This question I felt was likely already answered, but I was unable to find a related post and would like to know before I plug anything into the mosfets.
<skip>: I have a great, unfinished build going (pictures attached). With the dewalt 660 and continuous air on the end mill, I ripped through some aluminum with more precision than I was expecting (about .05mm xy) in a vise, with the whole thing bolted to a metal pallet. I have attached a test cut for an aluminum hydro pump housing, I sped up the perimeter to test some limits (snap) but the 12 center holes and precision gasket insets came out with tight pocket corners with the speedtiger 1/16" bits on amazon. With these, recommending 80mm/min for everything with .6mm passes, only helical plunging, not to cut straight grooves and find well shaped stock when possible (conventional and only cut with half the bit). I have yet to center-fix the 24" milled rails or connect the PID, so these stats are at 20-30k rmps with variance by cutting resistance. Very excited to get this think finished, but I am moving in early 2020 and I am waiting to build a sturdier table on which to mount the control boards, drainage, and compressor. For now, I am trying to get it 3D printing with left overs from an anet A8 printer, so I can accommodate that feature into the final.</skip>
I did find material related to 3D printing with the ramps board on the MPCNC, I am running a RAMBo with dual endstops which would be nice to use with a 3D printer, alongside my vice home command and potential suite of fusion 360 presets with the endstops. I have attached a Frankenstein tool mount as a .txt with a V6 hotend and the Anet A8 extruder. I was wondering if the 6th stepper plug was automatically configured to push the extruder, or if I would need to flash new firmware? Are the default extruder mosfet plug and thermistor plug operational? If so, can I get a link to a power supply for all this?
I would recommend you to consider having two boards: one RAMBo for milling with the dual stepper square system, and a Arduino+Ramps for the 3D printing.
The big advantage in doing that is you can tweak up the firmware so it is just perfect for doing either 3D printing or milling without having to reflash, you just have to make it so you can just unplug everything from one board, drop the other board and plug back, then run a new job.
Basically you just have to come up with a convenient wiring system, if you do it well it can be a matter of connnecting just three-four plugs (one for the power, the screen cables and an other custom one for all the I/O). Arduino+Ramps+Drivers are very cheap, so it won’t cost you a lot, the only hassle it to create a clever wire harness system, unless you’re ok with plugging and unplugging all the wires everytime you change boards (which doesn’t really take much time once you’ve got used to it to be fair, but I’m not sure how and if the connector actually match between the Ramps and the RAMBo).
That really sucks. I’m not too mad, I’m also not going to swap the wires every time I switch, I foresee problems there. I could build a chip to connect to my Anet A8 Mobo with diodes so they do not fry themselves if I switch boards, but I am not doing that either. I could probably find a way to drive the whole thing from a PC host, but I don’t know if I want that config. As much as I wanted the build area and definite precision/rigidity, probably easier to have a separate 3D printer.
Still, I am building an active cooling system for the PID, I could add a heat-sink to the RAMBo board and try to Overclock it, maybe I can get enough extra juice to run a 6th driver. I don’t see how static endstop drivers could possible effect the working load on the CPU if implemented correctly. A smaller LCD might help the load as well. Let me know if this sounds like a possibility.
There are already break outs to add drivers to the Rambo’s if you are not intimidated by that. I believe there are pins for up to 3-4 more drivers, maybe even defined already, if not just add the pins to the pins file.
This is an interesting suggestion, and I think I might try it out myself. I got a bunch of 4PDT ice-cube relays with 12VDC coils off aliexpress just now for 2 bucks each. They’re rated to switch 5A so that’s sufficient for steppers. I think I’ll just have a SPDT switch for the coils. My original plan was to have a bunch of 4PDT switches directly switching the steppers, but I like this way better myself.
Your secondary board (3D printing) could be one with 6 drivers to not have to worry about swapping between individually wired X/Y and series wiring.
