Standard Operating Procedure for Cutting Stainless Steel on the Rofin Laser Machining Station Version 1.1, August 15, 2007, by Steven Sergenese Reviewed and up-dated 02-02-2010, by D.Turnbull. Introduction This standard operating procedure applies to the Rofin-Sinar laser machining station located in V-15. This station is a 2D laser cutting station using a 100 Watt SPI air cooled fiber laser. This SOP is not intended as a self training instructional guideline. Training from a qualified operator is required before unsupervised use. Manufacturer: Rofin-Sinar Laser Type: Air Cooled SPI Fiber Laser Class: IV Enclosure: Class I Power: 100 Watts The laser machining station in V-15 is capable of cutting two dimensional images, stencils, and other useful parts from various materials. It has been rated to be able to cut up to 1mm thick stainless steel (SS) and to date we have been able to cut up to 1.5 mm SS with good results. The system is also capable of importing.dxf drawings via the Cagila software installed on the computer. The system is controlled via a touch screen monitor (visible in picture) and can support both USB flash memory keys and floppy disks, for uploading images and other files.
Start-up 1. Check the laser cutter log book to make sure the cutter was left in good operating order. 2. Turn on the main valve for the compressed air on the wall behind machine. The regulator on the back of the cutter (image below) is preset to 45 psi and should not need to be adjusted under normal operation. 3. Turn on the oxygen assist gas cylinder and adjust the regulator to approximately 150 psi (Pressure may need to be increased depending on the thickness of material being cut). 4. Turn on main power switch on back of machine by turning clockwise.
5. Log onto the computer (no password is required). 6. Press the blue E-Stop Reset button then the Power On button on the machine. If the machine does not power up, check to see that the Emergency Stop button is in the out position by turning it clockwise. The power is on when the power on button is lit. 7. Make sure sliding door is closed on the enclosure. 8. Select NView MI(2) icon to bring up the laser cutter control center.
9. When prompted, select to home the axes. The stage will automatically begin to move to calibrate the machine. Do not perform any other task until the homing process is complete!! Alignment of Material 1. Press the Next button on the side of the screen to cycle through the various controls until the clamp operation buttons are shown. 2. Slide the workstation door open. 3. Open the clamps (clamp buttons will be gray) and load the material. 4. Close one clamp (Clamp buttons are highlighted yellow when closed). 5. While holding down the material, close the other clamp. This helps to fix the material in the flattest position. 6. At this time it is advised that you adjust the focus as required. Simply turn the dial on the cutting head. Focus values are given in the laser recipe sheets.
7. Slide the door closed. 8. Select the Home Page button in the lower right corner, to bring up the home page, and select Manual to control the stage motion. 9. Select each of the axes X, Y, and Z buttons to turn them green and allow control of each axis. 10. Lower the z axis using the appropriate control until slightly above the material (~1 cm) and position the head at the point of origin for the cut (see Cagila). Note in the image below the left box is setup to move the x and z axis in the free run mode with a Z axis velocity of 10 and the right box to move the x and z axis in the distance mode with a movement of 0.1 mm each time the direction arrow is pressed. These can be changed as per user preference so it is important to carefully double check they are set as below before making any head
movements because if used incorrectly, serious damage to the cutting head could occur. When moving the cutting head near the material with the jog type = distance, the operator must make certain the distance setting in the box for the Z axis is set to 0.1mm. This will move the head 0.1mm each time one of the directional arrows is pressed. 11. Using a feeler gauge to check the distance between the cutting head and material, slowly lower the head until it is 0.30mm above the material (use extreme care!). Record the negative number that is in the z axis measure as it will be required later.
12. Slowly move the cutting head over the area to be cut (this can be done using the arrows or by deselecting the x and y axis (step 9) and manually moving the x and y stages) while checking the material is flat throughout the cutting area and the 0.3 mm gap is maintained (0.2mm to 0.5mm gap is acceptable for reasonable quality cuts). Outside this range, the material will have to be removed/reinstalled the above procedure redone. 13. When aligned, select Home near the z axis controls. This will return the cutting head to its home position. Loading Cutting Program 1. On the NView HMI screen select Home Page button in the lower right corner and select From File.
2. Select Open on the right side and select the correct file. 3. Within the code where it has the z axis height ($zfocuspos=), enter the negative number from the alignment process. This will allow the cutting head to move to the cutting position automatically. Be very careful about this number. Failure to do so will crash the cutting head and cause damage.
4. If you would like to change any of the parameters at this point (defaults are set in the Cagila software; see Cagila SOP), you can enter the numbers under the PSO section and laser power section. 5. Make sure the exhaust hose is connected to the air extraction unit and that the unit is turned on. (F-1800C IP systems from Rofin). This unit should only be turned on when needed as the cost of a replacement HEPA/carbon filter is expensive (~$500) Model Airflow Power Supply Motor Rating Filtration F1800C 400 cfm 115VAC, 60Hz 400 W pleated pre-filter / HEPA / carbon 5 lbs (2.5kg)
6. Select Save on the right hand side to save the change, then Error Check to check for errors, and then Run. 7. From the NView HMI screen select Cycle Start (or the cycle start button can be pressed on the front of the work station).
Pay attention that the cutting proceeds as was planned. The operator should be ready to press the abort button at the bottom of the NView HMI screen should anything not work as was planned. In the worse case the e-stop can be pressed but this shuts down the entire work station. End of Cycle and Removal Be sure to verify that the laser enable light on the control panel is off before opening the door. 1. Open the door. 2. On the NView HMI screen, select the Next button to bring the clamp buttons on the screen. 3. Release the clamps by pressing the left and right clamp buttons (will go from yellow to gray when open).
4. Remove the material carefully. If some of the pieces that were cut are small, they may have fallen into the tray underneath. 5. Turn off the fume extractor if not immediate additional cutting is being done (Note: fume extractor is also used by the laser marker so care should be taken that it is still not in use on that piece of equipment before shutting down). Shutdown 1. Close the door. 2. Close the NView HMI. 3. Shutdown the computer system. 4. When the computer is off select the black Power OFF button on the machine.
5. Turn off the assist gas and return their regulators to the lowest setting. 6. Turn off the compressed air. 7. Turn off the main power supply switch on the back of the machine. 8. Sign the logbook. Brief Notes about Operation Never leave the laser cutter operating and unsupervised. Damage to the cutter, and fires from the combination of oxygen assist gas, high temperatures, and plasmas generated by laser are possible hazards. If any unresolved issues occur make sure the lab technologist is aware of them. A message in the logbook stating the cutter is not working correctly is not sufficient. Locate, phone, or e-mail the lab technologist. Be careful when handling the cut pieces of material as they may be sharp from the cutting process. Leave the workstation clean. Any scrap metal should be placed into the scrap metal bucket. Do not leave any scrap metal inside the workstation. If a fault occurs at any time, you must acknowledge the fault on the NView HMI screen by selecting the Fault Acknowledge button. If an error that can not be reset occurs, try close the NView HMI and start over again. If this does not clear the fault see your instructor or the lab technologist.