No Fuse center secton w/ old wing kit

I just bought a partially completed RV-4 empennage and wing kit. The person I bought it from is not the original builder and it the kit was built from plans (his 2nd RV-4 build). I have been reading some websites and it appears that I should have a fuselage center section that is matched drilled to the spar. I do not have that part.

On RV-4 kits is this going to be a big issue? Is there some way to get a center section that would work?

I jumped on a good deal for a mostly finished kit (right wing needs to be skinned, fuel tanks almost finished). I had no idea that this could be an issue until I started reading some more in depth RV wing construction websites.

Thanks,

Branden

Shouldn't be a huge issue; check with Van's and see if they can sell you the parts undrilled and then match drill them to what you have. You might also want to check as you proceed with the fuselage kit that the method of joining the wing at the rear spar and fuel tank has not changed significantly and adjust accordingly. Having mated 1993 kit wings to a 2003 kit fuselage I can tell you that that is almost a non-event. Your biggest problem will be aligning and drilling the wing-to-bulkhead holes for the main spar. The kits pretty much assume it is drilled correctly (at close tolerance) from the factory so you don't get any positioning info. The plans for the plans-built should have that but if you don't have them then you can probably get it, again from Vans. The other big problem you're going to have is that it will be next to impossible to get the spar in a drill press so you will have to rig up some kind of drilling fixture. Remember, the bolts here are close tolerance, so you want to drill undersize and ream to final and I wouldn't trust doing that free-hand. Sounds tough but the RV line started out plans-built so it's not impossible at all.

I have dealt with a similar situation myself and upon considering the options I spoke with Vans who recommended me to phlogiston about recreating my original... $470 labor plus parts. Luckily I ended up not having to have this done.
Good luck

Branden,

As far along as you say your wings are, I assume the root ends of the spars have already been drilled for bolts? If that is the case and Van?s won?t sell you undrilled bulkhead parts, Rocket II parts from John Harmon will work fine. Go to www.harmonrocket.com and click on PARTS/MATERIALS Order & Pricing
HRII.

The HRF404A&B uprights are identical to Van?s F404A&B other than not being pre-drilled. The (undrilled) HRF404C&D crossmembers are identical to each other (buy two) and are 3- ? inches wider but identical in every other way to Van?s F404C&D. It would be an easy job to trim them per RV-4 wing plans. The F404E side plates can be fabricated from flat stock per plans, or possibly purchased from Vans. Even if they are predrilled, that would be OK as they just tie the front/rear uprights together and don't interface directly to the spar. The W-420 steel splice plates might be a bit more difficult but there?s enough info on the RV-4 plans to fabricate, match drill, and have them heat treated.

To match drill the raw bulkhead parts to your spars, you?ll need enough shop space to clamp both spars in their final position relative to each other. My shop was long enough that I moved the workbench to the center of the shop and clamped the spars and bulkhead parts flat to it for drilling. That might be a bit trickier with completed wings but should be very doable.

Hope this helps, and let us know how it goes.

Miles

Thanks for all the info. The spars almost look like their from Van's because I can see the "L" and "R" stamp on the inboard ends of each of the aluminum spars sandwiched together. I have already arranged some of the local RV guys to come and inspect the kit and what I have so far.

With their help and this board I am sure I can get through this snafu.

Thanks again,

Branden

Resurrecting an old thread here. Facing a similar situation. Has this been successfully completed? Details would be appreciated.
Thanks, Tom