The .25 powered trainer I designed - RC Groups
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Dec 02, 2012, 08:54 PM
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The .25 powered trainer I designed

This is the little 4 channel trainer. I made one rib template and just started cutting wood and gluing.
The fuse is a little long but that wont hurt anything. I still had to add about 3/4 ounce of lead to the tail to balance it, so I certainly did not overbuild the back section.
When I went to but the wing on with all the servos in I found a major lack of planning on my part. The aileron torque rods would not clear the rudder and elevator servos. I solved that little mistake by building a bit of cabin area on top of the wing mount area. It actual looks better this way I think and might improve flight characteristics a bit.
Last edited by greyflight390; Dec 02, 2012 at 09:00 PM.
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Dec 25, 2012, 07:32 PM
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Clean up and rearrange

Rearrange and cleaned up the spare bedroom / work / plane storage room. It got so I could nit see the top of the card table I build on. But I had no place to put anything and start a clean up. So I made I trip out to my bud's storage garage. Took a car load out of that room and the little storage room on the patio. Brought back my big guy ( Super Tiger 300 powered ) plane.
I add a bunch of angle brackets up high to store planes on. Brought in the plastic storage bins form outside in the patio storage room and arranged them for easy access.
Then I cleaned the card table and rearranged the outside storage room for access to tools, sander and drill press.
Still more to be done, nut at least now I can work.
Dec 25, 2012, 07:38 PM
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Plane storage.
There is room for a few more angle brackets for plane storage, not much more though.
Dec 25, 2012, 07:56 PM
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Working on the funny wing

Once I got some table top visible I resumed work on the funny wing plane. Got the rear fairing done. It is just $tree foam board, paper off. Then Servos and engine installed.
CG checked and it was off by about 10 miles. No way to shift things enough to compensate. The forward sweep of 7" really throws things for a loop.
Much thought, Much debating of tossing the fuse and starting over.
Finally decided to to cut the nose off and add a new much longer section to the fuse.

So I cut the front off. Next I taped the motor and battery to a stick and with the wing wing I started moving the stick forward till I hit my desired balance point. Measured to the back of the motor and that is now were the firewall is.
Just cut some new front end sides, Glued 'em on added the fire wall Some more bottom sheeting. Still have to add splice doublers and stiffeners and tri stock to the back of the firewall.
But at least it is back on track again, and should not take much more work till it is ready for the maiden flight.
Jan 01, 2015, 11:22 PM
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Life has been in the way of airplanes for the past year. Some intermittent build, no flying at all. Well two flights on my little .10 powered trainer.

Now in Modesto CA.

Thought to get this little .25 trainer flight ready. Also I intended to modify the wing and put plug in polyhedral tip panels on it. Well looking at the wing. It is toast. Burnt toast. Not real sure why. But we have moved numerous time this year from temporary place to another temporary place. In a word we have bean homeless. The planes have undergone the same thing and bean stored in far from ideal conditions. That may account for it????

So any way having to build a new wing. Going fast. Lost the original rib templates. Made new a better ones. Cut a birds mouth notch for the L.E. Then needed stick stock so a trip to the hobby shop about 30 minutes away. Picked up some thin ca. Glad I did too.

Did not find any 1/2"square balsa that was semi straight. So I have done something way different. I laminated up 2 1/2" square pieces. The laminated L.E. consist of one 1/4" square bass, one 1/4" square balsa, and one 1/4' x 1/2/" balsa epoxied together. The bass is piece that fits first in the birds mouth. leaving balsa to more easily shape to the correct shape.
One heck of a lot lot stronger than the LE of the original wing. It also started as 1/2 square stock (all balsa) but the most of it cut and sanded away to make the proper shape. So it really was flimsy. This new LE will be much stronger having a 1/4 square bass at it beginning in the wing.

The spars are over kill, but I was only able to find bass that was straight enough.
TE is 1/4 x 1/2 balsa that I will shape.

Have not started the polyhedral tips yet. they will add 10" each to the wing. Using a piece of 1/8 birch ply for the joiner. I put a lot of force across the width of one to no effect. Combined with anti rotation pins, I am confidant of it. The joiner boxes are made, just need to epoxy them to the spars at the tip ends.

Pic 1 is how the LE is constructed.
Next the joiners and joiner boxes.
And the wings. Still need to join and add shear webbing between the spars.
Jan 09, 2015, 12:46 AM
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Glued the Joiner boxes to the ends of each main wing panel.
Then joined the two main wing sections. Added shear webbing and dihedral brace.
So it is basically a wing. $8" with out polyhedral tip and with 10" for each tip, 68" with tips.
No very much dihedra, but after the training wheels come off (tips) I really wont need much.
I have worked out how to put ailerons on the tips and link them to the ailerons on the main wing sections with just one snap ball link to engage a disengage.

At some point I am going to make floats for this little guy. Should be fun,
Jan 17, 2015, 12:08 AM
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I am pretty much on target with my trainer wing. I have just been forcing the time to be available to work on it.
The 2 wing halves are joined. The aileron torque rods are on. Salvaged from the original wing. And center section just got glassed. The resin should be cured by morning. I left the garage at 80*s. And the two polyhedral tip panels are joined up with the main wing section. Slide in and out fairly well. All 4 ailerons are on but not glued.

Lets see. I have the bellcranks for the tip panels that connect the main and tip ailerons to make up yet. Figured it out in the shower a few minutes ago (a semi annual event).* big grin Got to install four hard points for the screws that I am going to loop a strand or 2 of tie wrap around to keep the tips from sliding off. Got to install the aileron servo. That will go fast. I made a pocket for it as I sheeted the center section.
Cover the wings and then CA the aileron hinges. That it is it other than program the TX.

So real close I think
Jan 18, 2015, 12:02 PM
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Linking the tip aileron via pushrods and a bell crank is a non starter. I am just going to use a micro servo each tip. Got to make a 3 servo Y type connector to tie all 3 servos to one lead.

In the meantime the center aileron servo is in.
Jan 23, 2015, 12:01 AM
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I goofed up the tip aileron installation . My first attempt I by accident reversed the 2 servos. Since they run off the same channel that is correct. But Overall I had the servos backwards to the main ailerons. So I had to cut everything loose and redo them. Made darn sure the directions were correct this time.
I also installed four screws and made a connecting wire from real small piano wire.This is to hold the tips to the main wing.
Then I started to cover one side. Totally screwed that up so I have to strip it and do it again.
Jan 24, 2015, 10:55 PM
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Basically done. I still have to install the RX and battery. Will buy a new battery payday and 2 24" servo cables for the tip aileron servos.

So February when my buddy in Reedley is free is the maiden, or re maiden.

So in the meantime on to other projects.
Jan 24, 2015, 10:59 PM
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And here are the polyhedral tips. They lock on with a small piece of piano wire and 2 screws. Only have to remove one screw to add or remove tips. Well also the servo cable.
The tips add about 40% more wing area besides helping to stabilize the plane in roll.

semaphores any one? I could send messages via semaphore
Feb 28, 2015, 11:43 AM
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I just ordered the servo cables and battery (plus 1 spare). The spare will find it's way into Funny Wing I think
Cheetah Packs 6.6V 850mAh 20C Lithium Iron Battery
Item: 1 of 10
Weight 50 grams - 1.8 oz
Dimensions 17 x 30 x 54 mm - 0.7 x 1.2 x 2.1 inches
Output Connector Futaba J Servo
Balance Connector Male JST-XH
Max Continuous Current 17 Amps (See note below)
Price: $6.75

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