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Spring the sides?


Cozy1200

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I'm in the process of testing fitting the bulkheads.

 

Does the sides need to be squeezed in a little to fit F22? I had expected all the sides to fit nicely, but the Seatback, IP, & f28 seem a little wide. If I fit those, then I'll need to slightly squeeze the sides to bring into F22. Maybe 1/2 inch. Does this sound normal?

 

I've triple check all the bulkhead widths and I believe they are the correct width. I think the sides may have sprung open a little while taking them out of the jig.

Drew Chaplin (aka the Foam Whisperer)

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www.Cozy1200.com - I'm a builder now! :cool:

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I'm in the process of testing fitting the bulkheads.

 

Does the sides need to be squeezed in a little to fit F22? I had expected all the sides to fit nicely, but the Seatback, IP, & f28 seem a little wide.

...

I think the sides may have sprung open a little while taking them out of the jig.

Did you notice much spring back when you removed the longerons from the jig? (Prior to laminating them onto the side foam)

 

I'm pretty sure my F-22 fit fairly snug 'out of the box', but the doubler needed slight trimming to match the curve of the fuse sides. Same for the IP and formed wire trough.

 

I waited on F-28 til the IP and F-22 were done/cured, and trim to fit. It also needed trimming at an angle. YMMV.

 

Lastly, do your bulkheads match up to the "M" drawings? (Assuming you're using the large M drawings).

 

Rick

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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Did you notice much spring back when you removed the longerons from the jig? (Prior to laminating them onto the side foam)

IIRC, I don't believe the longerons sprung open much at all. I remember thinking how well they held their shape.

 

I'm pretty sure my F-22 fit fairly snug 'out of the box', but the doubler needed slight trimming to match the curve of the fuse sides. Same for the IP and formed wire trough.

 

I did trim the seatback and IP to fit snug. I too needed to shave a little off the doubler.

 

Lastly, do your bulkheads match up to the "M" drawings? (Assuming you're using the large M drawings).

 

The widths are as close as possibly (possibly anally close :o )

My first thought was that F22 was off, but it the correct width.

 

I did just a quick trial fit last night when I found the issue. Hopefully tonight I'll get a better idea. I'm still scratching my head. It may just be the sum of all tolerances are just more than I expected.

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

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Brace for impact...

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The widths are as close as possibly (possibly anally close :o )

 

Nuttin wrong with that.

 

If'n ya want me to measure my tub in any way (assuming I made it right), holler. Might be able to dig up, and post, one of the pix I didn't put on my website too.

 

I'd say just put everything together... tape, ropes, and clamps. See how the big picture looks before mixing up flox.

 

Rick

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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Mine fitted so nicely, that it amazed me how well it all goes together :)

 

see my illustrations on:

http://mysite.mweb.co.za/residents/cvh/Cozy%20ch_567_8.htm

 

Regards

I live in my own little world! but its OK, they know me here!

Chris Van Hoof, Johannesburg, South Africa operate from FASY (Baragwanath)

Cozy Mk IV, ZU-CZZ, IO-360 (200hp) 70x80 prop

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One thing to remember Drew is that you used Hoop pine where most others have used Spruce. IIRC Hoop is heavier and also stronger than spruce. Possible that had some impact.

 

If you can squeeze it together without damaging the foam/glass I'd just do it and find something else to worry about.

 

Good thing to know though because I will probably use hoop pine so I might have to adjust the jigs to suit. I might chat to you in private about that.

Adrian Smart

Cozy IV #1453

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It sounds normal. The front and rear bulkheads go on first, then you fit the other ones in. Then you clamp it togeter with threaded rods or whatever. You squeeeze it together and glue it. 1/2" sounds like a real nice fit.

Andrew Anunson

I work underground and I play in the sky... no problem

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Drew, if your bulkheads are the correct size then squeeze it in like Raiki says. If you have a heat gun clamp the whole thing up then hit the longerons with the heat gun. Make em' nice and warm. Not too hot to touch. This will temporarily soften the epoxy to give a little. Then they'll cool stronger and help keep the shape better. While you're at it, move the front seat back an inch or two for some leg room.

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I was away the last two days for work, but I did take these pics before I left.

 

With one side correctly on the longeron, the other side is 1/4 inch short. :( It doesn't sound like much, but it's more than I would expect. Pic 1 & 2 show this. It's enough that it doesn't align with the outside foam like it should.

 

REQUEST

Would someone, please measure from the inside of one tip to the other on F-22? I would expect exactly 30" on a standard cozy. Also please confirm width of the IP. I've triple checked them, but would like to compare.

 

With the seatback in position, I can certainly squeeze the sides to fit. With the sides squeezed together, then F-28 no longer fits. I would have expected them to both fit when squeezed. If I position F-28 and then squeeze the 1/4, then F-28 bends! :irked:

 

 

I've confirmed the longerons jigs were built to the correct dimensions. Holding it up to the sides, it doesn't appear they have sprung open any as Raiki is suggesting. When cut so thin, I don't believe marginal extra strength has any impact on them springing back.

 

I'll most likely just squeeze it to shape, then cut the F-28 to fit as needed. I'd like to know where I'm actually off.

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post-336-14109016061_thumb.jpg

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

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Brace for impact...

