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Old Sep 26, 2012, 05:29 PM
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United States, IN, Fort Wayne
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Eddie, that's a real beauty.

Modifying kits is what we Woody Builders love to do, just part of the enjoyment of building our own.

Ray
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Old Sep 26, 2012, 11:03 PM
Good, fast or cheap, pick two
robh's Avatar
Napa, California
Joined Jul 2006
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Quote:
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.

Ray
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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 though...so 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?

Rob
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Old Sep 27, 2012, 04:31 AM
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Rob, Only one way for YOU to be sure if Gorilla glue will work on carbon ...
experiment by gluing them together and then experiment with stress tests.

Ray
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Old Sep 27, 2012, 03:04 PM
Dragons, Windmills. All Same.
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United States, IN, Indianapolis
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True, to test.

For C/F to wood; *laminating epoxy first, followed by rubberized CA.
If RB CA, even though it is about medium to slow, I would still have a jig set up to apply and clamp for quick straight n true.
I still have not used PU on anything but wood and some foams.

*Quality first. If not, then the slowest cheap stuff you can get (60-90min)

Jared

Going to get my Sky Bench V1 Oly II built this winter, in some form.
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Old Sep 27, 2012, 03:43 PM
Good, fast or cheap, pick two
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Napa, California
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Ray - Thanks, and you are correct, nothing like a test to see I guess!
Jared - Thanks also for the information -greatly appreciated. Good luck on your Oly II build. Please post your progress?
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Old Sep 27, 2012, 04:04 PM
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On pre cured CF to wood:
Not so long ago, I tried to make up some spar caps with precured .014 carbon on top for another project. I used laminating epoxy that I got from a boat builder. I've used it before for wetting out fiberglass and carbon, seemed fine. . It peeled off the wood easily. 30 minute epoxy did a much better job. Is the rubberized CA on the carbon side or the wood side?

On the tail, what is the density of the wood? If you don't cut lightening holes, you don't have to cover the tail and you can just use sanding sealer or something. (I like SIg Sanding Sealer). If smell is a problem, you can put on water based polyurethane as described here:
http://www.djaerotech.com/dj_askjd/d.../lightfin.html

I find it easier to use the sanding sealer, but it does have a penetrating smell. The water based urethane is ok, for me not quite as nice results, but ok. On the small sample pieces I was doing, weight was about the same.

Nitrate dope mixed with talcum powder was good, but not as good as the sanding sealer.

If you use light c-grain on the stab, and you taper it with a plane so it is thinner out near the tips, it will be just as strong and almost as stiff for most purposes, particularly in the air, but you can save quite a bit of weight. I am not sure but my guess is that it will be as light as a built up stab for less work.
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Old Sep 27, 2012, 04:53 PM
Dragons, Windmills. All Same.
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Interesting info on your epoxy types and experiences lincoln. Will have to do like Ray suggest, and as know, to test samples.

"Good luck on your Oly II build. Please post your progress?"
Perhaps. Lots of threads. Not sure what to add. Some variations are considered as bone stock, electric with flaps or spoilers, both with different fuses, mod to IIS or IISX. I do like the shoulder mount wings for the SB OlyIISX version for several reasons.

Jared
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Old Sep 28, 2012, 09:47 AM
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United States, MT
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for carbon to wood try G-Flex epoxy, great stuff
http://www.cstsales.com/G_flex_epoxy.html
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Old Sep 29, 2012, 09:53 AM
Good, fast or cheap, pick two
robh's Avatar
Napa, California
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Quote:
Originally Posted by IHAVAWDY View Post
for carbon to wood try G-Flex epoxy, great stuff
http://www.cstsales.com/G_flex_epoxy.html
Hey thanks for the information. I purchased the CF that I have from CST and was looking at that epoxy but didn't know whether or not it would work. I wish that I had added it to my order! Thanks again for the lead...

Rob
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Old Sep 29, 2012, 10:11 AM
Good, fast or cheap, pick two
robh's Avatar
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Hey Eddie, thanks for your comments, sorry not to have responded sooner! I like the look of your OLY III and I had considered going with the III also but thought that the motor I have would suit the II better and it was perfect timing with Ray's release of the II SX

I know what you mean about the quality of the kit. This is the first SkyBench kit for me and I'm sure that it won't be the last. In addition to the kit quality, Ray's support and interest in providing great customer service is second to none.

Cheers,

Rob
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Old Sep 29, 2012, 10:38 AM
Brian, Southern Oregon
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Eddie--you did an excellent job on your OlyIII. It looks great!
Brian
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Old Oct 03, 2012, 04:06 PM
R2R
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Quote:
Originally Posted by Ray Hayes View Post
Greg and all ...

This time it is going to happen, Bill Grenoble and I are all set to fly Max Patch.
We will arrive in Newport, TN, Monday, Oct 1st during the afternoon. We are booked at the Red Roof Inn thru Wednesday night ( check out Thursday am ).
We will be flying winch in the nose, hand launch and Hi Start if needed.

Join us ..... ???

Ray
Sky Bench ... Woodys Forever
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Guys, I am heading to Max Patch this weekend! Arriving Friday, 10/5. Too bad I will miss you Ray. The wife and I are staying in a cabin for our anniversary, 5min drive from the car park. Will be bringing a woody and short hi-start in case the opportunity to fly presents itself (low crowd, pleasant winds).

Allan
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Old Oct 05, 2012, 06:22 AM
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Originally Posted by R2R View Post
Guys, I am heading to Max Patch this weekend! Arriving Friday, 10/5. Too bad I will miss you Ray. The wife and I are staying in a cabin for our anniversary, 5min drive from the car park. Will be bringing a woody and short hi-start in case the opportunity to fly presents itself (low crowd, pleasant winds).

Allan
Bummer, sorry our schedules were mixed. I returned Thursday night, Bill and I had a great time and both agreed to return to Max Patch. We had a group of people standing around the Surveyor"s Marker on top of Max discussing "which way is North", let us know if you determined "North". When I came down off the summit, my SUV's compass settled it. I took a Hi start too.

Bill will be posting his Videos on U-tube, I think he is 88Hawksnest. When I get caught up answering Sky Bench emails, I have 2 pics of Bill to post here. I took a very short movie of Bill launching his electric 2M Lil Bird and that was all the time I could take away from my first flying experience on the MAX. Will write some more later. I Love flying the MAX.

Thank you Doc Bell for the heads up on MAX Patch.

Ray
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Old Oct 07, 2012, 05:49 PM
Good, fast or cheap, pick two
robh's Avatar
Napa, California
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Hi all, Ray if you happen to read this I'd appreciate your thoughts on this, and anyone else can certainly lend their thoughts also!

I'm considering doing a built-up vertical stab and rudder for the Oly II SX and have a question about whether or not to build it as the drawing shows (a portion of it counter rotates to the main surface) or build it with a simple hinge line as is the case with the solid pieces?

Thanks!

Rob

P.S. Also, for reference (and if you are interested), the built-up h-stab and control surface weighs in at 17 grams, vs. 36 for the solid. Just an FYI.
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Old Oct 07, 2012, 07:37 PM
Dragons, Windmills. All Same.
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United States, IN, Indianapolis
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Only looks like about another oz or so in the nose with solid. At 100" is couldn't make much of a difference. Although built up is sweet with transparent covering.
Plus, solid is quick to build and resist hanger rash better. Not that I would know the ol' Opps/Doof/Ouch much.
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