C

chris mitchell

Well Known Member
Patron
Continuing the remediation of my part-built RV-4, I have now reached the point where I can fit the rear top skin. I'd be grateful for any hints on how best to do this line of rivets and end up with a nice, fair, even line of rivets....

The F-407 - back end of the cockpit - is very "wavy" and no amount of tweaking will get it straight. I have marked the centre of the flange, and marked 1 1/4 inch intervals in preparation for drilling (flange first then back drilling through skin was what I planned), but I want to end up with a fair even curve with the rivets all in the same plane. Do I need to notch the flange as on the other bulkheads?

I lfoted the bulkhead tops as per the plans/instructions and that seemd OK - will need a bit of shimming but not too much.

Hope I've described teh problem in a recognisable way!!

Thanks

Chris
 
Do not be afraid to cut off flanges that do not fit right. When yo do that, make a new flange from some .032 angle and curve it to match the skin. Now drill it to the skin and THEN drill the new flange to the bulkhead. This will give you a perfect fit with no shims. Make the bulkhead fit the skin. Also, you can move the bulkhead forward or back a bit to make it fit the skin better.
 
Making the new flange

Tom, thanks - so I will need to notch the face of the flange that will be riveted to the F-407, if I'm following you correctly?

So in effect, I'm putting the flange on the top skin and then fixing it to the bulkhead top? Sounds neat!

Thanks

Chris
 
Straight river lines

This little technique may not solve your flange problem but it helps locate the rivet where you want it on the flange . Draw an ink line on the flanges where you want the rivet to wind up. Draw the straight line with correct spacing on the skin and when drilling through the skin first, go slow, find the line on the flange and move it as required to locate the hole on the flange. I don't think your rivet lines will be as straight if you back drill through the bulkheads.
 
You must log in or register to reply here.