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Fixing miss-drill

General building discussions, not model specific.
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cgroves
Posts: 129
Joined: Wed Aug 23, 2017 5:30 am

Fixing miss-drill

Post by cgroves » Sat Mar 20, 2021 7:40 am

Found this gem when I went to debur a part, must have moved after measurement. Suggestions on how to fix this? Hole is only 1.5D from outside edge. I could fabricate a new rib but would rather not if I don’t have to, would need to drive hour each way to use the chapter’s box break. This is a diagonal rib and these are the holes attaching to the trailing edge. Whole assembly gets fabric covered so extra holes are not a cosmetic issue. Only looking at structural.
4FF589B8-8E6A-4A0D-A44F-D87F443AAE17.jpeg

snowyriver
Posts: 1161
Joined: Wed Feb 22, 2012 9:10 pm

Re: Fixing miss-drill

Post by snowyriver » Sat Mar 20, 2021 4:15 pm

Well you could put a doubler on the underside to make the area stronger.
Craig Walls
Retired Firefighter
Flying as of September 2011

Elite583
Posts: 184
Joined: Wed Feb 29, 2012 9:11 pm

Re: Fixing miss-drill

Post by Elite583 » Sat Mar 20, 2021 5:05 pm

You may feel better about it after reading this article. It puts a bit of math into the discussion.

https://www.eaa.org/eaa/news-and-public ... e-distance

At the end he skips quickly over the math but the idea is that for a rivet with a given shear load capacity (force to shear it off) there will be an edge distance (loaded area) in the sheet metal that equals the shear load capacity of the rivet and you get nothing by increasing the edge distance because the rivet fails first and in his calculation that's <1.5D. Per the Q & A on the ACS web site these are Avex rivets.

https://www.aircraftspruce.ca/catalog/h ... rivets.php

Cheers,

Dave
Elite 583

snowyriver
Posts: 1161
Joined: Wed Feb 22, 2012 9:10 pm

Re: Fixing miss-drill

Post by snowyriver » Sun Mar 21, 2021 7:16 am

The piece looks to be a channel so some sort; if so, it seems it would be loaded like a beam, in tension on one side and compression on the other. The force on the rivet would be a stretching, not a shear. Craig
Craig Walls
Retired Firefighter
Flying as of September 2011

cgroves
Posts: 129
Joined: Wed Aug 23, 2017 5:30 am

Re: Fixing miss-drill

Post by cgroves » Sun Mar 21, 2021 10:27 am

This is the trailing edge of a control surface, kind like this:
IMG_3639.png


cgroves
Posts: 129
Joined: Wed Aug 23, 2017 5:30 am

Re: Fixing miss-drill

Post by cgroves » Mon Mar 29, 2021 4:32 pm

The math sounds good but it is a straight rib so it is relatively easy to fabricate a new one that is a hair longer.
08950623-DDAF-42AC-8BE0-43E8B887BBA2.jpeg

snowyriver
Posts: 1161
Joined: Wed Feb 22, 2012 9:10 pm

Re: Fixing miss-drill

Post by snowyriver » Wed Mar 31, 2021 10:14 am

Yes, almost every part in your kit can be made with a hammer, brake, and some aluminum. A router with a pattern bit, some mdf, and a spindle sander are also helpful. Glad you got it figured out!
Craig Walls
Retired Firefighter
Flying as of September 2011


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