86972Re: [atlas_craftsman] Re: Atlas Mill limitations??
- Apr 9 3:08 PMThat's about what I was going to say. Except that period sources that I've read only said that the zinc was either impure, not of sufficient purity, or contaminated. The contamination referred to may well have been lead. In any case, at this distance in time if anyone acquires a mill, lathe or shaper with all good Zamak parts, they will still be good parts when we all go to our rewards. Unless of course the operator crashes the machine in which case any parts failure is his or her fault, not the part's. :-)
Now it is true that even as late as about 1972 Atlas designers used Zamak in places that it wasn't suited for. Apparently the company memory didn't quite last from the mid 1930's until 1972. But other than that, the Zamak issue is just something that Atlas bashers like to trot out and tell to people who don't know any better. Like the bad batches of parts from the 1940's, the information is contaminated.
Robert Downs - Houston
wa5cab dot com (Web Store)
In a message dated 04/09/2014 04:45:20 AM Central Daylight Time, wmrmeyers@... writes:
From my understanding (which may be flawed, as I have a Atlas MF, still in pieces, and no experience using it) the Zamak gears are only a problem if you get gears that were made with a bit of lead in the alloy to increase fluidity. THEY have problems because the lead doesn't actually alloy, it separates the zinc &aluminum to form electrolytic cells. In the presence of moisture you get corrosion on the intergranular level, and gears that disintegrate. Properly made the alloy is as strong as cast iron, and quite a bit lighter, and easier to machine, while also being nearly as durable. Improperly made, it's every bit the crap most people seem to think it is. Most of my experience with the stuff is not in machine tools, but in die-cast carburetors for old cars. Two carbs stored under identical conditions, one good as new, and one crumbling to the touch after a couple of years.
Bill in OKC
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