Z Axis homing $H

[wildbill9]

I have the carve king. When I use the $h to do a homing cycle my z axis never makes the homing switch. It will rise and stop short of the switch then back off but never touches switch. The X and y axis starts and it works perfect.

[Derek the Admin]

Sounds like some electrical interference. Can you please tell me if it's traveling just a little in Z (for instance: 1/8"), or is it traveling a more significant distance, such as 2+ inches.

Also, can you please show me your settings by typing $$ in the command line, then enter.

[wildbill9]

Seems to travel just a short distance in z like an 1/8 to 1/4 inch. Here are the settings I have from $$.
>>> $$
$0 = 10 (Step pulse time, microseconds)
$1 = 255 (Step idle delay, milliseconds)
$2 = 0 (Step pulse invert, mask)
$3 = 0 (Step direction invert, mask)
$4 = 0 (Invert step enable pin, boolean)
$5 = 0 (Invert limit pins, boolean)
$6 = 0 (Invert probe pin, boolean)
$10 = 1 (Status report options, mask)
$11 = 0.010 (Junction deviation, millimeters)
$12 = 0.002 (Arc tolerance, millimeters)
$13 = 0 (Report in inches, boolean)
$20 = 0 (Soft limits enable, boolean)
$21 = 0 (Hard limits enable, boolean)
$22 = 1 (Homing cycle enable, boolean)
$23 = 0 (Homing direction invert, mask)
$24 = 35.000 (Homing locate feed rate, mm/min)
$25 = 1200.000 (Homing search seek rate, mm/min)
$26 = 94 (Homing switch debounce delay, milliseconds)
$27 = 4.000 (Homing switch pull-off distance, millimeters)
$30 = 12000 (Maximum spindle speed, RPM)
$31 = 0 (Minimum spindle speed, RPM)
$32 = 0 (Laser-mode enable, boolean)
$100 = 200.000 (X-axis travel resolution, step/mm)
$101 = 200.000 (Y-axis travel resolution, step/mm)
$102 = 200.000 (Z-axis travel resolution, step/mm)
$110 = 3500.000 (X-axis maximum rate, mm/min)
$111 = 4400.000 (Y-axis maximum rate, mm/min)
$112 = 3000.000 (Z-axis maximum rate, mm/min)
$120 = 240.000 (X-axis acceleration, mm/sec^2)
$121 = 240.000 (Y-axis acceleration, mm/sec^2)
$122 = 240.000 (Z-axis acceleration, mm/sec^2)
$130 = 432.000 (X-axis maximum travel, millimeters)
$131 = 432.000 (Y-axis maximum travel, millimeters)
$132 = 95.000 (Z-axis maximum travel, millimeters)

[Derek the Admin]

It could be an electrical interference issue where the wires are laid next to each other "just so" and causing a false positive, but that's quite unusual. We haven't been able to pin down why that happens on rare occasion, but the solution seems to be putting the switch wire on the outside of the drag chain versus the inside.

The face that it only goes a little distance makes me wonder if the switch is wired to the wrong side though. Do you have the red wire on NO and the black wire on COM? IF you right click command line and turn on verbose output do you see a Pn:Z at the end of the text that streams across the file? What about when you press the switch and hold it?

[Bruce]

Make sure the power cord of the router is moved away from the controls also.(includes all motor and limit switch wiring and the electronics)

[wildbill9]

Yes I am plugged in Red wire to NO and black wire to COM. When I turn verbose on I do see the Pn:Z at the end. If I hold the switch on it will show the Pn:Z as being on. I will try and run the homing switch wires on the outside of the drag chain. Do not think it is the power cord to the router that is not plugged in. I am just using a diamond drag bit to try and test movement.

[wildbill9]

OK I think it is fixed I removed the z axis homing switch wires and ran them on the outside of the drag chain. Seems to be working Thanks Derek and Bruce.

[Derek the Admin]

Excellent.

Cheers

[Bruce]

You could try some shielded wire like this: www.amzn.com/B077QP9PZH/ for the limit switches, if you want to run the wire in the drag chain.
Connect the shield (bare wire) to the ground back at the CNC shield.