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Section 21 dimpling question

LettersFromFlyoverCountry

Well Known Member
Stopping so I don't do something stupid. Need clarification on Section 21iS/U-03 step 3 which tells you to rivet F-01221-R-1 to the floor, F-01224-R-1.

Step 2 says dimple the two #30 holes but says nothing about the #40 holes in the ribs.

That's significant because 21IS/U-02 tells you in step 4 to dimple those holes in the floor.

Those dimples can't be accommodated in the rib. But there is no instruction I see to do so..

That would be very un-Vanslike so I'm missing something. What is it?
 
2 cents

Stopping so I don't do something stupid. Need clarification on Section 21iS/U-03 step 3 which tells you to rivet F-01221-R-1 to the floor, F-01224-R-1.

Step 2 says dimple the two #30 holes but says nothing about the #40 holes in the ribs.

That's significant because 21IS/U-02 tells you in step 4 to dimple those holes in the floor.

Those dimples can't be accommodated in the rib. But there is no instruction I see to do so..

That would be very un-Vanslike so I'm missing something. What is it?

Hi Bob,
I'm not near my plane nor the plans, so I looked at Van's site and pulled up the drawing. I remember this is an area where I had to "walk away for a bit", clear my head and start fresh. A couple of thoughts...OK maybe more...
Thought 1 - pay attention to the dotted lines in the illustration that tell you to do things only in certain areas.
Thought 2 - the instruction says to dimple holes in the ribs "that correspond to dimpled holes in the floor" (paraphrase) so you're building on what you did earlier, make sure that was done correctly.
Thought 3 - The illustrations are rotated between figure 1 and 2, so make sure you "have your bearings"
Hope this is helpful. It's an area of the construction that is a maze of parts, holes, and lines/arrows. Go slowly and carefully, it'll be fine.
Also, I saw a revision for Section 21 listed. I don't recall if it was related, but worth checking the Mothership.
All the best,
Dave
 
Stopping so I don't do something stupid. Need clarification on Section 21iS/U-03 step 3 which tells you to rivet F-01221-R-1 to the floor, F-01224-R-1.

Step 2 says dimple the two #30 holes but says nothing about the #40 holes in the ribs.

That's significant because 21IS/U-02 tells you in step 4 to dimple those holes in the floor.

Those dimples can't be accommodated in the rib. But there is no instruction I see to do so..

That would be very un-Vanslike so I'm missing something. What is it?

You do need to dimple nutplate holes, which are #40, not #30; you’ll want to dimple every hole that matches up with the baggage floor, except for the screw holes. Later on, you’ll find out that you’re using AN526 screws, which are truss head and do not use dimpling. Just do the holes where the flanges match up with the baggage floor.

BTW, this would be a good time to verify that your fuselage complies with SB 14-12-06, as you would install the SB parts in step 8 on this page...and nothing sucks like re-work.
 
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You do need to dimple nutplate holes, which are #40, not #30; you?ll want to dimple every hole that matches up with the baggage floor, except for the screw holes. Later on, you?ll find out that you?re using AN526 screws, which are truss head and do not use dimpling. Just do the holes where the flanges match up with the baggage floor.

BTW, this would be a good time to verify that your fuselage complies with SB 14-12-06, as you would install the SB parts in step 8 on this page...and nothing sucks like re-work.

That's what I thought. There are two #30 holes on that edge that need dimpling but not having the 40's called out was a signal to stop.

This is the new RV-12iS design, so I'm presuming the fuse complies
 
I just got to this step and was confused as well. Thanks for doing ?the leg work?. I will dimple away!
 
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