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Fuselage Side Curvature

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Has anybody made a Cozy with fuselage sides that have vertical curvature in addition to the lengthways curvature? Not having the plans yet, I'm guessing that the jigging of the compound curve might be a pain, not to mention that a lot of things that are connected to the fuselage would have to be tweaked. However, it should provide a little more elbow room, depending on the degree of curvature, and it should also increase fuselage stiffness.

Are there any aspects of this modification which would be considered a major divergence from the original plans design?

 

Joe


Joe

Cozy Mk IV #1550

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I'm looking at doing this on my Long-EZ. My approach is (in theory) is to use blue foam cut to the size of the fuse sides. profile them to the curvature I'm looking for then slice them via hotwire on the vertical plane in about 1 inch layers. Attach each layer one at a time to the plans fuse side with 3m 77 glue one layer at a time. do a final contour and glass.

 

This is how I'm planning to do this area but keep in mind it will also make the strakes more difficult.

 

Nothing previously mentioned has been completed at this time in my project.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Sounds like a lot of work. Plus, you'd be sanding through different densities of material (epoxy, foam, epoxy,...) when contouring the surface, which I've read can be problematic. It also doesn't give you any more elbow room, just more fuselage bulk.

Why not add more curvature to the fuselage side by adding curvature to the mould? It might require pre-scoring then heating the foam to get it to conform to the tighter compound curve.

 

Joe


Joe

Cozy Mk IV #1550

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well, once you bend the sides into a curve from top to bottom you won't be able to curve it on the other axis. I just want to eliminate some of the box look to the sides.

The method i spoke of is used a lot in creating complex curves in woodworking. By creating the curved sides with a solid piece of foam you can create the cuved profile between wl 0.0 & 20.5. By slicing it into 1 inch thick layers from inboard to out, you can easily get it to conform to the sides of the fuse.

 

If it's more elbow room you want, make the strakes fatter or widen the fuse.

 

In either case, curving the fuse on more than 1 axis is a big job no matter how you slice it (pun intended!)

 

Mating the strakes to a curved profile where it meets the fuse will make your project even more challeging than it already is.

 

If you want to see what it takes to actually do this, check out ShaleDC's project at this link. He's got about 1 1/2 years into it.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Looks like the two different techniques you and I are describing both appear in the thread you reference. Your way was used to make the blue foam plug (seen in the video), and I'm describing the way the fuselage (nose) was done. Both seem to work.

 

Joe


Joe

Cozy Mk IV #1550

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Both seem to work.

No doubt. If I was 20 again :D I would look into building a plug and laying the glass over it and then build my bulkheads to match.

The downside (if I recall correctly) of being 20 again is I'd be broke and have no place to build.:o

It's fine to blue sky it. I'm working on my plane (mentally) all the time. Get your plans and foam and get to work! Your priority of mods will surely change. I know mine did.

T Mann


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Has anybody made a Cozy with fuselage sides that have vertical curvature in addition to the lengthways curvature?

Yes... sort of. I redesigned the entire fuselage of the cozy. It has circular-to-oval cross section, similar to the SQ-2000.

 

I'm close to finishing the shell of the fuselage. (bulkheads, lower hull, nose, and turtleback are done, working on canopy frame, interior elements such as armrests etc...)

 

 

You can see details of my project on the other forum: http://www.canardaviationforum.dmt.net/showthread.php?t=1893

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I'm getting to the point that I am working on the curved fuselage sides.

Here is how I approached it.

 

The circular tubes cut into the side cores are for elctrical and hydraulics.

The smallest access tube on top will service any needs between the nose and strakes only.

 

The rudder conduit is embedded in the wall of the original fuselage foam and is floxed and micro'd into place.

post-2251-141090156025_thumb.jpg

post-2251-14109015603_thumb.jpg


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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There is a reason that blue wing foam is not used in the fuselage. Gas goes against the sides in the back. That means if you get a tiny little leak all your foam in your fuselage it basically melts. The foam in the sides of a plans built Longeze, cozy or any other properly built rutan derivitive does not melt when exsposed to fuel. my .02 STeve


