Rudder Leading Edge Template Deviance

Hi All,
I've been struggling with my rudder rolled leading edges the past couple of days. Searched the VAF Forums for best techniques and adopted a couple that made sense. The upper small flanges rolled OK and match the template for that area closely. The middle section has been far harder and despite my best efforts the curve of the edge doesn't come close to matching the curved part of the template. Midway through the radius the max gap is approximately 0.2" despite hours of massaging and hand forming. The 2 sides are symmetrical and it looks good when clecoed together. I fear creating a crease at the spar or other damage if I continue working the metal. Access to where it needs to bend more is very restricted with the other bent flange in the way. I know the whole point is to create a nicely curved leading edge that fits well within the vertical stab hinge line overhang.

My question is: How critical is this template dimension and what are the ramifications if the actual leading edge doesn't conform to it exactly? Trying to figure out if I need to correct it or not worry about it so much, rivet it all and build on. Thanks for anyone's input and time.

Scott

It's not critical, but it needs to be as close as possible for clearance purposes to the vertical stab.

Definitely avoid any creasing, the skin should come straight off the spar and start rolling after the edge of the spar.

Are you using PVC pipe to roll? If so, what size? You may need to go to a smaller one, depending on your method and the area you are working. I ended up using several different sizes.

Also, once the rudder (or any of the control surfaces) are installed you won't notice if your roll isn't perfectly symmetrical so no need to try to get the perfect half circle.

Thanks for the quick reply. I'm using a 1" PVC pipe and a .84" OD electrical conduit pipe. Tackling the lower flanges now. Trying to figure out where to place the pipe longitudinally to get the radius where it needs to be. Taping the pipe to the edge seems to put the radius too lose to the edge. Maybe a bigger pipe diameter?

It is not clear from your post how you are checking them....

They do not have to match the template when static. Only when they are clecoed together as they will be when riveted.

The purpose of the template is to assure a shape that will not have rubbing interference on the rear spar of the vertical stab.

Sorry for not being clearer. I'm using the templates only with everything clecoed together. At the midpoint of the radius the max gap between template and skin is about 0.2". Some of the skin radius is closer to the spar. Not ideal I know. But I can't figure out how to fix it without damaging the skins. The rivet line where the skins join is very close to where the template indicates it should be. Not sure how much clearance exists between the very front of the leading edge of the rudder and the back of the vert. stab spar.
I'm using both a 3/4" PVC pipe (1.0" OD) and 1" PVC (1.3" OD). Any thoughts on which would work best and in what order? Do you recommend using something smaller then a 1" OD?
I appreciate everyone's time helping a newbie.

If skin joint where the rivets will join the two sides matches the template pretty close then it will probably fine as is and you can probably just finish it and see how it matches up to the vertical stab.

If there is a small rub, it can still be massaged slightly after it has been riveted.

Meat said:

The middle section has been far harder and despite my best efforts the curve of the edge doesn't come close to matching the curved part of the template. Midway through the radius the max gap is approximately 0.2" despite hours of massaging and hand forming. The 2 sides are symmetrical and it looks good when clecoed together.

Click to expand...

Same here, ended up with 1/4" gap on one of the templates. Looks good and there's still plenty of clearance to the vstab. Leave it and move on to much more baffling problems that are coming your way.

Thanks for the everyone's time and feedback.