Touch Plate not working

X-Carve Troubleshooting
82

I sent a g20 command to force inch mode, still no movement. I guess I did not really need to use my touch probe after all.

83

on the jog window…make sure it is set on inches…

84

I did that also. Tested that jogging .5 Z down moves the Z down 1/2 inch.

But G38.2 Z-.5 F1 does not move at all.

85

No idea then…sorry.

86

Thanks for offering suggestions. I am going to think about it for a while.

1 Like
87

grbl 0.9g or later

first command to move spindle down

G38.2 Z-.5 F1 ( Probes down max of .5 Inches at 1 inch per min.)

Second command to set z at zero

G92 Z.275 (This will set the current position of the spnidle is at .275 Inches which
is the thickness of the touch plate)

Cut and paste this line to macro, hit enter then stays there permanent.

M30;G38.2 Z-.5 F1;G92 Z.5;G0 z.25
Make sure your plate is 38.2, or change it if necessary.

1 Like
88

I have 0.9i loaded and yes, those command look correct to me.

89

M30 is missing on your command line I think. Ups, I saw that.

90

I rebooted my laptop, restarted UGS powered down the Arduino and gshield then powered them back up again and the touch probe started working.

Never underestimate the value of a good power cycle.
MAGIC!

2 Likes
91

Good to hear it.

93

you dont really need the m30 command

1 Like
94

That’s what I have on my macro command. I thought it does something. Good to know that.

95

i just joined and was looking for details of the connections to and from arduino for the G38.2 touch probe command,i hope you got it working fine,seeing as it was from 2015,however,if not did you see the touch command in a youtube video,i can’t find the resolution to the question ,but i did notice you use “z-.5”,do you use inches or metric mm,if you use mm ,then .5 would i suspect relate to .5mm and still not touch the probe plate,maybe causing an error,seeing as .5mm would be hardly noticeable,it may have been over looked,if not,grbl version may be the problem.

98

Thanks for the very good tip which solved my problem. I don’t know about everyone else, but, when I start a new project, liking getting this CNC up and running, I tend to verify “simple” things first. So, it was some time before I tried “probing” on my original X Carve but got it working after solving a noise problem.

Then, last year, I upgraded to the X Controller. Didn’t have any problems getting it up but waited until now to try probing again. I had been using Charlie’s 3 axis Triqueta, but have decided that I need only Z axis probing (for now anyway). Took Charlie’s code, already modified by me, and tried just sending the Z axis probe command via UGS. Z stopped immediately with “Probe Error” displayed.

With so many variables like “new controller”, “new wiring”, “new s/w in the X Controller”, “how exactly does the G38 command work”, etc., it was hard to know where to start. Probe wiring to X Controller was good. So, with your post here, I first sent a G20 to convert to imperial units. I also reduced the speed to F1 as someone else had suggested (which may not be necessary). I was then able to run G38.2 and short the two probe ends with expected (good) results. Thanks for saving me perhaps a lot of time spinning my wheels! Gary

1 Like
100

I experienced the same problem with my touch plate, however the issue was a fried pin on Analog 15, you could easily diagnose this by checking the voltage on that pin, if you got none, you got a problem if the defaults are left alone on the Mega 2560 version of GRBL 1.1e. To fix, i edited the cpu_map.h, changed the PROBE_BIT from 7 to 5 (Pin A13) and re-uploaded GRBL… now all is peachy. p.s. pin 14 was fried too. My fix is temporary as i ordered a new Mega. This was most likely due to me somehow overloading the pin… may consider using an external resistor. Either way, i search for a very long time, to no avail, so i tried assigning a different port for the probe and voila. Hope this helps someone, i certainly could’ve used it!

p.s.s. I know the op is for an Uno, but the same applies.