Hi there new to the board.
I am planning to CNC a Clausing 8520 mini-mill along with a Clausing 11" lathe (Harrison M250) and have a couple questions.
For the mill I have decided to use a Gecko G540 since they are just up the road form me and figured it would get me started and easily acquainted, well that and I'm feeling a bit lazy and don't want to have to do any extra wiring. I am not looking for any fast rapids etc. so the plan is to run Nema 23 steppers geared down. From what I have read the Gecko will handle my 4-axis as well as my spindle VFD, but lacks any decent amount of I/O's.
I want to add at least 1 MPG along with the accompanying axis and multiplier selectors, and then of course there are the cycle stop, e-stop, run, hold, etc. switches. I plan to maintain manual ability on the mill for sure, and use encoder feedback for DRO. Therefore I obviously need an additional BOB, the ones I have been looking at are the SmoothStepper and the Sound Logic (roger machine) encoder boards. So my questions are the following.
1) What are the strong points, weakness's of either of these, and can they both equally accomplish the necessary I/O's?
2) Is it possible with either of these to fully control either Gecko or DMM servo drivers (if I choose in the future) and/or send pulse-train to other AC servo drivers?
3) Can either of these boards do tool offset positioning and/or edge limit/homing using the encoder with a proper plugin in Mach??
4) My mill has the original screws and they have ~.006" of lash, do either of these handle backlash compensation, or does Mach do this? Or should I replace the screws?
5) If neither of these can perform all my requests, is there another board that can?
6) Which are the best affordable through-shaft encoders that will interface well with either board for position feedback?
I have ordered the G540, steppers, and purchased a Mach license, now I just need to figure the BOB and encoder situation plus any other bits that I need to make a complete and proper system. If neither of these bob's with encoders can perform limiting, which are the best switches to use, proximity, or mechanical?
Other than that I am open to suggestion, any advice regarding things I should avoid, or try to implement, or if anybody has CNC'd one of these machines already and want to share their thoughts it would be greatly appreciated. Lastly, is it at all possible to save to 2 instances of Mach one for mill and one for lathe, which would allow the use of a single computer, HMI interface, and bob to control 2 machines (each having their own drives and encoders) by swapping the DB25 input from one set to the other. These are just home shop machines right next to each other, so I was thinking I could make one really nice setup (touchscreen, MPG's, AB switches and buttons) that could control both machines??
Thank you for any and all help.