CB CNC Part 16 – Extending VFD Display Panel, PWM toggle Switch, Estop and Controller Buttons

In this video I will push forward to finish all the wiring from the VFD and Phonix CNC controller. The video will be quite long but I will write a list of what I’ll be doing in the description alongside time code in case you wish to jump to a scene.

To start with I am extending the VFD display panel to the outside of the enclosure, alongside a PWM to Potentiometer toggle switch. The switch will allow me to override the pre-set spindle speed from the controller to a speed controlled by the potentiometer.

The VFD I am using came with a mount for its display, but I had to file the opal plastic a little so it could clip into place.

I then connected the display panel using a ribbon cable which was supplied with the VFD. But to create the length needed I had to use a 10 pin IDC box header, which I attached using the machine vice by pressing the headers two ends together. While shortening the cable I also placed it through a copper braided shielding, which will be earthed, and is there to reduce the likelihood of electromagnetic interference.

So I’ve just soldered the wires onto the normally open terminals so when this is pressed it closes and the signal comes in from the VFD.

I am also going to wire PWM and Spindle Enable signal from the controller to the VFD. This could be as simple as the short length of four core wire on screen now, but I want those signals to go via an on/off/on switch so I can swap between sending the signal to the VFD and eventually a laser driver. If I also add a relay via the spindle enable pin, which I plan to do, I could use a normal router and prevent the VFD from receiving those signals by keeping the switch at the off position.

So this is the bottom front panel, and I’m going to have three buttons which will go to the pause, resume and abort… The panel onscreen will become the bottom front panel, which will include three momentary buttons for the hold, start and abort pins from the controller and a USB panel extension. I am laying out the components before marking and drilling the mounting holes.

one two three four five will be drilled out to 16mm, those two will be about 3mm and then whatever that is – 5 or 6 mm.

So I am just preparing the wires to connect to the switch and I’ve just tinned these and added a bit of cable for the shielding.

Now I just need to connect these terminals here to the back of this pin here and move it, its a bit tricky that one. I’m going to use the same colour coordination for the front panels going into the stepper drivers. So one was red, and two was black,

I’ve actually wired the five pin aviation panel mount without taking into consideration the DC power needed for a laser driver board. I guess I could wire that as a separate shielded cable from another panel mount, or depending on the type of driver I use I could unsolder the spindle enable pins and use their pins for the power instead.

Ultimately knowing how to solder didn’t stop me from soldering the wrong things.

And those are the spindle enable and pulse width modulation wires being screwed into their terminals.

I think I’m going to take this gland off here, and put power cables coming out from the bottom. And then have all the signals going to the controller out of this little holes here.

So this is now coming through this opening here, I’ll just zoom out. And the power coming in from the bottom. It makes it a lot easier to separate the cables. While I’m at it, I’m going to connect these three switches to the start, hold and rest terminals on the controller down here.

I guess green should be the start, red should be the abort and white the reset, and all the blacks are ground.

Those wires actually run beneath the stepper drivers.

I’m just connecting the ground of the shielding up, and I’ve bought slightly bigger ones for some of these just so I can put a few more wires in.

So I’ve just put the ground for the wires going to the switch, and what will be the wires going to the laser driver eventually.

I am wiring the estop to the VFD now, but before I commit a length of expensive shielded cable I use some inexpensive speaker cable to test that I am wiring everything correctly.

So I’m just going to simulate the spindle enable pin, being activated so and if I press this button here, and move (potentiometer) this up it’s as if the frequency is being sent to the spindle and now if I press the emergency stop.

That’s gone down to zero, and in fact the signal from the controller would also stop because there’s no power… this is weird, I’ve just taken that little bit of wire off and it’s still running.

Ok, I’m not sure why the fan keeps going after I’ve pressed the emergency stop, but the estop is connected to the power supply of the controller and to the estop terminal on the VFD. So the source of the enable and the PWM is going to be turned off, and the signal to the VFD to break the spindle is also going to be sent so I think this should work but obviously I’m only going to know until I actually wire everything up with the spindle and see what is actually does. So I’ve just cut the wire for the emergency stop on the VFD. That is roughly 92 cm.

X1 goes to the emergency stopping. X2 goes to the latching button at the top of the enclosure which is the PWM toggle switch now. X5 is the spindle enable terminal. And then I have the common ground right at the end where all three of these have their ground over there. And then underneath I have the analogue in for the PWM 0-10v and that will set the spindle speed via the Gcode file I’ll be sending.

Ok I went back over some of my previous videos to see how I soldered these together, because I couldn’t find any drawings in my notebook. And then I realised why I couldn’t find any footage of this part, because my soldering was diabolical. It was before I had the better soldering iron, and actually done some research into what solder I should use. So this is a bit messy. It would have been a bit nice to put some heat shrink over these just to neaten them up, in any case I just want to know the colour coordination so I can rewire the opposite end, so I’ve done a little drawing there. So one is brown, two is black, three is grey, four is green/yellow. Ok this is going to be the panel mount and the socket for the VFD, I just need to decide where on the enclosure I’m going to put it. I could stick it on the back but it would protrude quite a bit. If I shove it up here, it means the wiring is quite short in there and I keep it away some of the other cables that go to the front of the enclosure which include the proximity sensors, and some of the more sensitive things. I might put some of this braid on top as well just to protect it a little bit.

Because I had a green/yellow wire in the cable I used a spare piece of white wire for the screening to the panel mount. But I soldered this too far along the braid which interfered with the gland, so I had to re-do this.

I feel I can do this a little better.

I’m just pulling the braid along from one end to get it to come as far down as it possibly can, and then on top of that I’ll put a bit of… tighten that up and the gland will hold that in place.

One is good (beep) two is good (beep) three (beep) four (beep) and the check the braid (beep). Cool.

I repeat the screening for the spindle cable coming into the enclosure.

I bought the weipu panel mount before soldering finally clicked and these are of the screw terminal variety. So since I’ve learned how to solder doing the screw terminal like this is actually a lot harder, I was not filming at the time but that took a lot longer than it should have. You gotta be careful you don’t let too much wire come through the holes because they can contact.

I am going to need to use framing tacks on the panels as two machines screws are not enough to hold the larger ones without them flexing.

So it’s brown, grey and black. You really need a magnetic screwdriver for this section because I think it almost impossible to do.

I’m now going to check if the spindle can turn on and also if the estop works. I hold the jumper wire between the enable pins to simulate the spindle being activated.

After I press the emergency stop I’m left with this error message at the top O.OL – and if I remember correctly there’s a section at the back with faults and abnormalities so OL is overload. The thing is now if I put the piece of wire back between the x5 and common ground terminals, the spindle won’t turn on. And you have to reset the VFD before you can reuse the machine. So I think I have to have a look at the manual for a little bit just to work out whether I can reduce the length of time that the break is applied while the emergency stop is being pressed.

So all the wires to the VFD and controller are now in place and everything seems to work. In retrospect I guess I could have wired the abort pin on the controller to the Estop as well but I decided to for a harsh-stop killing power. Anyway I think this video is long enough. Until the next one, thank again for watching.


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