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WSBuilder

Well Known Member
Can anyone point me to a well-documented spar build website? My wing kit ships this week and it would sure help to stand on the shoulders of a giant!
 
The spars are pre-drilled. Really the only hard part about building them pounding the huge rivets that hold it together. I built both my -4 spars in a Sunday morning.
 
Couple of items

Bill,
1st check the size of the rivet holes with a rivet. Mine were drilled to the nominal size but all of them had to be drilled out to the correct size for the rivet. The time to discover this is BEFORE you clean and prime all the parts.

Of course, test fit the fueelage bulkhead before going very far.

Buy hardware store nuts/bolts and put them in all the holes that don't take a rivet. They all look the same after a while and it's easy to make a mistake.

Make sure the tiedowns go in the bottom of the wing and not the top :).

When riveting a thick and thin piece together, place the spar with the thin piece on the bottom. That way the pressure from the thicker pieces will help to hold them together. Inspect for gaps before you rivet and clamp if necessary. If you don't do this, you increase the risk of the spar strips spreading apart. Van doesn't seem to sweat this but the mil-spec says "not good".

I did mine with the Avery C frame tool and a 3 lb sledge. It was quite a project and it took me a bit longer than a Sunday morning :).

Lastly, go to Sam's site ( The RV jounral ) for nice pictures.

Good luck with your project.

John
 
John_RV4 said:
Bill,

It was quite a project and it took me a bit longer than a Sunday morning :).
John
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Great input. Thanks, John. I took the "Sunday morning" timeframe tongue-in-cheek. I think we have a scamp in our midst!
 
WSBuilder said:
Great input. Thanks, John. I took the "Sunday morning" timeframe tongue-in-cheek. I think we have a scamp in our midst!
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hey... it was a long sunday morning :rolleyes:

Edit:
Actually what takes so long? The rivet holes didn't need to be re drilled. The bulkhead is match drilled at the factory, no worries there. I just drew a line where the rivets were to stop. I primed the parts, set them up in order to be assembled, used "long" clecos to hold everything in line, threw on a few clamps to keep it tight and start riveting. I used a 3x rivet gun open ALL THE WAY. Set the tie-down up for drilling, drill it, bolt it... walk away. Must of been 5 hours for both.
 
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Spar Rivets

If you can find someone close that has a Big Nasty Squeezer like the one on my build site, it will really make your life much easier.

www.gen-aircraft-hardware.com/tom/plane_proj.asp

If you cant find one I can put you in touch with the guy I borrowed mine from. PM me if you like.

I think I gave him my 470-6 set when I gave it back, Hmmmm.

My pre-drilled spars came with kinda ugly #11 holes which is a good size if they are cleanly drilled, I had to clean them up to a #10, which is still acceptable for a 3/16" rivet, it will just take a little more squeeze and may leave the shop head towards the minimum height.

It really helped me to use an3 bolts of the correct grip to hold mine together, although they are not snug in the hole, it did keep them a little better aligned than than the commercial fully threaded screws.

I also definitely recommend putting washers under the head and nut of the bolts holding your spar sandwich together, my motto, donta scratcha my spars, hey! :cool:

Have fun, it was one of the more rewarding parts of assmbly for me.
 
No bounce...

John_RV4 said:
......................
I did mine with the Avery C frame tool and a 3 lb sledge. It was quite a project and it took me a bit longer than a Sunday morning :).

Lastly, go to Sam's site ( The RV jounral ) for nice pictures.

Good luck with your project.

John
Click to expand...

If you use the C-Frame, make sure it's on something solid and secure (such as a concrete floor... :) ...) and have an assistant holding the spar in place squarely on the rivet set.

The hardest thing is to make sure there is no "bounce" as you hit it with the BIG hammer....

gil in Tucson

I cheated and drove from LA to Bakersfield to see John Harmon and his "Big Bertha" floor mounted squeezer... I guess it's a little too far from TX... :D
 
If you use the C-Frame, make sure it's on something solid and secure (such as a concrete floor... ...) and have an assistant holding the spar in place squarely on the rivet set.

The hardest thing is to make sure there is no "bounce" as you hit it with the BIG hammer....
Click to expand...

Yep, you need to put on the kneepads and get on a concrete floor. I built some wood platforms to hold the spar level at the right height and handled it just fine solo. If you are having to wrestle the spar then you don't have everything set up correctly. It should just be a matter of sliding the spar from one rivet to the next. As has been mentioned earlier, use some bolts and clamps to make sure all the bits and pieces are lined up and tight.

It's like the old carpenter that told me one time as we were setting up some roof framing; "If your gruntin', you ain't doing it right".

The C-frame needs to be hit firmly! This will prevent any "bounce" of the rivet set. The method that worked well for me was two quick hits, the first to confirm my aim and the next to finish setting the rivet....sort of like pow, POW. I was really impressed at how nicely the C-frame set the rivets.
 
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