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How to bend trim tab leading edge?
- Thread starter LuisR
- Start date
Pool Shark
Active Member
Jason, that's the question: with what did you give it a bend? A hand-seamer, block of wood, fingers, etc. Also, did you wait until after the spar was riveted in place?
I'm surprised that there haven't been more questions on the Forum about this; Vans gives no details in the plans, and being a concave bend over a relatively long sheet of thin skin, it seems like a tricky operation.
Maybe I'm just over-thinking it, but it would be a shame to 'bork-up' a very tricky flight surface on the final step.
Pool Shark
Active Member
Bump
Now that I'm at this step, does anybody have a response to my above inquiry?
Now that I'm at this step, does anybody have a response to my above inquiry?
Auburntsts
Well Known Member
I made a brake from some 2x8s and door hinges as the steel brake that came with my tool kit wasn't wide enough for the skins. But like Paul said, the angle isn't critical so do whatever method is easiest for you and get'er done.
Pool Shark
Active Member
Thanks guys!
Funny that bending the end tabs on my trim tabs and elevator skins was the easiest and fastest step (I made a simple aluminum mini-break), but that bending the leading edge of the trim tabs was freaking me out
I think I'll try Paul's 'rub a wooden block along the bend to form a crease' method...
Funny that bending the end tabs on my trim tabs and elevator skins was the easiest and fastest step (I made a simple aluminum mini-break), but that bending the leading edge of the trim tabs was freaking me out
I think I'll try Paul's 'rub a wooden block along the bend to form a crease' method...
Auburntsts
Well Known Member
Thanks guys!
Funny that bending the end tabs on my trim tabs and elevator skins was the easiest and fastest step (I made a simple aluminum mini-break), but that bending the leading edge of the trim tabs was freaking me out
I think I'll try Paul's 'rub a wooden block along the bend to form a crease' method...
I found that many times reading ahead I'd get myself all worked up into a "how am I going to do that or this is going to hard as h*ll" state of mind but invariably when I actually got to that step and did it I'd walk away wondering why I thought it was going to be so difficult because it rarely was.
Truth in lending -- the flip side applied as well. A few times a task I thought was going to be a piece of cake turned out to be a time consuming, expletive filled, pain in the butt.
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OK, I'm continuing this conversation because I think it's the only one out there on this 15-degree bend in the trim tab (in my case, for an RV-10).
But first, the back story. I'm focused on finishing the elevators so I can mount them on my HS, and then add on the tips, so I can transfer the whole HS to my hangar. So I was disappointed when I got to the "let the elevator dry for a few days" step. What am I going to do for 3 days? All I have left is these tiny trim tabs that hardly have any parts!
Well, now I'm not sure if I'll finish these trim tabs in three days. What a pain! I think the instructions are just not very good here. You are supposed to very precisely fold the leading edge and make sure it is perfectly straight, and then you are supposed to use a rivet gun and clamps to fold the ends down, which will mess up your perfectly folded trailing edge. Then you get to this 15-degree bend on the front spar of the trim tab and they don't give any direction at all. I would have loved to clamp it to my workbench with a piece of wood, but I couldn't figure out how how to do that with the end tabs already bent in.
So, if I could do it all again, I think I would first do the 15-degree bend, then I would fold the end tabs, then I would fold the trailing edge. Perhaps there is an issue I'm not seeing with that order, but it sure seems it would be easier.
Finally, back to the 15-degree bend in the leading edge. Here is what I did: I cleco'd the skin to the spar. On the bottom (where I needed to do the 15-deg bend), I cleco'd in every single hole. Then I got my seamers and I just bent the skin against the front spar. It was easy and it looks great. I couldn't figure out another way to do it that wouldn't be problematic. And as a bonus, you can't bend the wrong part of the skin because it is already properly cleco'd to the spar.
I hope this helps somebody else, good luck!
PS - some things that worked for me on the leading edge fold. I used my bench and a 2x4 to start the folding process, and then I fine-tuned it using the brake described in Section 5. I did end up over-folding a portion of one of my trim tabs. Remember those wedges that you had to cut out of the wood blocks to fit the trim tab? Well, I took a wedge, I cut off about 1/2" off of the point, and I rounded the edges on my sander. I now had a wedge that I could put into the skin and tap it down into the inside of the fold. I was able to gently un-fold the part that was over-folded.
But first, the back story. I'm focused on finishing the elevators so I can mount them on my HS, and then add on the tips, so I can transfer the whole HS to my hangar. So I was disappointed when I got to the "let the elevator dry for a few days" step. What am I going to do for 3 days? All I have left is these tiny trim tabs that hardly have any parts!
Well, now I'm not sure if I'll finish these trim tabs in three days. What a pain! I think the instructions are just not very good here. You are supposed to very precisely fold the leading edge and make sure it is perfectly straight, and then you are supposed to use a rivet gun and clamps to fold the ends down, which will mess up your perfectly folded trailing edge. Then you get to this 15-degree bend on the front spar of the trim tab and they don't give any direction at all. I would have loved to clamp it to my workbench with a piece of wood, but I couldn't figure out how how to do that with the end tabs already bent in.
So, if I could do it all again, I think I would first do the 15-degree bend, then I would fold the end tabs, then I would fold the trailing edge. Perhaps there is an issue I'm not seeing with that order, but it sure seems it would be easier.
Finally, back to the 15-degree bend in the leading edge. Here is what I did: I cleco'd the skin to the spar. On the bottom (where I needed to do the 15-deg bend), I cleco'd in every single hole. Then I got my seamers and I just bent the skin against the front spar. It was easy and it looks great. I couldn't figure out another way to do it that wouldn't be problematic. And as a bonus, you can't bend the wrong part of the skin because it is already properly cleco'd to the spar.
I hope this helps somebody else, good luck!
PS - some things that worked for me on the leading edge fold. I used my bench and a 2x4 to start the folding process, and then I fine-tuned it using the brake described in Section 5. I did end up over-folding a portion of one of my trim tabs. Remember those wedges that you had to cut out of the wood blocks to fit the trim tab? Well, I took a wedge, I cut off about 1/2" off of the point, and I rounded the edges on my sander. I now had a wedge that I could put into the skin and tap it down into the inside of the fold. I was able to gently un-fold the part that was over-folded.
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