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tx_jayhawk

Well Known Member
This should be obvious, but I don't see it specifically called out in the plans...

Should both the hole in the bottom skin and the corresponding hole in the 7A gear weldment be enlarged to 5/8" for the AN brake fittings? I see it says that the skin hole should be enlarged, but I don't actually see that the gear weldment hole should be enlarged.

I hope so, as the unibit already has it on its way...

Thanks,
Scott
7A Fuse
 
you'll need to enlarge the weldment, but I don't think it's 5/8".. Grab the appropriate fitting and just make sure it fits.. (the fitting won't go through the existing hole as it's too smal.. but looks just a little too small.. ).. so don't rush with that..
 
Doh!

Yeah, I think I blew it. I thought it would be smart to drill out the skin with the weldment in place, and I enlarged the hole in the weldment to 9/16". Without rewelding or replacing the weldment, is there a way to mount the right AN fitting in an oversized hole?
 
5/8 It Is

Refer to drawing 28, bottom left. It shows the call-out for the hole size.

Mike R.
 
tx_jayhawk said:
Yeah, I think I blew it. I thought it would be smart to drill out the skin with the weldment in place, and I enlarged the hole in the weldment to 9/16". Without rewelding or replacing the weldment, is there a way to mount the right AN fitting in an oversized hole?
Click to expand...

Not a huge problem - the exact location of the fitting isn't critical (within an 1/8" or so is fine). If it were me, I would use three rivets and rivet a sheet of .032 or .040 aluminum onto the weldament and redrill the sheet. You are just looking for something for the fitting to get tightened down on.
 
Thanks Kevin...I think riveting a doubler is the way to go. Does the nut go on the bottom or top of the weldment? Anyone have a picture of the weldment with the AN fittings installed outside of the airplane that they could share? I'm having a little trouble visualizng this, and I still don't see where it is shown in the plans.

THanks,
Scott
7A Fuse
 
Glad I read this post

I hadn't really looked at the weldments to closely at the time I was enlargening the bottom skin, so I avoided the 5/8" mistake. I have my weldments in place and just looked at the hole you are talking about. I measured the fitting and it came to 7/16", so I drilled a test hole in some scrap .063 to 7/16". The threads on the fitting made a very tight fit, but once I worked the fitting in, it fit very nicely in the 7/16" hole, so I drilled the weldments to 7/16" and they fit fine. The hole must be close to it initially. Perhaps the powder coating simply needed to be removed to get them to size.
 
Radomir,

Would you happen to have a pic of the bottom side of the weldment (with fitting installed)? I am trying to determine whether I should rivet the doubler to the top side or bottom side of the weldment. I've seen pics of the bottom of the skin, but I was wanting to see how the fitting mounts to the weldment itself.

Thanks,
Scott
 
Sorry don't have one.. didn't even occur to me to take a pic like that.. And now that the weldment is installed, best I have is bottom of the skin.

There's plenty of clearance, so you could put the doubler on either side and I don't think you'll have a problem. Bottom side may be a bit better cosmetically (doublecheck it though).

I put up some new pics, not sure how helpful they'll be:

http://www.vitez.net/rv7/fuse


HTH
Radomir
 
I hadn't heard of people doing that to keep the cabin from collapsing. I HAVE heard of people doing that to preent the arm rest from collapsing when passengers mistakenly use it to pull themselves up to get out of the cockpit.

I didn't bother. Didn't want to add the weight and it seemed fine.
 
As Bob Collins mentioned it.. it would help a little if pax would try to pull himself out using the armrest. I only put it on the passenger side, thinking "pilot will know better"
 
Bob Collins said:
I hadn't heard of people doing that to keep the cabin from collapsing. I HAVE heard of people doing that to preent the arm rest from collapsing when passengers mistakenly use it to pull themselves up to get out of the cockpit.

I didn't bother. Didn't want to add the weight and it seemed fine.
Click to expand...

A couple of years ago the Australian Transport Safety Bureau followed up the investigation of 2 fatal RV6 crashes with a report suggesting that the cockpit area may not be strong enough. It suggested that the buckling of the cockpit walls in both crashes had allowed the occupants to move forward in their seat belts and impact the panel.

As a result I understand some builders have put in a stiffening member in that area.
 
Why rivet on a doubler...just use some washers on the fitting and tighten the fitting down. I do that on all the fittings on the firewall since the SS since extra support is needed there. If the hole is a little oversized, it won't make a difference.
 
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