Ivan's RV-7

Removing the crotch strap bracketsTimer icon3h

January 12, 2023

I've got my replacement parts, and removed the crotch strap brackets!

I verified that the new brackets have the same holes as the old ones, and drilled out the old ones. It was quite a bit of work. Nothing too difficult, just tedious. First, I cut away as much as I could using the snips, so I get good access to the factory rivet heads (they are on side of the brackets). Then I marked the center of the hole and drilled them with the #40 drill bit first, then the #30 drill bit. The #30 drill bit would snap the head half of the time, in the remaining cases I used my side cutters to cut the head off (since they were on the bracket side, there was no risk of damaging the "good" parts).

Finally, convince the rivet to come off. Drill the remaining stump with the #40 drill bit to help it squeeze through the hole. Then, either push it with the center punch or pull it by carefully grabbing the shop head with the side cutters.

The old bracket is drilled out.

I put the new brackets, they fit fine. However, since the rib web is a bit wavy now, I need to figure out how to flatten it enough so I have everything good and tight. The holes seem to be still in the range of the LP4-3 rivets (the #29 drill bit does not fit, so the holes are less than 0.136"), but I will take a closer look and decide if maybe I want oversized CherryMax CR3243-4-2 rivets. Pulling them might be a bit of an issue, given how much spacing I have there.

The new brackets are clecoed.