Rudder AEX angle

[tsw94r]

1st time poster

I am working on installing the AEX on the TE
I have clekoed the skins, aex and Alum angle together and have noticed that the AEX strip has a steeper angle than the angle of the skins. This is causing the trailing edge of the skins to leave a gap between the AEX and skins at the TE.
This tail kit is an older kit, 2008

Is this normal or has the AEX changed over the years?

Thanks, Tom

[wirejock]

Originally Posted by tsw94r

1st time poster

I am working on installing the AEX on the TE
I have clekoed the skins, aex and Alum angle together and have noticed that the AEX strip has a steeper angle than the angle of the skins. This is causing the trailing edge of the skins to leave a gap between the AEX and skins at the TE.
This tail kit is an older kit, 2008

Is this normal or has the AEX changed over the years?

Thanks, Tom

Welcome Tom
Order a new AEX wedge just in case and compare the two.
If you plan to tape or proseal, the gap may be a good thing.
I used proseal.

[tsw94r]

Thanks Larry,
I am planning to use pro-seal, but shouldn't the TE be a fairly sharp edge?

I also saw in another post about an elevator using the AEX, has this changed or just not for the 7

If somebody could measure the angle of their AEX I could compare mine and decide if I just need to order a new one.

Tom

[tsw94r]

I measured about 12 degrees on the AEX and about 8 Degrees on the rudder skins. I have the ability to machine the AEX to match the rudder skin angles. I can also just order another AEX, but if 12 degrees is correct, there is no point ordering and if it is supposed to 12 degrees I guess it was meant to be this way for a reason.

Any input or verification would be helpful.

Thanks in advance, Tom

[wirejock]

Originally Posted by tsw94r

I measured about 12 degrees on the AEX and about 8 Degrees on the rudder skins. I have the ability to machine the AEX to match the rudder skin angles. I can also just order another AEX, but if 12 degrees is correct, there is no point ordering and if it is supposed to 12 degrees I guess it was meant to be this way for a reason.

Any input or verification would be helpful.

Thanks in advance, Tom

I can't get an accurate measurement on the wedge edge but if I look really close, it does appear the wedge is slightly wider. Nothing anyone would see and you need the width to correctly set the double flush rivets.

The 7(a) only has a wedge on the rudder. There are other models with wedge edges other than rudder. Be glad you only have the rudder.

Yes, the edge is the thickness of the edge of the wedge plus the two skins.

[tsw94r]

Thanks again Larry,

I do think I may be over thinking the process. I calculated the gap and it works out to .0131" (not even a 64th) between the AEX edge and either skin. I think I will continue on.

Maybe this is why it has taken 8 years to get to this point.

Tom

[Lionclaw]

The -9 and -10 have wedges on all control surfaces, so we get lots of practice with this! I like to use an edge roller (very light application) prior to dimpling and it keeps the TE nice and sharp.

[PilotjohnS]

Someone asked if the trailing edge needs to be sharp. Turns out the trailing edge needs to be blunt, not sharp with the exact thickness determine by things like Reynolds number, airfoil, etc. but for us, all that really matters is not sharp. In race cars, they use Gurney flaps to do this, but the race car guys didn't really understand this and started using gurney flaps to increase downforce and it ended up making more drag which they thought was more downforce. If interested, there is a nasa paper out there that talks about blunt edges and the ideal gurney flap height. I think I might still have a copy in my race car archives.. JMHO

[Aero_Octaveus]

A blunt edge is music to my ears. My rudder does not come to a sharp point due to lack of enough countersink on the wedge. I was going to fill the slight gap with 3m 2216 epoxy and sand it smooth. Sounds like I may have failed positive on this one... Woohoo