Thread: Alert Sky Bench
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Old Sep 26, 2012, 11:03 PM
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Napa, California
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Originally Posted by Ray Hayes View Post
Have you actually weighted the stab and the corresponding pieces you are considering to replace the kit stab with for comparison?

Have you determined/considered the weight saved by cutting additional holes drilled in the kit stab ?

Have you determined/considered how the plane will balance after installing the RC and Electric components ?

Probably more benefit can be gained by sanding a slight symmetrical airfoil shape to the kit stab. Use a Perma-A Grit sander, they are much faster than paper, etc.. The source link is on my web's "Links" page.

Sky Bench ... Woodys Forever
Hi Ray, thanks for your thoughts and comments.

I've not weighed the components against each other yet, but, and this is only a but, I'm thinking that the balsa "sticks" that I plan to use are probably lighter than a solid sheet of equal thickness. The supplied pieces in the kit are very light maybe there would not be as much of a difference.

As for cutting additional holes in the supplied stab, I'm not thinking too much weight savings would be gained by this activity, but maybe some.

As for the electric components, I've got the motor that I plan to use, and the ESC to go with it, all that's needed to decide is the battery size (and weight of it). The plan is to build the plane so that I can insert the known components, and use weight (and component location) to determine the final battery size.

Thanks for the link to the perma grit on your site. That sounds like a good idea and one that I may go with.

Lastly, and I'd like to make it clear why I'm considering this activity in the first place, I built a kit a couple of years ago that I electrified, and although it flew fine I eventually cut off the nose and lengthened it 1.75 inches in order to get the moment arm further forwards of the CG, thereby allowing me to remove almost 140 grams from the overall airframe. Needless to say it flew much, much better after this mod. I keep thinking that I wish that I had built the tail lighter -it also has solid control surfaces with lightening holes in them, and I wonder how much lighter I could have gone with the electrical equipment if I had.

My goal is to try and build this Oly II SX as light as possible, so as to not have too much of a weight penalty for going electric. I also don't want to too negatively effect the original airframe. We'll see how I do?

Thanks again for all of everyone's thoughts/ comments/ suggestions! By the way, if glueing balsa to CF, must one use epoxy, or rubberized CA? Would Gorilla wood glue work?

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