danielhv

danielhv

Well Known Member
I made my first attempt at bending the tabs at the end of the trim tab. I figured I'd start with the trim tab as its cheaper/easier to replace that the elevator should I screw it up. Im not really 100% sure what I did wrong... I tried to make the bend where the plans show... perhaps my wood wedge form was at the wrong angle of bend? Dunno. Here are some pics... let me know your thoughts/suggestions. The smaller tabs I bent with the blue plastic in place, so it looks like it dented the aluminum all up, but it didnt, all is still straight with no dings... i hope!

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Don't feel bad. You're not the first and won't be the last. Thankfully there is a good solution that is elegant, looks better almost every time, and is easy!

Cut the ends off the actual trim tab itself (throw them away), then proceed to make yourself a little rib and rivet it in there. Looks good, finishes nicely and will be as strong as trying to get the bend perfect!

Just my 2 cents as usual.

Cheers,
Stein
 
Consider mini ribs

which I found to be a much cleaner solution. First, I cut off the ears on Van's part. Second, I made some small form blocks from hardwood to fabricate 3 mini ribs; one for each end of the trim tab, and the third for the "inside" of the elevator. Much more work, but I'm really happy with the result. PM me if you want to borrow the forms and blanks. Unfortunately I won't be able to send to you until early September (out of town 'till then).
 
I would definately consider making these "mini-ribs"... Any pics on the final product? And maybe some of how you formed the ribs? I guess I'm having problems figuring out what angle to make this stuff at... I can cleco the part to the spar, and just guess what the angle is from the trailing edge to the leading edge, but have no idea for sure and usually means messing up several peices trying to get my guess narrowed down. :(
 
frazitl said:
PM me if you want to borrow the forms and blanks. Unfortunately I won't be able to send to you until early September (out of town 'till then).
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That would be great, but what am I gonna do till then? :cool: Ill look around and see if I can find a way to make some in the mean time... if I still haven't gotten this done by September, I may seriously take you up on your offer!
 
Before you make the next one try de-burring the edges first and also radius the ends of the metal. You should radius all corners on every piece through-out the entire plane as you build. It will relieve the metal of stress risers which can lead to cracks. Your trim tab doesn't look all that bad. Small ribs will make the ends look nicer but not make it function any better. You can also use the flush snap on your rivet gun to make the folds in the skin a little tighter but that takes a lot of care or you will end up with a big mess. Have fun and enjoy the build.
 
If you have a sheetmetal handseamer, or buy one from Home Depot, you can bend the new rib flanges with it.

There is also a folding tool they sell. But I'm not sure if it has the 1" deep side to use for a 5/8" flange.

L.Adamson
 
danielhv said:
I would definately consider making these "mini-ribs"... Any pics on the final product? And maybe some of how you formed the ribs? I guess I'm having problems figuring out what angle to make this stuff at... I can cleco the part to the spar, and just guess what the angle is from the trailing edge to the leading edge, but have no idea for sure and usually means messing up several peices trying to get my guess narrowed down. :(
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Don't make them, buy them. Here's what I did.
 
Heh - I made three trim tabs before I got it right. Doing it again, I'd do the ribs as others have suggested. While I'm really happy with how the final tab turned out on my project, it wasn't worth the time, aggravation, or expense.
 
I messed up the bends on my skin, so I made a mini-rib for them, then tried bending the tab. It worked fine (a little better than yours, but good enough in my opinion.) so I used that bent one.
 
Maybe it's just a bad picture, but it looks as though every single edge is unfinished and loaded with burrs. This is not good.
 
szicree said:
Maybe it's just a bad picture, but it looks as though every single edge is unfinished and loaded with burrs. This is not good.
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No, I did not debur anything on that piece yet. Haven't even match drilled it or dimpled anything either. I figured I'd wait and see how the bend turned out before I wasted my time. Dont worry though, I debur everything before riveting. ;)
 
danielhv said:
No, I did not debur anything on that piece yet. Haven't even match drilled it or dimpled anything either. I figured I'd wait and see how the bend turned out before I wasted my time. Dont worry though, I debur everything before riveting. ;)
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I think what Steve was talking about is that it would be next to impossible to properly deburr under the "flap." That'll have to be done before making the bend, otherwise you'd have to unbend it again:

TrimTab-Deburr.jpg
 
danielhv said:
Did you make all 3 from just 1 E-703? Or did you have to buy 3 to make the 3 ribs?
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Unfortunately you have to buy three and cut the tips off to "fab" your ribs. I don't remember them being that expensive, probably paid more in shipping than anything else. The advantage is that you know it will be a perfect fit since the slope matches the inboard rib on the left elevator.
 
