X0, Y0 is 60mm away from homing switches

Hi guys, so ive been wrecking my head with this one. I have sculpfun S30 (this has L/switches as standard), i can home no problem but my origin or 0,0 is about 60mm away from my XY home switches. the first 60mm in the X & Y is totally good space that appears to be unusable.

any help would be great

1 Like

Are you saying you machine pulls off the homing switches by about 2 inches?
If so, enter $$ in the Console window and look at the $27 parameter. It should look something like $27=1.000, where this is in mm. This is the distance the X and Y will pull off the limit switches.

1 Like

Here we go
$$

$0=10

$1=25

$2=0

$3=4

$4=0

$5=1

$6=0

$10=1

$11=0.010

$12=0.002

$13=0

$20=0

$21=1

$22=1

$23=7

$24=1000.000

$25=3000.000

$26=250.000

$27=1.000

$30=1000.000

$31=0.000

$32=1

$100=80.000

$101=80.000

$102=250.000

$103=100.000

$104=100.000

$105=100.000

$110=6000.000

$111=6000.000

$112=1000.000

$113=1000.000

$114=1000.000

$115=1000.000

$120=1000.000

$121=1000.000

$122=1000.000

$123=200.000

$124=200.000

$125=200.000

$130=400.000

$131=410.000

$132=200.000

$133=300.000

$134=300.000

$135=300.000

ok

i do apologies, it moves out 20mm in both X & Y. still losing 20mm space on each axis (70mm considering the nozzle)

That is still almost an inch. Your $27 parameter ($27=1.000) looks right, so I suspect the extra travel is something built into the controller by the manufacturer. An owner of this type of laser may be able to provide additional help with this.

do i have the ability to offset, someone mentioned a G54 command?

thanks ill contact sculpfun

This is a datum shift command. The G54 command tells the CNC machine where your part is located. To put it differently, the G54 code sets the work offset zero location to be used currently in your CNC program.

Solving machine issues with Gcode edits is not recommended. :grin:

i agree, thank you for your help, ill update if a find a solution

Hi i dont mean to hinder you but i dont think its a manufactor offset, as when i send the toolhead to X0Y0, then click “get position” it returns X20 Y20. so i believe lightburn is doing it cause it knows my Coords,

just my 2 cents

No hinder felt. We are working together to determine what is happening. Any info you provide will help me understand the issue.

Do you see it actually pull off the switches almost an inch? I expect a yes here…

0,0 is the trip point of the switch, and the 20,20 is the pull-off to clear the switch. Whatvwe are trying to determine why it is so different frim the $27 parameter. I still have some ideas for testing, so give me a bit to work up a plan.

Launch Lightburn, let the machine HOME (or Home it), then open the Console window.
Next to the text box is Show all. Click on the button to make it green.
Now enter in the text box $H, then copy/paste the results from the window here.

Are your Home switches mechanical (with a lever) or sensor type?

image
oddly enough $H doesnt return anything useful (the maachine homed when i hit enter on $H).

For clarify the 20mm is not from the retract off the switches, because i can see that when i home. it homes and instantly pulls away 1mm.

what i am experiencing is after that, say i enter X0Y0 (in theory the gantry will not move when i hit enter). the toolhead moves 20mm in the X & Y. similiarly if i enter X5Y0, for example the printer will move to X25 Y20.

i feel like there is an offset applied. is there a way i can factory reset the software incase i messed something up, although i think it done this from factory (have the machine about 4 weeks)

It will home to the switch, back off the switch, then home again at a slower feed rate. It then applies the $27 value, to move the 1mm distance off the switches. It dose this because these become limit switches after it homes.

Limits and home switches are not always handled the same way, it depends on the controller.

Doubt you can tell the difference, even an Arduino can process and move things faster than a human can really keep track of… some things are visible if you watched them long enough.

Unless other machines by this manufacturer do this, I doubt it’s a manufacturer setting…


It seems to think it’s completed the home operation… which is good.

Good luck

Not supposed to, the Ok was the useful response. It means GRBL thinks the machine completed the homing cycle.

Now we have what we are looking for. In the Console window, enter $I, then $#, and then $G and paste the redults here.

Be warned that the answer may not be here. On my machine, I get X-2.00 Y-1.00 Z-2.00 even though the pull-off should be -1.00 for all three. But when I enter G0X0Y0 it will move back on the switches. If I enter G0Z0, it will alarm a hard limit, but I can G0Z-1 and it will do that. Soooo…

You did not tell me what kind of limit switches you have. It matters. My opinion now is that it a machine issue, pending what the $'s report.

In the Laser tab what is the “start from” set to? If it says user origin then you may have set an origin at X20Y20. This then becomes X0Y0. Just a thought.

This is definitely no firmware problem. The way you describe it, the laser / firmware works perfectly fine. It’s LightBurn that’s adding the offset somehow. You can also try LaserGRBL to check this. Just to make sure, you can send $RST=# in the console window to delete all workspace offsets in case there are any. But I don’t think so.

I suspect that you might have added a “laser offset” in the device settings. There should be none. The laser always counts from the limit switches position. Do not consider the mechanical frame as workspace, the workspace is only the area the diode can reach.

1 Like

my apologies for the delayed response, my child was unwell for a few days and didnt get up to the man cave.
ok

$I

[VER:1.1h.20220925:]

[OPT:V,15,128]

Target buffer size found

ok

$#

[G54:20.000,20.000,0.000]

[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

$G

[GC:G0 G54 G17 G21 G90 G94 M5 M9 T0 F0 S0]

ok

sorry they are mechanical NO/NC switch.

it is set to Absolute coords, however pressing the “Go to origin” button does move it to X20Y20. in reality i want my origin to be (0,0)

I have reproduced your symptoms.You have an origin set to x20y20. Open the move tab and click “Clear Origin”. Then home the laser and click “set origin”. This will give you an origin at x0y0. However if you are using absolute coordinates this will, i believe, ignore the origin you set. You only need to set the origin if you use “start from user origin”