Which side is on top?

RVG8tor · #1 03-19-2008, 06:44 PM

I am nearing the point where I need to bend the leading edges of all of my tail surfaces, due to an injury I have not been able to do this task. I have been stewing over the process. One think I can't figure out from the instructions or the DWGs is which side ends up on top of the roll. On all of the pieces that need to be rolled there is one side slightly longer than the other side. The DWG shows an image of the shape of the roll but it does not say which direction the view is from, so you can't figure out what side is the top, perhaps it does not matter. Also the DWG on the rudder makes the rivet line appear to me in the middle of the rolled surface but when I did the small top section of the rudder the rivets will be offset from the middle. On one of the elevator DWGs it does show the rivets offset at the narrow end of the roll.

So to get to my questions, which flap goes on top the longer (my guess) or the shorter or does it matter? Will the rivets be centered on the rolled surface or will they offset to one side? Thanks for the help, I did a search for this but found no one with the same question.

Cheers

Bugsy · #2 03-19-2008, 06:53 PM

mine have longer flap overlapping the shorter and yes my rivets are centered .

pierre smith · #3 03-20-2008, 06:14 AM

.....make it easier, Mike. Be sure to hold the tubing down on the table firmly as you roll or you can end up with a sharp bend at the flat surface of the elevator....where the rolled portion transitions to flat.

Regards,

vmirv8bldr · #4 03-20-2008, 07:24 AM

If I remember correctly, the overlapping part should prevent water from seeping into the elevator (same goes for every other piece of overlapping skin on the whole plane.) So, you know which is left (trim tab) and which is right. Based on their orientation on the HS (control horns point down), the upper most flap of skin overlaps the lower, so water would roll off without seeping into the overlap when rolled and riveted together.

That doesn't help much for the rudder, but you should see a paradigm and be able to follow it to the rudder.

Hope that helps,
Bart

RVG8tor · #5 03-20-2008, 08:28 AM

Quote:

Originally Posted by vmirv8bldr

If I remember correctly, the overlapping part should prevent water from seeping into the elevator (same goes for every other piece of overlapping skin on the whole plane.) So, you know which is left (trim tab) and which is right. Based on their orientation on the HS (control horns point down), the upper most flap of skin overlaps the lower, so water would roll off without seeping into the overlap when rolled and riveted together.

That doesn't help much for the rudder, but you should see a paradigm and be able to follow it to the rudder.

Hope that helps,
Bart

Bart,

Why I did not try to apply logic to this is beyond me, I do it it most other parts of my life. What you say makes total sense, once I look at how this works on the elevators it should shed light on whether the long or short flap ends up on top.

Thanks to everyone for the tips.

Cheers

Pirkka · #6 03-20-2008, 11:55 AM

Quote:

Originally Posted by vmirv8bldr

That doesn't help much for the rudder, but you should see a paradigm and be able to follow it to the rudder.

At least in RV-7 case the rudder has no options to choose from. Only one has pre-punched holes (would this been the case with elevator as well?) and another skin has 90 degree bending to keep it more straight which obviously can't go anywhere else than "bottom".

RVG8tor · #7 03-20-2008, 01:09 PM

Well after taking the logic that Bart pointed out, it seems that the longer of the two flaps goes on the bottom. On my elevators the short flap is the one on top of the elevator so that is the one you want on top of the roll so that water does not run into the elevator and pool up. The rudder does not have this issue but I assume it is designed to have the short flap on top of the roll.

I hope this answers this question for others out there in RV land.

Cheers