building question

rv4dude17 · #1 07-01-2014, 09:33 AM

On drawing page 26 and 31 of the rv4 plans set, there shows to be a 3/4 x 3/4 x 1/8 piece of angle that attaches to the WD-403L&R. It is in addition to the lower longeron and it is angling up toward the F404 bulkhead.
I cannot find the detail of this anywhere in the plans. Am I missing something?

chris mitchell · #2 07-01-2014, 04:14 PM

You should have two pieces of angle, somewhat splayed ie the angle is greater than 90. Run from WD403 back to F404. Need to fit around F402.

But I agree that the details are sketchy at best. I haven't quite got there yet, hence no pictures. Perhaps someone can post a few plus a "this is how I did it".

Good luck!

Chris

rv4dude17 · #3 07-01-2014, 10:16 PM

I don't mean the splayed angles on the floorboard, I mean the angle that is a few inches above that.

I see how it attaches to the WD-403 and goes through the 402 bulkhead, but I am not sure how it attaches to the 404 bulkhead or is just riveted to the fuselage side skin.

I am considering making another anchor similar to the F-443 and bolt it to the wing spar like the center tunnel is done.

Suggestions or comments??

chris mitchell · #4 07-02-2014, 12:01 AM

Sorry - my mistake - too idle to go look at the plans out in the garage.

Front end - look at romeolima.com, fuselage section. There a few photos of how to deal with the front end, with an extra gusset.

The length of angle is definitely riveted to the fuselage skin for its entire length.

At the aft end I think your idea of a bracket sounds good. Look at drawing 27, section E-E'; there is a convenient bolt at the lateral margin where the angle runs to, though if the rear of F413 and the rear of this piece of angle are at the same level at F403, the bolt hole is a little high. I think the limiting factor is the front of F428 as this will determine a minimum angle for this bit of angle. (We need a name or number for it!).

Unless anyone chimes in with better info I think this is what I'll be doing.

Chris

rbibb · #5 07-02-2014, 07:29 AM

The angle piece in question is riveted its entire length to the side skin. There is no additional attachment to the main spar bulkhead. At the forward end the thickness of the angle has to be milled such that it will lay flush with the side skin while overlapping the firewall weldement as shown.

Does that help?

rv4ross · #6 07-02-2014, 08:27 AM

Spence,
I would be glad to email you a picture of that stringer. Send me a PM with your email and it will be on the way.

Ross Scroggs
RV4-3911 Canopy fun

Brian Vickers · #7 07-02-2014, 09:04 AM

If I understand you correctly, drawing #39 shows the angled component, but doesn't give any dimensions for placement. These photos are the best that I have. The aft end has some metal removed, so it overlaps the doubler surrounding the spar opening in the fuse sides. The RV-4 drawings are really great, but do have a few small omissions.

rbibb · #8 07-02-2014, 10:15 AM

OK so much for going from memory. My earlier comment should have said the aft end was the one that needed milling to lie flush wit the skin. And it does technically attach to the wing spar bulkhead as it is riveted to the piece that frames the spar opening. The previous pictures should make this clear?.

az_gila · #9 07-02-2014, 10:38 AM

If it's like the RV-6, that stiffener is too thin to "mill away".

This is what the RV-6 plans show at the similar location at the main spar bulkhead - a notch and a joggle in one side of the angle -

rbibb · #10 07-02-2014, 11:02 AM

The -4 is different. There is a single 0.063 plate that the angle has to overlap. So milling (IIRC correctly the plans state "file away material as required" or something like that. Since the angle is 0.125 thick you remove half (or in practice a bit less to get the angle to lay flat against the plate piece of the bulkhead assembly and the fuselage skin.