Author: Rich Lopez
Edition: Model Aviation - 2010/05
Page Numbers: 127,128,129
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Making fast pit stops

Rich Lopez <[email protected]>

In July 1977, I wrote an article titled "Quick-Pit" that was published in Model Builder magazine. Members of the Flying Tigers model airplane club got together and built a batch of identical pit boxes. The idea was to have similar pitting equipment so we could easily and successfully pit for one another in competition situations. I am still using that same pit box, and it is still very effective.

During the past 33 years, that pit box has undergone a number of modifications. Holders for syringes have been added. The original compartment that was designed to accommodate a big, heavy dry-cell doorbell-type battery was replaced with a couple of holes that permit zip-ties to hold the Glow-Bee battery in place.

Frank Sims had a bunch of glow plug caddies made to hold six Nelson plugs. Two of those beautifully anodized caddies were added to the pit box. The glow plugs are screwed into one of the six holes in the caddies. It takes only a few seconds to get a fresh plug out and ready to replace the blown one that way. However, there is an even faster and more effective way to hold and retrieve fresh glow plugs: the use of magnets.

At the 2010 AMA Convention in January, Utopia Tools was selling powerful 1-inch-diameter, 1/8-inch-thick magnets. It takes quite a bit of force to separate two. I made a couple of wooden rectangles with 1-inch-diameter holes to hold the magnets and attached them to the pit box with small countersunk wood screws. I can have them hold glow plugs or a variety of tools.

When flying Combat, you need to keep spare fuel bladders handy in case you have to replace one in a match. An easy way to do this is by bending music wire so it will slightly pinch the tubing and be open at one end so you can quickly slip out a new bladder. You can make a small loop at one end of the music wire so it can be held to the box with a wood screw.

Anything you might need for a competition pit stop must not be buried in the bottom of the box or in a drawer, which is why the Flying Tigers' setup makes things easier during contests. You might know where everything is in your pit box, but your pit person must also know.

Equipment Maintenance

From time to time, I remind you to look carefully at your battery connection, glow plug clip, and the cord. With the start of a new flying season upon us, this is something we should all do.

I am guilty of not looking at the battery terminals often enough. Recently I took a vintage Glow-Bee apart to clean it and found corrosion on the terminals, and the internal ground wire had turned green. I replaced the battery, terminals, ground wire, and external cord that goes to the glow plug clip. This should make an immediate difference in battery performance.

I like to give my fueling syringes a close inspection as well. After a certain period of time, the plunger tips deteriorate and send bits of black debris into the bladder that will, in turn, travel to the spraybar, where it can jam against the needle valve. Syringes also lose their smooth operating action and stick. Black streaks on the barrels of the syringes mean that it is time to get rid of them. They were not designed for our application and are considered disposable, so save yourself some agony by keeping an eye on them.

World Cup F2D in Houston: Mike Willcox

Mike Willcox (2002 F2D World Champion) has sent e-mail messages to a large number of modelers in the U.S. and around the world about his World Cup contest at the Jetero R/C Club field in Houston, Texas. It will be held May 1–2, 2010.

According to Mike, the current F2D World Champion, Stas Culachkin, and Igor Dementiev of Moldova will be there. It is expected that the Mexican team of Federico Quezada and Leonardo Silva will also make the trip.

U.S. pilots rarely get the opportunity to have a go at the Europeans on home ground. The last time I can remember is after the 2004 World Championships in Muncie, Indiana, when we sponsored an FAI model competition with the kill rule.

If you have any interest in participating in a quality contest, make the effort to be at this one in May. The Sources section at the end of this column contains contact information for the Jetero R/C Club and Mike Willcox.

Scratch-Built Foam Models: Russ Hester

Russ Hester flew in competition many years ago in Southern California and has recently been bitten by the bug again. He built his aircraft from scratch and is currently experimenting with foam FAI designs.

Russ and I have had several discussions regarding trimming and balancing these models. His designs have required the addition of tip weight so that the wings will be flat during both level and inverted flight.

In an effort to keep the models light, Russ cut big circular lightening holes in both the inboard and outboard panels. I suggested he make these holes only in the inboard panels so there will be more weight on the outboard side, along with additional strength. He uses a wingtip rib on the end of each panel, both of which are made from the same material.

The suggestion here is to make the outboard tip from a heavier material such as basswood. This way, the aircraft would have additional strength and weight at the tip. The pennies that Russ uses for tip weight ride in the model as free passengers and contribute nothing to the strength of the airplane. The idea is to have every piece of material contribute to the overall performance of each model.

Repairing Tips

If you fly in either competition or practice Combat matches, you will probably break models. This is part of the cost of doing business.

I like to save my new airplanes for competition, but I do fly practice matches almost every weekend. I end up collecting piles of broken aircraft, some of which are total write-offs and others that are reparable.

It is relatively easy to splice wing halves together to make a good, usable practice model. It is a matter of making sure you have equal-length sections and that they are thoroughly scraped clean throughout the gluing surfaces.

I have butt-jointed wing sections using Popsicle-stick material under the top and bottom spars and extra trailing-edge (TE) material behind the front spar. You can push the Popsicle-stick into the foam, up against the spar on both sections to be joined. Then remove them, add your glue, and push both sections together with the repair material sticking out of one section. All of this presupposes that you took the time to carefully sand and align the wing sections.

For TE joints, I prefer long angle cuts that give lots of glue surface. These joints are then reinforced with carbon-fiber-tow material and thin cyanoacrylate on both the top and the bottom.

Russ Graves has become adept at model repair and keeps his fleet airworthy from weekend to weekend. He has gotten so good at splices that oftentimes he needs only to make a minor adjustment to get them in perfect trim.

Sources

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