So have my new 1515 all hooked up and moving nicely, now we are getting to the nitty gritty. I have a Chinese VFD (YL620-A) and an Everlast 60amp plasma. I am hoping I can have both wired to the black box and just basically change out the spindle for the cnc plasma torch and vice versa. I have the block box and as far as I can see the VFD would be connected to the toolhead output (Gnd, 10v) and the Plasma cnc port would be connected to the relay. For plasma I see the Relay jumper must be in the M3/5 position, does it matter where it is for VFD operation? From the one thread about the YL620 it seem to me like they said it was in the same place. and does anyone know if there is a colour code to the 4 wires that come from the spindle? Like which is U,V,W? I assume the black is ground.
The Relay and PWM both come off the same signal, but its super easy to make one or the other ignore the signal: Just turn off their power Want to Plasma? turn off the VFD, Turn on the Plasma inverter's power Want to CNC? turn off the Plasma, Turn on the VFD's power The UVW order doesn't matter much, if it spins the wrong way round, just swop two of them around. More importantly is the, as you call it, Ground. Firstly, NB NB, that is an Earth - do not connect it to GND - they may sound similar, but GND = DC-, EARTH = copper spike outside your house, connected to your DB board, and routed to every socket. See XYZ Probe Plus with VFDs and other ground-loop inducing components Avoiding that possible mistake, next up refer to docs:blackbox:faq-emi [OpenBuilds Documentation] - VFDs create a tonne of EMI, so you have some work ahead to mitigate that - in particular the link in the last point of section 2.8 - is very very good bedtime reading.
Thank you for the reply. I was really hoping that it was going to be that simple as just not use one or the other. I'm not particularly excited about battling EMI.. although the cable that came with the spindle to go between the spindle and vfd box is pretty serious lol. my vfd and the black box are completely opposite sites of the machine from each other so hoping that helps some. As for the earth of spindle... it can be connected to the same earth/ground that is coming in with my 110v correct? In my manual it calls it FG with the grounding symbol.
"FG" is usually Field Ground, which isn't very helpful in this context. Field ground is usually low-voltage level (24V) signal DC-, and distinguishes it from logic ground, which is TTL-level (5V) signal DC-, both of which around here we usually denote as GND, since that's typically how it's silkscreened onto PCBs. Peter's (and the UK's) "Earth" is equivalent to the US "Ground", which I always spell out to differentiate it from DC signalling GND. Whilst they can be connected sometimes without any harm beyond care with limit switch wiring, in high-EMI situations like this they absolutely should not be. This also means isolating the USB GND, which usually has continuity with the PC case, which itself grounds through the PSU case. You don't want that loop here with two very-high-EMI systems. VFD should be in a separate steel case to everything else. Should probably get as close as you can to that with the plasma, too. Peter's normally the one with this link handy, but I happened to click on one of his recently, so have a read through this re: VFD wiring: Problems VFDs cause and cable types that help solve them Plasma may be tricky if it has HF start, you might need to disable that if it knocks your electronics out, not sure. Torch height control of course doesn't exist in grbl, though you can buy separate auxiliary boards that work separately to your CNC system, which might be helpful.
Thank you for the info. It’s not a HF start plasma, made sure not to cheap out in that department. So all that being said, the black wire from the spindle should be “grounded” with the bare copper wire ground with the 14/2 that powers the vfd itself?
So found a diagram online that answers that question. the answer to that is yes. The #4 pin needs to be attached to earth ground which would also be the FG on the vfd box where the ground from the mains (line and neutral)would also attach. the rest of the wiring seems fairly straightforward. I ordered a bunch of ferrite cores to attach to the lines. I would attach them closest to the black box?
Thank you sir... Seems on the EMI issue many issues can be solved or reduced at least by running a separate circuit for just the VFD... I think I might try that. My panel is just on the other side of the wall from my workshop. Run another 20amp 110v circuit thru the wall.
Well after fixing/adding the ground wire to the spindle I used the settings I found in another thread here to set up the VFD (boy that was interesting to figure out) but I successfully had an air cut of the hello logo. Now I only let it run for about 5 minutes but no failures due to emi... so hopefully that’s a good sign. Tomorrow will be a real test cut... this should be interesting. Is there any literature here about feeds and speeds for different materials? Guess there are lots of factors.. bit size, flutes etc. Definitely a different learning curve then a laser cutter lol...
Well update to this project... Router is working mint! Had very little for emi issues... Had to put some ferrite cores on the BB side of the wires but that seems to solved the rare emi issue I was having. So next on to the plasma torch... I have it mounted and the mechanical parts of the floating head complete just need to wire up an endstop and the control signal. Switching from the router to plasma isnt too bad takes maybe 5 minutes.
