quote:

ORIGINAL: chistech

Hello all,
Throughout the years all I've ever done was construct built up wings and I am unfamiliar with installing retracts in foam core wings. I will be starting a Jemco hellcat and possibly a P47 and could use some ideas. I understand there was supposed to be a additional set of instructions with the Hellcat for the retract install but my kit didn't have them in it. Does anyone have a copy of those?

Thanks in advance,
Ted

quote:

ORIGINAL: DAN REISS

Gary, That sounds interesting. Please post some images if you have them. Dan.

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ORIGINAL: fockewulf37

Thanks Guys,

I did not show it but I usually cut the ribs back further into the wing to carry the load over a bigger area. But i have not ever torn the gear out even as small as this area is. you would really have to slam it down to break it out...

Ty

quote:

ORIGINAL: BadSplice

I am working on a Jemco P-47, and I have been scratching my head about the retract install. This will be my first foam core wing. The p-47 gear retracts inward, but also somewhat aft. When extended, the legs lean down and Forward... How does one go about figuring out what angle to install the mounts in the foam so that the gear will operate in the right way, and the wheel will end up straight when extended, and flush with the wing when retracted?

quote:

ORIGINAL: invertmast

Now for the boring words, since i have some time to write them :)

All of the ribs and gear plate are 1/4'' 5-ply aircraft plywood. They are laminated w/ 1 layer of 3k carbon cloth on each side w/ each layer of cloth oriented 45* to the other. The ribs are notched to fit into the semi-spar, and the gear-plate slides into place in the slots in the false ribs.
The Gear plate has an additional piece of 1/4'' thick x 1/2'' wide aircraft ply doubler in the area of the landing gear bolts.
the Plywood ''semi-spar'' that runs the parallel to the span of the wing is 1/8'' 5-ply aircraft ply w/ lightening holes cut into it and rests roughly 1/8'' below the surface on the top and bottom.

I replaced as much of the foam core that was removed back into the wing before it was sheeted. I used Hysol to glue the wood parts to each other, and Gorilla Poly-U glue to glue the wood parts to the foam. the Wing also had the leading edge installed BEFORE sheeting the wing. the reason for this, is I designed the gear structure to use the leading edge as part of it. So in order for the forward mount to transfer stress to the leading edge and the LE to transfer stress to the rest of the wing, the sheeting was placed over the leading edge, so the LE is sandwiched by the wing skins and the skins transfer the load to the rest of the wing from the LE.

The only thing i would do different, is make the gear plate approximately 1'' longer in span that what is shown in the photo's and move the outboard false rib out with it as well.

quote:

ORIGINAL: ram3500-RCU

quote:

ORIGINAL: invertmast

Now for the boring words, since i have some time to write them :)

All of the ribs and gear plate are 1/4'' 5-ply aircraft plywood. They are laminated w/ 1 layer of 3k carbon cloth on each side w/ each layer of cloth oriented 45* to the other. The ribs are notched to fit into the semi-spar, and the gear-plate slides into place in the slots in the false ribs.
The Gear plate has an additional piece of 1/4'' thick x 1/2'' wide aircraft ply doubler in the area of the landing gear bolts.
the Plywood ''semi-spar'' that runs the parallel to the span of the wing is 1/8'' 5-ply aircraft ply w/ lightening holes cut into it and rests roughly 1/8'' below the surface on the top and bottom.

I replaced as much of the foam core that was removed back into the wing before it was sheeted. I used Hysol to glue the wood parts to each other, and Gorilla Poly-U glue to glue the wood parts to the foam. the Wing also had the leading edge installed BEFORE sheeting the wing. the reason for this, is I designed the gear structure to use the leading edge as part of it. So in order for the forward mount to transfer stress to the leading edge and the LE to transfer stress to the rest of the wing, the sheeting was placed over the leading edge, so the LE is sandwiched by the wing skins and the skins transfer the load to the rest of the wing from the LE.

The only thing i would do different, is make the gear plate approximately 1'' longer in span that what is shown in the photo's and move the outboard false rib out with it as well.

Nice description pal. Don't see anyone having problems after all this. The only tricky part is getting the angle and cant correct. Some trial and error is sometimes needed for this, if you don't have detailed plans.

quote:

ORIGINAL: invertmast

quote:

ORIGINAL: ram3500-RCU

quote:

ORIGINAL: invertmast

Now for the boring words, since i have some time to write them :)

All of the ribs and gear plate are 1/4'' 5-ply aircraft plywood. They are laminated w/ 1 layer of 3k carbon cloth on each side w/ each layer of cloth oriented 45* to the other. The ribs are notched to fit into the semi-spar, and the gear-plate slides into place in the slots in the false ribs.
The Gear plate has an additional piece of 1/4'' thick x 1/2'' wide aircraft ply doubler in the area of the landing gear bolts.
the Plywood ''semi-spar'' that runs the parallel to the span of the wing is 1/8'' 5-ply aircraft ply w/ lightening holes cut into it and rests roughly 1/8'' below the surface on the top and bottom.

I replaced as much of the foam core that was removed back into the wing before it was sheeted. I used Hysol to glue the wood parts to each other, and Gorilla Poly-U glue to glue the wood parts to the foam. the Wing also had the leading edge installed BEFORE sheeting the wing. the reason for this, is I designed the gear structure to use the leading edge as part of it. So in order for the forward mount to transfer stress to the leading edge and the LE to transfer stress to the rest of the wing, the sheeting was placed over the leading edge, so the LE is sandwiched by the wing skins and the skins transfer the load to the rest of the wing from the LE.

The only thing i would do different, is make the gear plate approximately 1'' longer in span that what is shown in the photo's and move the outboard false rib out with it as well.

Nice description pal. Don't see anyone having problems after all this. The only tricky part is getting the angle and cant correct. Some trial and error is sometimes needed for this, if you don't have detailed plans.

You aren't lying with that one my friend! Especially when it comes to a FW-190, or any of those other odd landing gear jobbies (spitfire, ME109, etc). Luckily the plans for my short-kit had the dimensions for where the rail should be from the wing skin, and how far from the trailing edge the axle should be. Unfortunately, most plans that i have seen do not do such a nice job of making the builders life easy.