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Assemble Fuselage per plans or upside down?


CFernandez

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I split this topic into its own discussion.

 

Okay, upside down looks good, but why exactly is it better? I don't know of anyone who's actually gone through both techniques, so all I have to go on is Wayne (who's experience I certainly value and respect) and several others who say "it's better". Is it that the jigging is easier? Easier access to most areas needing BID tapes? Specifically, what?

 

Here's what Wayne says on his web site:

 

What better way to keep the upper longerons nice and level than to put them against a flat, level surface? Logistically, jigging upside down is easier and I was able to guarantee level longerons without futzing with the jigging set-up. It was very simple and very reassuring to walk around with a square and spot-check things to ensure all bulkheads, centerlines, and perpendiculars were where they needed to be.

Definitely sounds good -- I like the thought of using the squares against the flat & level surface.

 

Ideally I would locate a door I could use for this... which, come to think of it, I have one I'm using for my mini-shop in the basement.

 

For those that don't have a door, or a shop table that can be taken to the floor, or don't want to climb on top of their table, the per-plans route still looks to be the best.

Jon Matcho :busy:
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Now:  Rebuilding Quickie Tri-Q200 N479E
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I'm trying to figure out how to do it without cutting a slot. Here's what I have in mind:

  • Temp firewall hangs over edge of table, instrument panel is not mounted.
  • (need to compare next w/plans procedure, but...) mount aft LG bulkhead
  • mount forward lower LG bulkhead
  • mount forward upper LG bulkhead
  • mount seatback
  • mount F22 (skipping instrument panel)
By now, the whole assembly should be stiff enough to proceed with the following...

  • remove temporary firewall, and setup to overhang instrument panel over workbench
  • mount instrument panel
  • mount permanent firewall
The only worry is setting the permanent firewall to be perpendicular to the longerons. A slot would definitely be easier so the whole assembly would remain in place. I'll take a look at that spare door I have...

Jon Matcho :busy:
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Now:  Rebuilding Quickie Tri-Q200 N479E
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I did mine right side up.

 

I have a one foot thick table top with no legs. I use saw horses to support it. Instead of saw horses, I set it directly on the floor and made it level. Then, I attached the 2x4s and drew a centerline. I clamped F22 and the temporary firewall in position to level the longerons. Once clamped, the longerons stayed level for the rest of the process. I didn't find it difficult to make sure they were in the same plane. I was able to check for level lengthwise along the longerons and also diagonally across the fuselage.

 

Since I had a flat table reference plane, I was able to use a square on the table to make sure the bulkheads were vertical. So, I went against the latest trend in fuselage assembly and did not encounter any problems. There are a lot of claims that it is easier to do it upside down, but few people have done it both ways. So, it is just an opinion. I had to attach a couple 2x4s to my table instead of cut a hole in it (and repair it later). After that, I don't think the workload is any different. So, I would argue it is easier to do it my way.

 

(Alright, I'm going to go hide from Wayne now.)

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I installed all bulkheads except the IP and F28 upside down. I didn't want to cut the table. After cure and tape I flipped the whole thing over and installed the IP and F28.

 

Upside down also allows you to hang the LG bulkheads on the bottom longerons and they set there.

 

The plans way seems like a balancing act. I'm sure it works fine but I knew that the longerons were level with checking them once or twice because the table they were on was level.

 

It seems to me less jigging is involved with the upside method.

 

Thanks Wayne.:)

Carlos Fernandez

AeroCanard FG

Plans #206

Chp. 13

aerocanard.kal-soft.com

Sales & Support

GRT Avionics

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I installed all bulkheads except the IP and F28 upside down. I didn't want to cut the table. After cure and tape I flipped the whole thing over and installed the IP and F28.

So, basically you had to jig the fuselage for both the upside down method and the right side up method. So, there is extra work involved.

 

Upside down also allows you to hang the LG bulkheads on the bottom longerons and they set there.

This wasn't a factor since I would never depend on gravity to hold the bulkhead in place during cure. The landing gear bulkheads were clamped in position during cure with the appropriate spacers.

 

The plans way seems like a balancing act. I'm sure it works fine but I knew that the longerons were level with checking them once or twice because the table they were on was level.

Well, another factor is that I knew my table wasn't perfectly flat. It is within plus or minus 1/16" over 12 feet, but not perfect. There is also a slight twist to it. By assembling right side up, I didn't need to worry about it. If your table is perfect, then you won't have this problem.

 

Thanks Wayne.:)

I second that! But, I don't have to adopt every suggestion on his web site.

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So, basically you had to jig the fuselage for both the upside down method and the right side up method. So, there is extra work involved.

 

Not really, after it was taped and cured the fuse was pretty rigid. I checked it right side up but just floxed and taped the bulkheads in.

Carlos Fernandez

AeroCanard FG

Plans #206

Chp. 13

aerocanard.kal-soft.com

Sales & Support

GRT Avionics

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I still haven't decided, but may get to it this weekend. Another question I have regarding the plans method is whether the 10' 2"x10" board is susceptible to warping or twisting? Let me rephrase -- wood standing alone practically always warps. Since assembly on the jig will take many days, how much is this a problem?

 

If anything, this would be another case for the upside-down-on-the-table method.

 

Thoughts?

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I still haven't decided, but may get to it this weekend. Another question I have regarding the plans method is whether the 10' 2"x10" board is susceptible to warping or twisting? Let me rephrase -- wood standing alone practically always warps. Since assembly on the jig will take many days, how much is this a problem?

 

If anything, this would be another case for the upside-down-on-the-table method.

 

Thoughts?

I have the same question - my 10'x2"x10" was nice and straight when I bought it two weeks ago, and it's been laying on the basement floor, but I can see that it is not as perfect as it was. I'm still working on the sides, so it may be a few weeks yet before I get to Chapter 6... :scared:

Phil Kriley

Cozy #1460

Chapter 13 - nose

Right wing done - working on right winglet.

