Monport K40 - homing error

I just received my new K40 from Monport. Copied all settings from the manual but I can’t get my homing right. I checked all connections but this is what happens:

  1. I have selected to return to the homing position when I turn the machine on. This does not happen.

  2. when I select the home button in LB, the Y-axis only moves about 1 cm backwards. When I click home again, the X-axis moves to the left and the Y-axis moves back another cm. When I click home again, it moves another CM backwards. etc. etc.

  3. GRBL tells me this:
    MonPort
    Grbl 1.1f [‘$’ for help]
    [MSG:Check Limits]
    [MSG:‘$H’|‘$X’ to unlock]
    [MSG:Caution: Unlocked]
    ok

Any ideas?

Thanks, Jaap

$$
$0=10
$1=25
$2=0
$3=5
$4=0
$5=0
$6=0
$10=1
$11=0.010
$12=0.002
$13=0
$20=1
$21=1
$22=1
$23=5
$24=1500.000
$25=3000.000
$26=250
$27=25.000
$30=1000
$31=0
$32=1
$33=1
$34=1
$35=0
$36=0
$37=1
$39=1
$100=160.000
$101=160.000
$102=800.000
$110=8000.000
$111=8000.000
$112=100.000
$120=600.000
$121=600.000
$122=20.000
$130=300.000
$131=200.000
$132=200.000
ok

I would change this to 3.
Do all your jog controls work properly?

yep, jogging works. Getting this now:

Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring.
ok
MonPort
Grbl 1.1f [‘$’ for help]
[MSG:Check Limits]
[MSG:‘$H’|‘$X’ to unlock]
sys.aborts
JY230 INIT SUCCESS
MonPort
Grbl 1.1f [‘$’ for help]
[MSG:Check Limits]
[MSG:‘$H’|‘$X’ to unlock]
[MSG:Caution: Unlocked]
ok

And this:

Starting stream
ALARM:2

G-code motion target exceeds machine travel. Machine position safely retained. Alarm may be unlocked. (Right-click the ‘Devices’ button to reset the connection)
On or near line 0:
Stream completed in 0:00
[MSG:Reset to continue]
ok

Is it trying to home now?

No change after changing $27 to 3…

Nope, it’s doing the same thing. I will try to link a video in a minute…

Here is de video:

Monport K40

So it doesn’t go any further when I’m trying to home it…

EDIT: one other thing I saw is that the Y-axis belt is quite loose, it could be a bit tighter but that is very difficult to do because the screw for that is on the back of the Y-axis and that’s very hard to reach without taking the whole gantry out.

Anyone with some tips what I could try next?

EDIT:

  • I have followed the instructions by Monport (40W Lightburn Setup)
    result: problem still not solved. Laserhead X goes to the right, Y only moves 1 cm

  • Invested X-direction in setup. When homing, X goes to the left now and stops at hard limit. Y still goes back but only 1 cm

  • checked hard limit switches with mulitmeter, both work OK and are connected correctly. BUT, when I manually push in the X limit switch, I see that in the LB console, when I push in the Y limit switch, nothing happens in the console.

BTW, jogging works ok but on the Y axis, while jogging the Y back, the Y limit switch does not work when reached.

Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring.
ok
MonPort
Grbl 1.1f [‘$’ for help]
[MSG:Check Limits]
[MSG:‘$H’|‘$X’ to unlock]
sys.aborts
JY230 INIT SUCCESS
MonPort
Grbl 1.1f [‘$’ for help]
[MSG:Check Limits]
[MSG:‘$H’|‘$X’ to unlock]
[MSG:Caution: Unlocked]
ok

  • When jogging works, it seems that wiring is not the problem here, right?
  • When the limit switch works (tested with multimeter) + wiring limit switches also ok, why don’t I see that in the console when I press the Y-limit switch?

Did you check continuity down at board level or just across switches.
If you try and home and then manually press switch does it stop that axis?
Also, when you check switches with meter do they show continuity before you press them?

Down at boardlevel…
For homing, the Y-axis doesn’t move more than a cm at most when homing. It doesn’t come close to the limit switch
Last question, yes, they do…

How many terminals on your switches?
Did it come prewired?

3 terminals and everything was pre-wired…

From what you are saying your switches are normally closed, contrary to the norm.
I would try changing $5= to 1 and see what that does.
Maybe this will also help
Limit Switches - Diode Laser Wiki (diode-laser-wiki.com)

When you mean closed as in “a closed circuit, yes. When the switch is pressed, the signal is interrupted. I will try the $5 setting and read the wiki, thanks!

Ok, thanks @Dskall for helping out, problems are solved right now. At the end of the day it tuned out to be a broken connection in one of the plugs from the Y-axis end switches to the controlboard. After replacing the plug, the issue was solved.
Thanks for you help!

Jaap.