Hi all! First post here. Really excited to see such a huge community on CNC.

I am a masters student and have been included in a project to build a CNC which runs on STEP-NC. The ultimate aim of the project is to achieve a basic feed-rate optimization while running on STEP-NC. I am relatively new to CNC machining and as such have a number of questions. I will be grateful to anyone who could help out in answering the following questions:

1. I know that feed rates are hard-set into the G-code conventionally. Is it possible to vary the feedrates dynamically based on some sensor inputs while the machining process is going on? Or does it always require an operator to stop the machining process in between, change the feed rate manually and then resume the machining process?
2. Has anyone worked with STEP-NC format in the past? What is your take on the same?
3. Steptools ( STEP Tools, Inc. - STEP and STEP-NC Software for e-manufacturing ) has done a lot of work on STEP-NC. Anybody ever used their ST-Developer tools?
4. I am also looking for information on Canonical Machining Command (CMC) functions. Apparently they are meant to be commands which can be universally accepted by CNC controllers. The reason for this is that I have found a toolkit to convert a STEP-NC file to CMCs directly( https://code.google.com/p/iso-14649-toolkit/ ). But I don't know whether these CMCs can be used to drive a CNC machine.

Any information on these questions will be really helpful. Kindly condone my lack of knowledge on the subject, in case I asked any naive questions.

Regards