Messages

1

Mach4 General Discussion / Re: Pokeys57CNC and probing

« on: March 26, 2019, 02:00:51 PM »

Another solution would be removing the sanity check in mcTouchOff.lua. Replace the function CheckProbe(state) with:

Code: [Select]

function CheckProbe(state)
wx.wxMilliSleep(20)
return true;
end
But that is dangerous and might lead to errors, even crashes.

2

Mach4 General Discussion / Re: Pokeys57CNC and probing

« on: March 26, 2019, 05:34:15 AM »

RC Filter -> Resistor + Capacitor
This is what I did:
The red area is the RC filter and the rest is an inverter (N-Channel Mosfet) because @NeoTO said using it with the invert option and also forcing a cleaner on/off state.

I selected the values by choosing an R (500) significantly lower than the Pullup (10k). Based on that I choose a time constant of 10ms and calculated 20µF for C. I didn't measure with the scope, I just pulled the 10ms out of thin air, they might be one or two orders of magnitude to large.

But that doesn't matter because I am probing at 50mm/min, the 10ms will lead to 8µm offset, which stays constant and can be included into the calibration.

3

Mach4 General Discussion / Re: Pokeys57CNC and probing

« on: March 24, 2019, 02:14:22 PM »

I had the same problem. Turns out that Pin 19 has no input filtering so sometimes it triggers too early especially if you use a mechanical sensor. Mach 4's touch UI checks the state of Pin 19 after each G31 move and throws an error if it is inconsistent. To fix the issue you need to add a RC filter between the probe sensor and Pin 19.