It worked for us

Just started on the practice kits and soon ran into some problems. A buddy and I began the riveting learning process as per the instructions, after dimpling the skin and the stiffeners-inserting the called for rivets-taping them into place and inverting the assembly on a steel surface plate.



The immediate problem was properly aligning the rivet gun with the rivet. We got several shop ends with quite an angle in the top;



My buddy quickly suggested gluing a bubble level to the top of he gun;



Using the bubble level we consistently got shop heads perpendicular to the rivet shaft. I figured we would be doing a lot of riveting in a vertical plane rather than the horizontal plane with the surface plate, so I added a line level to the top of the gun, these little levels can be glued to bucking bars as well to keep them aligned with the shin being held in a vertical position. Of course, this only works if the riveted object is either horizontal or vertical.



The other immediate sticking point was dimpling in the small end of the converging angles of the two end ribs. The instructions go to some length explaining how this is a problem area and requires special dimpling dies for the small available area. While this is certainly a problem, using a squeezer on this operation without distorting the thin metal is another big problem. Assuming this problem would arise on many occasions in the future I made some very crude fixtures to do the job without distorting the metal.



The internal wedge in recessed with a .375 drill to accommodate the existing dimples. If you are smart enough to do the hard ones first you do not have to make the dimple recesses. I did these with a band saw and a drill press, it certainly can be done much more precisely but not worth it for the practice kits. On the plane I will take an hour or so and do it right. A simple inclinometer will tell you the angle needed to keep everything perpendicular to the dies in the DRT. Unfortunately, you will probably need a couple for the entire projects because different angles are probable.



If you drill the pilot holes for the dimple recesses .110 your 3/32 clecos will hold all this stuff in alignment making it a simple one man operation.

Here is a picture of the result with no metal distortion except the dimple on the left with the displaced hole that I did without the wedges, which is what convinced me there had to be a better way

Hey Vern, good to see you getting started. I finished my practice projects a few weeks ago and I had an issue with the back riveting too. It was fairly tough to get the back rivets straight as well. Then I realized that I was using the mushroom set, and a back rivet set came with my kit.

http://www.cleavelandtool.com/Back-Rivet-Set/productinfo/RSB35/#.WY0Xs1FLe00

This was 100 times easier and pretty difficult to get the shop heads angled as the length gives you a good marker of perpendicular to the plate and keeps you from slipping off the rivet to boot. Looks like you figured out your own method though Hope the kits go well and keep us posted on how they turn out!

Agreed, that is the exact tool we were using but still managed to get angled shop ends. May be something to do wit our age

Very cool idea with the bubble level, I have not seen that before. Cleaveland makes a vice grip with dies welded to it for them tight areas, I highly recommend getting a pair.

http://www.cleavelandtool.com/3_32-VISE-GRIP-DIMPLER/productinfo/550/#.WY8TUVWGOUk

The best way?

This concerns the RV-10 elevator tip rib which was the first section I started on. Not first in the plans but I was unable to start with the vertical stab due to a missing part. The first item in the elevator section, after cutting a bunch of rib sections apart, is this tip rib. It's a three piece combination which should be simple enough except for the fact that two of the three pieces are far from straight/flat/perpendicular. I suspect this will be an issue going forward so I thought I better get my expectations in line with reality.



Now this is the way it came and the bend angle was somewhere around eighty degrees rather then ninety. Since getting true ninety degree bends requires going over center (100 degrees) to accommodate the tendency to revert back, this is to be expected. Some fluted depressions had been made in the rib flange to pull the sides to ninety degrees but not enough. When I made the depressions deeper with the special fluting pliers from Cleveland Tool achieving ninety degrees was no problem. The problem is the bow in the picture about increased by 100%. As you shorten the length of the flange it has to pull the bow tighter.

My question is how do you have your cake and eat it? Without anticipating this in the forming dies I don't see how it can be properly straightened after the fact but guys have been doing this since Lindbergh so someone may have found the answer.



My solution was clekos and brute force. Surprisingly the finished product looks pretty straight and when attached to other components will probably move around enough to work. Somehow, I thought building airplanes would be a little more elegant and I would not be needing the eight hundred pound surface plate and a massive clamp However, we have plenty of both.

The purpose of fluting is NOT to square up the flanges, but to make the web flat, and rivet lines straight. You have over-fluted this rib, resulting in that banana shape.

You can use the vice-grip flinging tool to square up rib flanges, but here is a tool I built for squaring rib flanges. Do a search on "flange squaring tool" in these forums, and you will likely find plans for building the tool. You will consider this tool worth its weight in gold by the time you get done squaring up wing rib flanges.

I just built a rib flange tool a couple weeks ago. If you go to my build log here:

http://www.vansairforce.com/community/showthread.php?t=149050&page=4

go to post #39 for tips on it.

As Miles already mentioned fluting is just to "flatten" the main web of the rib and make all the holes on the flange line up in a straight line. Go with light squeezes first and I like to start where the bow is strongest at first.

vernon smith said:

Just started on the practice kits and soon ran into some problems.

Click to expand...

I am in the process of assembling this kit and wonder if noticed anything funny with it:
While riveting the skins to stiffeners with AD3-3 did you measure the shop end with the 3/32 gauge? Were you able to bring it to 1.5 of the rivet diameter?
While dimpling what was the final size of the skin and stiffener holes? Mine is in excess of .111
I am just wondering if there is anything wrong with my avery dimple dies and my avery rivet gauge?

PipeDreamer said:

I am in the process of assembling this kit and wonder if noticed anything funny with it:
While riveting the skins to stiffeners with AD3-3 did you measure the shop end with the 3/32 gauge? Were you able to bring it to 1.5 of the rivet diameter?
While dimpling what was the final size of the skin and stiffener holes? Mine is in excess of .111
I am just wondering if there is anything wrong with my avery dimple dies and my avery rivet gauge?

Click to expand...

No, the larger hole is a result of the dimpling process and acceptable. As Scott would say, nearly 100 million rivets are installed like this on RV's!

There's actually a mil-spec'd upper (and lower) limit on hole diameter for each rivet size. That said, probably 80% of the holes in all the RVs that have been built, were deburred with 3-flute tools and are not only over-sized, but have stress risers cut by the 3 flute bits. Doesn't seem to affect actual safety.