Author: "Andrew" <dorandrew@...> Time: Thu Sep 4, 2003 7:45 pm PDT Link
Hi every one.I have spent 7 hours clamping, grinding, measuring, and
a lot of head scratching. I have come to the conclusion that
something is wrong or I need to sleep on it. All of my formers from
F407 aft are sitting 1/2" or less high(as measured in the jig).I can
get the center, bottom flanges to line up for skin installation. How
important are these dimensions? Will I have enough skin to cover? It
starts at 1/2" at F407 to 1/8" at F411. I know ther will be other
dimensional consideration I need to check going Fwd.
Thanks Andrew
Author: "Jeffrey Hall" <jhallrv4@...> Time: Thu Sep 4, 2003 9:24 pm PDT Link
"7 hours clamping, grinding, measuring"
Andrew, I hauled out some pictures to remind myself of what the F407 was, and as I suspected, it's the one right behind my wife.
When you say "height" do you mean the bottom of the formers as in the jig, or the rounded "tops" as it will sit out of the jig and in "airplane noises" position? Both obviously will have to be in-line in the end! I had to, and I think most did have to expand or contract the F407 top and bottom parts "to fit" as opposed to lining up the tooling holes. That said, you will need a tight line or laser (preferred method)to line up the formers. The F407 to F410 are the most critical, as these hold single length pieces of skin. The bottom line (right side up)though goes to F412, and the top line (right side up)stops at the little separate piece that sits at the aft end of the aft top skin. That little piece doesn't have to go exactly where shown on the plans...it goes "to fit", as it just attaches to the rear deck and holds the end of the aforementioned skin. Clamp the stringers all in place to line up the formers, and you can move the F409 fore or aft a bit to fit, as there are no skin overlaps at this location that needs to be riveted to the formers. The F408 is a little less forgiving, as the baggage floor ribs go there between the F407 and 408. In fact, this area may help establish the line for the rest of the formers aft. This would be a lot easier to show than to explain. (obviously) Where are you located? Let's see if we can't get a 4 builder out there!
I hope this rather rambling essay gives you a starting place, and hopefully some other, more recently done builders can add their 75cents worth. (Used to be 2 cents, inflation ya know)
One more thing, while you want to get the top fwd skin as close to fit as possible, many of us have had to use little dimpled spacers (.016, .025 etc.)between the former and skin to get a nice smooth surface. Remember, when you rivet, the skin and former may give a bit, so you want it to start out with no "give" before riveting. Back riveting works best there, it's noisy in the tailcone regardless!
Jeff H.
[Non-text portions of this message have been removed]
Author: "staart" <staart@...> Time: Fri Sep 5, 2003 9:09 am PDT Link
Andrew
I don't know what vintage your kit is but I do know that some needed to either move the bulkheads fore or aft, or "float" the flange at the bottom to sit on the skin. Fit the bulkheads to fit at the top of the turtle deck then if you come up short or long at the bottom you cut the flange off and make a new one. Seen this several times, even did it to 2 of my bulkheads. I removed the flange plus about 1/2 inch up of the bulkhead, got the skin clicoed in place, made a flange, cut the part of the flange that is to be riveted to the bulkhead so it would curve with the skin. I riveted the new flange to the skin first then to the bulkhead. It doesn't take long, hope I didn't confuse you.
Randy
----- Original Message -----
From: Andrew
To: RV-4@yahoogroups.com
Sent: Thursday, September 04, 2003 6:24 PM
Subject: [RV-4] Aft fuselage jigging questions
Hi every one.I have spent 7 hours clamping, grinding, measuring, and
a lot of head scratching. I have come to the conclusion that
something is wrong or I need to sleep on it. All of my formers from
F407 aft are sitting 1/2" or less high(as measured in the jig).I can
get the center, bottom flanges to line up for skin installation. How
important are these dimensions? Will I have enough skin to cover? It
starts at 1/2" at F407 to 1/8" at F411. I know ther will be other
dimensional consideration I need to check going Fwd.
Thanks Andrew
Yahoo! Groups Sponsor
ADVERTISEMENT
To unsubscribe from this group, send an email to:
RV-4-unsubscribe@egroups.com
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]