Re: Lower spindle rpm when feed rate decreases
I'm not sure you'll be easily able to achieve this in CAM.
The problem you are dealing with is deceleration into the corner and acceleration out of the corner.
The sharper (smaller radius) the corner, the slower the feed rate will be at the corner.
Most CAM is not aware of / accounting for acceleration speed. Acceleration varies a lot across different machines and sometime different axes on the same machine.
For pockets a good solution is to use a smaller cutter so that it sweeps around the corner (rather than stopping).
Difficult to solve if you need both sides of the cut unchanged. (I.e. you have two profiles that can't be altered).
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Posting a picture of parts may help
7xCNC.com - CNC info for the minilathe (7x10, 7x12, 7x14, 7x16)