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Old 12-23-2011, 08:42 AM
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gkamysz
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Default RE: Mini F-16 vintage project consideration

ORIGINAL: RickP

The next step is to tackle the power plant. Original engine was the Tee Dee .049, but I am thinking Tee Dee .090. However, I have no idea how that is going to work with the fan. maybe it works well with the .049 but surely just swapping in a .090 is likely going to need a different size FAN.

So please give me your questions and comments. Is this a waste of time? What do you think about the power plants? What motor should I use? NIB cox motors can be had, but is there a modern equivalent I should consider?

Once we get past these critical issues then the real fun stuff can start. For instance, the plans show a flat bottom wing. Really? Can we do better and make it go faster?....

A fan or prop with twice the power input will only turn 2^(1/3) or 26% faster. I don't know what the fan runs with a TD049, but if 26% faster is still within the RPM range of a TD .09 I'd go with it. The issues might be more finding an engine that can handle the RPM and make the power required. I'm not sure that a TD .09 makes twice the power of a TD.049. Since RPM will increase 26% the speed will also only increase this much. Compared to the .049 this should be very noticeable, but still relatively speaking slow.

I wouldn't worry about the wing. That is not going to be limiting your speed at all in this case. The airframe is not sleek, the fan is much oversize to the airframe. Speed will be limited by the thrust and velocity available from the fan.

If it flew in 1980 it will fly today. I'd save weight with lighter radio gear, but wouldn't change anything except the power plant. If the power plant gets heavy, you might have to reinforce things. Take it for what it is. It's a simple design and will not be fast. I have this plan and have thought about building it, but having looked at the numbers I've lost interest without redesigning it for a smaller optimized fan unit. That means drawing a new plan. I also have Ziroli's plan for an He-162 for the Axi-flo fan. That would be much easier to modify to a smaller fan, so chances are it would be built before anything else. Regardless, my list is so long it will be a while before any of that happens.

Greg