Tip : Another dimpling technique for narrow ribs

larrynew · #1 04-08-2009, 09:15 AM

I haven't seen this technique for narrow rib dimpling so I thought I'd share it. This is the tip of the upper rib in the RV-7 Rudder. I first tried my visegrip dimpler but the access for the last hole was just too narrow. Then I tried going through the opposite hole with the pop-rivet dimpler but the head of the nail was too big to fit through the hole and I didn't want to make the hole any bigger.

What the picture shows from the top is the head of the nail for the pop-rivet dimpler then the male die, then through the rib, the female die, several spacers to keep the flange square during squeezing, then through the opposite hole in the rib, then another spacer, then the pop-riveter.

I used some electrical connectors for spacers because I didn't have washers handy plus they had handles which made it easier. Be sure the hole in your spacer is big enough so that it doesn't smash the opposite dimple. I used a female dimple die on the outside of the rib as spacer to keep from scratching the rib but any washer would do.

Worked just fine:

llavalle · #2 04-08-2009, 03:13 PM

I also used this method. Make use you use a spacer with a big hole. You don't want to flatten the 1st dimple when making the 2nd!

I found this trick on Smitty's website.

http://www.smittysrv.com

miyu1975 · #3 04-08-2009, 07:04 PM

good idea...Where were you 4 months ago though..

rwtalbot · #4 04-08-2009, 07:16 PM

OK, so now you got your rib nicely dimpled, you can spend some time thinking about how you're going to get the solid rivets in there during assembly. :-)

A tip from me... put the solid rivet in the most cosmetically pleasing location and then consider the pop rivet on the other side. Actually there are places in a 7 where the two rivet heads virtually touch when installed...

Richard

niblettda · #5 04-09-2009, 05:56 AM

Personally I used this method.

http://link.brightcove.com/services/...tid=5337092001

It's tight, and I found that I really had to use a 3/16" thick piece of steel. It's not the finest driven rivet I have, but it's not going any where. Also be extremely careful that you don't touch the skin (obviously).

SmittysRV · #6 04-10-2009, 04:39 AM

Philippe mentioned my dimpling method. Here's a pic:

I put the nail of the dimpler set through the male dimpler, then through the rib hole, then female dimpler, then through a large lock washer, then through the other rib hole, and then capped off everything with a over-sized nut. After squeezing the dimple, I reversed the process for the other side.

climberrn · #7 04-11-2009, 08:43 PM

There are some tight areas on the elevators that the holes do not line up so another process is needed. You can bend the rib open, and use the nail dimpler, but the best way I found is on the EAA web video (will post a link when I get home) and uses a cleveland female dimpeling tool and an adapter to put the male die in your rivet gun. This makes better dimples than the pop rivet tool for me, and very quick.

The tools ended up costing about $50, but who's counting.

As for the rivets, I was able to use solid rivets on most tight holes by first using my 1/4" backing plate as a bucking bar with fair results (but better than a pop rivet). Or, I got the tnin nose yoke for the pneumatic squeezer. That will set rivets in about a 1/4" clerance, and better quality.

AF_Alan · #8 04-12-2009, 09:33 AM

... and save a few bucks. I used the heavy aluminum plate that was in the Emp kit (intended as a bolt lenth guide).

Drill a #40 hole near one corner and countersink it. Mount it with the corner just off the edge of the table and use the rivet gun with an old male die.

Unfortunately I tried all the other techniques and didn't get this one until dimpling the flaps....

I'll know for the next RV!

Alan
RV-9A Fuse (started and holding)
N984AW Rserved

Experimental Chaos · #9 05-09-2009, 10:33 PM

The method that has always worked for me, was to take a piece of ? or 3/16 flat steel bar stock, and drill and counter sink a hole near the end. Put the steel flat stock in a vice and use rod that comes with your C-frame dimpler and a male dimple die, all loaded into your rivet gun, use the steel flat bar for the female die, and a couple of rattles with the rivet gun and you have a perfect dimple. I think it helps to hit the home made female dimple die with a scotch bright wheel, and you must be careful to keep the rivet gun straight, or you risk breaking the guide pin on the male dimple die. I?ve done this for years and only broken one die. Of course practice on a piece of scrap.