latter is called "H2Go" - save me). The plastic material should be of the soft variety. Even though the size I'm using here is a tad larger in diameter than crankcase diameter, it still makes a nice enough fit.
The cap has a neat little ridge about 50 thou down from the top, so a matching groove has been cut into the flange allowing the cap to snap on and off. Some hunting around on the shelves of the local supermarket revealed that polypropelene fuel tanks are available for $1.06 (tap water in a designer bottle, with go-fast stripes), or $0.86 (same tap water, house brand, no go-fast stripes), or the real find, a 6-pack of tanks for $3.06 (more same tap water, kiddy pics on label to arrouse yuppette appeal). This shot shows the tank top, spacer and a tank in the before and after condition.
After parting off, the part is reversed to finish the top and add a decorative bevel. The diameter is too large to permit fitting via a central hole, so an offset hole is arranged so the venturi end falls even with the start of the bevel making it almost look like it was planned that way. Add a hole for filling and a thin spacer to go between tank top and ventur, then everything gets clamped up with the lower spraybar nut.
And here is a finished Weaver. At the time this shot was taken, the engine has had about tem minutes of running. Mysterious speed fluctuations having been observed and traced to a leak between crankcase and cylinder, a gasket has been added that could stand a bit of additional trimming. It does the job though. I'm very pleased to say the engine started after the first few flips of the prop (especially since I had quite an audience, electing to make the initial run at our local control line club field). It spins an 8-4 wood prop at 5500 rpm and is not exactly a fuel miser - drops of unburnt fuel being observed flung back from the exhaust ports.
Gotta get your ducks all in a row. The end result shown here, a brace of Weavers, complete with tanks, neatly lined up for inspection. I'm thinking the tank tops would look good in red (like Russel's), but the snap on fit is so good, some are not going to come off easily.
Back to Weaver Journal front page