Daniel....all is not lost

hey dan,
I fretted over this stage also. I called T Frazier for help and he loaned me his forming blocks if I chose to cut the tabs off. His look great in person(better than the pics he posted). It was too early in the game for me to become a fabricator so I chose to bend them. I went to the best machinist I know, my gunsmith, and he machined my blocks out of some really hard african wood. edges very sharp. Using these with very thin and agressive two sided tape on every piece including the bench top and c-clamped all down was able to make perfect bends. It looks like your blocks may have slipped producing the round bend. First deburr everything. You have cracks that need to be removed at the trailing edge. It doesnt look like you have bent the trailing edge yet. GOOD! That way you can use sqeeze rivets on the bottom of the spare. Remove all the vinyl, redraw your lines a little inward but parallel to each other, clean up your blocks so that they fit well, use the 2 sided tape method and reposition your blocks. Start your new bend with a piece of square hard wood and a mallet right up against the block and tab (tight). Then take your flush set with your rivet gun at about 20lb or so and lightly tap all across your bends back and forth without stopping end to end. The pressure up against the blocks really flattens it all out beautifully. The manual shows this. I still have Terry's forming blocks and will mail them to you if you choose the rib method and or will mail my blocks to you if you wish. I'll post a pic when I get a new camera today or tomorrow. Any one find a nice digital camera at Redbull San Diego race? All my build pics were in it. Bummer. BTW what camera are you using? I could use some help on choosing a new one
 
RV7Factory said:
Sounds like it is time to revive this old thread. :)
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Thanks Brad, I saw this earlier... Looks like Im either going to be a rib manufacturer or I'll be joining the 2nd tab club. :D

Btw, Im still sucking all your bandwidth on your site... so much good info! I dont even know what Im building or how, Im just copying everything you do! ;) (j/k!) :D
 
All-Metal Trim Tab

So just to clarify here, is it OK to use riblets instead of the 2 mid-span foam blocks in the RV-9 trim tab, as well as for the dreaded folded ends?

I like rivets; I hate glue and chemicals.
 
Ok, so Im about to order another trim tab because I screwed mine up trying to fix my screw up... Im going to make an attempt at making my own ribs while I wait for the replacement tab to get here... but Im lost on where to start... How do you make a rib with the perfect angle and bends, etc? Is there a write up on it anywhere? I have no idea how to do this. Worse case scenario, if I cant fab some ribs out of scrap, then I make another attempt at bending the tabs on the replacement...
 
danielhv said:
How do you make a rib with the perfect angle and bends, etc?
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All you need to do is take your trim tab and lay it perpendicularly on some 020 or thicker sheet. Just trace where the top and bottom skin of the trim tab meet the sheet. There's your bend line. Mark out 3/8" to 1/2" from the bend line and there's your cut line. I bent mind with the hand seamers. Turned out GREAT.

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Don't make it any more difficult than it needs to be. Do exactly what was listed and shown previously regarding the tracing the shape with a sharpie, then go bend it!

If you want to drag it out a bit further you can do the steps below, but if I were you I'd just grab some scrap aluminum, grab a sharpie, and grab a pair of seamers. If not, then:

#1) Get some cardstock or heavy paper.
#2) Cut paper to approximate shape.
#3) Fold paper and experiment until you get your perfect "rib"
#4) Unfold paper
#5) Get some thin aluminum
#6) Bend aluminum based on your paper template with a seamer.

No machining or creating blocks, no calculating, etc.. . Either way is quick and easy - and even it it takes you three or four or five tries those tries will be fast! Personally, I like the "trace with a sharpie method" the best, but whatever works! :)

My 2 cents as usual.

Cheers,
Stein
 
danielhv said:
Ok, so Im about to order another trim tab because I screwed mine up trying to fix my screw up... Im going to make an attempt at making my own ribs while I wait for the replacement tab to get here... but Im lost on where to start... How do you make a rib with the perfect angle and bends, etc? Is there a write up on it anywhere? I have no idea how to do this. Worse case scenario, if I cant fab some ribs out of scrap, then I make another attempt at bending the tabs on the replacement...
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Well, since you are ordering a new tab why not have van's throw in a couple of 703's? E-703's are 9.69 a piece and you are already paying for shipping ...

Cut the tips and you have instant ribs ...
 
too late! I figured I'll give the manufacturing method a shot... Gotta learn some day huh? Plus I've got plenty of scrap!
 
Fabricating stuff...

...is not so hard, even if you have to make a few attempts. By the time you end up at the end of the fuse you'll have fabricated and/or modified all sorts of bits and pieces. In my case, not only several brackets for things, but the entire top skin from sheet, aft canopy slide track and soon to modify the stock canopy frame:eek:. Mate, if even I can do that stuff, then you can certainly bend up a riblet!!! Good luck.
 
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