Negative value for rapid position with Y axis --- please help


(John) #1

after I performed rapid position to the front-left β€” front-center β€” front-right
The Y showing -27.58
why it is showing Negative values??? What should it display
I am running on a SO3 XXl
below is my log setting
GRBL_FEEDHOLD
GRBL_RESET
SET MACHINE STATE: WAIT_FOR_JOG_STOP
SET MACHINE STATE: INIT
Grbl 0.9g
<Idle,MPos:-420.000,-770.000,-5.000,WPos:-420.000,-770.000,-5.000,Buf:0,RX:0,Ln:0,F:0.>
gc_not_motion
___________G1F100 ___________
ok
gc_wait_for_status_updates
<Idle,MPos:-420.000,-770.000,-5.000,WPos:-420.000,-770.000,-5.000,Buf:0,RX:0,Ln:0,F:0.>
gc_wait_for_idle
___________N0 G4P0.005 ___________
ok
gc_spindle
___________M05 ___________
gc_not_motion
___________G92.1 ___________
gc_not_motion
___________G54 ___________
gc_not_motion
___________G10L2P1X0Y0Z0 ___________
gc_not_motion
___________G21 ___________
gc_not_motion
___________G49 ___________
gc_not_motion
___________G90 ___________
gc_parser_state
___________$G ___________
[G1 G54 G17 G21 G90 G94 M0 M5 M9 T0 F100. S0.]
ok
gc_get_offsets
___________$# ___________
[G54:0.000,0.000,0.000]
[G55:0.000,0.000,0.000]
[G56:0.000,0.000,0.000]
[G57:0.000,0.000,0.000]
[G58:0.000,0.000,0.000]
[G59:0.000,0.000,0.000]
[G28:0.000,0.000,0.000]
[G30:0.000,0.000,0.000]
[G92:0.000,0.000,0.000]
[TLO:0.000]
[PRB:0.000,0.000,0.000:0]
ok
gc_wait_for_idle
___________N0 G4P0.005 ___________
<Idle,MPos:-420.000,-770.000,-5.000,WPos:-420.000,-770.000,-5.000,Buf:0,RX:0,Ln:0,F:0.>
ok
gc_sync
<Idle,MPos:-420.000,-770.000,-5.000,WPos:-420.000,-770.000,-5.000,Buf:0,RX:0,Ln:0,F:0.>
gc_not_motion
___________$$ ___________
$0=10 (step pulse, usec)
$1=255 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=6 (dir port invert mask:00000110)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=255 (status report mask:11111111)
$11=0.020 (junction deviation, mm)
$12=0.010 (arc tolerance, mm)
$13=0 (report inches, bool)
$14=1 (auto start, bool)
$20=0 (soft limits, bool)
$21=0 (hard limits, bool)
$22=1 (homing cycle, bool)
$23=0 (homing dir invert mask:00000000)
$24=100.000 (homing feed, mm/min)
$25=3300.000 (homing seek, mm/min)
$26=25 (homing debounce, msec)
$27=5.000 (homing pull-off, mm)
$100=40.000 (x, step/mm)
$101=40.000 (y, step/mm)
$102=40.000 (z, step/mm)
$110=5000.000 (x max rate, mm/min)
$111=5000.000 (y max rate, mm/min)
$112=5000.000 (z max rate, mm/min)
$120=400.000 (x accel, mm/sec^2)
$121=400.000 (y accel, mm/sec^2)
$122=400.000 (z accel, mm/sec^2)
$130=838.000 (x max travel, mm)
$131=838.000 (y max travel, mm)
$132=80.000 (z max travel, mm)
ok
gc_dwell
___________N0 G4P0.05 ___________
gc_get_offsets
___________$# ___________
[G54:0.000,0.000,0.000]
[G55:0.000,0.000,0.000]
[G56:0.000,0.000,0.000]
[G57:0.000,0.000,0.000]
[G58:0.000,0.000,0.000]
[G59:0.000,0.000,0.000]
[G28:0.000,0.000,0.000]
[G30:0.000,0.000,0.000]
[G92:0.000,0.000,0.000]
[TLO:0.000]
[PRB:0.000,0.000,0.000:0]
ok
gc_parser_state
___________$G ___________
<Idle,MPos:-420.000,-770.000,-5.000,WPos:-420.000,-770.000,-5.000,Buf:0,RX:0,Ln:0,F:0.>
[G1 G54 G17 G21 G90 G94 M0 M5 M9 T0 F100. S0.]
ok
<Idle,MPos:-420.000,-770.000,-5.000,WPos:-420.000,-770.000,-5.000,Buf:0,RX:0,Ln:0,F:0.>


can anyone get this setting correct and can you please tell me what the number should be for the (9 positions of the rapid position should be and how to edit to correct the setting for them.

Thank You


(William Adams) #2

Those values are shown relative to the currently set zero β€” move to where you want zero to be and then set it.

Please see:


(John) #3

Hello Adam. Sorry for not understand what you want me to do, pls give me step by step instruction


(Carl Hilinski) #4

This confused me originally. The Home position is to the back right when you’re facing the machine. So negative X is to the left and negative Y is towards you. From Home you will always be moving in a -X and -Y direction. Does that make sense? By β€œfacing the machine,” I mean you are on the same side of the X rail as the spindle.


(John) #5

Thanks for the repond to my post. I am so confuse, just get involved with CNC less than 3 months ago, and never know anything about CNC at all. I appreciate all the help from you guys. It is so hard to get a hang on, Will be able to try to cut maybe in the next few days and it will be on wood, before trying to attempt to cut aluminum so God help and lead me.


(Jerry Gray) #6

This picture helped me with XYZ positive and negative direction, from zero.hand

You can cut blocks of stryrofoam the first time, so you dont have to stress too bad.


(Patrick Andersen) #7

I found this a most valuable resource when I started with CNC. Very basic and written by our own Edward Ford.

https://www.amazon.com/Getting-Started-CNC-Fabrication-Computer-Controlled/dp/1457183366/ref=sr_1_1?ie=UTF8&qid=1501739106&sr=8-1&keywords=getting+started+with+cnc