G

GRANT ED

Active Member
I am up to the stage of bending the trailing edge of my elevators. I have read in the instructions the size of the radius is mentioned on the plans but for the life of me I cannot find it. Can someone please put me out of my misery and tell me what it is!?!
 
Elevator radius

I couldn't find it in the plans either. I read where a lot of people have used a 1/8" wooden dowel placed inside the trailing edge to keep it from bending too tight. That's what I did and it worked good. You can find these dowels at the hardware store.

The aileron drawings have a full size side view of the radius. Do you have you wing kit yet? The instructions for the ailerons say to bend them like the elevators.
 
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I am with you. I couldn't find it either. I used the fiberglass tip for my reference. Basically, I put the trailing edge in the back of the bending form and pushed down until the stiffeners wouldn't let me push any more (gently). The fiberglass tip was a perfect fit. I had a friend with another 7a look at it and he thought it was good. I then bent the other one in the same exact manner.

AltonD
Ready to build the Elevator trim tab.
 
Mine too, but.......

Yeah, well.... My bending fixture looked just like yours. The boards were nice and straight. But both my elevator trailing edges came out with a bow. They are certainly airworthy, but they are not nearly as straight as other finished RV's I have checked. Pisser. :mad:

I sent pictures to Van's of my right finished (and bowed) edge and also the left elevator prior to bending with what looked suspiciously like a bowed initial factory bend. I pretty much got blown off by the factory, so I tried the second elevator. No difference. Bowed like the first.

I may build them over again at the end of the project. After drudging through wing rib prep and conquering proseal, elevators are kids work.

Rudder TE is knife straight. I wish the 7 had riveted elevator TE's.. Hmmm.. :rolleyes:
 
I bent mine just like Jeff's. I put it in the rig and pushed it all the way back till it touched the hinge. Turned out good. Since it bottoms out on the stiffeners, I don't hink you can overbend. but, if you push to hard when it bottoms out, you will leave stiffener impressions in the opposite skin, so gently.
 
rzbill said:
Yeah, well.... My bending fixture looked just like yours. The boards were nice and straight.
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My fixture also looks the same. It was nice and straight for the elevators, but now the planks have dried more and taken on a bow and warp. So much for "premium" lumber from HD. Before I bend the ailerons or flaps, I am going to remake the fixtures using two layers 3/4" MDF laminated together. I should have done it that way from the start.
 
The boards I got from good ole Aircraft Depot were very heavy sap saturated pine. They are like concrete. I doubt that aided in any way. I think if you have them laying on a nice flat surface while pushing down may help. Like Alton said, just push them till they touch the hinges and squeeze them as much as the stiffeners allow. The skin will always spring back apart some but if you are bending right near the trailing edge is the trick. After I bent mine what I thought was enough you can see in pics of the completed elevators that the skin still has a balloned appearance. A little more sqwishing would have made a flatter skin. From what I understand about the trailing edges of the ailerons and elevators not being bent nice and crisp affects the controls a bit by making them a bit mushy. But thats only what I was told and have to experience with this. Not something to beat yourself up over. All in all I have never heard a report of a crappy flying RV! ;)

-Jeff
 
RV7Factory said:
My fixture also looks the same. It was nice and straight for the elevators, but now the planks have dried more and taken on a bow and warp. So much for "premium" lumber from HD. Before I bend the ailerons or flaps, I am going to remake the fixtures using two layers 3/4" MDF laminated together. I should have done it that way from the start.
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Same here!! used some "good quality timber" That was good at the time but warped over the past few days. I'll make a new one out of MDF and try again. Thanks for the advise guys.
 
Bent elevator trailing edge

3/32" radius or 3/16" diameter. Imagine looking at a 3/16" rod from the end. That's about the right size. Should be somewhere in the empennage drawings. I'm not near my plans to tell you what page.
 
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