Bending the right elevator

[JurgenRoeland]

I started today bending the right elevator.
I followed the procedure, used a steel dowel about 4mm (0.1575 inch so even a bit more then 1/8 as prescribed) , the bending brake, lots of hinges.

I got the following results as in the images. Then trailing edge is really nice and evenly bend.

When inserting the side ribs, I am pleased about one side.
The other side, when installing the rib seems like the radius on the bend is too small. Any advice which way to go here?

- try to close the end of the rib more ?
or
- try to increase the radius of the bent on one side ?

The good one:

The other side:

 

[SeanB]

Hi Jurgen,

I notice by your pictures, the "good one" does not have any clecos installed in the top or bottom. Also, the position of the rib flange appears to much nearer the edge of the skin compared to the "bad one".

Have you tried this with clecos installed in the top and bottom of these ribs (every hole) to see if the skin repositions? Sometimes it can make a difference.

 

[flion]

My set of preview plans is a few years old, but it shows the radius to be 3/32 so the rod diameter should be 3/16 or 0.1875, so you're a bit tight. I'm not sure it's enough to cause what you're seeing, though.

 

[JurgenRoeland]

To clarify a bit further.

The radius of both sides is equal.
It fits perfectly on the one side. The rib is closer to the edge here as it is the inboard rib and there is no tip attached here. On that side, the fit is perfect.

On the other side, the rib is mor in because of the spacing for the tip.

My impression is that the end of the rib is larger on the outboard side then on the inboard rib side making that there is this little bulge down after the rib.

installing cleco's everywhere doesn't change it.

My idea is that the reason is indeed a bend radius which is maybe a little too tight on one side.
Surprisingly it's good on the other side so if you would make the radius larger,you would be imperfect on the other side.
I think the only option that would really help here is to tighten the end of the rib of the 'bad one' so it fits better to the tightness of the skin.

 

[mcencula]

Shorten the rib

I forget if those ribs are prepunched or not. If not, you could cut the forward flange off the rib, scoot the rib forward a bit, and fabricate a new forward flange. Just a thought.

 

[JurgenRoeland]

The two front holes are not prepunched. so there is a bit of flexibility.