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Standard Modern 12x30

You pretty much have to do that if you use carbide inserts anyway.

What is your thought there? Is it because carbide inserts, because of how they’re formed/sharpened, will cut to a different size/depth depending on things like depth of cut?

Just curious.

D :cool:
 
I don't really have any special insights but I do have an opinion.

If you watch carbide cutting steel using high speed microscopic photography, it sorta plows or gouges the metal out. Carbide inserts for steel are usually quite dull vs those for Aluminium.

Fast forward to 6:40 to see the action.


Minimum cuts don't usually work with Carbide inserts for cutting steel - you have to take a fairly heavy cut to get a good finish.

I figure carbide sorta ploughs and smooths the surface behind it as it removes metal, and the steel sorta rebounds back behind the cutter. The result is a new diameter that is not what you dialed in. So you have to measure, cut, and measure to know and anticipate what's gunna happen.

With this approach, errors caused by worn ways (or tool/work springback) would automatically get taken into account in the process of measuring what really happened and compensating for it on the final cut.

Is that sufficient or would you like more explanation? Happy to go a bit deeper if you want.
 
I don't really have any special insights but I do have an opinion.

If you watch carbide cutting steel using high speed microscopic photography, it sorta plows or gouges the metal out. Carbide inserts for steel are usually quite dull vs those for Aluminium.

Fast forward to 6:40 to see the action.


Minimum cuts don't usually work with Carbide inserts for cutting steel - you have to take a fairly heavy cut to get a good finish.

I figure carbide sorta ploughs and smooths the surface behind it as it removes metal, and the steel sorta rebounds back behind the cutter. The result is a new diameter that is not what you dialed in. So you have to measure, cut, and measure to know and anticipate what's gunna happen.

With this approach, errors caused by worn ways (or tool/work springback) would automatically get taken into account in the process of measuring what really happened and compensating for it on the final cut.

Is that sufficient or would you like more explanation? Happy to go a bit deeper if you want.

Ok, that’s about what I thought the discussion would be but wanted to be sure I wasn’t missing something.

D :cool:
 
I was able to work on the lathe last night and put a 0.003'' shim on the outer vee (motor side) for the headstock. After that I was inside 0.0005'' on the diameter for 5 inches in length.... this is way better than what I though I could get. I won't be regrinding the lathe after all, this will fit my needs.

On an other subject anyone has the drawings for speed and feed selectors? both of mine are quite rough.

Thanks

Julien
 
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