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Old Jun 10, 2007, 10:37 PM
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GWS J3 Cub

Just a few quick questions......................

Has anyone built the wing on the GWS J3 Cub with absolutly no dihedral..?

Is there any concern about the wing saddle on the fuse having any adverse affects when doing this......?

How does this fly with this mod...? I am putting a small brushless on and laminating the tail feathers with some balsa for added strength to reduce the flexing.

This is my third one and I just love this little plane for backyard flying but never have changed the dihedral

Thanks

The Fonz
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Old Jun 10, 2007, 10:51 PM
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I removed the dihederal on several different ones to put ailerons on them, but if your going to just use rudder and elevator, you'll need the dihederal.
On my dihederal planes, I use 12k carbon fiber tow and wet it out with 30-60 minute epoxy under the wing on the front and rear to stiffen it up. Butch
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Old Jun 10, 2007, 11:16 PM
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If you are on your third one and love it the way it is, don't change a thing. That way you will keep loving it.

Reducing (or eliminating) the dihedral reduces stability and allolws the ailerons to be more effective (if you had them) but as Butch pointed out you need the dihedral if you continue to fly the plane with rud. and ele. control.

Robert
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Old Jun 11, 2007, 06:00 AM
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I love my GWS Pico Cub too. Flies equally well on snow, water or a school vacant parking lot. I'm trying to locate the cub minus the power system, will use my own motor. Any suggestions? Thanks.

Regarding reducing dihedral. I agree with the earlier post, if you eliminate the dihedral, u need to add ailerons. Very unstable if you don't.
GWS Piper Cub (0 min 56 sec)
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Old Jun 11, 2007, 09:18 AM
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I just purchased one. I am thinking I need to reinforce the stock wing, as it it fairly weak. I guess cf will do the trick. The instructions aren't great, but looks like there is a piece of plasctic you cut out and glue to the wings with the dihedral in place. Does that make sense?
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Old Jun 11, 2007, 09:25 AM
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[QUOTE=georgefromvt]I love my GWS Pico Cub too. Flies equally well on snow, water or a school vacant parking lot.

Nice video, thanks.
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Old Jun 11, 2007, 10:13 AM
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Thanks for the replies...

I will add ailerons as you suggest. Do you have any pointers on adding them to this type of wing?

For wing strengthening I added cf to both the leading and trailing edge. I also ditched the plastic wing joiner and added some cloth with epoxy...............................strong as nails and survives many crashes!!!

For the dihedral bend in the middle I used a small piece of brass tubing bent to 10 degrees that coupled the cf rods.

I know I shouldn't screw with a good thing but I wanted to try something new with this little beauty.......

I have already joined the wing halves without any dihedral and then I had some remorse....lol. I then posted here looking for agreement that it was okay. I never thought about the stability factor.................GOOD POINT!

I will post some pics tonight when I get home......

Thanks again for the replies

The Fonz
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Old Jun 11, 2007, 10:35 AM
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For wing strengthening I added cf to both the leading and trailing edge. I also ditched the plastic wing joiner and added some cloth with epoxy...............................strong as nails and survives many crashes!!!

I didn't think about the epoxy. That's really good idea, I was thinking of using the plastic thing with glue. I may use the plastic thing but I'm sure I will enjoy flying this plane and buy others in the future!!
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Old Jun 11, 2007, 11:29 AM
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It is a great little flyer......

I opted to with the epoxy for the wing joiner because on my first, I made a mess trying to get it glued down. It didn't seem to fit well and was abit warped. I cursed so much I ditched it on the first, second and this my third. If you get the same vocabulary trying to put it on cleanly and wreck it....let me know, As i can send you a replacement...............

The Fonz
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Old Jun 11, 2007, 01:22 PM
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As i can send you a replacement...............
vocabulary? LOL I was thinking when I did it to clamp the plastic piece onto the wing, maybe with gorilla glue it will set ok? Or should I use 5 min epoxy?
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Old Jun 11, 2007, 01:22 PM
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How does the fiberglass stick to the foam? Does it work well with the cloth?
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Old Jun 11, 2007, 04:18 PM
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I first mate up the wing halves together with a bit of epoxy on the edges and push together to get them into one wing.......

You may have to make the seam between them straight with your knife as the molding makes them less than ideal.

Once dried ,I punch a bunch of small holes around the area to be glassed. I mostly use my woodpecer tool but you can also use a toothpick or "t" pin.

I then mix some epoxy (15min) and cover the area to be glassed masking off the sides

Lay your cloth on and with an old credit card squeegie the cloth down getting it all soaked in. You may have to add more epoxy as you go...

This is just how I was doing it and you can add some mineral spirits to thin it out (paint thinner)if you like


Good luck

The Fonz
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Old Jun 12, 2007, 06:53 AM
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Hey,

Coolamundo sir. Thanks for the mini how to. If I have time, I will try it. Gonna be a fun easy flyer.
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Old Jun 12, 2007, 09:25 AM
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I have a GWS J3 Cub that I currently fly but I upgraded the motor to an EPS300C (GWS brushed motor).

It flies well outside but now that I put a stronger motor on it this thing really wants to climb. I just finished reducing the wing incidence angle and I think I might nudge the center of gravity forward to help keep it level at full throttle.

My real question is what are you guys using for a battery? I have a 300mah Nimh battery and I wanted to get a larger one when I realized it won't fit. The battery compartment is straddled by the landing gear wire which prevents me from digging out that area to accomodate a bigger battery. I'm curious what other people are doing for the battery.

Thanks!
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Old Jun 12, 2007, 10:31 AM
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You probably don't want anything bigger than a 8 cell nimh or a 2 cell lipo. How many cells are your currently using, 7 or 8?
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