VS/HS intersection bracket ?

[alpinelakespilot2000]

Currently fitting my VS to the fuselage.

1. I've bolted the rear spar to the rear elevator stop the correct vertical distance from the bottom rudder hinge bracket to the top of the longeron. However, I cannot determine (from the plans or dwgs) the proper vertical position of the forward VS spar where it meets the bracket bolted to the HS. If you look in the picture below, you'll note that the forward spar is as far down as I can put it without the bracket trying to overlap the VS rib flange. It fits well enough where it is at, but the VS rear spar flexes enough that I could lift it up or push down the VS forward spar a little in either direction if I wanted. Since the plans called for trimming the bottom of the VS spar, I'm surprised the spar is as high off the HS spar as it is. Am I missing some callout on the plans? How do I determine where it should fit?

2. Also, am I correct in assuming that if I center the bracket in the VS spar web then I will have the correct offset on my VS? Is there some other correct way for determining the offset (aside from the extra washers that I will be putting on the rear spar)?




Thanks.

 

[Finley Atherton]

Steve,

Question 2. I asked Vans this exact question. Their answer:

Yes, center the F-981 plate on the front spar web. This will give
you the proper VS offset.

Fin
9A
Australia

 

[Finley Atherton]

Steve,
It is a while since I did this, and without looking at the plans, I think the idea was to put a straight edge on all three rudder brackets. When they are in-line, the rear spar is straight and this will determine the position of the VS fwd spar. As I said this is all from memory.

Fin

 

[n2prise]

Installing vertical stabilizer...

I noted that my RV-9A photos and text did not get into the details of this step in the VS assembly to the fuselage and horizontal stabilizer. I did get a good page on how it is done when helping a friend build his RV-8. I also mention in that text the differences in the RV-8 VS alignment and the RV-9A. Check out this page and you should get the idea.

http://www.n2prise.org/wfrv8018.htm

And yes, the forward spar of the VS is cut to length. You can see how mine was cut and installed in a photo on my construction page.

http://www.n2prise.org/rv9a031.htm

I hope that answers your questions about putting on the tail feathers to these fine birds.

Jerry K. Thorne
East Ridge, TN
RV-9A N2PZ
Hobbs = 210.2 hours

 

[alpinelakespilot2000]

Thanks for the help Finley and Jerry.

Jerry, yesterday I did a search and used some of a very lengthy and informative post you did a long time ago commenting on how you set the HS and a little bit on the VS (minus forward spar info.). I really appreciated that detailed write up. Thanks.

Also, one other question. My plans indicate that the extra washer is used primarily to compensate for the VS offset. Is the extra washer just used at the elevator-stop bracket? That's the only extra one I see on the drawings, but it seems logical that there'd be another extra washer on the very bottom left side of the VS spar where it bolts onto the lower-most part of the bulkhead.