Alarm 8: Homing Fail on Acmer P1

[ferlopezdiaz (Fernanda)]

Hi! I just bought an ACMER P1 but I can’t get it to home. I keep getting Alarm 8. I saw some related posts in here, so I tried resetting the console because that helped some people… it didn’t work for me. If I place the laser in the middle of the workspace and then try to home it, it does move to the left but it doesn’t move up. I already tightened the belts but nothing changes. This is the message I get:

ALARM:8

Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring.

ok

SimpleLaser 1.1h [‘$’ for help]

Start OK

[MSG:‘$H’|‘$X’ to unlock]

[MSG:Caution: Unlocked]

ok

?

<Idle|MPos:1.000,-1.000,0.000|FS:0,0|Pn:PY|WCO:0.000,0.000,0.000>

ok

Can someone help me? Thank you!

[soniclab (Jeremy Hutchinson)]

@ferlopezdiaz

Cycle failed to clear limit switch when pulling off.

Have you increased the pull off distance to make sure your limit has enough space to disengage?

$27=xx , increase this value a couple mm at a time until it clears.

[thelmuth (Tim Helmuth)]

@ferlopezdiaz

If I place the laser in the middle of the workspace and then try to home it, it does move to the left but it doesn’t move up.

If your laser head is in the middle of the bed, nowhere near a limit switch, it sounds like a limit switch has failed, possibly the wire came disconnected, possibly the controller is bad, possibly the switch has failed.
Do a close visual inspection for disconnected wires.

[ferlopezdiaz (Fernanda)]

Well, I tried. I tested it with several numbers from 10 to 100. The greater the number the further the y axis moves (towards the front, where the on/off button is), but I still get Alarm 8. All the wires are connected. I’m guessing I might have to return the machine, right?

[thelmuth (Tim Helmuth)]

Has it ever worked properly?

Was this a fully assembled machine or did you assemble it?

[misken (Melvin)]

@ferlopezdiaz

<Idle|MPos:1.000,-1.000,0.000|FS:0,0|Pn:PY|WCO:0.000,0.000,0.000>

This message shows that your Y limit switch is pressed (Pn:PY). Check that one and the cabling. You can check/repeat this output by sending the ?-command (sending question mark sign) in the console. Then you get the line above, showing the current status.

[ferlopezdiaz (Fernanda)]

It’s the first time I try it, so it makes sense to me that I might have have never worked in the first place. I unwired and rewired axis Y and got this:
Homing

[PRODUCER:MKS DLC32]

[VER:1.1h.2023082801:]

[OPT:VMPH,63,254]

Target buffer size found

[MSG:Using machine:MKS DLC32]

[MSG:Mode=STA:SSID=:Status=Not connected:IP=0.0.0.0:MAC=08-F9-E0-9F-8B-78]

[MSG:Mode=AP:SSDI=ACMER_P130859:IP=192.168.4.1:MAC=08-F9-E0-9F-8B-79]

ok

ALARM:8

Homing fail. Cycle failed to clear limit switch when pulling off. Try increasing pull-off setting or check wiring.

ok

SimpleLaser 1.1h [‘$’ for help]

Start OK

[MSG:‘$H’|‘$X’ to unlock]

[MSG:Caution: Unlocked]

ok

[thelmuth (Tim Helmuth)]

Does it follow the proper homing cycle?

1. Trolley and gantry rapid move towards the switches.
2. When the switches are hit, the machine will stop and reverse.
3. The machine will pull off the switches slowly until the switches open.
4. The machine will reverse back onto the switches very slowly until the switches close.
5. The machine will reverse and pull off the switches slowly until they open.
6. The controller establishes this as the Home position.

[ferlopezdiaz (Fernanda)]

No, what happens is this: the trolley moves towards the switch, but the gantry, that’s when it gets weird: it moves only a little, away from the switch. It never hits the switch

[ferlopezdiaz (Fernanda)]

here’s a link to what happens when I press Home on LB https://drive.google.com/file/d/1FwAhrR8PSQJ8dwR_eWUkQQCUWsHJuCXv/view?usp=sharing

[thelmuth (Tim Helmuth)]

OK, this goes back to what Melvin said about your switch being in the closed position. It thinks it’s already in contact with that switch, so it performs the pull off, but it never opens. Since you rechecked the wiring, I believe it’s time to contact the manufacturer.

Access denied on the video.

[ferlopezdiaz (Fernanda)]

Thank you, @thelmuth and @misken for all your help ! I’ll be contacting the manufacturer (the video should be visible now, in case you’re curious)

[thelmuth (Tim Helmuth)]

I watched the video and I do believe what I described is what’s happening.

[misken (Melvin)]

@ferlopezdiaz

This looks like the switch is directly screwed to the frame. This can create a short circuit which activates the switch logically. Loosen the screws, put a piece of tape /plastic/cardboard behind it to prevent contact between frame and switch and fasten it again.