Hi,
This is my first post on this forum. I will start by saying thankyou to the many people who have posted over the years that have enabled my to learn as much as I have from just reading.
This forum inspired me to buy a mill to convert to CNC. I have started, and have acquired a number of the required components. I have a KFLOP and a KSTEP sitting on the table awaiting me to start wiring, but before I commence I like to have a solid plan. I post this here seeking any advice/feedback on how I have done things, and because I would like to have my lessons available for others. There is currently very limited detailed info available on setting up a basic open loop system with the KSTEP.
I am comfortable with the motor side of the wiring, but have limitations on the circuitry side of things. I have attempted to design a circuit that achieves the following:
1. E Stop physically cuts power to any element moving under motor control (spindle & steppers)
2. Limits wired to stop all axis movement if tripped (currently through KFLOP firmware, I will likely set the KFLOP to kill motors, but will need to insert a manual override to the limits to enable this - or is it better to run this on the same circuit as the E Stop and have physical relays cut power when a limit is tripped?)
3. Independent home switches for each axis.
4. Spindle direction and speed control.
I think I have managed to achieve all of this from the KSTEP, leaving the KFLOP I/O for future additions such as coolant, PDB, tool changer, the sky is the limit. In particular, I am seeking feedback on:
1. Have I made any foolish conceptual mistakes that are going to cost me a fortune?
2. How I have set up the E Stop - is there a better way?
3. Any thoughts on whether the limits should be separate from the E Stop, or in series (or for that matter, independent on each axis).
4. Comments on grounding. My homework tomorrow is reading the siemens document on star grounding for further research posted by Al the Man, but any advice in this are would be great. It seems counter-intuitive to me to ground different DC voltages and AC to the same node, but I have a very basic understanding of electronics.
5. Review of how I have wired this home limit switches. I bought them before I fully comprehended the difference between PNP and NPN. Based on my research it should still work, but I am not fully confident.
I apologise for the amateurish nature of my wiring diagram - this is the first I have ever drawn. I used LibreOffice Draw, but am currently looking for a circuit specific program if anyone has a decent recommendation.
Once I have this circuit finalised and have finished acquiring mechanical bits and pieces I will be doing a full build thread in the benchtop mill forum, as there is limited info on the mill I bought aswell (Titan TM25V).
Thanks in advance for any help.
Cheers,
Mick.