WattFlyer RC Electric Flight Forums - Discuss radio control eflight - View Single Post - Great Planes Spirit 2M Electric conversion by rip
Old 10-19-2013, 10:48 PM
  #14  
AEAJR
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Join Date: Aug 2005
Location: NY, USA
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Cool

Originally Posted by Turbojoe View Post
Not trying to take over this thread. Just bringing it back to the top. I have a few questions...

I just picked up a G.P. Spirit 2M kit a few days ago for $20.00. Complete except for plans. Thanks to Wattflyer member DEG my kit is now complete. (I can't thank you enough for the generous help Don!)

I haven't built or flown a sailplane since the 80's and the one that I ultimately flew I put a glow motor in the nose and added tricycle gear. It was a Mark's Models Wanderer 99. Flew great but was it really a sailplane anymore? It was a skinny glow powered fuse with a really big wing....The other was a C.G. Gentle Lady that I built and gave to a friend before I got to fly her.

I've got piles of electric planes but just want something different now. Maybe the Spirit will fill that void for me.

The first thing I've noticed with this kit is that while the wood looks really nice it is Gawd awful heavy! Much heavier than even glow powered kits I built back in those days. I mean this stuff weighs like OAK. Does this bird WANT to be that heavy? For better penetration maybe? If not then I'll be cutting a lot of new parts from much lighter wood. I'm sure I can easily drop 3+ ounces from the fuse weight alone.
No the glider does not need to be heavy. Make it as light as possible. Replace any heavy wood you can.

Move the servos into the nose area if you can. I would recommend mini/micros like Hitec HS81/82

My first pure glider was a Spirit but it flew better after I crashed it and rebuilt the fuse moving servos to nose and dropping almost 4 oz.

Originally Posted by Turbojoe View Post

I've never flown from a winch or Hi-start. Looks like a monumental P.I.T.A. to me. I've got electric power systems coming out of my ears and can outfit this thing up to 1200+ watts if need be. If electric is the better way to go then obviously I'd rather go with a lower power and lighter setup. What are the pros and cons of hi-start vs electric power? Cost really isn't an issue for electric power as I already have everything. A Hi-start I would have to buy. What about a power pod? Just not sure on all of this. I'm thinking 150-200 watts should be sufficient to haul her (slowly) up to altitude.
In the old days of pre lipo and pre brushless motors, electric gliders were VERY heavy so pure gliders were the way to go. But with modern motors and batteries going electric is easy and will introduce very little penalty if you keep the battery size down.

Now, understand that I fly pure gliders from winchs and hi-starts most of the time. But if you prefer electric. go for it. I would recommend at least 75 watts/pound. I fly my e-gliders in ALES contests so I shoot for about 130+ watts per pound for those.


Originally Posted by Turbojoe View Post

I've done a little searching on this bird and one thing that pops up a lot is the need to enlarge the vertical fin/rudder. That's easy and I can go ahead and easily implement that. Anything else? Spoilers may be an interesting add. Useful or a huge waste of time and weight?

Not sure when I'll start on this build. Before I build anything I always like to do my research and be fully prepared before that first drop of glue comes out. It's much more important for this build because I have so little experience with sailplanes.

Joe
The larger vert fin and rudder is a very good mod. And I love the spoilers on mine so I would recommend that.


Keep it as light as you can and you will enjoy it!
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