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Old Sep 03, 2012, 10:00 AM
Jack
USA, ME, Ellsworth
Joined May 2008
17,001 Posts
I browsed that thread a little more, that was for a 48" wing and should work for you.

If you want to try a different wing, I would recommend a Kline-Fogelman airfoil wing with polyhedral tips. That would look something like this:

\_______/

The tips could be short, about 8" long and would only need about 2" of dihedral or rise at the tips. The advantage of that wing, if you made it 48" wide, would be that you would have a flat 32" center section and that is much easier to build and much stronger than having a dihedral joint in the center of the wing.

Look at the way this wing is built, that is what I am recommending for your wing:

Blu Baby 33" KFm3P Polyhedral Tip Wing Build - http://www.rcgroups.com/forums/showthread.php?t=1474665

You can leave the 75% step off on that and it will be a KFm2 wing and a little lighter. It is easy to add spar to the center 32" section and the tips will be strong enough if you use the tape wrap and PU glue joint as I did there.

That is a slow flying and stable wing, it would be good for a trainer as long as you use your head a little and do a test glide to get the CG right and don't try to fly at full throttle from the start. Start of easy and it will go fine.

Here you can see a KFm2 wing with polyhedral tips on its first flight on a full sized (48" wing) Slow Stick clone. That plane had plenty of power, the pilots are experienced, but a newbie could fly that plane too. This was the first ever flight of this type of wing on that plane:

KFoenix Stick with KFm2 Polyhedral Wing (5 min 48 sec)


The details on the build on that wing is here:

http://www.rcgroups.com/forums/showp...6&postcount=36

Jack
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Old Sep 07, 2012, 05:45 AM
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thats correct its the same diagram, made the fuse its not as per the diagram but measures 34",motor stick is around 19" so boom should be 15" over lap tightly would b 2inches its a tight fit not heavy
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Last edited by romanxdsouza; Sep 07, 2012 at 05:58 AM.
Old Sep 07, 2012, 06:26 AM
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this is the drwing
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Old Sep 07, 2012, 07:29 AM
Jack
USA, ME, Ellsworth
Joined May 2008
17,001 Posts
Looks like you are making good progress.

One of the nice things about the stick planes is that the wing can be moved on the fuselage to adjust the planes CG more easily.

It is typical that the CG needs to be located back from the leading edge about 1/3rd of the chord distance. So, as an example, on a 100mm chord the CG would be about 33mm back from the leading edge.

So when you have your motor on and are nearly complete, you can find the balance point of the fuselage and then put the CG point above the balance point. You have to have the wing located reasonably close to where all the others have put it but you can move the battery and other heavy parts around to get it all where you want it.

Keep up the good work!

Jack
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Old Sep 08, 2012, 04:34 PM
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the drawing u attached is exactly what i have in mind, this fuse i made into two parts easy for transport will b puting a wire skid for the boom,,im ok with 48span The tips short 8" long and about 2" of dihedral rise at the tips like u said,but measurments of wing cord 10,elev 14 and cord 6,rudder 6 x 6 would b the same as per link i sent b4,but have to work out on making it ditachable wings from centre tht means 2 halfs of 24inches,so full plane fits in lets say a 26inch box,any ideas to join the center , i was thinking about tubes,,but what about size for wing post on the diagram,its not mentioned so
how abt thes wing post some wht like in this pic down made of foam
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Old Sep 08, 2012, 04:56 PM
Jack
USA, ME, Ellsworth
Joined May 2008
17,001 Posts
So you want to split the wing in the center?

I did that with some fiberglass tubes and rods for this build:

Big Blu 96 KFm9 glider - http://www.rcgroups.com/forums/showthread.php?t=1470211

That was made using a thinner foam, 6mm thick +/-, so I was a able to put the tubes between two layer of foam. The glue used as polyurethane or PU glue named Gorilla Quick. That glue foam up when it is wetted so it fills all the voids, joins the tubes and the foam, and spreads the strength over a wide area. You can see that in that thread.

Where are you home ported? What part of the world. Some of these materials may be harder to get in other places. The place where got them is listed in that thread above.

Jack
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Old Sep 08, 2012, 05:02 PM
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was thinking of making polyhedral tips like u said wich means like the SSS correct, only diff is 48inch wing ,dihedral break is 8inch , 2" of dihedral at the tips,is this diagram below what u mean
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Old Sep 08, 2012, 05:13 PM
Jack
USA, ME, Ellsworth
Joined May 2008
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That will work very well as you show it. It will work good as RET or rudder and elevator control only. If you want to have ailerons too they can be used or can be added later. This plane here is a good example of how well it will fly with ailerons:

Trainer Type Plane - http://www.rcgroups.com/forums/showthread.php?t=1281056

I built the wing and flew it rudder only on stick style plane and it flew very well that way.

And the dihedral joint is always a weak spot on slow stick wings so keeping the wing flat in the center makes for a stronger wing. The shorter 8" tips do not need as much strength at the joint there, the PU glue and a wrap of tape has made those strong enough for me.

How thick is that white foam you are using for the wing in the photo? Are the grooves in it so that it will curve?

Jack
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Old Sep 08, 2012, 05:21 PM
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what u feel about this rudder made som changes in diagram jack
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Old Sep 08, 2012, 05:29 PM
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tht pic is not my plane its an example
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Old Sep 08, 2012, 05:39 PM
Jack
USA, ME, Ellsworth
Joined May 2008
17,001 Posts
Quote:
Originally Posted by romanxdsouza View Post
what u feel about this rudder made som changes in diagram jack
We started talking about you building for a 24" wing span. You have mentioned a 48 a couple of times too. Is the plan changed now, it is for you to build a 48" wingspan now?

The reason I ask is because the vertical stabilizer and rudder you show would be maybe a little small for a 48" build. As the span gets wider the fuselage gets longer and the vertical and horizontal stablilizers get larger too. The attached drawing is what I used for the 48" and 56" wings I made for my KFoenix Stick. That worked well on both of those. I prefer to have them over sized to under sized.

Quote:
Originally Posted by romanxdsouza View Post
tht pic is not my plane its an example
OK, I thought it was yours.

The foam you will use, do you have it yet? If so, is it in sheets and how thick is it? And if it has a name (EPP, Depron, etc.) what is it?

Jack
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Old Sep 08, 2012, 05:45 PM
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jack im sailing on the danau river in europe,here its difficult to get stuff so gathering all info and will go back home to india on 18 sep and with ur help build it ,this is my plan for the wings and elevator ,the pics are not my construction,but the 48inch wing will have a tip short 8" long ,so i have to ony plan the wing joints i like the trainer planes idea
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Old Sep 08, 2012, 05:53 PM
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sorry dint mention 48 inch wing span ,k so im building a 48inch slow stick ,fuse nearly ready just need a wire skid,plan for making wings are above in pics ,will draw a good diagram for you about my plan with all measurments then you can guide me, not decided foam dont knw what its called in india, righy now i need to set my plan then we can go for material
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Old Sep 08, 2012, 06:14 PM
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k the picks below are not mine it is what i plan on making, i only want to change the rudder a bit, tip cord and LE for rudder is the difference , wings like in above pics,with polyhedral tips like u said below are the measurments for the plane im goin to build,if this is all good need to knw on the wing , wich will have a tip short 8" long and about 2" of dihedral rise will there be full depth ribs between them thats the wing cord and dihedral break
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Last edited by romanxdsouza; Sep 08, 2012 at 06:27 PM.
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