[AntiGravity]

I'm a little confused here and not sure how to proceed. I've match drilled all the ribs to the main spar and rear spars. Van's instructions now say to deburr, prime and then rivet the ribs to the main and rear spar. All well and good, but then I wondered about the rear spar flange. The skin flange and rib all get rivetted together. Looking further on in the instructions (page 7-8) it says to dimple the rib and the rear spar. Trouble is, by that time the rib will already be riveted on; so I won't be able to. No problem, thinks I, dimple now. Of course, that may potentially lead to an alignment problem when match drilling the wing skin since the underlying hole will already have been opened out to #40. If the wing skin hole is a little off to one side I could end up with an oval hole underneath. Checked DanC's website, but the only thing I noticed was a photo on this page (http://www.rvproject.com/20020711.html) which shows (I think) that the rear spar is countersunk. Looks that way to me anyway. No other mention is made that I have found (Dan, you reading this? [in the 'wrong' forum!!]).
What did you other boys do?

 

[LettersFromFlyoverCountry]

I can't remember exactly what I did here but you won't have an alignment problem because when you get the skeleton in the structure, when you true it up -- plumb bobs off each end to check the distance and make sure you don't have a twist -- and add the skins....all of those holes in the spar, the rib, the rear spar and the skin are going to bring everything into alignment. Assuming you line up the prepunched holes at the locations you desccribe, you'll be fine.

One thing the instructions DON;T tell you exactly -- is to dimple those doubler plate locations to the rear spar flange NOW. (they actally say to do this with some of the inboard holes, but not the other two double plates. Otherwise you'llhave to countersink these later on.

Of course, don't dimple the ribs yet except for those that you describe, because you still have to get the skins lined up (hint here: this process will go much easier if you line the skins up to the forward spar first...clecoe along the top, and move back toward the rear spar. Don't ask me why. But it does. Then match drill, disassemble, deburr, dimple.

Deburring wing ribs. At 1300 hours into my project, that task remains...unquestionably.... THE least enjoyable part of building.

Regards.

 

[rzbill]

Don't predrill and dimple the ribs/rear spar. The wing skeleton needs to be squared up on the jig with the skins cleco'ed prior to match drilling. If it is not done this way, a wing twist or skin wrinkles are a much greater risk.

You say that you can't dimple after riveting the skeleton. I think the accepted technique is to use squeeze dimple sets in a hand rivet squeezer (whether manual or pneumatic). With those tools, it is not hard to dimple the skeleton in the jig.

The thin doubler areas at mid span and tip are also easy to dimple (through both thicknesses at the same time) with a squeezer although you may have to grind a little bigger radius on the female die so it does not dig into the doubler. Don't worry, nearly every dimple set you own will need one edge radiused like that before you are done.

My instructions said to dimple the rear spar flange and, if desired, touch them lightly with a countersink to make the skin dimple fit better. I can't remember if I did this or whether I used tank dies (deeper dimples).

Prior to that, you will need to debur the holes. I needed a longer reach debur tool. Standard tool was a hassle. You may want to plan for this or somthing of your own creation. See this link:

Deburr Tool Extension

 

[rwtrwtau]

Jeff,

The instructions for the RV7 say to dimple the rear spar for those rivets attaching the skin to the rear spar, then "Crisp up the holes" by running the countersink and the counterstop cage set through too. Check the thickness you should find they are slightly too thick to dimple, hence Van has you do it this way.

Read on in the instructions that came with your kit and you should find it after you match drill this area.

If you are asking about when to dimple the rear of the rib in the corner where it is riveted to the rear spar and the wing skin it is OK to go ahead, drill, debur and dimple this one hole on each rib. Just be careful when you drill throught these holes later to make sure everything is lined up.

Alternately, drill the corresponding corner holes in the skin by running the #40 drill through but do not match drill them in assembly. You are building a match hole kit. You are very unlikely to build a twist into it in any case and doing this will not impact anything as long as everything is square when you match drill the rest of the skins and rivet it home.

I would not suggest it but Van and others have built these things on the bench without a jig. I found the jig was mainly useful to hold the wing up and no real alignment issues but do check it as some have reported issues and needed to straighten/hold it straight while drilling and riveting. The holes are all there drilled slightly undersize.

Good Luck,

Richard

 

[RatMan]

I had to read your post a couple of times to get at what you are talking about. It's the tab on the rib flange that connects the ribs to the flange you're concened about, yes?

I'm a little confused here and not sure how to proceed. I've match drilled all the ribs to the main spar and rear spars. Van's instructions now say to deburr, prime and then rivet the ribs to the main and rear spar.

Yes, the rivets that go through the rear spar web only, not the spar flange and tab on the rib, leave those for the skin.

All well and good, but then I wondered about the rear spar flange. The skin flange and rib all get rivetted together. Looking further on in the instructions (page 7-8) it says to dimple the rib and the rear spar. Trouble is, by that time the rib will already be riveted on; so I won't be able to. No problem, thinks I, dimple now. Of course, that may potentially lead to an alignment problem when match drilling the wing skin since the underlying hole will already have been opened out to #40. If the wing skin hole is a little off to one side I could end up with an oval hole underneath.

If you think about it further, the skin will be matched up with all of the holes in the ribs and matched up with all of the holes in the rear spar flange. It isn't difficult to line up that one hole in each rib at that point.

Checked DanC's website, but the only thing I noticed was a photo on this page (http://www.rvproject.com/20020711.html) which shows (I think) that the rear spar is countersunk.

If you'll take a look here you will see he dimpled the rear spar and that's the same way my spar looked at that point as well.

Good luck!
Rat

 

[uk_figs]

spar and ribs

I am at work so this is from memory (just finished the wings) but I remember that there are some rear spar areas that need to be dimpled before the doubler plates are riveted on otherwise you cannot get to the backside of the flange. If I remember correctly I dimpled the rear spar flange when I dimpled the ribs, this was after the wing was assembled and riveted and in the wing jig (used a pneumatic squeezer) and then I ran the deburr tool in each hole as suggested. In the areas where the rear spar flange overlaps the rib flange I dimpled them both together. The lower rear spar flange is I believe countersunk in the flap area as the flap hinge is riveted to the backside later and needs a flat surface.
Another tip that I got from Dan's site was to rivet the ribs to the main spar first and then rivet the rear spar, this allows you to put the manufactured rivet head on the rib side (the thinnest material) as you can move the ribs to allow you to keep the rivet set square on the rivet. The rear spar can then be mostly done with a squeezer.

 

[AntiGravity]

Thanks again

Thanks again guys. I love this forum!!

It was indeed the little tab/flange on the rear end of the rib that rivets to the rear spar flange and the skin that I was thinking of. I shall go ahead and dimple these now since once they are together later on I won't be able to.

With regards to dimpling the small doubler plates: I did that when I assembled the rear spar, but now I'm trying to remember whether I dimpled the spar as well; I hate that, I've got the rest of the day to worry about that before I get home from work!!!
Thanks again...