Anyone dealt with this before??

The pins that transfer the load from the wings to the fuse are installed
in the wing. There are holes on the fuselage side. It's an older
glider and as such doesn't have the replaceable swivel bearings on the
fuse. In this case, the holes are elongated vertically from wear and
the pins have wear on their top surface. The result is play in the wing
to fuse connection.

The pins appear to be glassed in to the wing root and the metal that has
the holes on the fuse side does not appear to be replaceable.

Making the holes a little bit larger on the fuselage side will be a
little bit of a trick only to keep the hole centered on where the
original hole center was. There is plenty of "meat" and opening the
hole up is not going to affect the stregth of the part on the fuse side.
This would fix the fuse side, but then the harder task would be either
replacing the pins in the wing or sleeving the existing pins somehow to
achieve a snug fit. Since there is already a recessed area on the pin,
just putting a thin sleeve over it isn't going to last because it will
likely be crushed to contour with the exsiting recessiion. I think I
might have to do something like add some metal with a welder onto the
recessed area and then carefully machine it down to match the existing
profile before making a sleeve to then upsize to match the new holes on
the fuse. This being said, I haven't even dug into weather the metal
the pins are made out of could be welded. ie heat treated or just too
high a hardness, etc.

Has anyone ever tackled a similar problem such as this? If you have,
please contact me offline.

Thanks,

Gary

What make and model would that be ?

"Gary Emerson" wrote in message
et...
The pins that transfer the load from the wings to the fuse are installed
in the wing. There are holes on the fuselage side. It's an older glider
and as such doesn't have the replaceable swivel bearings on the fuse. In
this case, the holes are elongated vertically from wear and the pins have
wear on their top surface. The result is play in the wing to fuse
connection.

The pins appear to be glassed in to the wing root and the metal that has
the holes on the fuse side does not appear to be replaceable.

Making the holes a little bit larger on the fuselage side will be a little
bit of a trick only to keep the hole centered on where the original hole
center was. There is plenty of "meat" and opening the hole up is not
going to affect the stregth of the part on the fuse side. This would fix
the fuse side, but then the harder task would be either replacing the pins
in the wing or sleeving the existing pins somehow to achieve a snug fit.
Since there is already a recessed area on the pin, just putting a thin
sleeve over it isn't going to last because it will likely be crushed to
contour with the exsiting recessiion. I think I might have to do
something like add some metal with a welder onto the recessed area and
then carefully machine it down to match the existing profile before making
a sleeve to then upsize to match the new holes on the fuse. This being
said, I haven't even dug into weather the metal the pins are made out of
could be welded. ie heat treated or just too high a hardness, etc.

Has anyone ever tackled a similar problem such as this? If you have,
please contact me offline.

Thanks,

Gary

Earlier, Gary Emerson wrote:
The pins that transfer the load from the wings to the fuse are installed
in the wing. There are holes on the fuselage side. It's an older
glider and as such doesn't have the replaceable swivel bearings on the
fuse. In this case, the holes are elongated vertically from wear and
the pins have wear on their top surface. The result is play in the wing
to fuse connection...

If this is a composite glider, I'd bet that the holes in the fuselage
side are actually bronze or similarly soft bushings installed in steel
sleeves. The most common such installation is such that the sleeves are
steel tubes that go all the way across the fuselage to the opposite
side so as to transfer compression loads from drag or thrust to the
opposite root rib.

Wandering off topic, my experience with newsgroups is that you will get
the most useful responses for stuff like this when you explicitly
specify the glider make and model, and state the nature of the issue in
the Subject line. For example "Lift pin socket wear: how to address?"

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com

"Bob Kuykendall" wrote in message
oups.com...
Earlier, Gary Emerson wrote:
The pins that transfer the load from the wings to the fuse are installed
in the wing. There are holes on the fuselage side. It's an older
glider and as such doesn't have the replaceable swivel bearings on the
fuse. In this case, the holes are elongated vertically from wear and
the pins have wear on their top surface. The result is play in the wing
to fuse connection...

From an engineering viewpoint, if the pins are not significnatly worn
(measure - don't rely on sighting) the easiest way out would be to reamer
the holes out and insert a reducing bush to reduced the enlarged hole down
to the original size.

If the pins are worn. they could be reduced to circular (provided there are
no imperfections or cracks) and the reducing bushes for the holes made
undersized.

Building up and re-turning the pins is likely to be a more expensive option.
It is likely that there is an approved method of maintenance for your
machine - have a word with an agent for that particular type.

Keith

On Jan 10, 12:25 pm, "Keith W" wrote:
have a word with an agent for that particular type.

He's not gonna tell us what it is.
My bet is its a Pegasus.

See ya, Dave

wrote:
On Jan 10, 12:25 pm, "Keith W" wrote:
have a word with an agent for that particular type.

He's not gonna tell us what it is.
My bet is its a Pegasus.

See ya, Dave

My guess is a Jantar 2A

Earlier, Dave Nadler wrote:

He's not gonna tell us what it is.
My bet is its a Pegasus.

I go with LS1f.

Bob K.

My guess is its actually a model glider and NOT fullsize.


Bob Kuykendall wrote:
Earlier, Dave Nadler wrote:

He's not gonna tell us what it is.
My bet is its a Pegasus.

I go with LS1f.

Bob K.

The sockets in the fuse are steel and don't have a bushing. The
thickness of the receptical (and thus the width of the contact area for
the pins) is only about 1/4". This was probably underengineered.

The wear on the top surface of the pins is therefor localized to the
1/4" wide area where the pin was in contact with the fuse. I measured
the wear at one point, but don't have those numbers handy. I'm guessing
it was on the order of 1/32" With something like 0.015 to 0.020
elongation in the hole. In smooth air, it was no biggie. On a final
glide it rattled and bumped, but didn't affect flight stability, etc.



Bob Kuykendall wrote:
Earlier, Gary Emerson wrote:

The pins that transfer the load from the wings to the fuse are installed
in the wing. There are holes on the fuselage side. It's an older
glider and as such doesn't have the replaceable swivel bearings on the
fuse. In this case, the holes are elongated vertically from wear and
the pins have wear on their top surface. The result is play in the wing
to fuse connection...


If this is a composite glider, I'd bet that the holes in the fuselage
side are actually bronze or similarly soft bushings installed in steel
sleeves. The most common such installation is such that the sleeves are
steel tubes that go all the way across the fuselage to the opposite
side so as to transfer compression loads from drag or thrust to the
opposite root rib.

Wandering off topic, my experience with newsgroups is that you will get
the most useful responses for stuff like this when you explicitly
specify the glider make and model, and state the nature of the issue in
the Subject line. For example "Lift pin socket wear: how to address?"

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com

Making the holes a little bit larger on the fuselage side will be a
little bit of a trick only to keep the hole centered on where the
original hole center was. There is plenty of "meat" and opening the
hole up is not going to affect the stregth of the part on the fuse side.

Actually, not that hard. Secret modelers trick is to oversize the
hole, make new backing plates. Put a precise size hole in the backing
plate, assemble glider, get wings true in place and glue plate in
place. Instead of glue you may need to hit it with a tig welder just
to tack it. Then disassemble glider and secure further. We use epoxy
of course for models.

Darren "U2"