flyingagin

Working on an idea to return my Kadet JR to flight with a bit of a new twist.

I recently built a new wing from scratch for another plane, that has plug in extension tips using plywood joiner that slide into a joiner box at the ends of the wing. I really like it. It was a bit of a learning curve. But I thought it had future applications.

So that got me to thinking, and that is all ways a very dangerous thing.

I really like the JR. Cheap on fuel and fun to fly, will spin like a top.
Why not make new wing panels for my JR. Make a new center section, that is only as wide as the fuse, and bolts in place of the original wing. Make a pass through joiner box on the spar, that joiners just snugly pass through into matching joiner boxes on the inner end of new wing panels.

By changing from straight to bent joiners The dihedral can be change to any angle desired. Also additional wing can be made that use different airfoils, symmetrical comes to my mind immediately.

And while I am at it add a pass through joiner box at the bottom of the fuse. I can then go from high wing to low wing. In fact the possible configurations are numerous.
High flat bottomed wing with dihedral of any angle by cutting new joiners to that desired angle. Also can be done low wing.
High symmetrical wing dihedral of any angle by cutting new joiners to that desired angle. Also can be done low wing.
Gear blocks for wing mounted main landing gear when in low wing configuration, flat or symmetrical wing.

We have been streaming Star Trek DS9. Started at season 1 episode 1, and are now in season 4. So that adds to the insanity raging in my head. Kadet Jr is going to become; ,,,,,,,,,,,,,,,,,,,

wait for it




Wait for it











A Kadet JR Changeling
named Odo

Ken

And on that note I am out to the garage to make wing rib templates.
I can get the wing rib templates made, 2 pairs.
And some light ply ribs made to carry the joiner. I have to wait till after pay day to buy the 1/16" sheet balsa for the rest of the ribs and wing sheeting.

I have already rethought how to bear the wing joiners. Do it more like the bigger planes with joiner tubes do. Eliminates a joiner boxes, 2 for fuse and two per wing panel pair. I hated making those blasted things. Should be lighter.
Now to the garage.

N1EDM

My Feedback: (2)

Skylark, you're not a 'dirty ol man'. You're a Sexy Senior Citizen.....

flyingagin

First set of templates are done, the flat bottom. The original wing ribs for the Kadet JR.
Tomorrow I will make the symmetrical rib templates. Then I can start making the key ribs for my changeling Kadet JR.

Ken

Pork Chop

My Feedback: (5)

Has anyone heard from Gary Harris?

flyingagin

No not in over a year maybe 2
no idea why or if he is OK
That is why Dave took over the thread

Ken

flyingagin

3rd attempt to cut perfect template for symmetrical wing ribs. 3rd failure

Getting rather upset, but will try again after I chill

Ken

EJWash1

My Feedback: (3)

What's giving you fits?

flyingagin

I think ME!
I tried a different way that I thought would be faster and waste less wood. I finished on side of my master second and then thought I could just flip the second one and use that to do the unfinished side of the master. And then flip back and finish both. It is a bit tough to describe what I was doing. I confused myself a few times when I had to stop for a moment then come back to it.

Tomorrow I will do it the way I have always done it.I can't print at the moment so I am just using the good ol mark 45 eyeball (standard navy issue) and drawing till it looks right. Use the sander to get a smooth curve. The I run my fingers over the cure with mu eyes closed checking the curves.
I will get the top curve (same as the bottom), and the transfer that back to paper. with a fold on the center line. I find if I put a lair of scotch tap on the paper template it is nice for tracing after cutting with scissors. I can then transfer the paper template back to ply. It is not exact, but it is close enough.

I was just trying to be more exact. I will eventually get that figured out. But for now, I am going to do what has all ways worked for me when I can't print a foil

Ken

skylark-flier

His last post ANYWHERE was 5/10/2013
He mentioned a death in the family on 5/7/2013, I volunteered at that point.

I've sent several PMs over the past year or so - zero response. I've also been wondering what happened.

FlyerInOKC

My Feedback: (6)

A death in the family can really put a lot of things in a tailspin especially if its the death of a child. I don't know who Gary loss so I can only speak in generalities and from my own experience. My grandmother was in a nursing home when my 61 year old aunt died and it really hit her hard. She never expected to out live her children.

acdii

Well if you come to Toledo, I can do a strip tease for you at the SIG booth.


Just kidding,


Might get all the ladies over excited.


With that said, anyone thinking of meeting up like we did last year?

ETpilot

Well, I made a bonehead mistake on my LT-40 wing. I was installing the shear webs and main top spar I- beam style. When I went to do the rear spar and shear webs I realized my mistake; I installed the main spar shear webs horizontal instead of vertical.

This is is going to be a D-tube wing. Will it be strong enought to leave as is? Or should I add face glued vertical webs to the spars. This is only on the left wing. The right wing I did correctly. If I add shear webs I will weigh and check the difference. Shouldn't be to much difference. Thoughts, thanks.

acdii

Sheer webs must have the grain vertical to the spars, otherwise they are useless. They are used to stiffen the spars, and if the grain is in the same direction as the spars, there is no stiffness to them, they can split in the middle under the stress of flight. They also carry the load of the bottom spar to the top spar and vis verse the top to bottom when inverted. They fight against compression when climbing and positive G's and pull from negative G's.

