I forgot to congratulate you on successfully starting your own business, that is a big step. Great job. :cheers:

People actually calculate feeds & speeds? I normally use the insert manufacturer's recommendations as a guideline as well as my 50 years of experience making chips, then cut that about in half to start using the feed and spindle override. Then I watch and listen, making adjustments as needed for the first few parts. Then look at the number of parts / edge, and look at the failure mode of the insert. I also stock a number of different insert types so if one insert is not working to my expectations for the job, then I'll change to a different insert(s) to find one that does work.

I ordered some inserts from my local tool vendor, gave them the operating parameters, and let them decide what was the best for the job, $18 each. I was getting 18 parts out of an edge, well that wasn't acceptable, so I ordered some cheap inserts (~$5 each) in different types and through some experimentation was able to get 50 parts out of an edge. Because of my product mix, I am only working with 304SS and 6061 aluminum on the CNC. Other materials are normally one or two parts and are done on my manual lathe.

Overall, you just need some experience to learn what combinations work best on your machine and materials, every machine is different, and even the material varies between batches.

Best of luck to you.