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Rivet Spacing Main Beam Inner Wing
http://t18.net/thorpforum/viewtopic.php?f=3&t=8673		 Page 1 of 1
Author:  rrobut [ Wed Jan 19, 2022 5:52 am ]
Post subject:  Rivet Spacing Main Beam Inner Wing
Deciphering the plans on Drawing 227. Called out are 144 AN470 AD 4-8 rivets between BL18.0816 and BL41.375

Does this mean there are 36 rivets on the top Spar Cap and 36 on the bottom angle cap at each end.

Thanks for the help

Rob
Author:  Ryan Allen [ Wed Jan 19, 2022 7:21 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
Rob
My DWG 227 only shows 18 rivets between BL18 and BL41. I may have an old set of plans. I was able to come up with 144 by counting the 18 rivets called out in my plans on the top cap (between BL 18 and BL41), and then I doubled that number to get 36 rivets across the top cap (for one side, I assume to address the smoking rivet issue). Then multiply 36 by 4 for each upper and lower cap to get to 144?

Im sorry, thats really not any help at all....
Author:  Rv3maker [ Fri Dec 08, 2023 5:42 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
I know this thread is a couple years old, but I am currently building/assembling my inner wing and I have run across the same question. My inner wing skins and center upper/lower caps are drilled with the single row of rivets per S-18 drawing 227 (and drawing 200) how Rob explains.

When I look at my plans, however, the notes left by the previous builder (who seemed to be very knowledgeable) says the stagger pattern was for the T-18 wing (longer inner wing section?). The SDR does not specify whether it is specific to the T-18/T-18C/S-18. Reads, "Extra Rivets Added To Main Spar- Refer to T-18 Drawing A-532, -537, Newsletter# 49".

Is there anyone who has built both wings and can provide experience/advice? I have only seen one other S-18 that is local to me and it it built per plans and only has the single row of rivets per plans. Currently thinking for S-18 a single row is acceptable as designed.

Thoughts?

Rob
rv3maker
S-18 SN46 - building inner wing

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Author:  fytrplt [ Sat Dec 09, 2023 7:36 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
I have built both T and S wings. Double row on each version. On the T, I had already single riveted the skins to the spar. A conversation with John Thorp assured me that beacause I had used .032 alclad on the inner wings, I could countersink the added row. I did and no problems after1500 hrs
Author:  James Grahn [ Sun Dec 10, 2023 5:05 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
I recommend a staggered double row.
Cubes
Author:  Rv3maker [ Thu Dec 28, 2023 11:11 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
Staggered second row marked and drilled out with #40 drill bit. I will transfer drill to the already drilled skins with a #40 13" strap duplicater on each end and then cleco and enlarge to #30. Then remove skins and debur/countersink.

Some pics. Thanks for the inputs...onward!
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Author:  Rv3maker [ Fri Jan 05, 2024 12:31 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
RH inner skin fitted and staggered rivet holes drilled. Now to disassemble, debur, countersink and dimple.

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Author:  James Grahn [ Fri Jan 05, 2024 3:08 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
And you made the skins wider than plans because you are fitting it on a T fuselage, correct?
Cubes
Author:  Rv3maker [ Fri Jan 05, 2024 3:25 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
Hey Cubes,

Verified skins are width of S-18 drawing 200 (-1L/-1R). There is one minor difference I see at the outer flap mount bracket cutout. I may have to make a filler piece there - still assessing.

Fitting to a S-18 fuselage.

Rob
Author:  Rv3maker [ Fri Jan 05, 2024 3:28 pm ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
I could move this thread over to the S-18 wing section. Started here since I was initially discussing the added staggered rivet pattern on the spar caps.
Author:  James Grahn [ Sat Jan 06, 2024 2:57 am ]
Post subject:  Re: Rivet Spacing Main Beam Inner Wing
Oh. Sorry. I thought you were fitting to a T fuselage. My bad.
Cubes
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