Auto Bed Levelling Switch Not Working

Hey,

I am wanting to see how auto bed levelling works on my printer before I get servo's and all that jazz, so I simply made a mount for a push button and swapped it with my extruder.

I am using Marlin - Jcrocholl's version.

Now, I have found something very odd!

I have all the inverting and all that set up correctly as my button is N/O rather than N/C.

When I do a straight G29 it goes through the motions and the button works, however as it isn't homed it starts off in the centre and moves all over the place!

When I do home it with a G28, then do a G29 it lowers it's self but doesn't stop! It doesn't even stop when I press the button manually!

This has puzzled me, and I am sure there must be a setting I have got wrong somewhere!

Thanks,

Alex

Hi Alex

If you go back to basics what does M119 report when the carriages are away from the end stops and the button on your temporary probe switch isn't pressed? They should all read open. As you press each one in turn and issue M119 the corresponding switch should read triggered. I assume you have your button on Z Min? The other common 'gotcha' is that you need to have X Min and Y Min set to -1 in Pins.h. I saw you mention servos in your post. How do you plan to implement them on your effector. I ask because I was toying with using a servo deployed probe on my Cherry Pi printer. I have already successfully used them on my core xy PrntQB design but it's a little more challenging on a delta.

Andy

Hey,

M119 works perfectly and it says triggered when I press the buttons and they all work independently.

My X Min and Y Min are all -1 so thats not the issue.

Since my last post I am thinking of doing a servo-less probe. Maybe a manual deployment as I think servo's are too much hassle for what they are worth.

Thanks.