Steve Harmon

Lovin Life in Idaho

Cozy IV Plans #1466 N232CZ

http://websites.expercraft.com/bigsteve/

Working on Chapter 19,21

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Yeah, I know Steve. This is just the prelim fitting. The strake area will be cut out of the wing foam back to the original fuselage foam. It will make more sense when I can post the next phase of this design.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I think your work looks great. I wonder if you could hot wire the pvc foam if you wore a resperator and flushed the area of the gasses when done. I know that a hot wire will cut pvc foam but it is poisonous. STeve


Steve Harmon

Lovin Life in Idaho

Cozy IV Plans #1466 N232CZ

http://websites.expercraft.com/bigsteve/

Working on Chapter 19,21

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You can but a fresh air mask would be in order.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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There is a reason that blue wing foam is not used in the fuselage. Gas goes against the sides in the back. That means if you get a tiny little leak all your foam in your fuselage it basically melts. The foam in the sides of a plans built Longeze, cozy or any other properly built rutan derivitive does not melt when exsposed to fuel. my .02 STeve

Not only can the fuel seepage melt the blue foam, but it will also pool in the cavity. However, in this case, it sounds like the fuel resistant foam will act as a barrier, and the blue foam will simply be a cosmetic addition over top of the plans' structure. Right TMann?

 

 

Joe


Joe

Cozy Mk IV #1550

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Right you are Joe.

I'm working on it right now. I got my templates drawing printed out full size late last night. I'm cutting the out as we speak. I should have some updated photos by the end of the weekend. Who knows, with any luck, I make get it skinned by then. :D


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Well, I made my templates to guide what areas of the curved portion of the fuselage I need to cut out. To do this I created a my male mold of the strake from BL10 to BL23. Then I cut off the curve of the fuselage from the BL10 side.

I moved my template (for the curve of the fuse) back 4 inches (to match the foam billet I started with for the curved fuselage) and cut off another slice.

 

That gave me the profile for inside and outside of the curved blue foam I'm adding. I reassembled the waste foam to the curved blue sidewall to get back to the original billet dimensions. Put my new template on either side and ended up with the perfect contour to match my strakes.

 

The attached photo shows the strake tank mold (pink foam) mated to the cueved sidewall (Blue Foam.)

post-2251-141090156034_thumb.jpg


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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How much weight do you suppose your fuse. curve method will add?

 

Also have you thought of any way to utilize the space for equipment? Perhaps a transponder, radio, intercom, fuse block, map holder etc could be mounted on the side.

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I weighed the foam at 9.48 lbs total before I did the strake cutouts.

I'll weight the and subtract that out and post the net weight here later today.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I weighed the foam at 9.48 lbs total before I did the strake cutouts.

I'll weight the and subtract that out and post the net weight here later today.

I just weighed my cutouts for the strakes. 3.63 lbs so the net weight of the mod (not counting what I'm taking out for shaping and before applying all rebates :rolleyes:) will be 5.85 lbs.


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Here are some new pics of the fuse. I should have it glassed this weekend and moving on to chapter 8:D

post-2251-141090156048_thumb.jpg

post-2251-141090156055_thumb.jpg


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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T, I applaud your ambition and creativity. Keep it up!


Jon Matcho :busy:
Canard Zone Member & Administrator
Now:  Rebuilding Quickie Tri-Q200 N479E
Long-term:  Building a Cozy Mark IV

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Chapter 7 & my curved fuselage mod is done. I started this chapter on 7/10 and finished today (8/6) . I figure the mod may have added a week to the chapter so not a major impact on my schedule.

 

I heard that the glass layup was a big deal so I picked up a 6 inch roller to wet out my glass and was done in right at 3 hours. In addition to the 3 UNI layups I added 2 layers of Kevlar on the bottom followed by a single layer of fiberglass deck cloth.

 

Looking back, this was a pretty easy approach for this mod. I spent a lot more time thinking about it than executing it. :D


T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I'm getting to the point that I am working on the curved fuselage sides.

Here is how I approached it.

 

The circular tubes cut into the side cores are for elctrical and hydraulics.

The smallest access tube on top will service any needs between the nose and strakes only.

 

The rudder conduit is embedded in the wall of the original fuselage foam and is floxed and micro'd into place.

that's a good point, dust had me use pvc on the strake leading edge

i had no idea you went so wide T, are you going to shrink your elevators or make your canard bigger ?


Steve M. Parkins

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