Building a 7A v. 12

[LettersFromFlyoverCountry]

People had opined that they wanted to hear my opinions (whaaat?) once I started the RV-12 and how it compares to the RV-7 project. I suspect very much my initial thoughts would mirror those of RV-6 owners v the 7 and 9 "crowd" when the prepunched kits came out.

Anyway, a few main thoughts.

1. I'm not building (at least not yet), I'm assembling. Because I'm building as an E-LSA, I have to do things exactly the way I'm told. These kits are incredible. There's (at least so far) nothing much to do but take the piece and match the piece to another piece that has been finely punched and pre-punched and pre-formed. The extent of "getting your hands dirty" is snipping off a part, kind of like when you had those plastic models and had to snip them off from all the other parts. Fortunately, no airplane glue needed.

2. I miss the ISO drawings.
The step-by-step instructions are completely dummy proof although once you build via the old method, it's REALLY hard to get used to the RV-12 instructions. It's like assembling something you just picked up from Ikea. I find myself longing to see how every part relates to every other part in the big scheme of things. But with the 12 plans, you just have to trust that eventually everything will fit together, so just shut up and do what the step tells you to do.

3. It's really nice not "tooling up." You have to really guard against cockiness on a second build. My goal with the RV-12 is not to order any replacement parts. Not one. When I built the 7A, I actually built two airplanes -- one flew. The other is still in the box marked "scrap."

But it's really great having (most of) the tools needed to build -- excuse me: ASSEMBLE -- the 12 and having the knowledge of what needs to be done (the instructions on the 12 won't tell you to pre-drill (mostly) and deburr, or prime or any of that stuff (that's contained in the pre-build chapters of the instructions.

4. Things go together FAST. I think it took me 4 or 5 months to build the VS on the 7A. That was back when you had to use the jig to do things, and also when I was too stupid to know what I was doing. I build the VS in just a few hours. Working on the rudder now. It took even less time.

5. Van's is really good at this stuff. But I already knew that.

[ppilotmike]

This is probably the way plans-only builders felt when they built their first pre-punched airplanes. Eventually, I fear, the right of passage for our community might only be governed by one's bank balance.

[gfb]

Out of curiosity, for those building an RV-10, is it like this also?

On the RV-12, I heard you don't need to final-match-drill the skins like you do on the 7/8/9, is this true? What about deburring?

[KatanaPilot]

I built my RV-10 empennage, tail cone and fuselage at Synergy in Oregon. Per the plans, the skins need to be match drilled, then deburred and dimpled.

In most cases, we went right to dimpling and skipped the match drilling and deburring steps. Synergy has approval from Van's to do this. We had zero issues with anything lining up. We also back riveted as much as we could of the skins and they turned out beautifully.

They build RV-12's there (Synergy is the "factory" for the S-LSA models) and there were also several RV-14's under construction while I was there. The RV-14 goes together much quicker than the 10, as much of the match drilling seems to be eliminated.

[scottmillhouse]

To echo what Bob said the biggest challenge for an "experienced traditional RV builder" is to follow the RV-12 instructions exactly. I slowly build my 9A and with that experience did not spend much time with the plans on 7 construction since construction is nearly identical. That did not work for the 12. Every time I jumped the gun and did economy moves like riveting in all the nut plates at once, I had to redo because something unexpected went in place and you did not have clearance. The fuselage main section is very different than the other RVs. You would have caught it with the traditional RV full size plans since they show everything but you don't as easily get the full picture with just the illustrated instructions. Not bad, probably better for the first time builders, just different.

To put everything in perspective, it took me 7 years to build a painted flying RV-9A but only 15 months for the 12 even with building lapses.

[rvbuilder2002]

Originally Posted by KatanaPilot

In most cases, we went right to dimpling and skipped the match drilling and deburring steps. Synergy has approval from Van's to do this.

This is totally false

On kits that have the holes punched slightly undersized (RV-10 is one of them), the holes are expected to be final drilled.

Wally has been promoting this for quite a while but it is not with Van's approval.

[60av8tor]

Originally Posted by rvbuilder2002

This is totally false

On kits that have the holes punched slightly undersized (RV-10 is one of them), the holes are expected to be final drilled.

Wally has been promoting this for quite a while but it is not with Van's approval.

I can't imagine even being able to dimple without drilling. Of the thousands of holes that I drilled, deburred, and dimpled, I always knew when I missed one, because my male dimple die would not go in the hole without a considerable (uncomfortable) amount of force. Would imagine that force/stretch isn't doing much good for the hole...

[Lemmingman]

All you have to do is look at a dimpled hole that you didn't predrill through a jewelers loupe and you'll understand why drilling is essential.

[gfb]

Originally Posted by KatanaPilot

In most cases, we went right to dimpling and skipped the match drilling and deburring steps. Synergy has approval from Van's to do this.

Wally was talking about this at OSH last year and I asked him about it during audience questions and he insisted Vans told him it was approved. I walked down to the Vans tent after and was told it is NOT approved and NOT to do it unless I planned to inspect every single dimple for cracks with a loupe.

The problem is not the holes lining up, it is cracks getting created in each dimple from the stress. I was under the impression that this was no longer an issue with the RV12/14 but it sounds like it's still not true?

[David Paule]

Originally Posted by LettersFromFlyoverCountry

....2. I miss the ISO drawings.....

The first page on every chapter shows the iso with the big picture. I've found that helpful when I help a friend with his -10.

Dave