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equipment:cnc:mill:maintenance [2024/02/22 15:17] – Remove axis image temporarily samp20equipment:cnc:mill:maintenance [2024/11/19 21:42] (current) – external edit 127.0.0.1
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 The touch probe signal ''probe-hw'' is connected to ''motion.probe-input'' through a oneshot pulse generator. This effectively pulse stretches the incoming signal to ensure a clean trigger. The touch probe signal ''probe-hw'' is connected to ''motion.probe-input'' through a oneshot pulse generator. This effectively pulse stretches the incoming signal to ensure a clean trigger.
 +
 +===== Emergency stop =====
 +
 +The emergency stop system is split into a hardware e-stop circuit and a software stop.
 +
 +The hardware e-stop circuit runs at 240V and provides power to the VFD contactor and 48V stepper power supply. This circuit is fed from the following chain:
 +
 +  - Main power NVR switch.
 +  - E-stop button.
 +
 +The software e-stop has a few different sources:
 +
 +  * GPIO from the e-stop button (''estop-button-fault'').
 +  * LinuxCNC internal faults.
 +
 +While the MESA card is configured with an ''estop-relay'' output that would link the software e-stop to the hardware, we have decided not to connect it. The main reason is to allow the VFD active braking to work correctly during a soft e-stop. We may revisit this later, perhaps with a time delay before cutting the relay.
  
 ===== Axis limits and homing ===== ===== Axis limits and homing =====
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 Each axis of the CNC mill has a pair of limit switches. Each pair is wired to a single input. The soft limits in the image below (B/C) are configured to be a small distance away from the hard limits (A/D). For X and Y the machine origin is set at negative soft limit (B) such that all coordinates are positive. For Z the machine origin is set at the positive soft limit (C) such that all coordinates are negative. Each axis of the CNC mill has a pair of limit switches. Each pair is wired to a single input. The soft limits in the image below (B/C) are configured to be a small distance away from the hard limits (A/D). For X and Y the machine origin is set at negative soft limit (B) such that all coordinates are positive. For Z the machine origin is set at the positive soft limit (C) such that all coordinates are negative.
  
 +{{ :equipment:cnc:mill:axis-limits.svg |}}
  
 For each joint we can home on the negative or positive limit switch, and this can be different to the machine origin. For convenience we have chosen the following homing directions: For each joint we can home on the negative or positive limit switch, and this can be different to the machine origin. For convenience we have chosen the following homing directions:
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 MIN_LIMIT = -(travel_z - (margin*2)) MIN_LIMIT = -(travel_z - (margin*2))
 MAX_LIMIT = 0 MAX_LIMIT = 0
-HOME = MAX_LIMIT - 20+HOME = MAX_LIMIT - 5
 </code> </code>
  
  • equipment/cnc/mill/maintenance.1708615034
  • Last modified: 5 months ago
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