RV-8 vs. RV-7 horizontal stabilizer

RobinHou · #1 08-11-2009, 03:02 PM

I just brought a used RV-8 tail kit with tools. The seller completed the horizontal stabilizer before he quit. But what I really want to build is a RV-7. Looking at the plans it seems that only the horizontal stabilizer and rudder are different between RV-8 and RV-7. I can order a RV-7 rudder. But can I modify my completed RV-8 horizontal stabilizer for RV-7? What is involved in the modification?

Thanks in advance.

rbibb · #2 08-11-2009, 03:51 PM

The center section of the RV-7 stabilizer has to be wider as the fuselage is wider on the -7 than the -8. Think of the angle the fuselage makes from the rear to just behind the seats. On the -7 it is a greater angle (taper) than on the -8.

The center attachment between the forward spars has to be different as well.

I suppose you could start with one and end up with the other but if it were me I'd sell the kit and buy the correct one. The time and effort to modify one would more than eat up any additional costs.

The rudder/fin would probably be almost inter-changable but without having both sets of plans to compare it is hard to say.

msturgis · #3 08-11-2009, 05:30 PM

Quote:

Originally Posted by RobinHou

I just brought a used RV-8 tail kit with tools. The seller completed the horizontal stabilizer before he quit. But what I really want to build is a RV-7. Looking at the plans it seems that only the horizontal stabilizer and rudder are different between RV-8 and RV-7. I can order a RV-7 rudder. But can I modify my completed RV-8 horizontal stabilizer for RV-7? What is involved in the modification?

Thanks in advance.

Sent you a PM.

rbibb · #4 08-11-2009, 05:36 PM

Wasn't there some guy that wanted to go the other way on here recently?

I sense a trade in the making....

msturgis · #5 08-11-2009, 05:38 PM

Quote:

Originally Posted by rbibb

Wasn't there some guy that wanted to go the other way on here recently?

I sense a trade in the making....

Yeah I would entertain it.

Craig23 · #6 08-11-2009, 07:53 PM

The only thing I saved from my RV-7 HS after I finished it was the rear spar assembly. Everything else had to be redone. The skins, ribs, main spar, etc. were all different because of the different sized gap in the center of the HS. It wasn't that bad, and far easier than some of the later parts of construction on my slow-build 8.

ryanturner · #7 08-11-2009, 08:24 PM

Quote:

Originally Posted by rbibb

Wasn't there some guy that wanted to go the other way on here recently?

I am the guy who is thinking about going the other way (RV-7 to RV-8). It is a big change, so I am still considering my options.

Ryan

ryanturner · #8 08-11-2009, 08:28 PM

Quote:

Originally Posted by RobinHou

I just brought a used RV-8 tail kit with tools. The seller completed the horizontal stabilizer before he quit. But what I really want to build is a RV-7. Looking at the plans it seems that only the horizontal stabilizer and rudder are different between RV-8 and RV-7. I can order a RV-7 rudder. But can I modify my completed RV-8 horizontal stabilizer for RV-7? What is involved in the modification?

Thanks in advance.

I would send an e-mail to Vans and ask there opinion. I recently inquired about a similar change. I am about to finish the RV-7 HS and want to switch to the RV-8. Van's said that I could just purchase the parts for the RV-8 HS and RV-8 rudder, but it would be cheaper to buy the RV-8 tail kit.

Ryan