C

chris mitchell

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I'm working on the right elevator. I've spent the last three hours fluting and bending E-703 (end rib) and E-704 (counter balance rib) in an effort to get E-713 (counterbalance skin) to fit over them without any of the prepunched holes being to far out of line. It seems like the E-703 and E-704 won't sit close enough together, though I've made sure they are tight together with the clecos. The mismatch with E-713 is maybe 1/32-1/16 and I don't want to start drilling if the parts aren't properly matched first. Am I missing a trick here? Is there some way to drive the flanges a little closer together? If the bend between the web and flange was a little sharper there would be less of a problem. Do I keep bending and fluting, or am I sweating for no good reason and should just drill?

Thanks

Chris
 
takes time

You probably already have done this, but make sure the flanges are at right angles to the web. I don't remeber much about the tail anymore, but I spent a lot of time on the wing ribs making sure the flanges were all 90 deg to the web and the ribs were as close to perfectly straight as I could get them (shrinking or fluting the flanges). I used a shrinker and a strecher instead of fluting but both work well.

Tom
 
c/weight skins

Hep, I fought with mine and thought there was a problem with Van's pre-punch operation.......naaaa, it was just me. Try to cleco just the "tail" of the c/weight skin then by pulling the over the rib...streching if you will, the skin over, into place. Then cleco the other side, starting at the tail first. It was a bear!

Good luck
My .02 cents (Canadian)
 
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I just did my elevators and had exactly the same experience. Holes were not lining up as if 703/704 were too wide.

Just use as many clecos as possible to bring them together when drilling and then when riveting and the result is decent. My drilled holes were ever so slightly oval despite using extra clecos to draw everything together tightly.


As a side note, when doing the final riveting:

I think you will be much happier if you rivet out of order when doing 703/704 to the spar. The plans call for riveting 703 to 704 and then the assembly to the spar. When you try to rivet the shorter piece (can't remember which is the short one that mounts to the face of the spar?) it is very hard to get the 2 470 rivets placed due to the angles involved. I instead did as suggested in another thread and placed the 2 470 rivets that join the spar to the aft end of the short rib. Then rivet 703 and 704 together. Hard to say clearly in this space but look at the plans and it should make sense.
 
What a timely discussion. I will be working exactly this area over the weekend.

From what I can understand of the problem from the posts, you're probably just hosed. If the 703/704 are snug back-to-back and the holes are still too wide inboard/outboard to match the skin, there is really nothing you can do to fix that. I'll look at my parts, but if I have the same problem, I may just drill them #40, then take a look. If the holes are too oblong, I'll probably just drill them all to #30 to make them round and install NAS1097's. Assuming there is enough edge distance... :)

I'll let you know if I have the same problem.

Robert
 
Define TOO oblong!! :)

One advantage of the solid rivets is that they swell to fill the hole slightly. How much??


Oh so many questions I have??


Ain't this fun :D
 
After another couple hours fluting, bending, pushing, and clecoing they eventually fit together. It seemed to be a matter of getting the 703 and 704 surfaces completely flat so they butt together really well. Had to flute the front flange quite hard to get the ribs flat in the vertical plane. Then I clecoed on the 713 (counterblance skin), using every single hole, clecoed the whole thing to the elevator and drilled #40 taking only a single cleco out at a time, so that the chances of anything getting out of line were minimised.

Grant, I already spotted the upcoming problem with the final rivetting and will do as you suggest. Anything to make life easier..... :)

Thanks for the helpful comments. I'm sure I'll be back!

Chris
 
While we're talking about this area I have a question about 713??


What are you using to dimple and countersink for the counterweight??

I have the "Complete RV Tool Kit" from cleveland and none of the dimples or countersinks seem to match the screw head that attaches the lead weight?

