How do I "think" about plan instructions?

Hello all

I've in the middle of the wings on my first -7 build and have been struggling with how to "think" about the rather clumsy (IMO) instructions published by Vans.

Don't get me wrong, they work, eventually, but leave a lot to be desired!

As you'll likely know, the emp kit is a step by step walk on the path to completion, easing up a little as the process finished. The wing instructions are much less directive, leaving more to your own ingenuity during the build. There is a mix of "Do this exactly" and "Do what you've done before in a similar manner".

I'm OK with all that, but it can be difficult to parse out the "Must do" from the "We recommend this" methods described. And without a good summary of the work to be accomplished (thought process), it can take many rereads of each section to determine where the next step is going.

In the end, I've decided that what I'm seeing is a haphazard mixture of "Procedure" and "Technique".

For example, while making the Z brackets on the front spar, the instructions clearly state to mark the centerline of each Z flange and drill your holes on these lines. Then later to use the same lines to "ensure" that the holes in the spare line up with these lines before match drilling.

This all sounds great until one of your holes miss the line! At this point the hole on the other side of the Z is already drilled, and now you're in a spot where edge distance is at risk, especially near the root (more than one poster has run into this problem). And since the holes in the spar and ribs are pre-punched, your only only option is to...

search the forum for advice, only to find that there is a helpful soul saying that they had the same thing happen, and to offset that particular Z over 1/16" to fix the problem... ! Argh


I think the instructions would do well to instruct you regarding the end result desired, and then the recommended "Technique" to attain the result!

My conclusion: It's up to the builder to look through the instructions and drawings to determine what is Technique and what is Procedure, and decide where following an instruction blindly (or without a well developed big picture) will result in an error.

Having an experienced buddy nearby who is willing to walk you through all the gotchas (and has nothing else to do!) would likely prevent the errors, but to me would detract a bit from the satisfaction of building a plane yourself!

So assuming that I don't have the dedicated onsite advisor, and don't want to look up every step in the forum before proceeding, what do you all recommend?

Any advice (I know there is!) to share?

Wb

I find this forum (and supporting online build logs) to be an indispensable supplement to the instructions. With the z brackets in particular, I spent the most non-build research time trying to understand the enhanced technique for getting those Z brackets drilled to the fuel tank. Slow if fast in the workshop and for me, copious research prior to starting the next step aids in understanding and reduces mistakes.

Bill (wild): sent you a PM


Doug
Seattle area (74S)
-4, wings
VA-196 '79-82

Hey Bill, I understand your frustration.
For the empennage you are relatively spoon fed, which is a good thing at that stage. Beyond this, Van's start taking a step back and I think in hindsight it's not all bad.

At some stage of the build you have to make the transition from being a aparts assembler to an aircraft builder, as the aircraft you finnish will have little resemblance to the prototypes they wrote the instructions around 20 years ago. Back then there were essentially no autopilots, EFIS screens, electronic ignitions, sikaflex canopies, insulated firewalls, andair wing root gascolators, brake piston spring upgrades, carbon fiber canopy skirts, lithium batteries, LED lights etc etc etc... so you will enevidably get to the point where you have to start taking a step back and looking at the larger implications of your actions rather than just believing that this will be a spoon fed process all the way to the end. Having this awakening now is a good thing, as it is generally cheaper making mistakes early in the process then it is toward the end (both from a time and $$ perspective). I feel sorry for people with no experience picking up a 90% complete kit, thinking that it will be a fast track to the endpoint. For them, mistakes become costly quickly and they know little about their aircraft at the end of it.
The upside is that many have been through your point beforehand and have taken the time to document it. I got to the point where I barely picked up a part without googling "vansairforce partnumber" before I did anything to it. The vast majority of the time, google would lead me to a thread where the issue had been discussed on this forum. I do have to give it to Van's in that their drawings for these earlier kits are amazing and rarely have mistakes, but yes, the written instructions leave a lot to be desired from the wing onwards.
There is also the gottcha thread that many have contributed to:
http://www.vansairforce.com/community/showthread.php?t=120747

I also had to order a second set of Z brackets, but keep in mind that I'm on an island on the other side of the world to the factory, so being able to get the part tomorrow in your case isn't so bad (mine took an average of two weeks, but often longer if they got stuck in customs). Besides, you wouldn't believe how often you end up using those z brackets (or bits of) when you make small fixtures/mounts etc as you get toward the end of the build, so they won't be wasted.
You'll feel so much better at the end of this rather than someone who "builds" a two week to taxi aeroplane, as you will truly understand every piece of it.

To wrap things up, what you are looking for to resolve your z bracket problems is the method formally known as the Checkoway method. Dan doesn't like it being called this because he says he didn't make it up, but he sure made it famous. If you want a copy of my log that outlines how I botched then addressed properly this z bracket issue, shoot me a PM and I can forward you my build log, which is just a 100,000 word MS Word document that you can quickly word search for solutions.

Good luck.

Tom
RV-7

Gotcha thread

The Gotcha thread is your best resource for identifying steps where it pays to slow down. Before starting any component, run a search for the part number. If there's a problem, someone posted it. Find a few builder web sites you like and read how they did it. I get a lot of hits on mine. Finally, if you find a better way, post it to the Gotchas thread so the next builder ca benefit.
The Z-bracket tip works great. I detailed it on my blog.

To echo sentiments above...never stop reading. I think I've read through two or three build logs from "cover to cover." IMO there's no such thing as too much information - the more reading you do, the more you'll identify common gotchas like the tank brackets.

I used the Checkoway method for my tanks and it worked great.

But...

Yes, information is good...but...you have to avoid ?paralysis by analysis?.

Realize that there will always be a better way or a new gadget or new mod that you absolutely have to have. At some point you can?t wait any longer and must push forward...if you want to finish your project...

All instruction manuals are a compromise between being too light and too heavy. Too light and people complain. Too heavy and people stop reading.

I challenge anyone to write up their own procedure for any set of instructions that seem lacking. Then post them here. Everyone wins!

Bill, I feel your pain! I’m slightly behind you - working on the spar. Lately I’ve spent more time searching the drawings for an elusive detail and doing internet searches than actually working with a tool in hand, and I’m just hoping that I get better at it because at this rate.... What keeps me going is knowing how many RVs have been built, many with less pre-fab than our -7s, and in those dark times before internet.

Sorry, I know that’s not an answer to your question!

Good Luck!

I feel your pain, been there myself- you are asking the right questions. The way to think about the plans is to think them through before beginning any task. A big part of getting an airplane finished is to learn how to think like an experienced craftsman. Finding all the details in the plans is really part of the job description- accepting that is the first step to really learning how to visualize a task and anticipate mistakes. In your off time, when not building, think about what is next to be done and how to do it- for me it's on the drive into work or when I first wake up. It's amazing how a good night's sleep clears the mind. Set the task, not the schedule. Hang in there, the journey is well worth the trouble! Stay positive, you are having fun, doing what you are doing. Hope this helps, and to finish, a friend once told me "it's an exclusive club"; finishing a airplane that is.

also try and be attuned to that small voice that says “I’m not completely sure”

If you hear it, STOP, and hit VAF.