Rob,
While flash heating the outer tube insert at the last moment a deep
frozen closely fitting item into the inner tube. This, for a few seconds
will allow differential expansion and contraction of both parts.
Hope this works.
Christoph Both
#223
Wolfville, Nova Scotia
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Rob Housman
Sent: Wednesday, October 01, 2008 1:13 PM
Subject: RE: Europa-List: Mod 72 - Undercarriage mounting frame
strengthening
Erich, Graham, and Richard:
Removal, with the insert now more than halfway in would likely be a real
chore, so for now at least I'll continue on with the brute force
approach.
I have considered rigging a press and still may do so. However, based on
my experience with Mod 73 where I used a similar scheme to extract my
dummy torque tube after a small amount of epoxy managed to get where it
should not be, and that threaded rod's 1/4-20 NSC threads were severely
damaged, I fear that the force needed would be greater than the strength
of the largest threaded rod that would fit through the ID of the insert.
I think the sash clamp would have a better chance of success since the
threaded portion (with high strength Acme thread) would be in
compression not tension as for the scheme noted above, but I'll defer
that pending further hammering.
With about 1.3 inch remaining to hammer in, and modest application of
heat to the landing gear frame helping, I have made sufficient progress
to keep pounding onward, so to speak. Progress is slow using heat
because heat works only when there is a temperature differential and the
insert soon reaches the same temperature as the frame thus requiring a
waiting period while both get back to ambient temperature. Heat,
hammer, cuss, wait. Repeat as required.
I hope that this discussion will help others that have yet to tackle Mod
72, though with almost two years having elapsed since the Mod was
announced I am probably the last to have this much fun.
Best regards,
Rob Housman
Irvine, CA
Europa XS Tri-Gear
A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Richard
Collings
Sent: Wednesday, October 01, 2008 3:04 AM
Subject: Re: Europa-List: Mod 72 - Undercarriage mounting frame
strengthening
Hi, Have you tried adapting a sash clamp to press the tube into the
hole. This is how I fitted mine but before mounting the frame in the
fuselage which made the job easer. You would need to cut the sash clamp
bar down to just the right length as the unused length would get in the
way.
Failing that remove the 2 fixing bolts holding the frame onto the
cockpit module and slide a suitable length high tensile bolt though the
tube put a large plate washer and nut on the end and as you tighten it
up you will draw the tube into the frame.
If you must use a hammer try to position a heavy weight behind what you
are hitting to act as a reaction. Best of luck Richard
From: Rob Housman <mailto:rob@hyperion-ef.com>
To: europa-list@matronics.com
Sent: Tuesday, September 30, 2008 3:32 PM
Subject: RE: Europa-List: Mod 72 - Undercarriage mounting frame
strengthening
Craig & Martin:
Good suggestion in re: taking advantage of thermal effect on
size. However, in my case one pin is in and the other is far enough in
to preclude removal and starting over.
Prior to starting the Mod I measured both pins and confirmed
that each was less than 16.5mm (PRIOR to applying the etch primer) and
not tapered, and the hand reamer was fabricated by a local shop with
whom I've done business for a long time, and it is to size. Were it not
for the factory's instruction to paint the pins (and my foolishness in
following that suggestion) the pins would have fit easily.
Best regards,
Rob Housman
Irvine, CA
Europa XS Tri-Gear
A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of craig
bastin
Sent: Tuesday, September 30, 2008 4:07 AM
To: europa-list@matronics.com
Subject: RE: Europa-List: Mod 72 - Undercarriage mounting frame
strengthening
If you can get the tubes out again, easier said than do
probably, I would suggest a shrink fit, if you are happy
the insert tubes are the same size as the ID of the tubes after
reaming then throwing the tubes in the freezer
and GENTLY heating the UC frame should give you the clearance
you need long enough to get them home
mine took about 4 decent taps and they were home, mind you i did
use a lathe and skimmed the tubes till they
were within .01mm, the heating/cooling dropped the tube size to
about .2mm smaller than the UC frame. I believe
quite a few have opted for this method with good results
craig
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Rob Housman
Sent: Tuesday, 30 September 2008 12:52 AM
To: europa-list@matronics.com
Subject: Europa-List: Mod 72 - Undercarriage mounting
frame strengthening
Having been working mostly on those factory mandated or
recommended modifications of late, I now realize that it is much easier
to build an airplane than it is to repair one. Mod 70 (Mass balance
arm) was merely tedious, working deep in the tailcone, one handed,
through small access holes, but Mod 73 (Tailplane retention) and Mod 59
(Shimmy damper) did not go well when following the written procedures,
and now with Mod 72 there is more of that wonderful English
understatement: "Insert the tubes - they will probably need a light tap
to fit them" it says in the procedure. English hammers must be
considerably larger and heavier than American hammers (or 16.5 mm
reamers must be a bit larger) because "a light tap" does nothing. After
pounding away for entirely too long, and peening the ends of the tubes
where the hammer repeatedly struck, I finally fabricated a steel spud to
put between the offending pin and the hammer. This made it easier to
keep pounding with less damage to the pins, or to the adjacent smaller
diameter tubes to which the engine mounts attach if I were to miss the
target. The steel spud is starting to look like a mushroom from all of
those "light taps."
I should have retained my initial skepticism regarding
the fit of painted tubes, which after painting with etch primer are
larger than 16.5mm, but no, I foolishly believed that the factory had
actually tried this procedure. Well folks, the paint makes the pin
almost impossible to fit.
Fearing complaints from my neighbors about so much
hammering on a peaceful Sunday afternoon I finally quit pounding with
the intention of resuming mid-day today when most of my neighbors will
be away at work. As of yesterday afternoon one pin was snug against the
bolt attaching the frame to the fuselage and the other was still barely
halfway home.
Now, if I could find one of those English hammers at
Home Depot....
Best regards,
Rob Housman
Irvine, CA
Europa XS Tri-Gear
A070
Airframe complete
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