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What is the definition of a Joggle?
- Thread starter MJarreau
- Start date
snopercod
Well Known Member
I think "joggle" is more of a fiberglass term. It's where the surface is recessed to allow another piece of fiberglass to be bonded into the recess. My Lancair kit used "double joggles"; The first joggle as above, and the second recessed even more to allow a bid tape to cover and reinforce the joint. These are double joggles where the empennage will go:
Peter Costick
Well Known Member
I think a joggle is a Zig, or a Zag - but not both together.
Example
Here is an example.
On the old RV-3 and RV-4 wings you cut out the holes for the inspection openings under the wings. Then riveted a "ring" (more like a "C") to the inside of the wing skins on which the inspection covers rested (nut plates on the "C" "ring").
I understand that the newer wing skins have the openings cut out (smaller) and the edge of the opening "joggled" so the inspection plates will sit flush with the skin. So a "joggle" is an indent along the edges of a skin.
I think some of the tool suppliers have tools to make such a joggle.
Yes a "Z", where the top and bottom are very close together (0.025 in case of wing skins I think).
Perhaps this is also true of the inspection openings at the rear end of the fuselage.
Finn
Here is an example.
On the old RV-3 and RV-4 wings you cut out the holes for the inspection openings under the wings. Then riveted a "ring" (more like a "C") to the inside of the wing skins on which the inspection covers rested (nut plates on the "C" "ring").
I understand that the newer wing skins have the openings cut out (smaller) and the edge of the opening "joggled" so the inspection plates will sit flush with the skin. So a "joggle" is an indent along the edges of a skin.
I think some of the tool suppliers have tools to make such a joggle.
Yes a "Z", where the top and bottom are very close together (0.025 in case of wing skins I think).
Perhaps this is also true of the inspection openings at the rear end of the fuselage.
Finn
cajunwings
Well Known Member
Joggle
It can be a small Z bend at the edge of a sheet so when the adjoining sheet attaches both sheets outside surfaces are flush with each other. Adds some stiffness there too. Check out the fuselage skins on a Cherokee.
Don Broussard
RV9 Rebuild in Progress
57 Pacer
It can be a small Z bend at the edge of a sheet so when the adjoining sheet attaches both sheets outside surfaces are flush with each other. Adds some stiffness there too. Check out the fuselage skins on a Cherokee.
Don Broussard
RV9 Rebuild in Progress
57 Pacer
Roarks
Active Member
/\ Exactly.
Also...
https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/media/amt_airframe_hb_vol_1.pdf
Page 4-81 and 4-82 (pg 247 of the pdf file)
Following is a Copy / Paste from the above document page G-20.
Joggle. A small offset near the edge of a piece of sheet metal.
It allows one sheet of metal to overlap another sheet while maintaining a flush surface.
fixnflyguy
Well Known Member
Every plane has them..
Joggles are very common in metal aircraft, and I doubt there is a plane built that doesn't have them. At my day job, we have a shelf full of joggle blocks and joggle forks as I call them for pressing joggles into repair parts and replacement parts we fabricate. Typically, the joggles are made while the material is in the annealed condition, and then heat treated to the required temper. We do this in house (heat treat), and while simple, isn't something you would do in a build. Thin sheet material can be joggled in the heat treated condition, but cracks may occur if the joggle is too severe. The joggle itself simply keeps the structure "smooth" on the skin mating surface, while allowing the framework to overlap internally. An RV kit has many of them on the ribs and bulkheads that were preformed during at the factory prior to heat treat. Skin joggles are usually created by the builder if he chooses to "flush" a seam rather than a standard overlap.
Joggles are very common in metal aircraft, and I doubt there is a plane built that doesn't have them. At my day job, we have a shelf full of joggle blocks and joggle forks as I call them for pressing joggles into repair parts and replacement parts we fabricate. Typically, the joggles are made while the material is in the annealed condition, and then heat treated to the required temper. We do this in house (heat treat), and while simple, isn't something you would do in a build. Thin sheet material can be joggled in the heat treated condition, but cracks may occur if the joggle is too severe. The joggle itself simply keeps the structure "smooth" on the skin mating surface, while allowing the framework to overlap internally. An RV kit has many of them on the ribs and bulkheads that were preformed during at the factory prior to heat treat. Skin joggles are usually created by the builder if he chooses to "flush" a seam rather than a standard overlap.
fixnflyguy
Well Known Member
One more thought..
While I agree with Vlad's bit about the emennage being a significant reward..you MUST then meet Vlad himself. At that point, your RV experience will be full circle...but have Scotch and Steak ready when you do!
While I agree with Vlad's bit about the emennage being a significant reward..you MUST then meet Vlad himself. At that point, your RV experience will be full circle...but have Scotch and Steak ready when you do!