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I think the best answer is to NEVER trust the 10' board to be straight. Just create the jigs and setup to be able to clamp so that the structure is level. When you're ready to do the assembly, do it as continuously as you can and don't let it sit there waiting for taping for weeks.

 

Still not sure how much this is going to impact me -- need to read through the plans here once again.

Jon Matcho :busy:
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Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I still haven't decided, but may get to it this weekend. Another question I have regarding the plans method is whether the 10' 2"x10" board is susceptible to warping or twisting?

 

My modification of the plans method did not involve a 2"x10" board. I assembled on top of my table, which I lowered to the floor. I just drew a centerline down the table and then attached the 2x4s to it.

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I might do the same, except for lowering the table to the floor. I'll just dance around on the top of the table. Heck, I already have a leg up by having a centerline already drawn on my table. :rolleyes:

 

Seriously, still up in the air. Maybe I'll actually make a decision tonight.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I like the idea of doing this on top of the table (either upside-down or rightside-up), to avoid any concerns about the 10' board warping (or even needing to buy one).

 

My only concern is how easy will it be to get up on the table and do the work. My table cannot be lowered to the floor. I know others have done exactly this, so it cannot be that bad.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I like the idea of doing this on top of the table (either upside-down or rightside-up), to avoid any concerns about the 10' board warping (or even needing to buy one).

 

My only concern is how easy will it be to get up on the table and do the work. My table cannot be lowered to the floor. I know others have done exactly this, so it cannot be that bad.

Well whatever you do, I'm glad you're going first so you can tell me how it went! :D My workbench is 4x12 and also cannot be lowered. I've already bought the boards for doing the jigging on the floor, but eagerly await your report as to whether or not you did it upside down and whether or not you stood on your table or moved it to the floor.

 

I expect to glass the inside of the sides this weekend... :yikes:

Phil Kriley

Cozy #1460

Chapter 13 - nose

Right wing done - working on right winglet.

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My workbench is 4x12 and also cannot be lowered.

Same dimensions as mine.

 

I've already bought the boards for doing the jigging on the floor, but eagerly await your report as to whether or not you did it upside down and whether or not you stood on your table or moved it to the floor.

I'm leaning towards doing it on the table, eliminating the need for the 10' board, and doing it either up-side down or up-side up. (;) I'll get back to you on that)

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I gave a look through my Long-EZ plans for how it's done there. The jigs are similar, BUT the Long-EZ plans don't use a 10' board on the floor. Instead, the 2x4s are mounted onto the table AND the fuselage is assembled upside down on the table.

 

I think Nat, having built a couple canards, saw that it was easier assembling the fuselage on the floor. He may also have thought that assembling right-side up was easier, for whatever reason (easier access to the upper longerons to check level?).

 

I spoke w/a builder about this last night as well, and he convinced me that it's definitely going to be easier doing the assembly on the floor instead of high up on the table.

 

So... I'm now planning to buy a 10' 2"x10" board (apparently a 10' 2"xanything is fine as well) and assembling on the floor. Upside down or up is the only question now, which I'll decide... soon.

Jon Matcho :busy:
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Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I am assembling per plans, on the floor. The only change I made was to use a 10' 2"x6" board instead of a 2"x10" "plank". Looking at it, a 10' 2"x4" would have been perfectly fine as well, if not better.

 

No disrespect to the upside down method, but I'm now a firm believer that the per-plans right-side up approach is best. Having the longerons on top makes it easy to check level, and why twist your mind with having to change measurements.

 

Follow the plans and you will not go wrong.

post-386-141090154456_thumb.jpg

Jon Matcho :busy:
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Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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I'm now a firm believer that the per-plans right-side up approach is best.

 

-----> How does one know "it's best" until one tries both methods? I started "per plans" and quickly abandoned it and proceeded upside down. The key is there's no jigging upside down. Just a level table guarantees level longerons. And...the dimensions are on my website. This isn't a slam. Certainly many, many fuselages started right-side up per plans. So it certainly works. It's a personal choice. Amy can still ride in my plane any time. :)

Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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This isn't a slam.

Of course not! And vice versa.

 

The key is there's no jigging upside down. Just a level table guarantees level longerons.

Taking your table top off, cutting a slot in it, and putting it on the floor IS jigging. For me, the best option I had was to invest in a $5 board and use the scrap 2x4s I had lying around.

 

Amy can still ride in my plane any time. :)

Ohhh yeah! Thanks SO much for that. I just broke through a mental barrier last night and updated my web site (even though I still have a chunk of prior-chapter progress to get on there). Next up is to write-up that visit, w/pics and the cheap video I have from my camera.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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Taking your table top off, cutting a slot in it, and putting it on the floor IS jigging.

 

-----> Nope, that's "set-up." :) , which took only 5 minutes. Jigging is never done in 5 minutes. Jigging is herding cats. Jigging is building that contraption to assemble the fuselage right-side up. Then ensuring each end of this contraption stays level and don't twist on you as you twist and pull on the sides.

Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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Nope, that's "set-up." :) , which took only 5 minutes.

Come on now, you're exaggerating. I'm sure it took you at least 7.

 

Then ensuring each end of this contraption stays level and don't twist on you as you twist and pull on the sides.

I test fit everything, except the instrument panel and F28, upside down on my table. When moving to the assembly jig the sides fit easily into the temporary firewall, and rested on the forward 2x4 jigs until I went there and leveled and squared the front. I was able to do everything I needed by myself and never once cursed the jig or thought of it as a 'contraption'. Nice word though. :)

 

I have no problem with either way. I just chose the route I felt was best suited to my situation.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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