How-To: Feed Rate Calculation

[Swarfing]

I've had a chance to visit many a company that does machining. If a single one of them used there tools as it should against the maths i don't think any of them would get any work done? It's all well and good to get a starting point but different tools from different manufactures behave very differently. A manual machinist will always listen to the cutting and a feel for the handles. Depends on what coolant you are using if any at all etc etc. I have a favorite 10mm cutter whether blunt or not will cut any material i throw at it by just changing the speeds and looking at the chips. I have a set of 12mm cutters looks superior sharpness and cost a fortune that could not cut bullshit if it saw it.
In most cases just use the maths as a guide and learn how to machine (take it slowly and build up). Experience will come out better than the maths any time, running at 20 sqwillion miles an hour because the maths says so will just keep costing you.
Just for the record Jonathan (because i know you will defend the maths) before you jump back with an answer, I' am a performance engineer by trade and have seen many things that should not happen but do happen for any given reason work well or do not......Black hole surfing anyone? :-)

[Jonathan]

In most cases just use the maths as a guide and learn how to machine (take it slowly and build up). Experience will come out better than the maths any time

I agree entirely. I did a lot of manual machining on the lathes and Bridgeport milling machines at school before any CNC and I'm sure it's helped a lot as I know what sounds/feels/looks right when cutting metals, and what does not.

A bit of common sense applies here - start a bit below the calculated speed and work up. If the calculation comes up with something unexpected that looks like it wont work then research it further to find out why. The problem is you *can* be too careful as going too slow can break the cutter just as fast as going too fast. The formula's are guidelines, no more.

[motoxy]

oooo! this is going to be fun!!!!