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What position are you installing F28 at? I have a note in my chapter notes about it, (attributed to the Zeitlen FAQ & Wayne Hicks' excellent website) but don't remember if it came from yours or not. It says:

 

Make F28 0.5” wider

Canard is longer than plans placement of F28 5.9”. Build the F28 bulkhead a half-inch wider (side to side) than per plans. (Later install at the F28.35 position instead of F28).

 

Assuming your F28 is .5" wider than standard it will look a bit like that if you are placing it AT F28 instead of F28.35. A bit obvious perhaps, but I thort I'd mention the discrepancy.

Mark Spedding - Spodman
Darraweit Guim - Australia
Cozy IV #1331 -  Chapter 09
www.mykitlog.com/Spodman
www.sites.google.com/site/thespodplane/the-spodplane

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Spodman has a point if I was to do mine over again I would make F-28 wider I barely got my canard elevators to fit I had to cut out all the inside foam. Build on. STeve

??

Canard attach tabs too far apart? Slight mod needed when I get there?

 

Rick

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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REQUEST

Would someone, please measure from the inside of one tip to the other on F-22? I would expect exactly 30" on a standard cozy. Also please confirm width of the IP. I've triple checked them, but would like to compare.

 

OK, I got out my crayon and string....

 

I've cut off the F-22 ears, so YMMV.

 

Width of F-22 Doubler, at the side foam, aft edge (it's tapered ever so slightly) 33.125"

 

Width at F-28, against the longeron, forward face, 32.375"

Forward face of F-28 is 6.125" from the forward face of F-22.

 

Width of IP at the top longeron, forward face, ~36.25"

 

Rick

[edit] Forgot to add my top longerons are a hair over .75" in width

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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What position are you installing F28 at? I have a note in my chapter notes about it, (attributed to the Zeitlen FAQ & Wayne Hicks' excellent website) but don't remember if it came from yours or not. It says:

 

Make F28 0.5” wider

Canard is longer than plans placement of F28 5.9”. Build the F28 bulkhead a half-inch wider (side to side) than per plans. (Later install at the F28.35 position instead of F28).

 

Assuming your F28 is .5" wider than standard it will look a bit like that if you are placing it AT F28 instead of F28.35. A bit obvious perhaps, but I thort I'd mention the discrepancy.

Nice Pickup Spodman, but there still more issues.

 

My F28 is .5" wider. I also have a template that is standard width. Neither will fit were expected.

 

The first photo is where the .5" wider f28 fits naturally. This is WITHOUT the sides being squeezed the needed 1/4". It's fits at 7.5"

 

Photo two shows where the regular width F28 fits. It's pretty close to the where Wayne actually suggests.

 

It shouldn't take much trimming to get them to fit correctly. I think it just confirming that somehow the front portion of the sides didn't take the correct shape.

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Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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Drew, sorry to hijack your thread but this whole F28 thing got me thinking. Do you think it would be a good idea to not actually build F28 until chapter 6. Ie build the fuse then build F28 to fit at the 6.25" dimmension ?

 

This way I think I could cut the foam a little oversize then keep trial fitting it and trimming. At the point that it fits I can then glass it.

 

Just a thought.

Adrian Smart

Cozy IV #1453

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Do you think it would be a good idea to not actually build F28 until chapter 6. Ie build the fuse then build F28 to fit at the 6.25" dimmension ?

It's not a bad idea, maybe not a good idea either! :) ha ha

 

F28 is very easy to make. you could go ahead and do the layup, but wait for the trim. Do get all the flat layup done in CH4.

 

Tonight I finalized the fitting of the bulkheads. Tomorrow Spodman is coming over to help flox them in.

 

You can see from the webcam pic that I used three sets of braces to squeeze the sides. I had to squeeze the front by about 1/2" to make the outsides line up correctly. With the the braces, it was fairly easy to get it to fit. It does look like the sides did spring out somewhere along the line.

 

 

Back to Raiki's F28 thought. Now to make my f28 fit, I'll probably have to take a least 1/2" off f28. That may make the inner curve a little closer to the sides than the plans. I don't foresee this being a problem.

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Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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REQUEST

Would someone, please measure from the inside of one tip to the other on F-22? I would expect exactly 30" on a standard cozy. Also please confirm width of the IP. I've triple checked them, but would like to compare.

I measured, the same way you are measuring in the photo. I do not have 30", I have 29.75 inches.

Andrew Anunson

I work underground and I play in the sky... no problem

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Guys

 

I have been working on a 3D CAD model of the Cozy for a little bit using the plans and full size templates as my reference. I have stuck some dimensions on there to see how they compare with Drews. This is a stock cozy, stock widths and incomplete, but I hope it helps.

 

F28 is not on yet but I should do that shortly.

 

post-1445-141090160624_thumb.jpg

Adrian Smart

Cozy IV #1453

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Adrian that does help. Spodman & I floxed in the bulkheads tonight. My inner-to-inner measurement of the tabs was a little too much. The outside foam didn't line up. I had to squeeze it a little more. So it looks like it's dead on now.

 

We are both very please how well it went together. I have to say, Flox makes corner look real good. It fills in all the small gaps! :)

Drew Chaplin (aka the Foam Whisperer)

---

www.Cozy1200.com - I'm a builder now! :cool:

---

Brace for impact...

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