X axis endstop not being hit

[slybunda]

Just got this issue today, carriage moves all the way to the right but doesnt hit the x axis endstop then when homing it moves too much to the left and makes that nasty grinding noise.
If i move carriage by hand i can make it press into the endstop and trigger it but dont know why its not doing it on its own. Is there something a miss here?
If endstop was about 1mm further out i think it would trigger on its own. Very odd

[CrazyIvan]

Have you tried resetting the controller?

I don't know whether the switch is NO or NC in operation, but the odds-on favourite has to be a faulty switch or the flexible cable connecting the switch to the controller (including the connectors).

However, I don't understand how that would account for your description of the symptoms, it's like the controller thinks the switch is being triggered when it isn't. Perhaps the switch is NC and the connection has become open circuit?

[The photo is for the benefit of other readers]

[CrazyIvan]

Perhaps the switch is NC and the connection has become open circuit?

Confirmed. Disconnecting the switch reproduces the symptoms you describe, and testing the switch shows it is indeed NC.

[Switch contacts are described as "NO" (Normally Open) or "NC" (Normally Closed). An NO contact completes the circuit when the switch is operated, whereas an NC contact completes the circuit while the switch is "at rest" and breaks the circuit when the switch is operated. The other contact is called "COM" (Common), as there are usually three contacts, with the COM being switched between NC and NO.]

[slybunda]

Oddly its working again after i manually pressed the switch a bunch of times, i think the switch may have been triggered by vibration or something that's why even trying to manually move x axis it was stuck to the left at 105mm and turning the knob to the left made the number get lower but grinding the motor since it cant go anymore to the left since its maxed out.
Done 10 auto homing on it now and no issues.

Also the end stop switch seems to have a hair trigger since it activates before even clicking when i touch it. Dunno if thats normal guess I should have checked the other 2 switches too.

[CrazyIvan]

I think your switch is on its last legs.

For one thing, I reckon some internal contamination caused a bad contact in the first place, and for another the click is the flip of the contacts, so the click should be practically simultaneous with the change of switch state from closed to open. If you're able to open the contacts without the click-over, that's a fault (in the world of microswitches).

[slybunda]

Will get a closer look at this switch it may be a standard type i can get from electronics shop, looks like its soldered on.

[CrazyIvan]

Any microswitch would do, if you can adapt the fit.

[slybunda]

Yep seems to be a common type on mouser etc.
Can probably get good quality branded ones like omron or honeywell.

[slybunda]

took a pic of the endstop for x axis.
will have to take the endstop off and get a photo off it from the other side to get part numbers. Probably do this later in the week.

[CrazyIvan]

I'm not convinced this is useful:



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