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Yes...the dreaded missed dimple.

T

tegwilym

Active Member
I'm finishing up the last few holes on the right side horizontal stablizer using the DRDT-2 dimpler. I guess when I was giving it a good push, it jumped the hole and made a new hole. ****!.
____, __________,_____________,_________ <---insert string of favorite cuss words there.

We all know that holding the folded skin, lining up the hole, and giving it a good push with the lever is awkward when we get up close to the folded half. And there it goes....

So the common question. Is a double hole like this (not an easier figure "8") something that can be worked around or is this a new skin?
This hole is in the middle of the stablizer.

I'm thinking it's time to contact Van's....unless someone has a good idea for this common problem?

Thanks,

Tom
Learning from mistakes.
:(
dimple.JPG
 
I did the same thing---twice! Once for each elevator.

The first time the holes were far enough apart that I could put in 2 rivets. I did contact Van's and they confirmed I could do that as long as the edge distance is enough. But remember you have to drill and dimple 2 holes in the stiffener too. Sometimes there is not enough room to do that if the hole is too close to the bend in the stiffener angle.

The second one looked like yours, too close together for 2 rivets. I bought a new skin and started over. I did not contact Van's on that one, just didn't see any other way.

Just my opinion, I am not an expert.
 
Thanks Bob. I have heard about the "oops" rivet method, but this is right over the forward spar and like you side, no room to put another rivet in there.
I have seen some ideas that other builders suggest to just keep going and fill it later when painting. Epoxy, bondo or something like that. I'm just not sure what is best. I'll share the photo with Van's and ask the advice from the experts.

So close to being done...about 10 holes left then, oops!

Tom
Renton, WA
http://www.mykitlog.com/tomtraci/
 
Hi Tom

Bottom line to me is that hole(s) has no integral strength as a fastener - it will crack between the 2 holes, if it has not already. However, provided the holes are cleaned up, I doubt it would go much further?

So strength wise you either assess (bravely) the fastener can effectively be omitted, or you substitute with additional rivets each side of it.

Cosmetically it can probably get filled and lost in paint, albeit then the missing / extra rivets will always remind you of the issue on every walkround :(

The complete opposite view is to play safe, and also "punish" yourself for rushing things, order a new skin and put it in the past. That is why you start with the empennage - make mistakes on the cheap / easy to replace stuff, and don't repeat them on the bigger stuff (e.g. wing skins).

I suspect you will go for the latter, and in the long term, you would not regret it...
 
Very often during the build you may need some scrap material to make something out of - Now you have some scrap material .. :)
 
You are not alone!

Reminds me so much of a mistake I made on my empennage....I posted a question here as well.

http://www.vansairforce.com/community/showthread.php?t=18188

Enjoyed going back and re-reading all the encouraging replies. And holy **** that was in 2007- I had way too many years of downtime on my project (resumed in earnest about 3 months ago).

You are certainly not alone in making this mistake.
 
Here is the fix for you Tom a double headed rivet. They are hard to get and very expensive. It happens I have one left :D


 
missed dimple

It must be a sickness. My HS has one too.
I went with a recommendation from a local builder/engineer and confirmed by the EAA Tech Advisor. Abandon the error and add two rivet holes equally spaced either side keeping edge spacing in mind. Once it's painted the only sign will be oddly spaced rivets in one place.
 
DRDT2 dimple tip..

Tom,

When you are dimpling holes that are close to the fold of the sheet metal, flip your dimple dies over, so that the male side is in the top and then flip the sheet metal over so the fold goes "under" your bench and the DRDT2. this will allow you to dimple all the way to the last hole and not have to pry open your nicely folded sheet. It will also remove the tension you talked about. This is important for 2 reasons: 1) keeps the work from jumping and 2) gives a nice round dimple instead of a potentially oblong one caused by the tension... Hope this helps. There's no reason you should have any figure eights with a DRDT2! :p Then again, as folks have said, it's fairly commonplace. KPTR my friend...
 
ppilotmike said:
Tom,

When you are dimpling holes that are close to the fold of the sheet metal, flip your dimple dies over, so that the male side is in the top and then flip the sheet metal over so the fold goes "under" your bench and the DRDT2....
Click to expand...

Male die on top is the orientation I always use in the DRDT. Lots fewer "tracks" on skins caused while looking for the hole.;)
 
ppilotmike said:
Tom,

When you are dimpling holes that are close to the fold of the sheet metal, flip your dimple dies over, so that the male side is in the top and then flip the sheet metal over so the fold goes "under" your bench and the DRDT2. this will allow you to dimple all the way to the last hole and not have to pry open your nicely folded sheet. It will also remove the tension you talked about. This is important for 2 reasons: 1) keeps the work from jumping and 2) gives a nice round dimple instead of a potentially oblong one caused by the tension... Hope this helps. There's no reason you should have any figure eights with a DRDT2! :p Then again, as folks have said, it's fairly commonplace. KPTR my friend...
Click to expand...

Good idea! I have seen people do it that way, but did I try that? No. I do think that was probably part of the problem. I was holding the sheet back with one hand, lining up the "male" with the hole and then trying to hold it open with my elbow, moving the lever with one hand and holding down with the other. It must have jumped out. :(
I'm in a smaller subgroup of the Dimple club - those who have screwed up with the DRDT2!
 
JanRV6UK said:
Very often during the build you may need some scrap material to make something out of - Now you have some scrap material .. :)
Click to expand...

That is true. I have ideas for for sheet aluminum, I might have some now. I would also have a lot of the real stuff to practice riveting on - that is probably where the next accident will happen I'm sure.
 
longranger said:
Male die on top is the orientation I always use in the DRDT. Lots fewer "tracks" on skins caused while looking for the hole.;)
Click to expand...

I've just been using the method of male on bottom since that is what I saw in the video I watched. It was hard to line up when you are holding the fold back and searching out the hole at the same time. I'll try flipping it - after I figure out the plan of fix or new. I'm kind of leaning toward "new" now.

Any idea how much this part costs to replace?
 
Pop Rivet Dimple Die

It also works to use pop rivet dimple dies in areas that are hard to dimple with your standard dimple technique. It's a bit slower, but it's much less likely to give you problems.
 
I'm back again - the same problem but different this time.

I've started riveting the skin on the spar and now I realize that the little un-dimpled hole is really the one that was there from the factory. The other hole that is dimpled is my mistake dimple. How did I figure this out? I'm clekoing the skin on the spar to rive and find that the hole I thought was good, wasn't the one that was lined up with the spar hole.

Does anyone have a good idea about a workaround to make this thing ok?
Should I dimple this other hole and have two dimpled holes next to each other then fill in one when it's time to paint?
Or should I try to gently pound out the dimple, put in a new dimple on the correct hole after making it to a #40 size and fill in later?

I already riveted in that single nose rib so I can't pull the skin apart as much as I would like now, but I think I could still wiggle in the DRDT-2 if needed.
Cr@p. Maybe I SHOULD have replaced that skin after all? But it seemed easy enough to fill the hole. Here it is again - http://www.mykitlog.com/users/displ...&project=2260&category=9013&log=172804&row=12

FP24062013A00036.jpg
 
My workaround. A friend suggested that I work out the dimple from the back with a spoon, and a buck bar on front. It took some careful pounding to get he dimple undone, then dimpled the correct hole. Here is the result. Just need some filler when the skin is painted and it should vanish. This photo is actually upside down from the other one, I really did swap the holes.
73104_10201108798138734_1840279778_n.jpg
 
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