Ruida controller, hard limit protect X

I just picked up this machine used, updated the controller to a Ruida and had it checked out with new mirrors & lens. Everything was working fine, until I got the “hard limit prot X” message. Can I unplug the limit switch from the controller & keep on running until I get a new switch? Is there any other work around? I thought about using the bottom Z axis switch, is that an option or will I get another alarm?

Just fix the switch is the easiest option. You have basically eliminated it from being able to home. A machine like this is much more likely to be damaged and is not cheap to fix if you ‘crash’.

Homing can be disable and you can run it. I really really really don’t suggest it, you will crash it.

Those switches are cheap, so don’t cost yourself a bunch of bucks because you’re excited and want to play with it… Been there done that. We’ll help you get it up properly. :slight_smile:

There’s a couple of things you can try, I’ll go over.

Unplugging it won’t help. The switch is a NO (normally open) type of contact. When the gantry gets withing a few mm of the hall switch it will ‘close’ and pull the limit line of the controller low. That tells the controller it’s been activated. Generally these switches fail open.

Just out of curiosity what makes you think it’s broke?


If you can power it up and stop it from homing (‘esc’). A chunk of metal will allow you to place it within a few mm of the switch (where the gantry comes the closest) and see if it detect it (lights up). Most of them have LEDs in them.

If it appears to work, then try adjusting it to the device. It has to be within about 3-5mm to detect it. Should be easy if the LED is working. If it still appears to work us a volt meter to ensure that LmtX- (assuming the X axes) is going low when it’s triggered.

Good luck :slight_smile:

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