==== 7. During Operation ====

During the process of machining, there are many actions which may need to be taken, either as a planned part of the program or to deal with issues which arise during the process. This module contains a few of the more common items which you should be aware of.

  * **Tool Changes and Stock Point Matching**: Often, a program will require multiple strategies to complete, and one of those is to change the tool for different parts of the program. Because there is no toolchanger on the machine, this is a manual process which includes steps outside of the tool itself.
    * Wait for the previous program to complete successfully.
    * Turn off the power to the spindle using the VFD power box and wait for the spindle to fully stop rotating.
    * Move the machine to a safe distance from your workpiece so you have clear and easy access to change the collet and tool.
    * Prepare a place for the tool to drop safely, as it is sharp and may be hot. Loosen the collet nut using two wrenches, in the opposite motion of tightening.
    * For the new tool, follow the steps from module 6 to select a collet and install it in the spindle.
    * Once installed, you will need to re-set your stock reference point, since the tip of the tool will not be in the same position. X and Y positions should not have changed. If the point is still accessible, repeat the process from module 6. Otherwise, use a strategy from Module 9: Troubleshooting, Tips and Tricks.
  * **Resuming an Interrupted Program**: If a program is stopped manually, or a fault occurs, it may be possible to resume cutting after the issue has been cleared. If this is possible, you can use the following process to help you resume with a minimum of repeated cuts. Be aware, this process can be difficult and it can be preferable to simply re-run the entire program.
    * If you have been watching Mach3’s ‘current line’ readout, take note of the last number you saw. Unfortunately this number disappears and there is no way to restore it. Otherwise, use your best guess to see how far along the program you have progressed.
    * Enter the line from which to re-start the program in the current line readout.
    * Check the toolpath preview to see if the position in the program matches your intention. Be aware toolpaths may be vertically stacked, or otherwise impede your view of the actual location; perform further checks if necessary to verify this.
    * Manually move the toolhead to a location where there is a clear ‘line of sight’ to where you will start the program. This is necessary as some movements of the tool may not be as expected during a restart.
    * Start the spindle using the VFD power box.
    * Click on ‘Run From Here’ on the Mach3 controller, followed by ‘Cycle Start’.
    * A dialogue should appear with coordinates for an initial move. When clicking ‘OK’ to this dialogue, the tool will move to these start coordinates, directly, and the program will //not// continue. Click ‘Cycle Start’ again to resume the program.
    * **IMPORTANT** //The machine will move in ways different to a normal cycle start. It will move to a starting point from its current point directly, so it is important that you inspect the information it provides about the move before you accept. It is unaware of your workpiece, or anything in its surroundings, so if this move goes through your workpiece, fixtures, or any other undesirable location, you are responsible for avoiding this. It will also dwell at that point until you click ‘Cycle Start’ a second time, during which the rotating tool may be in contact with your workpiece. If you are unsure, or do not wish to risk damage, either re-run your entire program or export a new program from Fusion360, updated to perform only the remaining cuts.//
  * **Chip Clearing**: While working, ensure that there is no buildup of chips or dust in the work area. Though a complete dust collection setup is not yet installed, you can use a vacuum to clear the chips away while the machine works, as long as you maintain a safe distance from the spindle. Never reach your hand into the work envelope.
  * **Coolant**: When in operation, the coolant keeps the spindle cool. When not running a program, touch the spindle to check that the coolant is working; the spindle should be warm to the touch, but never hot.