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Firewalling It

Ironflight

VAF Moderator / Line Boy
Mentor
RV-3 Progress report for the weekend ? we have a firewall! (Well, almost?.) Louise spent Sunday afternoon measuring, grinding, drilling, and clecoing to produce a very square firewall structure. Building a -3 is definitely an adventure made better by those who have posted their photos before on the ?net. Van?s drawing leaves out many details that have to be figured out by the builder, and I have no qualms in using the answers that others have come up with before. In this case, the corners would be a complete mystery unless you had seen one, or seen pictures of one ? but with that knowledge, they are a piece of cake. Louise is getting very good at precision measuring and laying out rivets, while I enjoy fabricating aluminum pieces from raw stock ? such as cutting the notches for the steel firewall mounts.

Here, Louise is hard at work making sure that the outside ?square? frame is perfectly aligned as she drills it to the stainless firewall:

IMG_3430.JPG


And here is the structure all clecoed together, waiting for dimpling and riveting ? after a little more fiddling with the corners. Need to go look at those pictures one more time?.

IMG_3434.JPG


Work continues!

Paul
 
Hi Paul,
A couple of points from my memory on the firewall:
1) Consider not riveting the steel corner/motormount bkts until you can position the firewall in you're fuse jig and check the fit. The side ear of the top bkt will not match the top longeron, mine were off enouph that I heated the parts and changed the radius slightly so the side was parallel with the longeron, i also put a slight dogleg in the longeron so that it intersects the firewall closer to 90 degrees. A little from both gave me good edge distance without pre-stressing anything.
2) Also think about rivet spacing on the side ear of these parts relative to the bolts in the top ear versus the most fwd #8 nutplates used to attach the top forward skin. The cowl cheek rides up past this point at the firewall making it difficult if not impossible to get a screw in. If I did it again I would attach a second angle on top of the longeron with nutplates for the skin.
Mike
 
Dude;
From what I saw of it, awsome shop!:D how about pics of the rest?

Well, if the shop is so awesome, how come I never have a clear bench-top to start something new? :rolleyes: :D

The shop is merely our hangar at home, with work benches scattered around the sides. A previous owner put in shelves around the walls - nice, but they aren't deep enough to store RV parts!:(

IMG_6684.jpg


Paul
 
dad gum brackets

Hey Paul:

We ended up cutting the side ears off the top brackets & welding on new flanges at the correct angle -- I'm not gonna tweak longerons in that area. We left about a .250 length of the original part for welding to.

One of the tech folks at Vans confirmed the parts were simply made wrong...

The F1 uses a doubler along the top longeron so there is a flange to attach the boot cowl to, and nutplate installation is easier. use .032 x 1.5" x whatever length works out -- we are not that far along yet.

Have you put the actuator brackets into the flaps yet?

Carry on!
Mark
 
Hey Paul:

We ended up cutting the side ears off the top brackets & welding on new flanges at the correct angle -- I'm not gonna tweak longerons in that area. We left about a .250 length of the original part for welding to.

One of the tech folks at Vans confirmed the parts were simply made wrong...

The F1 uses a doubler along the top longeron so there is a flange to attach the boot cowl to, and nutplate installation is easier. use .032 x 1.5" x whatever length works out -- we are not that far along yet.

Have you put the actuator brackets into the flaps yet?

Carry on!
Mark

Good feedback Mark - I'll see how they end up, and we might have to do as you suggest.

We do have the flap actuator brackets drilled and Clecoed in place, and then I quit until later - there's to much excess flap skin in the way to rivet right now, and I figured I'd wait to trim it until we are actually hanging them. Is there a time bomb waiting for me? I recall haveing to do a little trimming to get something to fit - I guess I've blocked out the details!

Paul
 
dad gum flaps

Hey Paul:

I'll take your advice and postpone the fitting until later, but I'm pretty sure one of those brackets is OUTTA HERE! One is .063 mat'l, and one is .040...I kinda doubt both are built to spec.

If this was easy, they'd do it at Wal Mart!

Carry on!
Mark
 
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