Hi everyone
Been working on my control box wiring diagram this is what i have so far and was wondering if i’ve missed anything or if there’s any errors with this?
Your start/stop button seems more like an emergency stop. I guess spindle on/off is done by rs-485, isn’t it?
Yeah I’m not sure of the wiring to the contactor so I just threw it in and yes the rs-484 handles all control of the spindle but I’m thinking of having one e-stop mounted on the door to just kill everything via the contactor
Check on vfd input is possibly to have stop/run
Add switch parallel with your e-stop
What kind of contactor do you have? The ones I’ve used doesn’t work like that, but needs AC power through A1 and A2 to activate the coil.
I would have used a two poled emergency stop right after the AC in, skipped the rotary switch and have the contactor control both fases. I have only taught simple automation, and haven’t wired up a cnc (yet), so I don’t know the best practice here.
Not bought the contactor yet was waiting for comments but from what I’ve researched so far the start/stop buttons get wired through an auxiliary contact to ac
@Gary_Wilson
Well personally I wouldn’t try to distribute the 5 volt rail like you have it diagrammed. The swing of 5V is too low, and the tolerance is too tight to realistically expect precision regulation of disparate remote loads. It can be made to work after a fashion, but in my opinion it is just asking too much of electronics to expect it to work. So I don’t. I distribute a higher voltage, then regulate it separately at each load. That works. It always works. It is very reliable too.
But this is all more of a personal opinion that I developed after years of experience working with electronics. Most (all?) professional designers share the same opinion with me too. At least it is the method I see examining their circuits. Which is to say it is just how things are done. YMMV of course.
But if you insist on doing it like you’ve depicted things here at least use a star distribution wiring scheme, and do use heavy gauge wires. That should go some way towards mitigating the disaster you’ve got planned for yourself. Oh, and good luck! You’re pretty much relying on luck. So you’ll need it.
My first CNC used a parallel cable and so the connectivity for the spindle speed control and the limit switches was poor. My two new CNCs use a USB breakout board that controls everything with Mach3 including spindle speed control. Don’t see why you need two separate connections to your PC.
Dennis the BOB is parallel cable so went with the rs485 board rather than get a new bob
@Gary_Wilson
Here’s a BOB I made http://www.instructables.com/id/Parallel-Port-Break-Out-Board-BOB/ Although nothing there is really the circuit in its final form. I needed a bit more current from it, so I ended up splitting some of its lines.