Canandaigua C.H.I.E.F.S. News

Canandaigua C.H.I.E.F.S. RC Flying Club, Canandaigua, N.Y.

October 2003

Vol 1, Issue 1

Smoke Signals From The Bench

Fall is quickly passing into the inevitable winter weather. Well, time to build!!! Let's pick a favorite project and get started. But how do we get started? Well consider the available space we have to work in, the money we have available, and very important, the TIME we have available.

Typically we do not have as much as we would like in all 3 of these areas so it becomes a matter of trade-offs. Once you determine the trade-offs you can set yourself a schedule that you're reasonably comfortable you can stick with through to the completion of the project.

I've found that without the commitment it's just too darn easy to get distracted. And for most of us, once we get distracted a few times, we begin to get frustrated, lose interest, and the whole thing just falls apart.

Now getting back to determining the trade-offs. As an example let's say you've got the space, you've got the time, but money is a bit tight. Well you could decide to repair some pre-enjoyed models or re-cover one of your current flying models to change it's look.

Another possibility would be to build a model from plans. Depending on your previous experience in this area, and your budget, you can select a plan that fits your interest and your current power plant, glow, gas, or electric. For those of you that would be new to this aspect of modeling, don't let that be an issue. Get some help, ask some questions, in picking the right plan, and the right wood, you'll be all right and well on your way.

If you lack some of the right tools to cut your parts, again, don't let that be an issue, There are enough of us around who have done this, so, as they say, NO PROBLEM!!! Well I hope this has helped at least a few of you, a little. 'Till next time... Jim

Prop Wash

This month let's look into throttling up those 2-stroke engines. A basic throttle control system on 2-stroke engines utilize a needle valve for high RPM, a second needle valve for low RPM adjustment and in a number of cases an air bleed adjustment is used in combination with the idle stop screw position for getting the right fuel mixture at low RPM.

The throttle intake has a rotating barrel that is linked mechanically to a servo for control.. The fuel intake tube is in the center of this barrel and the needle valve screws into the intake tube. This arrangement adjusts the amount of fuel going to the engine. By turning the barrel (in most throttles the needle valve and the fuel intake tube do not turn when the barrel is turned) the air flow into the engine is cut down and to a less extent so is the amount of fuel.

As the intake is closed down the fuel/air mixture richens. This is compensated for in a number of ways by various engine manufacturers. A second adjustment screw is added to allow for more air as the barrel is rotated to the slower positions. Another method is to cut down the fuel flow at lower speeds. This is automatic in some engines (though adjustable by the use of tools) or a second needle valve is used for adjusting the low speed fuel flow.

Most engines have an adjustment screw for setting the engine idle position of the rotating barrel. This setting is critical because the opening into the engine is very small. This idle stop position will also act as a stop for the high end rotation however that position is not nearly as critical.

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