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Moore rotary table surfaces - How did they do the final scraping ?

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Milacron

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In other words, the "appearance" half moon scraping (flaking).... all parallel lines ?

iu


This one below has no obvious flaking, but maybe it's the lighting/camera angle ??

6ea4db92-d0e2-46dc-a0cf-ab6301689e1c.jpg


I wonder if the second table might have been rescraped at some point ? I say that as it looks pretty beat up paint wise to have such a pristine looking table surface ...thoughts ?
 
Beautiful piece of equipment.

I can't say for sure, but I can speculate. I've seen a video of a Moore trained scraper with a technique that progresses his tool straight across ahead of him. With something laid as a straightedge and moved at the desired interval, you could do that gorgeous pattern.

And there may be some history of careful layout to produce a finished pattern. I had someone tell me of watching a man pattern the valve cover of a Bugatti engine. (Old, not the new one of the same name) He laid everything out in pencil lines before starting to scrape the pattern.
 
I'm friends with one of the last remaining scraping hands at Moore and he worked in the rotary table division back in the 1980s. If you want the actual answer to your question instead of guesses, he's the guy to talk to. Send me a PM with your email and I can put you in touch.
 
I didn't get a PM and I thought the question was interesting so I just reached out to my friend. In Moore terminology, "spotting" is that final pass that other people often call flaking. He told me they used spotting templates--pieces of thin plastic that fit the tabletop and had parallel grooves cut into them. The scraping hand followed the grooves with his spotting tool. I've seen him do the spotting before, but not with a template. He uses a long-handled scraper with a narrow carbide that's almost dead flat on the end (but with radiused corners, of course). Sounds like you had to have years under your belt before you'd be allowed to put on the final touch.

An aside: when you see the tools Moore used (and uses) to achieve its famous accuracy, it's somewhat shocking because you look at their tools and think--"This is the same stuff I have." The scraping hands are known as "geometry men" in the factory and becoming one is a big deal. It's their skill at taking measurements, making corrections, over and over and over that leads to the final result. There is an attitude of total dedication to refinement and also a sense of appropriate pace on the floor; building machines at Moore is a marathon, not a sprint. To give numbers to this, if I recall correctly, it was expected that a geometry man would require about 120 hours to establish straightness and perpendicularity to the required tolerances of just the x- and y-axis ways on the B18 and G18 machines.
 
I didn't get a PM and I thought the question was interesting so I just reached out to my friend. In Moore terminology, "spotting" is that final pass that other people often call flaking. He told me they used spotting templates--pieces of thin plastic that fit the tabletop and had parallel grooves cut into them. The scraping hand followed the grooves with his spotting tool. I've seen him do the spotting before, but not with a template. He uses a long-handled scraper with a narrow carbide that's almost dead flat on the end (but with radiused corners, of course). Sounds like you had to have years under your belt before you'd be allowed to put on the final touch.

An aside: when you see the tools Moore used (and uses) to achieve its famous accuracy, it's somewhat shocking because you look at their tools and think--"This is the same stuff I have." The scraping hands are known as "geometry men" in the factory and becoming one is a big deal. It's their skill at taking measurements, making corrections, over and over and over that leads to the final result. There is an attitude of total dedication to refinement and also a sense of appropriate pace on the floor; building machines at Moore is a marathon, not a sprint. To give numbers to this, if I recall correctly, it was expected that a geometry man would require about 120 hours to establish straightness and perpendicularity to the required tolerances of just the x- and y-axis ways on the B18 and G18 machines.

Very interesting information? Somehow I imagined that using a template at Moore would have been “a sign of weakness.” ;-)

Could you sketch a diagram of what that template might have looked like?

Denis
 
My Moore rotary has the same beautiful flaking aligned in rows. Pretty difficult to see in the photo but it's done with almost surgical precision.
baef76b8c862dadadec84e9df62bc281.jpg
 
Could you sketch a diagram of what that template might have looked like?

Denis

Based on his verbal description, a set of templates that look something like this and maybe with a few additional protrusions beyond the ones I sketched that would engage the edges of the table so it doesn't slide around.

Moore table template.jpg
 
I was thinking some sort of cross marks would be useful for getting your spots evenly spaced along the groove, but I guess after one pass and turning the grid 90 deg, the spacing would be set by the first pass and would be evident from then on.

Thanks for posting this, Borealis, as this is one of those valuable bits of knowledge that might otherwise simply evaporate as these hands retire and eventually pass away.

Denis
 
They were pretty damn good, that's for sure. I read an anecdote of some of their scraping hands being able to scrape in logos of customers while still maintaining perfect bearing. Pretty cool stuff.
 
I'm sure this has been mentioned many times, but if you want to salivate over Moore's scraping, pick up a copy of "Foundations of Mechanical Accuracy" by Wayne Moore. Used prices seem to be all over the map, but It "looks" to be still available from Moore for $150. I saw one on Amazon for $1150. The photography(done by a well-know Life photographer, I think) and quality of the book is well worth the price.
 
I have scraped and rebuild several Moore Jig bores and Jig Grinders over the years. We scraped them to 40 PPI. Professional Instruments and Kurt MFg is Minneapolis had several. I suspect the one table was re-scraped by someone other then Moore as the other one with the 1/2 moon looks original. Moore push scraped those in and their expert scrapers didn't need a template it was done by hand and eye coordination. I had a special 40 radius Biax 1/2 moon flaker blade so we could use it to duplicate the Moore look. It wasn't hand scraped their way. My Dad taught me how to do the push and lift or some call it a scoop, then we hand 1/2 mooned them with our hand hitting a hand scraper we called our 1/2 moon flaker. My student Hunter High Tower out in Portland met a Moore scraper who taught him to scrape the Moore way too. I just bought a Moore book as a present for a friend from Moore Publications at Moore Tool: Precision Machining Technology, Precision Tools

I met a fellow years ago who had worked for Pratt & Whitney as a scraper and he said he used the Moore method and showed me. This is how he showed me. How to rebuilding older machines using the hand scraping method ? - YouTube
 
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