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Brushless Bamboo Bomber

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Old 11-15-2008, 12:56 PM
  #1
Avaiojet
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Default Brushless Bamboo Bomber

I'm building a 72" Bamboo Bomber. The size will not be changed, 72" is what it is.

God I love messy model engines. However, there's absolutely no reason why I shouldn't consider electricity for this model! Or, it should be considered! Is there a reason why it shouldn't??

Anyway, is there a chart that converts, what would be the equivalent in gas engines, to those available in electric?

Thanks in advance,

Charles


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Old 11-15-2008, 01:06 PM
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Default RE: Brushless Bamboo Bomber

The T-50 will make an excellent, long lived, electric scale aircraft. I would put two AXi 2826-12s in it using 14.7 volts at 5,000 ma for both motors. Norm

one easily flies my 7 pound 81 in Cub, two in a 72" plane would be perfect.
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Old 11-15-2008, 10:11 PM
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Default RE: Brushless Bamboo Bomber

Norm,

Thanks for the reply and suggestion. I've read you for years and years with no exaggeration. An honer to hear from you.

The Bamboo Bomber:

At the moment, I have only one three view I'm currently working with until I get the Paul Matt drawings, hopefully in a week or so.

As I always do, before I draw plans to scratch build, I do some preliminaries or "playing around" with measurements. Here's what I have so far and please keep in mind, these are not yet working measurements. Just information, incorrect or correct? Compare yours with mine? I got mine off an 8.5 X 11 three view, the hard way!

First column of measurements is a model at 1/6 scale and 84" in span. The second list is at 1/7 scale and 72" in span. I round off.
I'm beginning to rethink my 72" model?

Wingspan at 1/6 scale, 84" at 1/7 scale, 72"

Root cord at fuselage. 17" 14.75"

Tip cord. 11.5" 10"

Cowling diameter. 7.5" 6.5"

Prop diameter. 15.5" 13.5"

Main wheel. 4.5" 4"

Track. 25.25" 22"

Tail wheel diameter. 1.75" 1.5"

Fuselage length. 65.5" 57"

Fuselage thickness. 10.25" 9"

Fuselage height. 11" 9.75"

Horizontal stab span. 30.75" 26.75"

Stab cord. 10" 8.7"

Rudder height. 15.75" 13.75"

Vertical stab & rudder length. 13.5" 11.75"


This is only the start of my playing with measurements. Obviously, I need to determining scale measurements, which I will use for the actual drawing of the plans.

The 101" model or the the 1/5 scale, being the same, these model's measurements can be obtained by simply multiplying 1.2 times any measurement in the 84" span column. Using different math, any scale and measurements can be determined by changing the 1.2 figure.

This is how I begin a scratch build project. It works for me but may not work for others. I'll actually know a great deal more when I view the Paul Matt drawings. Not to mention "web" research and who knows what else?

Please consider I may have made errors.

Charles









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Old 11-16-2008, 10:48 AM
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Default RE: Brushless Bamboo Bomber

Hi Charles, as a rule of thumb, two of the same motors does not equate to twice the power but to 2.25 the power due to better prop effeciency. I like to fly airplanes from 72in wing span to 85 inches. I can put them into my VW Vanagon Westfalia in one piece and not have to take them apart all the time, which sometimes leads to errors. I also fly a 1/4 scale Cub and that one I have to take the wings off. My 85" PT-19 and smaller models fit just fine, up to three at a time. assembled. I use only A123 Li Ion cells which I convert from DeWalt power tools and for my transmitter and receivers I use converted Black and Decker 1100 Li Ion (A-123) This way I can charge up in an hour all the batteries that need it rather than planning a whole night ahead. I have written many articles about the T-50 but never had the pleasure of flying one. Thanks for the kind words, I am still writing about 1/2 time now for various publications including Plane and Pilot and PlaneFax an Internet Aviation Newletter. Norm
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Old 11-16-2008, 12:30 PM
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Default RE: Brushless Bamboo Bomber

Quote:
Hi Charles, as a rule of thumb, two of the same motors does not equate to twice the power but to 2.25 the power due to better prop effeciency.
Norm,

Thanks for the reply! That's good news, and I thank you for it.

Quote:
I like to fly airplanes from 72in wing span to 85 inches. I can put them into my VW Vanagon Westfalia in one piece and not have to take them apart all the time, which sometimes leads to errors. I also fly a 1/4 scale Cub and that one I have to take the wings off. My 85" PT-19 and smaller models fit just fine, up to three at a time. assembled.
My interest is models of that size also, except for my 90" 1/3 scale Gee Bee Z. Are these models you mentioned electrics?

Quote:
I use only A123 Li Ion cells which I convert from DeWalt power tools and for my transmitter and receivers I use converted Black and Decker 1100 Li Ion (A-123) This way I can charge up in an hour all the batteries that need it rather than planning a whole night ahead.
Is this "top secret" information or do many others know this? I'm actually surprised this is going on? Very cleaver. Can we talk more about this, destroying Black and Decker and Dewalt power tools, for the benefit of modeling?

Quote:
I have written many articles about the T-50 but never had the pleasure of flying one.
I'm sure your referring to the actual aircraft.

Quote:
Thanks for the kind words, I am still writing about 1/2 time now for various publications including Plane and Pilot and PlaneFax an Internet Aviation Newletter.
No thank you necessary. It's not hard to believe I was reading you 20 years ago. Are you still "Stormin?" We are older but still young enough to be controversial? Or is it actually "ahead" of your time?

It comes to mind the Article you wrote on the Jenny. That article had an actual affect on me, as many others had, and now I have the opportunity to actually thank you for it, and all those other great "inspirational" articles.

I have extreme interest in knowing what you've written on the T-50? I've had interest in General Aviation my whole life, having taken my first flying lesson in 1965. I hold a few ratings, including Commercial Seaplane, and my last airplane, and I mean just that, my last, was a Lake LA4-200T. I actually built that model from some one's kit?

Anyway, because of you, good, bad or indifferent, I will build an electric model of the Cessna. You do have me on the hook, now make me a believer in electric's. It won't be difficult because you're actually "doing" electric. Besides, I know I can count on you for help in an area I know nothing about. Please, keep this in mind, I have absolutely no knowledge or experience with electrics. Never read a word about it.

Interesting math. At 84" in span, the scale prop size is 15.5". At 72" it's 13.5". I'll round it off. Now I'm considering the 1/6 scale at 84".

This would allow for the next size in engine choice. Possibly the AXI 4130?

Thanks again Norm,

Charles
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