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Aileron hinge lubrication


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In most machinery with a dry hinge I would say don't lubricate.

 

As Nev said all you do is create a paste of grit that will wear the hinge away

 

It always fascinates me when I see tow balls with grease on them, if they were meant to be greased there would be a grease nipple.

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In most machinery with a dry hinge I would say don't lubricate.

 

From the responses above, it would seem that the first step in keeping piano hinges working is to keep them clean. So a stiff brush and a bucket of clean water might be a starter. Then blow the hinges dry with compressed air. After that, the choice is to either leave them without any lubricant, or to use a dry lubricant, like graphite powder. Anything coming out of a pressure can, or any sort of petrochemical fluid is likely to attract muck. After doing a good job of cleaning the hinges, the next thing to do would be to determine a schedule for repeating the process. Probably include it in the aircraft's annual inspection.

 

I'm sure that an owner is not allowed to arbitrarily delete a manufacturer's maintenance function for the books, but can an owner add a function?

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Grease on the tow ball might as well be lapping paste.

 

Been towing stuff all my life including vans around Oz a few times in very dusty conditions, always greased the tow ball, never seen any wear that is detectable! The only downside is that they are messy if you brush up against a tie ball, yuk?

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Jabiru Aircraft Technical Manual JTM001-9, page 37 of 303 ~ 4 Cleaning, Ground Handling & Storage (All J Series) ~ 4.1.3 Exterior Surfaces ‘CAUTION’ DO NOT use Silicon based cleaning materials as Silicon is absorbed into Composite Materials and may effect reparability.. presumably includes Silicon based Lubricants.

5.14 Lubrication, page 56 of 303, the following points are designed to run “dry” if required however application of some graphite lubricant is recommended if excess friction is detected.

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From the responses above, it would seem that the first step in keeping piano hinges working is to keep them clean. So a stiff brush and a bucket of clean water might be a starter. Then blow the hinges dry with compressed air. After that, the choice is to either leave them without any lubricant, or to use a dry lubricant, like graphite powder. Anything coming out of a pressure can, or any sort of petrochemical fluid is likely to attract muck. After doing a good job of cleaning the hinges, the next thing to do would be to determine a schedule for repeating the process. Probably include it in the aircraft's annual inspection.

 

I'm sure that an owner is not allowed to arbitrarily delete a manufacturer's maintenance function for the books, but can an owner add a function?

I think most piano hinge style control hinges nowadays have a nylon or teflon tube between the hinge halves and the hinge pins and so, technically should not require additional lubrication. Certainly the ones I replaced on the Piper types did. Regardless of opinions expressed here, we always gave just a squirt of WD40, allow it to penetrate for a bit and clean off the outside. I still adopt this with my Zenith and have never, after an awful lot of years working on the accursed things, found it to be a problem!

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Slide the wire out clean it and reinstall. Silicone ON composites is never a good idea or even something you wish to Paint later that is absorbent at all. You try to make sure the hinge is not stiff, as that will make it bend and perhaps crack.. eventually.. Nev

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Grease on the tow ball might as well be lapping paste.

 

Go tell that to the many thousands of articulated truck drivers - check out the turntable/fifth wheel - all nice a greasy.

 

I understand your concept but correctly done greasing the ball/hitch must help in reducing "galling" between dry metal surfaces, under pressure, that are moving in relation to each other.

 

Been towing stuff all my life including vans around Oz a few times in very dusty conditions, always greased the tow ball, never seen any wear that is detectable! The only downside is that they are messy if you brush up against a tie ball, yuk?

 

Agreed in spoonfuls of lovely grease.

 

How can it be a good practice to have several hundred kg force acting on a dry socket (ball/hitch) that is constantly moving ?

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Go tell that to the many thousands of articulated truck drivers - check out the turntable/fifth wheel - all nice a greasy.

 

I understand your concept but correctly done greasing the ball/hitch must help in reducing "galling" between dry metal surfaces, under pressure, that are moving in relation to each other.

 

 

 

Agreed in spoonfuls of lovely grease.

 

How can it be a good practice to have several hundred kg force acting on a dry socket (ball/hitch) that is constantly moving ?

 

All true, well to me anyway. Doesn't bother me what other people do, having also driven semi's a good truck driver had plenty of grease for his turntable? since my apprenticeship days 47 years ago I'll continue spraying all my hinges and greasing everything that moves if I can,I sleep well at night?

