neanderthal mach
Hot Rolled
- Joined
- Dec 18, 2008
- Location
- princeton b.c.
Yes the Metrology or maybe the Antique Machinery and History sub forums might be a better place to post a question like this. But this general forum gets many more views with a much more experienced and diverse audience. Roughly 8 years ago I was sent this sine bar by a total stranger. Pictures in this link. What Is This - The Home Machinist! And given it's build location (Los Alamos N.M) it would be safe to assume they had what would have been the very best state of the art measuring equipment available in 1952. More out of curiosity than an actual need to know, I've tried a few times with a couple of YouTube video posters that seem to have a good back round in metrology and it's more modern history about what Los Alamos might have used to measure the roll distance with a certainty of 5 decimal places. So far that's been a total failure.The original poor condition paperwork and signed by I'd assume the person who measured it shows that roll spacing as being exactly + 5.00034". Anyone old enough or knowledgeable care to make some semi educated guesses about what they might have used? Gauge blocks and a very good high accuracy indicator on a height gauge / surface plate might have been been all that was required. But I honestly don't really know what else a place like Los Alamos might have had available to them during that time period to make high precision measurements. Fwiw and since there's absolutely no marks or even a scratch on this sine bar I don't believe it's ever been used for it's intended purpose. It's still in it's original 1952 condition. And R.D. Marlett whoever he was did a beautiful job on it. As well made as my 5" Suburban sine bar is it's not even close to this one.