I thought this section would go faster but soon learned that it is a fairly labor intensive sub-assembly. And...if I thought I was done doing ribs once I had the wings behind me, I was dead wrong. Between the seat ribs and the baggage ribs...plenty of fluting, yeah, remember that? deburring, dimpling and priming...time consuming.
It dawned on me...as I've evolved as an aircraft builder over the last couple years, how I've changed. When you first start on a sub-assembly such as this one, it all looks so confusing as you scan the prints and read the instructions....that hasn't changed.
But, as a seasoned builder, it now quickly begins to make sense...I find myself reading the instructions less and less as I now have a pretty good feel how things go together when I look at a print. The other thing I've noticed...by the time you spend ~30 hrs building something, by the end, when you are riveting it together...you are very intimate with every detail of the construction. Funny how that perception changes so drastically during the build.
These two tie-in pieces were kind of hokey the way Van's had them called out. I redid mine, and somewhat copied the way Jason Beaver (good RV7 site) did his to add a little robustness to them. I still don't think they will do much in the way of strength, but whatever...these are improved over the Van's version.
I kept thinking I was missing something as I was building this middle section? The crotch strap attach points!?? I seen no mention of them in the plans so I was left scratching my head, wondering why? Finally, after rummaging through my remaining parts I found a separate kit that had everything I needed.
Doing layout...mine came out crooked which kinda ticked me off. But...you wont see it, and it wont compromise the strength...build on. Just be careful when you do yours, they can easily get crooked.
I am going with either Hooker harnesses or more likely, Crow harnesses. Both of which use a 5/16" gap so make sure you adjust from what the plans say...the Van's version are not as thick.
Dan Checkoway had added a small hidden compartment in his baggage area for a quart of oil and tool kit. I don't think it was his original idea, but I liked it nonetheless. So, here I am cutting one (6" x 14") into my baggage floor.
As you can see, plenty of room for a quart of oil. It can also slide forward under the edge of the baggage skin. I will ProSeal this compartment, prime it and carpet it later for a nice finished look.
And unlike Dan, I did two of them, one on each side. I also am adding a piano hinge and cam lock. He used screws/nutplates. One side can have a quart of oil and small tool kit and the other can be used to lock up valuables when needed. Since it will also be under the carpet, it will be concealed for a little added security.
Disclaimer: whenever you cut something out of the original design...you must consider the consequences of what that might do to the integrity of the structure. I realize a cam lock wont offer any strength like a nutplate would. I don't think the aircraft will have high flight loads in this area, so I feel ok with it...but I could change my mind later. Just keep this in mind when and if you do mods...nothing is without its consequences, weigh them carefully before proceeding. I stared at this for an hour and a half, thinking about it, before I cut metal. :)
In the plans, it says to add some holes for adel clamps for wire routing if you plan to mount your battery in the tail. Not sure I will do that, but I liked the idea of adding extra holes for cable routing of any kind if I needed it later.
Dimpling the bottom, middle fuse skin...this bugger was kind of a pain to horse around...its shape makes it almost square, harder to manipulate than the rectangular wing skins. But...there's only one...and I knocked it out without too much trouble.
A removable bracket that will allow access for the control column to be added later.
Installing nutplates...did I mention that? ...another time consuming task on the ribs.
I used solid rivets (vs. pull rivets per the plans) on the crotch strap brackets. I figured why not as long as I have access to do it? I still have to drill a mounting hole for the strap attach point since the Crow's are slightly different here too, but I can do that later when I get my harnesses.
As you can see, I have this AN3 bolt (on the left side of the pic) torque sealed from earlier...I need to remove it for the outer seat rib. Oh well, not a big deal.
These outer seat ribs (far left in the pic) need to be match drilled to the bottom skin. As you can see from this pic, these ribs have a nice curvature to them whereas the others are straight. So, what you have to do is, flute them...but instead of fluting them to straighten them out like we normally do...over-flute them so you can get that needed curve. Lay it down next to your holes as a guide and you can perfectly match the curve.
Here is my centerline that I drew as a guide. As you can see, when the curvature comes out right, you can nail the centerline during your match drilling.
And here is my first riveting on the skeleton...attaching the seat ribs to the rear spar carry-through. Each rib also gets an AN3 bolt top and bottom. I torqued these...and then went back and double checked them again, then applied torque seal immediately after the second go 'round. These are important and you dont want to miss one. I think some builders are way too anal about too many things...but with stuff like this, you cant be too anal in my opinion....this is a vital part of the aircraft structure.
No comments:
Post a Comment