Do L'Hotellier Ball Fittings Wear?

L'Hotellier web site has little info. An email to them and I was sent the maintenance Instruction.

https://www.dropbox.com/s/ii53drru82...01-00.pdf?dl=0

Casey

I use spray lube to annual time. Work the sliding cylinder with something soft (like a brass key) and drown it with lube as you work it several times, until everything works easily, then wipe off excess spray and she's good to go for another year.
JJ

The Gliding Federation of Australia requires that L'Hotellier balls be replaced at some specified interval. They had to be replaced on my N3 when it was registered there. Tried to look up the GFA AD for details but their search engine doesn't find it.
The ball is inexpensive. If you need to replace the other part.... Not so.
It's a miniature trailer ball. Have a look at the trailer hitches on a few vehicles to see if they wear.
Jim

At 15:57 13 April 2016, JS wrote:
The Gliding Federation of Australia requires that L'Hotellier balls be
replaced at some specified interval. They had to be replaced on my N3
when
it was registered there. Tried to look up the GFA AD for details but
their
search engine doesn't find it.
The ball is inexpensive. If you need to replace the other part.... Not
so.
It's a miniature trailer ball. Have a look at the trailer hitches on a
few
vehicles to see if they wear.
Jim


The interval recommended by L'Hotellier (and taken over by several national
authorities as mandatory) is ten years or 3000 hours (whichever comes
first). Most manufacturers of aircraft who use L'Hotellier balls have
specified their replacement during the 3,000 and 6,000 hours and so
intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to them
being fitted in a different way and they have had threaded ends fail.

On Wednesday, April 13, 2016 at 9:06:58 AM UTC-4, Casey wrote:
Thanks for the comments.

I'm wonder what the dimensions of the balls are new.

My aileron balls on both wings are 0.02 mm smaller than the spoiler balls on both wings. Dimensions are same on each wing.

What is best lubricant? Thicker grease or thiner spray? I know the pro and cons of each but just wonder others thoughts.

Casey

I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.

The interval recommended by L'Hotellier (and taken over by several national
authorities as mandatory) is ten years or 3000 hours (whichever comes
first). Most manufacturers of aircraft who use L'Hotellier balls have
specified their replacement during the 3,000 and 6,000 hours and so
intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to them
being fitted in a different way and they have had threaded ends fail.

Erik,
Where do see that L'Hotellier recommends ten yrs or 3000 hrs? Also my glider manufacturer has no mention of this in the life extensions.
I emailed them this morning and all they sent me was the maintenance instruction and there is no mention in that of this recommendation.

Casey

I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.

pgs.
The balls are not out of round, just different between spoiler and aileron. But now I'm thinking these balls are of different diameter to begin with, a closer look, the stem to the ball is longer on those that are the 0.02 smaller.

Casey

The interval recommended by L'Hotellier (and taken over by several national
authorities as mandatory) is ten years or 3000 hours (whichever comes
first). Most manufacturers of aircraft who use L'Hotellier balls have
specified their replacement during the 3,000 and 6,000 hours and so
intervals. IIRC Schempp-Hirth has closer intervals (500 hours?) due to them
being fitted in a different way and they have had threaded ends fail.

Eric,
Where do see that L'Hotellier recommends replacement at ten yrs or 3000 hrs? Also my glider manufacturer has no mention of this in the life extensions. But does mention that maintenance must be done at each annual or 500 hrs for spherical.

I emailed L'Hotellier this morning and all they sent me was the maintenance instruction and there is no mention in that of the replacement recommendation.

Casey

On Thursday, April 14, 2016 at 8:53:54 AM UTC+12, Casey wrote:

Casey

I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.

pgs.
The balls are not out of round, just different between spoiler and aileron. But now I'm thinking these balls are of different diameter to begin with, a closer look, the stem to the ball is longer on those that are the 0.02 smaller.

Casey

Are the size differences large enough to prevent a control surface being connected to the wrong control lever? (assuming such a thing was geometrically possible)

On Wednesday, April 13, 2016 at 5:16:36 PM UTC-4, Bruce Hoult wrote:
On Thursday, April 14, 2016 at 8:53:54 AM UTC+12, Casey wrote:

Casey

I would not be surprised if 0.02mm was within the original manufacturing tolerances. Certainly a long way from the 0.1mm out of round tolerance that someone else mentioned.

pgs.
The balls are not out of round, just different between spoiler and aileron. But now I'm thinking these balls are of different diameter to begin with, a closer look, the stem to the ball is longer on those that are the 0.02 smaller.

Casey

Are the size differences large enough to prevent a control surface being connected to the wrong control lever? (assuming such a thing was geometrically possible)

Bruce,
Not possible. But the spoiler ball has a longer neck and is designed that way.

Casey