Dear David & Others
The units are only metric for the moment, until I can decide how much work needs to be done to make it useful and if there is enough interest by Forum members.. It would be helpful if I could be given some clues on what imperial units would be best to use (e.g. inches, feet, min, sec, HP, etc) for the various parameters.
I have not explored the more complex computations involving cutter deflections, so I don't have any formulae at hand, and I am not really sure of the complexities involved. For example, whether the rotating cutter behaves differently from a static one (for which one might try to estimate defections using some simple elastic materials properties).
I have now taken a closer look at the HSM online calculator, and if I adjust the cutting speeds and chip loads to those included in the HSM, then I am quite sure that my SFE is giving close to the same results. This may not mean that the results are optimal, however.
It might be useful if you could try out some more cases from your own experience in both HSM and SFE (making certain that the same materials properties are used) to see if you can find any significant differences that might be explained by the more (apparently) complex machining model being used in HSM.
The units used in HSM (after selecting "mm" units) are still a bit odd. For example Surface Speed is given in m/sec, and power in HP!, Otherwise, it is not too difficult to compare results.
The Sorotec data sheet is useful, thanks for the reference.
Geoff