gear weldment

Hi folks,

In the below photo, the plans recommend double flush riveting in the area where the gear weldment snugs up against the spar carry through flange (red oval). A couple of questions, it looks like there is room for a normal shop head (i.e., not double flush). Are most people finding they need to double flush? Also, what is the sequence here? The plans say to rivet on the side skins, but the gear weldment would have to be in place first, no? When does the F-972 bottom skin get riveted to the F-976 center section? Seems that would have to happen before positioning the gear weldment.

Any help??? Thanks again as always

I think many people, myself included, have found that there was plenty of clearance in this location for normal shop heads. That being said, I believe I very lightly countersunk mine just in case.

As for the sequence, the weldments will go on later, once the side and bottom skins are on and the fuselage is right side up. They do not have to be in to rivet the side skins.

Chris

Good question Tom. I remember I researched the same subject years ago and decided the normal shop head would fit. Well, the right fit but on the left side I had to shave couple rivets just a hair there was an interference. Stick to the plans Tom.

Thanks guys. I guess the question I have relates to the two screws that attach the weldment to the gear attach web - are they THROUGH the F-970 side skin so that the screw heads are visible from outside? That appears to be the case from the drawing below.

Yes they are visible outside. Take your time countersinking make it look better then mine

They should look like this on the outside.



Match drilling both holes from the inside is impossible due to the side flange covering one of the holes. Just transfer the location of the one hole that you can drill over 1" to match the spacing of the holes on the weldment. Start with a small drill size and then work your way up to full size with the weldment in place and it will get lined up perfectly.

Tom,

I'm building a taildragger -7, but in that first photo, it looks like it would be a close fit by the time you stack a standard shop head on top of a dimple. You might dimple one of the more inboard holes and see how high the dimple is, then add 3/64.

Thanks!!!

Thanks everyone for your help. It's all clear now. Ya really gotta love this forum!!!