Tool Length Sensor

Check your M31 macro - if the Z axis stops when the sensor is triggered then the signal has been recognised by the UCCNC I/O software. Check that the macro references the correct location.

What I believe should happen next is that the tool is raised slightly then lowered slowly until the next trigger is seen. At this point the Z axis position should be updated with the tool sensor Z dimension and the tool raised to a parking position.

Hi peter. The spindle lowers but does not stop. I downloaded the M31 macro file from the support website and replaced this as instructed in the training tutorial

I updated the pin and port macro

The sensor is not being recognized

Hi Richard,

If you have access to a test meter, check that tripping the sensor actually produces a signal at the probe pin on the interface board.

Do this with power off and check the resistance between the ground and probe pins on the interface board - I'm not sure whether the signal would go open (high resistance) to short circuit or vica versa when triggered - it should certainly change when tripped.

If this is OK, then you will need to check that the signal is being seen by the UCCNC software. I think that the input ports are continually scanned by the software and reported continuously on the Diagnostics page of UCCNC, so you should see the signal change there.

If that is OK then there must be a bug in the M31 macro - if not then suspect a h/w fault.

Not been down this route yet, so I cant elaborate more - I'm still making my sensor unit!!

Peter

I am still struggling with the tool length sensor. Peter suggested using a test meter to check. I have done this and all is OK

Also the simple test of pressing my thumb on the tool length sensor - on the diagnostics page of UCCNC I/O Monitor Port I10 Lights Up and I/O Function Monitor Probe Lights Up - so all is OK here. I have reinstalled the macros but its still not working

This is frustrating. Can anyone help here - any more suggestions before I throw it in the bin

Hi Richard,

Since my earlier comments in September I have built a DIY tool sensor based on the 6 ball touch probe principle. I wired this into my SC420 via a miniature jack socket and checked that the UCCNC was seeing a change of state when the probe was pressed - no problems here, the diagnostics showed the expected green indicators (I10 and probe).

Next I raised the Z axis and tentatively pressed the tool length sensor with one hand on the "Jesus
Christ" button. Much to my surprise the tool descended slowly and stopped immediately it touched the sensor!!!

It worked first time with whatever M31 code had arrived with the UCCNC revision 1.2 I had loaded - beginners luck with a vengeance!! The only thing I had to do then was to set the probe height offset correctly for my probe.

Tomorrow I will take a copy of my M31 code and post it on this forum for your info. I'll also check the probe pin configuration on the "I/O SETUP" page.

Peter

Hi again Richard,

For what it is worth, here is the M31 code from my UCCNC probe macro.

double Zmin = -100; //Max.Z depth
double Feedrate = 250; //Feedrate for probing
double retractheight = 10; //The retract height
double newZ = 32.58; //The new Z DRO value after probing

if(!exec.Ismacrostopped()) // If tool change was not interrupted with a stop only then validate new tool number
{ double Zup = exec.GetZmachpos() + retractheight; //Calculate the new coordinate for the retract of Z axis
exec.Code("G00 G53 Z" + Zup); //Retract the Z-axis
while(exec.IsMoving()){} // Wait while there is motion
}

After touching the sensor, the tool retracts by 10mm, and the "32.58" on line 4 is the calibrated height of my sensor. I checked this electrically using a piece of FR4 pcb laminate on which to rest the sensor. The tool is always within +- .001" of the laminate surface after probing (jogging can prove this).

The probe pin is defined as Port 1, Pin 10.

The profile I am using is "STEPCRAFT_V_420SC", this was originally supplied with my machine by Rory at StoneyCNC and was copied across when I updated from Rev 1.1 to 1.2. There were no compatibility issues at all when doing this. As far as I remember, the only changes to the original of note were related to backlash compensation and the soft limits on the Z-axis.

Peter