So , I would remove them and do them right, or leave them and run the webs on the back side of the spars, they will be stronger that way.

flyingagin

On the plane in avatar (it started out as an arf) when I stripped it for rebuild the shear web grain was parallel with the spars. I add vertical right over the existing webbing. Very little extra weight. Maybe 1 or 2 ounces. I did a ton of extra mods and covered with fabric and painted. Did I forget to say how much I hate doing pin stripping?

Ken

FlyerInOKC

My Feedback: (6)

That's an idea, glue sheer web over the existing sheer webs on both sides with the grain opposite of what was already installed. That way you balance out and if you think about it the webs would be made of balsa plywood which would be even more stiff. Just a thought.

ETpilot

Thanks for the info you all. I will add the shear webs in the correct direction. Good thing I caught it when I did. Easy fix now.

flyingagin

I have both sets of templates made. The symmetrical was kicking my rear. I started fresh and nailed it today or so I think.
Next will to start making the ribs that will take the loads of the joiners. Lite ply with birch reinforcements at the load points of the joiners.
Next week I reckon.

Ken

flyingagin

I got the Kadet JR fuse out of storage. Need some measurements and such.
I am starting this mod by first making a center section for the wing joiners to go into. I actually have to raise the wings (high wing position) about a 1/2" or so. I started by making a lite ply plate to join to the fuse bottom. I will cut litening holes into to reduce wight. Then three ribs, outer 2 of light ply with some birch ply where the joiners will put loads onto the center section.
Sense the symmetrical foil is thicker than the flat bottom I have to compensate in several ways.
There is some complexity in this mod but I THINK I have them figured out at this time.
I am doing the center joiner section first as it has several complexities that I have to solve before the bottom joiner fuse doublers are added.
I am trying hard not to mod the fuse in any way. That may be tough at the windsheild area. With the joiner section sitting higher, I have to find some way to blend that (and the back) in.

Last picture is what I am starting with. The wing will not be used or touched in any way.
Basically It will get 2 pair of new wings to either go high wing or low wing.


Ken

EJWash1

My Feedback: (3)

Interesting project. Don't think we're not watching!

flyingagin

Tested the fail point of the ply joiners. They fail way to soon. So Will try adding some other materials.
Pretty simple test method. Cut a piece of stock to length, fuse width (3") plus 2 rib bays (4"). Put 3" in a vice supported by wood both sides and then pressed down at a point 4" (inner support rib point). With out much pressure the wood started to crack,I could hear it start to fail. I tried some 1/4" luan (floor underlay) and a piece of 1/2" birch aircraft ply.
The test pice was 5/8" thick, the width between the spars of the flat bottom wing.
My thought was to test simply by hand pressure. If it survived that then hang known wights on the joiner to quantify the actual loads the joiner would take. Aim is to take 10G's. I don't know the actual wight of the plane, just guessing a high wight of 4lbs (likely three). 4lbs at 10G's is 40lbs and each joiner only bears halve the load. So figured if the joiner could take a 20lb load then good to go.

Will try some aluminum in the middle of the joiner. I have a 2.5 meter glider that uses that type of joiner. And it works fine. Will do the same type of test for the rib reinforcements that will bear the joiner loads.

And I thought 1/4" A/C ply would do the trick. Sure glad I tested.

If my approach to load testing is wrong. please jump in and tell me.

I will continue to make the lite ply joiner ribs until I test joiners further. Just won't box myself in with the full joiner rib construction.

Ken

I will start a thread outside this one that will be more detailed and just post highlights here.

flyingagin

Thank you EJ. I was typing up my last post as you posted.
I tend to work in spurts.

I have some 1/8 carbon plate but only small pieces. Doubled up it might take the load, but I guess I will never know. It is outside of my present budget to order more. Will try some aluminum in the middle.

The flat bottom wing is not as thick as the symmetrical. Any thing that works on the flat bottomed will for sure work on the thicker symmetrical wing. That is why The testing is for it.
I will test a 1.125" wide joiner (the full thickness of the flat bottom wing), And also test joiners for the thickness of the symmetrical wing.

I have lots of unidirectional carbon cloth (used to build vacuum bagged glider wings). I may make a mold and try to lay up a carbon fiber joiner. I never have worked with such thicknesses before though.

Ken

flyingagin

I am doing most of the documenting on a new thread now.

so as not to over clutter this thread.

Ken

michaelnel

Ooops sorry did not realize this area is for kit builders. Mine is an ARF.

Pork Chop

My Feedback: (5)

Michaelnel,

Nice looking Sig! I've had 2 Seniors and they fly great very easy to fly you'll love it. Good luck

TomCrump

Good luck with your maiden, michaelnel.

Every Kadet Sport Arf that I'm aware of has needed down thrust. If you haven't put any in, I suggest that you place a couple washers behind the top motor mount bolt holes, between the firewall and the motor mount. Take more washers with you. You may need them. No right thrust should be required.

My brother maiden his Kadet Sport last week, and it took 16 clicks of down trim. Mine took all the trim the radio had, and it wasn't enough. LOL Same with a friend's.

Have fun with your Kadet Sport. This issue is something to be aware of, but it's not catastophic. Placing the washers, beforehand, will allow you a more pleasant experience..