Hello all, I just set up inductive prox switches on my CNC Router, but having trouble getting the homing cycle to work. The controller in question is the Blackbox X32, and the software is Openbuilds. Homing performed flawlessly on my previous machine with mechanical limit switches, but I can't seen to get it to function on the new machine using inductive prox sensors as home switches. This is a very typical CNC router setup, with home position being full X-, Y-, and Z+. I've played around with the settings and finally got some verification that the switches must be functioning. When I hit 'Home', Z axis will move up (or sometimes down, until I abort) until it finds the switch, but then travel down until it stops & gives an Alarm 9 error. Seems like the switch it found doesn't seem to think it's the homing switch. BTW, the homing switches are the only ones I have installed. I want to use soft limits for X+, Y+, and Z-. I did set the Blackbox jumper to the higher voltage setting, and all switches seem to be triggering per the LED on them. I've attached my settings file here, if anyone should care to take a look. Thanks in advance!
1) should be NPN type sensors (important) as shown on docs.openbuilds.com > blackbox-x32 > inductives section. 2) remember to set the Limits Voltage jumper 3) use $5=7 for standard NPNs like SN-04s 4) make sure you are hitting a sufficiently large metal surface. If not add metal (steel Ideally) to enable sensor to trigger. Inductance = magnetic in essence = needs ferrous metal in front of it Note their advantage is being waterproof. Everything else about them is worse than mechanical switches (accuracy, repeatability etc) - they are only the right choice over mechanical lever microswitches when the tradeoff in precision is acceptable because the need to be waterproof is an absolute must (mist cooling or plasma cutters with a water table maybe if you can't shield a mechanical well enough) so if they give you a hard time on top of going to be terrible at accuracy, bin them and go back to mechanical switches Ps: also set your Max Travel in Grbl Settings (and accurate move distances in steps per mm) so homing doesn't time out before actually reaching home)
Thank you Peter. I did mean to mention, but forgot when I was creating the thread that yes indeed, I am using NPN type sensors. 2) Yes, as mentioned in my post 3) Yes, left at 7 4) As also mentioned, the sensors are functioning per their LED (although aluminum, but triggering just fine), and the fact that the Z axis is reversing direction when it reaches the Z sensor, but not giving normal home function. The sensors I'm using are TL-Q5MC1 Inductive Proximity Switch Sensor NPN Normal Open DC 10~30V As I mentioned, the sensors are indeed recognized and triggering, but I'm sure there's probably some setting I don't have quite correct in the GRBL settings. EDIT: Fully agree with your opinion on these prox switches. I'd much rather use mechanical, but this is what I happened to have and what I've already fitted to the machine via. custom brackets & mounting plates. I often question those that use prox homing switches and also wish to do auto-squaring on their machines with 2 Y-motors.
Update: homing working perfectly now. It seems that I had the SIG & GND wires reversed. After fixing that, they started working perfectly. The odd behavior of the Z motor was due to a loose connection. It was reversing when it got to the end of the travel, which was just a coincidence that it also happened at the same triggering point of the Z prox.