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Go tell that to the many thousands of articulated truck drivers - check out the turntable/fifth wheel - all nice a greasy.

 

I think you will find it's more to do with hitching up and dropping the trailer off, the grease is so the turntable doesn't bind to the trailer hitching pin and plate.

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For piano hinges I've always followed the advice of one of the kit-build manuals from US (might have been Tony Bingelis' Sportplane Builder). Make a mixture of Iso Propyl Alcohol and dry lubricant powder (graphite is OK but messy and not recommended on Aly, better is PTFE/Teflon powder), and brush it on the hinge liberally.

 

The Isopropanol carries the lubricant into the hinge and then evaporates leaving the dry lubricant dry, and where it needs to be.

 

Also - the hinge pin should be lightly bent into a series of gentle S curves which prevents it rattling and causing wear.

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An engineer will usually choose materials based on the application and design, and may well choose two suitable materials which will give years of use without any lubricant. In those cases separating the hinge parts at intervals, washing with water and blowing any dirt/dust particles out ensures a long life.

Or for another application, he/she may choose different materials such as steel and bronze to prevent lock up, and specify grease nipples.

In other cases oil bath or oil splash might be used.

I would be going to the manufacturer of the hinge for that specific model of that specific aircraft rather than relying on a generalised opinion on a public forum.

What you've read abive should put enough fear into you to be very careful what you do to an airleron hinge.

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There is one lubricant that is outstanding for dry lubrication in unsealed joints - and that is Molybdenum Disulphide.

A can of Moly Disulphide spray lubricant is superb for lubricating those components where the amount of movement is relatively small, and plain grease is undesirable.

Moly Disulphide continues to lubricate when totally dried out, and it has been proven to be the best lubricant for unsealed areas that generate friction, for many decades.

 

https://www.swiftsupplies.com.au/weicon-anti-friction-mos2-lubricating-spray-400ml

 

https://www.rocol.com/products/dry-molybdenum-sulphide-aerosol-spray

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it's unbelievably dirty. There's one that goes dry that I spray as a coating on camshafts for run in. Essential in some CV joints. GREASE. high% MoS2.Nev

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The Jabiru manual JTM001-9 details 100hry Control System Inspection at 5:13.

Lubrication requirments are detailed at 5:14.

No mention is made of lubricating flap and aileron pivots.

 

When I attended a Jabiru maintenance course, several years ago now, I pretty sure I recall being told not to lubricate these pivots.

So that is what I do. I just keep them clean.

Mention was made of not overtightening the flap pivots. These are secured with nylock nots and should be tightened so that the bolt and nut can be turned freely during the preflight inspection.

 

Well that is what the designer says

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Guys Guys think about the mechanism. It's nor like an engine part under constant motion. It only gets moved by a few degrees every now and then. So it is not surprising that the mfr does not require a lubricant.

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There is a new WD40 dry teflon lube in a spray can which I have been using, but I like the idea of teflon powder in isopropyl alcohol better... or maybe molybdenum disulphate powder. The moly only has the dawback of being black but at least you would know its there. I am planning to try this with alcohol hand-sanitiser as the carrier.

Some attention is warranted I reckon. A small amount of play can give a lot of aileron play. The technique I have been shown is to squeeze the hinge tight again with heavy pliers then clean and lubricate.

I have heard of aileron hinges being replaced and think this is overkill.

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My Flight manual says lubricate control moving parts with ACF 50 or like. WD40 can be used. I use INOX which I find is really good. The hinges on my aircraft are aluminum. Wear from lubrication in these areas is 1% of FA. Follow the manual but in agricultural opperations hinges were always lubricated and I can not recall ever having to change one.

TN

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I use a quality silicone spray such as WD40 professional, lubrication benefits would certainly outweigh any negative effects.

 

if your in a very dusty environment then perhaps not but to each his own.

 

a small amount of grease on the tow ball sme theory but it should be degreased and changed every so often depending on environmen..

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I think you will find it's more to do with hitching up and dropping the trailer off, the grease is so the turntable doesn't bind to the trailer hitching pin and plate.

The pin & locking mechanism take the acceleration/braking forces (keep the whole shebang in place). The weight of the trailer is taken by the two contact faces of the turntable. The two contact faces are in continual relative movement, every time there is even a slight change in direction. Without lubricant/grease they would be binding/galling. In addition, as you point out, the two contact faces must slide over each other when hitching/unhitching.

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