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Old 23-12-19, 21:44
Chris Suslowicz Chris Suslowicz is offline
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Join Date: May 2007
Location: England
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Quote:
Originally Posted by David Dunlop View Post
This part of the project is a ‘Planning Ahead’ segment, more than anything.

I will eventually be doing a restoration of the Supply Unit for my 52-Set, which is going to bring the two dynamotors into the picture. The main concerns with them will be the inspection and cleaning of the brushes and armatures, which is a relatively straightforward process. Where it will get interesting, however, is the cleaning and regreasing of the bearings.

This 52-Set was very likely last operated sometime in the 1970’s, and when the dynamotor bearings were last cleaned and lubricated prior to that is anyone’s guess.

Version 2 of the Parts Listings for the 52-Set, issued July 1948, identifies the grease used as GREASE, Lubricating, Andoc and it was available in 1-pound tins.

In 1954, Modification Order No. 4 was issued dealing with changing the original grease to one identified as 3-GP-683a, which was an Arctic tolerant grease, if the 52-Sets were being deployed there.

While checking the web today, it appears Andoc grease was an Exxon Product and version ‘Andoc C’ was discontinued in 2001. I have no idea what the qualities of this particular grease were, to be able to match it to a modern substitute, so I am very much open to suggestions for an appropriate substitute. I would like to track down suitable grease ahead of time, rather than have the project grind to a halt, when it reaches the point of restoring the Supply Unit.

David
Searching for Andoc C Grease in Google, got me a "Table 14a List of Consumable Material" and Item 55 is "Grease, ball and roller bearing" Specification "Commercial, Standard Oil ANDOC C" in 8oz. tubes, FSC 9G9150-261-8311, intended use "Lubricating bearings for high speed and temperature", which sounds about right.

https://www.nationalprecision.com/mi...lubricants.php suggests "Polyrex EM" as a replacement for Andoc C, though it looks like Beacon 325 or Royco 27 might be good substitutes depending on temperature range.

The last two are Lithium grease variants, and with any change of lubricant type it's very important to get rid of any existing grease before re-filling the bearing (to avoid chemical reactions between different grease types that can -under some circumstances- produce a compound of abrasive rather than lubricating properties).

I think these are aerospace/military lubricants and therefore Not Cheap. Any standard grease for small motor bearings should be fine.

(I made the mistake of looking up Royco 27 on Amazon and the first hit was "Royco Mchuzi Mix (Spicy Beef Flavour)" which to my mind has dubious lubricating properties and is unlikely to be suitable for this application.)

Chris.
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