Frage Tool Sensor

Tool Sensor
The Stepcraft tool sensor works. But after the second probe the Z axis wants to drive in to the table.
What’s the problem.
ATB Chris

Chris,

Sounds as though the M31 macro is faulty. Z should lower quickly to touch sensor, retract and then lower slowly to find exact position, then finally retract by a short distance (10mm - "double retractheight = 10"). DRO should read sensor height + 10mm.

Sensor height is in M31 text under "double newZ" - mine read 32.60 before I calibrated it. Attached is my version without calibration - I added comments to let me understand operation and syntax.

Check on diagnostics page that "Status Monitor - Probe" lights when sensor is tripped.

Peter.

Thanks
Yep it performs as you say but then just drives to the table. Will try your macro.
Thanks Chris

Just tried you macro still wants to drive to the machine bed. It will do the same if you use Fusion 360 have to remove G0 G53 Z0.
ATB
Chris

This what happens

Have you homed the machine?

yep
how do you post a video.
ATB Chris

Chris,

What program do you use for your machine WinPC-NC or UCCNC?
Because it looks like your Z-axis is not clearing to a save height after measuring, and an other thing can be that there is a inverted Z-coordinate somewhere in your program.

Have sorted ( I think ) have set the Z - soft limit to -200 uccnc. moves up about 10 mm.
ATB
Chris

Hi,

Glad you've cured your problem, though I cannot understand how the soft limit change can rectify the symptoms shown so well in your video

The cause would seem to be this piece of code :-

"
double Zup = exec.GetZmachpos() + retractheight;

if(Zup > SafeZ)
{
Zup = SafeZ;
}
"

So it all depends on the value in "SafeZ" !! This seems a bad piece of software if an incorrect setting of "SafeZ can drive the spindle down into the tool sensor!!

On my 420, soft limits are set to 80 (above the homing machine coordinate of 60.39) and -25 (above where spindle collet would hit the baseplate).

I've experimentally changed my "SafeZ" to low value (40 as it happens) and if I execute the probe macro so that the final value of Zup is indeed greater than 40, then the spindle drives down as defined in the code (that's no surprise!!)

So its a puzzle that the macro fails unless your machine coordinates are indeed above the value defined in the macro. It's also a puzzle that soft limits cure it.

Come on software experts - put me out of my misery!!

Peter

Hi Peter
This is a magical mistory tour for me I'm happy at the moment to have movement. ATB Chris

@ Chris B: Did you manage to rectify your problem? Because i have the same problem as you have.

Have sorted ( I think ) have set the Z - soft limit to -200 uccnc. moves up about 10 mm. UCCNC

ATB
Chris

Dear All,

I replaced the M31 file with the one attach and it worked fine. Thanks to Rory.