Graem,
Not to butt in, but, after a long build it is not uncommon that a once
easy to rig aircraft seems a bit sticky.
Graham has hit the nail on the head. Everything, pins and bushes need
to be aligned.
After a long build process and painting, interior work etc., you need to
work very hard to clean and prep everything. It is amazing to me that
all that finish work on the outside seems to allow the plane to develop
a sag sometimes changing alignment. But I submit it is only time
unrigged that is the cause. Like leaving the doors open for a year then
find they don't close. Duh fiberglass moves.
First clean and lube all rigging parts.
Wings,
Clean the root pins flawlessly clean and free from dirt, corrosion, glue
etc. Check for burrs, polish with a buffing wheel and lube them well. A
small amount of excess glue from the root layups can ruin your day.
Wing pins, clean and buff. Note the pip pin is a very close tolerance
(0.499 is what mine measured whereas the Allen head pin is about 0.495
or so) and if you rig with the pip pin first, the Allen will be tough.
Any corrosion or goo in the bushes will make alignment miserably tight.
Ensure the aileron quick disconnects aren=99t too tight.
Clean your sockets out and clean your bushings in the wing.
Rig one wing at a time and note that a bit of wing tip movement can bind
the pin easily or loosen it. I have wing walkers or a good stable wing
rigging platform which sets the wing precisely at the right angle so the
wing bushes are aligned and the pins slide in effortlessly. Check the
port wing first, then rig the other wing.
Each wing should slide in with a clear "thunk" sound. That is the sound
of the spar hitting on one or both of the sockets and the spar cap.
Once the wings are in, then ascertain how the pins fit. Have an
assistant lift one wing until the pin moves easily around.
Normally a single pin will go in when rigging. If you are still having
problems simply look through the holes and use a probe to determine
where the misalignment is. Front spar, aft spar etc. If it is out of
alignment on the side of the bush, the wings aren't in far enough. If
top or bottom the wings are not in at the right dihedral angle.
As a final last straw. Heat the pin until it is just about 250 degrees
F then push it in and let it set. The heat will transfer to the bushes
and align it. I do have a 1/2 inch reamer that I have used to clean up
the inside of the bushes but red scotchbrite is normally all that is
necessary.
I have found the spar strap to be of aid in rigging.
Technique:
I personally set the wings up horizontal using my wing pins. I do not
clamp the wing spars, I just use a bit of a clap on the end of the spar
to keep the bushes in contact with each other but do not pull the center
of the spar together. If you choose to use the bolts, the bolts are a
smaller diameter than the wing pip pin so the alignment will be off a
tiny bit. Use a generous amount of parcel tape and use a stout piece of
card stock (1mm or so) to make the bow on the spar top. I also peel ply
the the tapes but then wrap them in place with parcel tape until cured
as gravity works 24/7. By keeping the wing horizontal, the bottom of
the strap tends to be nicer looking and a slightly looser fit which aids
in rigging.
Stabs.
Clean and buff your tubes. Then lube them.
Check that the pins on the TP12s didn't get bent during painting. I use
a piece of wood held against the tube and check the pin is perfectly
aligned with it. I use a 1/4 inch ID tube to carefully bend the tube
into place.
Clean the TP13s well, as filler likes to get in there.
To clean out the TPs, I use a drill extension and install a 1.5 inch 120
grit flap wheel as a cleaner for the TP5 and 6 bearings.
I then put a piece of paper towel over the end and tape it up. It looks
like a gun cleaner when done. I lube it and I use it as a gun tube
swabber. Then the stabs slide on beautifully. Great for annual
maintenance or pre-rigging cleanup.
Getting the trim bar disconnected first before full pull to remove the
stab makes it a bit easier on everything also.
Personal note on stab installation:
I have found that holding the stab vertical balanced on the leading edge
with one hand, facing the upper side of the stab and holding the root
section with the other allows an installation free of torque or bending
on the TP5 bearing, possibly damaging or cracking it loose. Wiggle it
on by rotating the root section while carefully aligning the stab with
the tube and sliding it on until the inner TP6 is just contacted. Move
to the stab tip then rotate the stab to the near 12 to 13 degrees nose
down from the horizontal to get the TP13s aligned and push part way on,
insert the trim tube and push the stab home.
With all respect to Mod 73 and those clamping their stab tubes, if your
TP14 pins are lose, don't fly, do the larger pin mod and use loctite to
remove any play at the trailing edge of the stab. Any play will result
in eventual flutter which leads to bad things like death so don't accept
any, fix it.
Regards,
Bud
----- Original Message -----
From: GRAHAM SINGLETON<mailto:grahamsingleton@btinternet.com>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Saturday, September 10, 2011 1:44 PM
Subject: Re: Europa-List: Spar bolts tight
Graem
the T/P pins need to be exactly parallel with the tube, get a length
of 1/4" bore tube and use it carefully to check alignment then bend them
straight.
Graham
-------------------------------------------------------------------------
-----
From: graeme bird <graeme@gdbmk.co.uk<mailto:graeme@gdbmk.co.uk>>
To: europa-list@matronics.com<mailto:europa-list@matronics.com>
Sent: Saturday, 10 September, 2011 18:33:02
Subject: Europa-List: Spar bolts tight
<graeme@gdbmk.co.uk<mailto:graeme@gdbmk.co.uk>>
My paperwork is in for flight test approval but I find the spar bolts
very hard to get in particularly now as I have trimmed the starboard one
to length and no longer have a long feathered end to pull it in and also
have put the spar strap on.
It seems to be a job pulling in the last mm and I wondered if anyone
has used straps and a ratchet ?
Also I find the stabilizers hard to get on and off, again its the last
half inch or so - the pins seem tight and there is nothing much to push
on.
--------
Graeme Bird
G-UMPY
Mono Classic/XS FWFD 912ULS/Warp drive FP
Build nearing completion
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