In this module, you will learn how to properly set up the CNC machine for your project. This includes preparing the material, setting up the machine parameters, and ensuring that all safety checks are complete before beginning the machining process.
Prepare Material: Prepare your material so it is correctly sized and suitable for the planned operations. This includes checking that the material is flat, clean, and securely mounted on the machine bed.
Coolant: Turn the coolant pump on and verify that water is flowing through the lines. Also check water levels in the tank and top up with distilled water if necessary.
Tool Selection and Installation:
Select the appropriate cutting tool for the material and the operation as specified in your CAM operation.
Select the correctly sized collet for your tool by finding the smallest collet that your tool will slide easily into and which can be easily secured by squeezing only slightly.
Seat the collet in the collet nut, the short, flat end facing downward.
Install the nut and collet in the spindle and hand tighten. Then, install your tool with approx 2/3 of its length inside the collet; do not ‘bottom out’ the tool (when it cannot go in further) and ensure the collet is clamped on the shank only, not the cutting edges.
Tighten using two wrenches, one on the spindle (in the groove just below the motor housing) and the other on the collet nut ensuring that it is correctly seated and tightened. A good amount of force is required, but do not overtighten; all movements should be smooth and easy.
Home the Machine: When the machine is powered on, it does not know where it is. ‘Homing’ the machine moves each axis to one end until a limit switch is hit, after which the machine is in a known state, where it is capable of moving to any point specified, repeatably.
Set Reference ‘Stock Point’: Once the machine knows where it is, it needs to know where your workpiece is. In the CAM Setup, you defined a ‘Stock Point’, which correlates the virtual workpiece to the real world. Now, move the machine so that the tip of the tool matches this point and set each axis to ‘0’. Your stock point may end up being cut away, it may be different for each setup (if you re-orient your workpiece between operations, for example). There are ways to reference points that are not accessible to the tool itself, by entering numbers other than zero.
Check Toolpaths and Clearance: Double-check the generated toolpaths to ensure they do not collide with clamps, the machine bed, or other objects. Move the machine to the extents of your workpiece, and check if the program preview matches the position, orientation and scale of your workpiece. Perform a dry run if necessary by setting your zero reference point well above the workpiece, and re-setting it correctly when you are ready to cut.
Secure Workholding: Double check that all clamps or other workholding devices are secure and that the workpiece will not move during operation. Insecure workholding can ruin the part, damage the machine and pose a risk to those nearby.
Set Spindle Speed and Check Operation: The spindle on our CNC does not have any automatic controls, and therefore must be turned on and off manually, as well as setting the speed manually. Before beginning your cutting operation, turn the spindle on using the VFD power, and check it is rotating at the speed specified in your setup (the display shows 10x RPM, so if your operation is set to 24,000 rpm, set the VFD to 2400). You can control the speed as you cut if needed, by listening to the machine and adjusting accordingly.
Run Program: After all checks are complete, begin running the program while monitoring the machine for any issues that might arise during operation.
Prepare Material: Prepare your material for machining, ensuring it matches the dimensions and orientation set in your CAM setup.
Select and Install Tools: Choose and install the correct tools for your project, and verify that they are securely tightened.
Home the Machine: Perform the homing process to ensure the machine is in a known position.
Set Work Coordinates: Set the work origin on your material to ensure accurate machining.
Input Machine Parameters: Enter appropriate spindle speed and feed rates, based on your CAM setup.
Verify Toolpaths: Verify that the toolpaths are clear of obstacles and correctly positioned to prevent accidents.
Secure Workpiece: Properly secure your workpiece using clamps or other methods to avoid movement during machining.
Run Program: Start the program, ensuring that all safety and operational checks are complete.