Wing Jig Question

[johnb]

Hi guys, I'm wrapping up my spars and preparing for wing assembly. I'm curious how others are securing the spar tip / tip rib to the build jig. I've seen a lot of pictures using the wing attach holes for the root end alignment, but not much on aligning and securing the tip.

Since the tip rib is full length, and outboard of the spar, it seem I'll need some kind of an arm which will go through a lightening hole and up to the spar.

I have a few ideas, but any pictures or thoughts for how others have done this would be appreciated.

I'm working on an LSA, but the solution should be applicable to all models.

Thanks,
John

 

[mswain]

Initial setup I used some angle steel and wood through the lightening holes. When riveting the tip rib on I added a piece of (.04?) aluminum angle I made facing outboard. I used the angle for the remainder of the build. They are now useful for holding the wings in the storage rack while I finish my fuselage. They will be hidden inside the wingtip. I only have a crappy pic.

i tensioned a piece of stainless wire Between my jig uprights high enough to clear the nose ribs. this became my reference point for the build. I check the distance between the wire and main spar web/rear spar web before each day of work to ensure the spars were aligned.

 

[Chewie]

I was planning to use Enewton57 's method in the build manual and construct a little arm reaching from the post through the lightening hole and up to the spar with a C clamp. If memory serves, that support will be 1/4" higher than the root support because of the main attach plate build up.

 

[BTAZ]

I used Eric's method. Can be seen in the attached. Make sure whatever clamp you use inside the wing can come back through the lightening hole

 

[johnb]

Thanks guys, that confirms what I was thinking.

 

[Russellmn]

I was just looking through the Patrol Book that came with my plans, looks like Bob recommends assembly of the spars to ribs flat on the table and then moving it to the vertical jig for skinning? I can see the appeal to doing it all in the vertical jig, but kinda like the idea of building it out on the table first. Anyone have pros/cons on this?

 

[marcusofcotton]

I used the tabletop method and would do it again if I we're to be a repeat offender. Seems like it would be easier with a large, true, solid, supporting surface to work on.

 

[BTAZ]

One advantage to the "vertical method" is if you want to do both wings at the same time. Takes up much less floor space and building both wings at the same time is going to be more efficient.

You will need a lot(like more than 1K) clecos if you want to skin both wings at the same time.

But most skins can be cut to size and drilled two at a time.

If you haven't seen it, my LSA scratch built build log links can be found in the "First flight" link in the LSA forum section. Might not always represent the "best" way to do something but it does represent one way to get to a finished, flying airplane

 

[Russellmn]

BTAZ thanks, I'll take a look through your build.

 

[Chewie]

You will need a lot(like more than 1K) clecos if you want to skin both wings at the same time.

So you must have a bunch to pass on?

 

[BTAZ]

I have always found it hard to resell tools once acquired....

The LSA has been flying for three years now and there is an RV 9 tail kit in my garage.

Clecos are not something I will be short of

 

[Russellmn]

I've had a few members of my EAA chapter offer to loan me tools and clecos, I should be good. I have a few hundred already, but building hot rod stuff never needed nearly that many...

 

[stinger]

Johnb, do not go by booklet page 17 not if your building the Riblet wing, use Mylar sheet only to establish cord line. Do not align mounting bolt holes. The hardest task in building the wing is keeping the spars from sagging in vert. jig. Stinger

 

[davzLSA]

Hey Brad you do know that having tools like that lying around will always give you a REASON to build another airplane? Be careful!!

 

[johnb]

Stinger,
Thanks for the pictures. It's helps visualize the relationship between chord line and spar flanges. I had not yet checked dimensions to see if the root bolt holes were the same distance from the chord line, it's clear from your pictures they won't be.
Thanks,
John

 

[BTAZ]

Hey Brad you do know that having tools like that lying around will always give you a REASON to build another airplane? Be careful!!

As mentioned, I have an RV 9 tail kit in my garage waiting for me to finish up some other projects.

I think it is going to be strange having a set of instructions to follow....