X axis limit switch issue

[James Martin]

Lately I've been having an issue where the x axis limit switch is failing to engage, causing the machine to grind against the stop and fail to home.  Now it's gotten to the point that the machine will simply never home and the switch never functions.  I've ensured that everything is spotless around the carriages etc, and it seems as though everything is still plugged in fine.  i *think* i found the limit switches, but i'm not able to determine how they actually function or what they're supposed to 'indicate' off of.  has anyone had this issue?  any suggested fix?

james

[James Martin]

i've also noted that the thing that looks like a limit switch on the x axis only seems to have a green light, where the one on the y axis seems to have two blue lights as well that indicate whether it's active.  maybe the board shorted and fried or something?  i've cleaned it spotless and it's still just crashing... i'd check that whatever interface is correct physically but i can't seem to figure out how this thing is supposed to trigger for the life of me.  is it a hidden magnet somewhere or something?

james

[Jonathan]

James,

The home switches are a Hall sensor that is normally closed, so when it triggers the circuit drops low. The Y limit switch has more LED's because it also has the indicator for the A axis Hall sensor and the power indicator LED right next to it. You are correct about the magnet. There is a fixed magnet that is mounted in the main block. You can see it if you jog the X axis forward and look at the back of the main block about a half inch to the left of the X motor. 

When you jog the X axis across its home position at that back of its travel, (across the magnet) can you see whether or not the indicator LED stays on or does it flash when it crosses the home position?

Jonathan

[James Martin]

I figured it out!  Turns out that a bunch of little metal chips had gotten jammed up way under the x carriage, in front of the linear guides.  It was packed in there pretty tight and needed to be broken up and worked out with a little piece of wire.  Back in operation now :).

james

[Jonathan]

James,

Glad to hear that you got it figured out. Thanks for sharing hear on the forum about what the solution was.

Jonathan