View Full Version : Spars, and other questions

08-17-2008, 07:53 PM
I have a RV-4 wing kit sitting in my hanger. Some work has been started, but not alot. I figure, if i'm gonna build something as involved as an RV4, why not a HRII instead? I have a couple questions BEFORE I pop $150 on plans.

1. The kit I have has pre-built spars, with holes already in them for the ribs. Is that a problem for the HR wing (which I thought put all the ribs closer together)?

2. Is there any policy to mix/match of tailfeathers? I know both RV-4 and RV-8 tailfeathers work, the -4 HS and elevators are fine, but the VS is in need of a rebuild, so I was thinking about doing an -8 VS and Rudder... any comments?

I assume if I bought the plans it would clear up alot of these questions, but if it's too much to turn this -4 into a rocket, I'll just keep going with the kit as is. maybe just widening up the fuselage with those HR parts :).

08-18-2008, 12:16 PM
I used Phlogiston spars in my RV-4 kit turned Rocket. Having the rib locations established is no big deal to change; just drill out (very carefully) the rivets you want to and move those ribs to the nearest set of holes; and rivet the holes where the ribs aren't. Also the forward doubler with flanges that mount the fuel tank gets extended; in my case I just added a piece (the perfect way to deal with this would have been to replace the entire doubler with one-piece; but that would entail drilling out and replacing all those rivets; I considered this too risky). Then cut off the extra spar on the outboard ends.

I can't help you on the tailfeather interchange questions. I can say that I'm sticking with RV-4 tailfeathers with the change of skin thickness (per plans) and the addition of a counterbalance on the rudder.

I don't think purchasing the plans will answer many of your questions; they don't offer much information. If you decide to go with the Rocket, you'll just have to dive in and go for it ..... but don't worry, the water is fine :-).

08-18-2008, 11:48 PM
Well, I guess a diving I'll go then. I can't see NOT building a rocket at this point. :D