Van's Air Force
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Spar Carry-Through Section
- Thread starter Av8torTom
- Start date
cln1owner
Well Known Member
If you talking the wing spar bolts, they are close tolerence and should only be used to attach the wings for the final time. A trip to the hardware store is in order for standard size bolts that are cheaper and that will serve as your "guides" for assembling the center section and fitting the wings for the first time.
Take a standard hardware store bolt of the correct size and grind down the threads a bit so they won't scratch the inside of the bolt holes on the spar. Use those for all fittings up until the final time the wing goes on for good, that's the only time you will use the spar bolts supplied in the kit.
Av8torTom
Well Known Member
Update
OK, so I got some 7/16" and some 1/4" bolts, and they are WAY too loose - there was NO WAY they would be ANY use for aligning anything, so I used the supplied NAS1307 and NAS1304 bolts and tapped them in slightly with a poly hammer. They were easy to tap out with a drift from the other side.
Got everything riveted-up nicely.
OK, so I got some 7/16" and some 1/4" bolts, and they are WAY too loose - there was NO WAY they would be ANY use for aligning anything, so I used the supplied NAS1307 and NAS1304 bolts and tapped them in slightly with a poly hammer. They were easy to tap out with a drift from the other side.
Got everything riveted-up nicely.
Last edited:
Bolt issues.
I've come across the same problem myself now. Fusleage first, no NAS1307 bolts to hold the F-704 pieces together with. I bought some at the hardware store that said they were 7/16 but obvious that the measurement wasn't the same. Where do you get the right size? Is this a fit if you get an automotive 7/16 bolt?
Confused and at a standstill with progress.
Tom
Empennage done, fueslage started, Cessna bought (need to have something flyable!)
I've come across the same problem myself now. Fusleage first, no NAS1307 bolts to hold the F-704 pieces together with. I bought some at the hardware store that said they were 7/16 but obvious that the measurement wasn't the same. Where do you get the right size? Is this a fit if you get an automotive 7/16 bolt?
Confused and at a standstill with progress.
Tom
Empennage done, fueslage started, Cessna bought (need to have something flyable!)
sbalmos
Well Known Member
Tom, if you used the close-tolerance bolts meant for the final wing attachment, you'll probably want to order new ones down the road when doing actual wing attachment. You've now whacked the bolts into their interference fit, probably rubbing off "just enough". Just reiterating the collective sentiment of previous threads in the archives, so don't question me further on the logic of this.
BTW, I went up to Lowes when I came to this point in the build last year, and had no problem finding close-tolerance 7/16" and 1/4" hex bolts to use. I forget whether they label them Grade 8, or Grade whatever. But they're there, in the store. Not the same as standard 7/16" bolts.
BTW, I went up to Lowes when I came to this point in the build last year, and had no problem finding close-tolerance 7/16" and 1/4" hex bolts to use. I forget whether they label them Grade 8, or Grade whatever. But they're there, in the store. Not the same as standard 7/16" bolts.
The bolts I found at the hardware store fit fairly well, but I didn't have to pound or oil then to get them in. I then used a lot of clekos in most of the holes as well as a clamp and two 1/4 inch bolts from the kit to drill the two rivet holes in the F-704G parts.
Is that close enough? I haven't match-drilled any other holes yet though, maybe I need to find bolts that are tighter before doing that?
Tom
Is that close enough? I haven't match-drilled any other holes yet though, maybe I need to find bolts that are tighter before doing that?
Tom
Close Tolerance Bolts
I suspect your problem might be that the holes in the sheet metal former are slightly misaligned wit the holes in the spar. How is the bolt fit in the spar when the formers are not included in the assembly?
Open up the holes in the former just enough to eliminate the interference. The close tolerance bolts should go in with some light tapping and be re-usable when you are done. My theory is that by dealing with this issue now the wing install will require a slightly smaller hammer. This is just a theory as my wings are still in the cradle
I suspect your problem might be that the holes in the sheet metal former are slightly misaligned wit the holes in the spar. How is the bolt fit in the spar when the formers are not included in the assembly?
Open up the holes in the former just enough to eliminate the interference. The close tolerance bolts should go in with some light tapping and be re-usable when you are done. My theory is that by dealing with this issue now the wing install will require a slightly smaller hammer. This is just a theory as my wings are still in the cradle
wirejock
Well Known Member
F-704 C&D
Tom
On my kit the spar bolt holes in the C&D plates were just a hair off perfectly aligned. It caused the bolts to bind to the point they wouldn't go in. I called Vans about it and was told it was ok to polish or file the C&D plate bolt holes as long as the wing and center sections were not touched. I only removed a tiny bit where they were in a bind. It made all the difference. Bolts are still interference fit but they don't scrape on the C&D plates going in or out.
Tom
On my kit the spar bolt holes in the C&D plates were just a hair off perfectly aligned. It caused the bolts to bind to the point they wouldn't go in. I called Vans about it and was told it was ok to polish or file the C&D plate bolt holes as long as the wing and center sections were not touched. I only removed a tiny bit where they were in a bind. It made all the difference. Bolts are still interference fit but they don't scrape on the C&D plates going in or out.
DaleB
Well Known Member
I had a Spruce order about ready so I added some longer AN4 and AN7 bolts to it for temporary use with the center section. They were fairly cheap, not much (if any) more than good quality hardware store bolts. I also discovered that the length designations for close tolerance and regular AN bolts are different. That's the great thing about standards, right? There are so many to choose from.
So the only holes I drilled were the two deep rivet holes through the F-704G blocks. Are the 7/16 holes slightly out of line if I put in a bunch of clekos to hold it? Seems that if they were all properly drilled at the factory it should average out to a good fit.
But then if it does need some ajustment, sounds like it's ok to gently polish the edges later if needed when putting the wings on.
I'm sure I'm probably making this a lot more difficult and worrying too much over this! I just sometime fear a slight issue could turn into a huge problem later.
I should just bring my digital caliber to the hardware store and look for the closest 7/16 bolt I can find maybe.
Tom
But then if it does need some ajustment, sounds like it's ok to gently polish the edges later if needed when putting the wings on.
I'm sure I'm probably making this a lot more difficult and worrying too much over this! I just sometime fear a slight issue could turn into a huge problem later.
I should just bring my digital caliber to the hardware store and look for the closest 7/16 bolt I can find maybe.
Tom
N941WR
Legacy Member
Exactly what I used. However, I cut the threads off and l chamfered the ends. You only need eight of the big bolts.
I don't have the wing kits, so I don't have those bolts. No worry about needing new ones after using them.
I'll look for some Grade 8 bolts at the hardware store and try those out - grinding them down on the threads if needed. I did drill the match holes on the F704G blocks holding with a bunch of clekos, a clamp and two 1/4 inch bolts from another part of the build. I'll get some properly fitting bolts before I match drill the rest of the rivet holes.
Thanks for the advice, how could anyone build a plane without sites like this?
