Martin X. Moleski, SJ wrote:
> On Thu, 12 Jun 2008 16:03:39 -0700 (PDT), Mikie <mppg1@[EMAIL PROTECTED]
> wrote in
> <613cba08-8636-468c-9b51-0e603660f084@[EMAIL PROTECTED]
>:
>
>> I hate to be a pest, but I'm building a senorita, and from it, I'm
>> learning that I'm not as smart as I thought I was...or as I once was!
>> The plans are designed for gas engines; I'm planning on flying with
>> an electric motor.
>
>> But I don't know exactly how far to proceed using the plans. Would
>> the electric take the same configuration in the nose, cowel, etc, as
>> the gas?
>
> Yes.
>
> As best you can, build up a little box off the firewall (strongly
> attached!) on which to mount your electric engine so that the
> prop comes out where the gas prop would be. Try to get the
> thruslines right, too (any downthrust, any right thrust).
>
> Then you need to find out where to carry the batteries so that
> the CG is correct.
>
> Then you build a battery box and hatch system. MAKE SURE THAT
> THE BATTERIES CAN'T FALL OUT AND GET DISCONNECTED. This happens
> all the time with homebrew systems. The results, I hear, are
> generally not pretty.
>
> You also need cooling air to flow over the batteries.
> The key is to have much larger exit holes than entrance
> holes. I forget the factor--twice as large? Three times?
>
> Cool air comes in, picks up heat from the batteries, and then
> needs extra large openings to exit. Or something like that.
>
> Let us know how it turns out.
>
> There are lots of people who have done this already, of course.
> I'm not one of them. If you poke around, you may find
> a site that walks you through the whole process.
>
> Marty
Yea verily on the cooling air. When you first fly, test the cooling by
making some short, high-power flights, then land and _immediately_ check
the temperature of the batteries and motor. They should not be too hot.
Then make longer high-power flights, and check again.
Once you can fly for a few intense minutes without overheating anything,
relax and enjoy the plane.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
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