RV-7/7a Plan Gottcha's

[sahrens]

When referencing the rivet call out on plans page 28 be sure to check page 44 for the screw call out. There are nine locations under the horizontal stabilizer that will be tapped for screws to attach the lower tail fairing. On page 28 it shows rivets in those locations.

[bret]

QB wings will need the rear spar trimed to corect sweep when doing the rear spar - fuse drilling.

[wirejock]

I wanted to document some of the issues I found with the revised manual pages for noobies. If this is your first component, I suggest building the Vertical Stab first. There are a few tricky spots on the HS.
1. Page 6-2. Drill a #30 relief hole in HS702.
I marked the location of the hole according to plans then placed the 702 spar on a 45 degree square and center punched with the punch held 90 degrees to the bench. This placed the mark exactly at the 1/2 radius bend line of the spar flange. From here it's easy to enlarge to 1/4" and trim the ends of the flange per plan.
There is also a trim on the ends of the spar flanges shown on the trim detail where the most inboard skin hole would be. This part can't be cut until you know where the second hole from the center on the spar flange will end up.
2. Bend the HS 710 and 714 angles
Mark the line, place in a vice between pieces of wood block. Measure the starting point with a protractor and bend carefully till the protractor reads 6 degrees. Creep up slowly. Remove it and check several times. Note HS714 is much harder to bend than HS710.
3. Notch the aft flange of HS00006.
Don't do it per plans. Place it between 710 and 714 and see how much needs to be cut. It's not much.
4. Prepare the ribs.
I recommend drawing center lines on the flanges of the ribs and the spars. They come in handy later.
5. Page 6-3. Match drill the holes in the skin to the HS00005 rib.
The manual then directs to clamp parts together to drill flange to spar holes. I would not drill skin holes till all structural holes are drilled and clekoed tight.
As usual YMMV.

[gasman]

Originally Posted by sahrens

When referencing the rivet call out on plans page 28 be sure to check page 44 for the screw call out. There are nine locations under the horizontal stabilizer that will be tapped for screws to attach the lower tail fairing. On page 28 it shows rivets in those locations.

this faring will never need to be removed..... just rivet it on.

[wirejock]

When you fabricate the F-601J Angle, make note that it doesn't lay flat against the F-601M Stiffener. There's a note on the plan to set it 3/32" above the top face of the stiffener. There is a note to radius the edge to fit inside the stiffener but it requires very little as it is not resting on the flange.
More parts for my scrap pile and more waiting for aluminum angle. My fault.

[wirejock]

When you fabricate F601P, don't drill the hole per plan. Radius the edge, fillet the corners so it fits into the notch in F-601C. Place it in the assembly, cleko the surrounding parts and mark the hole from the back side with a sharpie. Then remove it and drill the hole where it needs to be. You'll get a better fit on the part. Yea. I made two more.

[wirejock]

The destructions say "fabricate F-633". After studying the plans for a detail, I finally looked at the inventory. It's already built. They are in Subkit 13.

[DaleB]

Maybe this would be a good place to mention...

I believe more than one of us has probably searched high and low for angle pieces to make F-628B, F-629B and other pieces. I know I had a stack of long angle pieces that were packed with the wing spars, all of it carefully put away and was not sure which were used for the fuselage longerons and which were safe to cut up.

Fuse longerons are .125 angle. The .063 angle can be used where needed, so you (probably) don't have to order more from Van's.

[wirejock]

This is starting to get an annoying.
The destructions say to grind the columns and bushings to a slip fit into the column weldments. No problem. Note that the control sticks should pivot smoothly on the bushings just like the bellcranks. So the bushing should be a 64th-32nd longer than the column. No problem. Done that. The problem is, in my case, the bushing does not fit well. I had to clean up the hole in the column so the bushing rotates smoothly.
After looking closely at these holes, the welding process leaves bumps inside the hole. They even zip tied the bushing inside the column as if it would fall out. Mine fit so poor, I had to drive them out.

[BillL]

Originally Posted by wirejock

This is starting to get an annoying.
The destructions say to grind the columns and bushings to a slip fit into the column weldments. No problem. Note that the control sticks should pivot smoothly on the bushings just like the bellcranks. So the bushing should be a 64th-32nd longer than the column. No problem. Done that. The problem is, in my case, the bushing does not fit well. I had to clean up the hole in the column so the bushing rotates smoothly.
After looking closely at these holes, the welding process leaves bumps inside the hole. They even zip tied the bushing inside the column as if it would fall out. Mine fit so poor, I had to drive them out.

These bushings in the stick are problematic. The tube welded to the stick gets distorted slightly, then the tube is DRILLED, and it is typically no longer round. I have two sticks to prove it. You would do well first to ream the tube for the bushing, then measure both. It will likely be loose, but with a little extra length before installation, it will crush slightly and expand to help fill the gap. More than .001 clearance and the stick will be loose.

I have many more details and a long tale to go with them. Let us know more specifics of your problem.

My original stick was loose, in the tale, a new stick was purchased, still loose, and I made a custom bushing to fit. Fits nicely now, no slop.