rjcthree

rjcthree

Well Known Member
I'm drilling the rear spars. I came up against an obvious issue that may be simple interpretation.

The rear spar bars are 1 1/2". The instructions require a 5/8" edge distance. The hole to be drilled is 5/16" diameter. See the problem? THe math doesn't work. I took this to mean there must be 5/8" stock all around the hole post-drilling.

OR . . . do the instructions mean that the CENTER of the 5/16" hole must have a 5/8" edge distance?

The engineering handbooks interpret this both ways, and since the GD&T of the drawings is a little weak (non existant) I've got nothing but you guys to ask.

Right now I'm about 1/64" off of dead center (vertically) of the rail at 1/4" dia hole, so I can center if I must. Just looking for some clarification. I'm likely overthinking this one.

Rick 90432

PS: it's entirely possible to install the wings by yourself with a table, car roller skates and some patience. Takes about a half hour. ;)
 
Rivet edge distance is defined as the distance from the center of the rivet/bolt hole to the nearest edge of the sheet.
 
Edge distance

I have that documented for rivets, but the bolt hole edge distance is not as clear(from a handbook/guidance perspective). In all honesty, I haven't gotten out AC-xxxx yet to see what it says. Rick
 
Drawing

The RV-8 drawings depict this on the plans. Looks like center of hole to edge of material to me. What do your drawings show?

RearSpar_zpsfc3ea6dc.jpg
 
I'm building an RV-8, and the drawing above is good.
I think you are doing the right thing being cautious. This is a very permanent hole.
In the end, it turned out to be fairly easy, but the important thing is to get that hole straight.
So I got some aluminum round stock, maybe 1 1/4" diameter. I cut off a couple of pieces about an inch long, faced both ends and center bored them for the pilot drill. I used a lathe.
I clamped these on the rear spar with the wings in alignment. Merely centering the round stock over the rear spar area-to-be -drilled helped asure the edge distance, which turned out to be good all the way around.
Then I drilled larger, and finally reamed for a nice snug bolt fit that required a good push of the thumb to slide in on final assembly.
The most expensive part was buying the reamer.
 
Rear Spar Drill Jig

I constructed this jig to drill the rear spars, way over kill, but it worked out very well.

2u8wfuq.jpg
 
Thanks

Drawing is exactly what I was looking for, even though it's for an -8. I will look again, but I don't think the exact same drawing perspective is in the -9 plans. Rick (one side now done and reamed to a light tap fit on an an5)
 
REAR SPAR DRILLING FIXTURE

the las vegas EAA has a good setup that they rent out for $20. i just used it - works great.

contact :
Terry Frazier
his VAF contact: frazitl on the member list
RV 7A N457RV
150 hours and lovin it!
Southern Nevada EAA Chapter 1300 - www.eaa1300.org

do a search for Rear Spar Bolt. half way down on july 5 2012 posted by rvg8tor. details are there.
 
rjcthree said:
Drawing is exactly what I was looking for, even though it's for an -8. I will look again, but I don't think the exact same drawing perspective is in the -9 plans. Rick (one side now done and reamed to a light tap fit on an an5)
Click to expand...

On my 9A plans it's on drawing 38 section G-G (upper right corner of page) and it does show the distance as 5/8" from the center of the hole to the edge of the material.
 
Great Jig !! I am going to make one of them :) Will only be used twice - but sure will make it easy to drill the all important hole .. Did you have any problem with drilling into the arm on the back ? - Maybe fit a swivel block with a hole in ? Make it a even bigger overkill !
 
("Did you have any problem with drilling into the arm on the back ? - Maybe fit a swivel block with a hole in ? Make it a even bigger overkill !")



A small block of wood (about 1" thick) is placed between the spar and the clamp to protect the drill and reamer from damage.

Open offer to anyone on VAF
Send me a PM if you are at the wing spar drilling stage and would like to use the jig.
 
Longeron Bending Dies Double Duty

I used the longeron bending dies as drill blocks and they fit and worked great. Didn't hurt the function of the dies either.

IMG_2092.JPG


Used a shim to make everything line up for clamping.

IMG_2093.JPG
 
;)

Greg-> you're right, it's there. My big azz paper clip binding the drawing stack covers it up. Now feel really stoooooopid. Rick 90432
 
You must log in or register to reply here.