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LazyTurn / Re: School me on tip radius.
« on: January 23, 2011, 03:17:05 PM »
Hi Rich,
Thanks for the exceptionally complete reply. I'm known to be dense to please bear with me.
It seems that your are making the argument in the PDF that the final pass is offset correctly in regard to the tip radius. I 100% agree. The point I was making in my first part of post #2 is that when I touch off on my work piece, that is NOT the zero point (as it is on a Mill). If I touch my tool to the work piece in the X direction, and I'm using a tip radius of 0.0156", then my tool center is actually at a point 0.0156" from the radius of the stock.
Example: I have a 1" bar. I touch my tool in the X direction to the stock, the actual location of the center of the tool is 0.5156". At least that is what I got from the manual (and your well made pdf). That works for me and I'm getting accuracies of about 0.0005" in finished diameter.
I believe that we are in agreement on the issue above.
Now to the issue I wrote of in post #2. Attached is my .dxf and .tap. I'm in radius mode. Note that the first cut is at X=0.475" when (from my understanding) it should be at 0.475+0.0156=0.4906 for a true 0.025" first cut.
When I run a program like this, my mill (lathe mode) nearly comes apart because the first cut is so deep. All subsequent cuts are smooth.
I'm quite certain that I'm just not getting it...
-Jim
Thanks for the exceptionally complete reply. I'm known to be dense to please bear with me.
It seems that your are making the argument in the PDF that the final pass is offset correctly in regard to the tip radius. I 100% agree. The point I was making in my first part of post #2 is that when I touch off on my work piece, that is NOT the zero point (as it is on a Mill). If I touch my tool to the work piece in the X direction, and I'm using a tip radius of 0.0156", then my tool center is actually at a point 0.0156" from the radius of the stock.
Example: I have a 1" bar. I touch my tool in the X direction to the stock, the actual location of the center of the tool is 0.5156". At least that is what I got from the manual (and your well made pdf). That works for me and I'm getting accuracies of about 0.0005" in finished diameter.
I believe that we are in agreement on the issue above.
Now to the issue I wrote of in post #2. Attached is my .dxf and .tap. I'm in radius mode. Note that the first cut is at X=0.475" when (from my understanding) it should be at 0.475+0.0156=0.4906 for a true 0.025" first cut.
When I run a program like this, my mill (lathe mode) nearly comes apart because the first cut is so deep. All subsequent cuts are smooth.
I'm quite certain that I'm just not getting it...
-Jim