Can't home / or enable soft limits

gSender ❓ Question
1

I’m not sure what changed but for some reason…now when I try to home I get an alarm triggered (click to unlock machine). I can’t enable soft limits in the firmware tool…I click the slider and it does nothing except enable the “Apply New Settings” which clicking does nothing.

This was all working prior but I used gsender with a different printer and I changed some wiring on the machine so I’m not really sure what is going on.

I’m running 1.4.4 on windows 11. Thank you for any help you can provide.

Screenshot 2024-03-26 175915
Screenshot 2024-03-26 1759151085×773 91.2 KB

2

Just to provide more information. When I first tried to use the cnc after the changes, the safety switches triggered (alarm) on the z+x but not y. Now they are not triggering for any axis. However they do trigger when I try to home.

3

Can you be a bit more specific in what alarm you are getting when trying to home?

If the machine is jogged away from all 3 limit switches, what does the calibrate tool show for which pins are enabled?

image

Try jogging/enabling the switches one axis at a time - do any of them not report “On” when they should be? Specifically to you second point, is the Y switch the problematic one?

4

I apologize. I’m not sure how to describe the alarm any more specifically. Here is a screenshot :

Screenshot 2024-03-26 175947
Screenshot 2024-03-26 1759471267×972 123 KB

In the calibrate tool I confirmed all pins show off when not engaged. I then tested all switches manually (each axis has two sides) and they all triggered “On” as expected.

5

Well, the alarm # helps. In this case, alarm 8 is the following:

Homing fail. Pull off travel failed to clear limit switch. Try increasing pull-off setting or check wiring. Streaming has been paused.

Which means that after triggering the switch while homing, the configured pulloff distance isn’t enough to disable the switch.

I’d look at adjusting $27 in EEPROM (homing pull off distance) to a slightly larger number and see if that helps.

It might also still just be a wiring issue since you said you were playing around with that - but I’d start with adjusting the pull off.

6

@KGN : Thanks so much for your help. I will adjust and monitor.

7

@KGN : Do you have any other ideas why this error would occur? Making $27 larger does not help. It only happens on the Y axis and it seems like the retraction speed is too fast for my nema17 + lead screw. It sounds like an motor overload only on the retraction. If I move the bed to the edge and back with the normal toggle it handles it no problem.

I’d appreciate any ideas.

8

Hi. Have you ever found out what caused that error? I’m running into the same problem but only on the y axis. It started happening after I moved the limit switch a couple of milimeters up the y axis. Increasing $27 and/or $26 didn’t help.

9

After trying a few things, the one that worked for me was to decrease firmware setting #25 “Homing search seek rate” to 4000 (defaults to 5000). I’m still not sure what happened as it was working before at 5000. My guess would be that there is a sweet spot the switch has to be to the moving metal part for this to work at any speed. It’d be nice if someone fron Sienci could confirm.