Thanks
 
The avery kit has a "pop rivet dimple" style to dimple for the counterweight...but it uses an allen bolt and nut instead of the pop rivet nail. As for countersinking the lead weight, try a one hole countersink, it works perfect. I also had a bear of a time with the e703 and 704...just keep bending, tweeking, etc the web untill it all sits correctaly. I believe I ended up laying them web side up and tapping them gentaly with a nylon faced mallet.
 
Sorry, Let me clarify the question: What size/style/tool name is required.

I want to say the hole was a #12 drill, what then do I dimple with for that screw size. Part of this stems from my inability to find the specifics of the screw nomenclature. As in if its a 345xyz12 what does the 345 mean, what does the xyz mean and what does the 12 mean? I'm at work so I don't have the actual screw type in front of me to give the actual info.

Thanks
 
Chris,

I think you may have spotted the problem. I grabbed my 703 and 704 this morning to take a look. I noticed the webs were bowed a little bit. I wondered quietly to myself if this may be the sorce of the trouble. After reading your post, I do believe I will be following your example. Thanks! ;)

Grant,

> Define TOO oblong!! :)

Ha! You want me to be specific? :D

The specs I have seen that specify allowable hole diameters for solid rivets are fairly generous to begin with. Unfortunately, I don't have the diameters for a #40 memorized, so I can't give you a specific example.

As far as TOO oblong, well, that depends on the situation. If it is just 1 rivet in a line of 30 is .004" out of spec, I wouldn't think twice about just slamming a rivet in there and moving on. Keep in mind, too, that dimpling enlarges the hole as well. So if the hole is slightly large, it will end up looking just like all the others once they are dimpled.

In general, I don't cut myself much slack regarding hole diameters. Rivets, after all, do hold the airplane together. If two holes in a row are large/oblong, they get stepped up to #30. It doesn't take long and I sleep better at night. :)

If I work fast, I'll get to drilling these parts tonight. I'll let ya'll know what happened.

Robert
 
grantcarruthers said:
Sorry, Let me clarify the question: What size/style/tool name is required.

I want to say the hole was a #12 drill, what then do I dimple with for that screw size. Part of this stems from my inability to find the specifics of the screw nomenclature. As in if its a 345xyz12 what does the 345 mean, what does the xyz mean and what does the 12 mean? I'm at work so I don't have the actual screw type in front of me to give the actual info.

Thanks
Click to expand...

You need a #10 screw dimpler, Avery #1027 for the e-713 counterbalance skin bolt holes for the lead weight. The lead weight screws are 10-32's, thus the #10 dimple dies. To countersink the lead, I recomend a"one hole countersink", such as part number DBB40 from Cleaveland aircraft tools, or other sources. A single flute countersink will probaly work as well, but the one one works remarkably well with the soft aluminum. As for hardware identification, pick up a copy of "Standard Aircraft Handbook" from Avery, its got all that information in it.
 
If you want to save $30 on the dimple dies just use one of the screws (or another #10 screw) and tap it with a hammer using the already c-sunk lead weight as your female die. If you use the screw that came with the emp. you will have to replace it but its only about 30 cents. Just order it when you order your wings to save on shipping.
 
Thanks for the reply's

As far as the slightly oblong holes I noticed, they were identical to the perfect holes once dimpled so whatever that oblongness was I felt comfortable with the final result.


Going back to countersinking the lead weight, I have a #10 countersink but it just barely wouldn't run down into the #12 hole in the lead. The #10 screws would pass easily though so that's why I thought I had the wrong tool. Maybe I just have to open up the first 1/4 inch of the hole in the lead to a #10 and then the countersink will pass??
 
Okay, countersinking is done, opening slightly with the #10 bit did it. I also figure I could have used modest force to pass the #10 countersink in the #12 hole in the lead it just seemed I shouldn't have to.

Now, as far as the dimple goes???

The cleveland "complete" kit does not include a #10 dimple. I used the number 8 dimple and it's close to complete. I wonder if the torque on the screw will complete the dimple or should I dimple with the screw for the 30 cent solution described above or are there enough #10's in the future to get the dimple for 36 bucks.

Thanks
 
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