Transcription of CNC Plasma Tool Training 4-29-2013 - Artisan's Asylum
1 CNC Plasma Cutter tool Training Gui Cavalcanti 4/29/2013. Training Goals 1. Introduction to CNC gantries and safety 2. Introduction to Plasma cutters and safety 3. Overview of routine Plasma cutter maintenance 4. Discussion of sheet metal safety 5. Overview of CNC Plasma cutting 6. Mechanical design for Plasma cutting 7. Example cutting of mild steel 8. Artisan's Asylum reservation infrastructure Introduction to the CNC Gantry Gantry Control and Height Control Unit CNC Gantry X- and Y- Axis Torch and Z-Axis Water Accumulator and Drain Important Notes The gantry system mostly does exactly what you tell it to execute simple G-code Open Loop stepper instead of Closed Loop servo Doesn't stop at table limits Doesn't stop for fingers/obstructions Doesn't stop for the grounding cord Doesn't stop for torch crashes Sometimes.
2 It crashes and does something you didn't tell it to do CNC Gantry Safety Clear torch work area of all Pinch Points obstacles Make absolutely sure rails are clear of obstacles and cords Be aware of the position of the gantry at all times . assume it can start moving at any time Keep your hands off and body away from the machine at all times while it's in motion Intro to Plasma Cutters Intro to Plasma Cutters Basic Functionality: Use electricity to heat a point of metal to melting Use compressed air to blow through that superheated point Drag the superheated point in a direction to cut a line Plasma Cutter Safety Light Arc flash is concentrated enough to cause headaches, dizziness, and blindness For an 85-amp torch, Shade 8 eye protection or better is required Electricity Plasma cutter cuts with 85 amps at 130 volts DC, or 11,000 watts; 1.
3 Watt/second for .5 seconds is enough to stop a heart. GROUNDING. STRAP IS REQUIRED, AND DON'T TOUCH IT WHILE IT'S cutting ! Special bonus: the water table makes everything wet and conductive, including your skin Sparks Sparks thrown off by the cutter can burn you, set things on fire, and destroy nearby equipment Heat Parts can be very hot when they're done cutting Plasma Cutter Safety Required Protective Equipment: Closed toed shoes Long pants and long-sleeve shirts (or cape sleeves). Non-polyester clothing; cotton preferred Safety glasses and/or welding helmets Available water for rehydration due to heat, if Plasma cutting for awhile Work Area: Remove all flammable material (oily rags, solvents).
4 Clean area of clutter, especially around your feet Make sure bystanders can't see arc flash Identify nearest fire extinguisher Plasma Cutter Safety Operation: NEVER LEAVE THE CUTTER UNATTENDED. DON'T TAKE YOUR EYES OFF THE TORCH. Don't touch the metal or the gantry while cutting Stay close to the computer to pause or stop the gantry and cutter in an emergency Make sure bystanders are protected and will not interfere Plasma Cutter Safety Special situations: The cutting area needs to be fully screened off from all other members (including other welding area and shop aisle). Auto-darkening helmets are recommended so that you can see if the torch has crashed during a cut Y-axis cuts along supporting rails produce a shower of sparks.
5 Don't stand to the immediate side of the gantry! Make sure water isn't getting all over the controls or power unit as you're cutting The MultiCam router and Plasma cutter can't operate at the same time due to power draw and operator safety concerns Plasma Cutter Specifications Example Cut Settings 85A. Shielded, Mild Steel Plasma Cutter Maintenance Maintenance Overview Identifying and maintaining consumables Debugging error codes on the Plasma unit Troubleshooting poor cuts Plasma Cutter Consumables Consumable Inspection Consumable Inspection Consumable Replacement ALWAYS TURN POWER UNIT OFF BEFORE SERVICING TORCH. Artisan's Asylum provides consumables, but be gentle on their use or cut costs will go up Average nozzle and electrode life = 3 cutting hours Replace the nozzle and electrode together for best results Inspect nozzles after any crash; do not reuse old nozzles Clean shield tip if starting to accumulate crud; replacement is relatively rare Swirl ring replacement rarest of all Check O-ring for damage Plasma Unit Error Codes Troubleshooting Cut Quality Special Note: Parallel kerf on two sides of a cut-out piece usually means a blown-out nozzle Sheet Metal Safety Sheet Metal Safety Weight of 4'x8' mild steel sheets: 22 Ga: 31 lb 16 Ga: 78 lb.
6 125 : 162 lb .250 : 324 lb Inspect cutting slats for irregularities before putting a sheet down Gloves and sheet metal dollies are recommended at all times Getting 1 to 3 other people to help lift is essential to position and remove large sheets Gantry crane lifting solution possible, but you will need special Training Sheet Metal Source Steel: Turner Steel Company, Inc. 800-521-8881. $150 minimum for deliveries Are happy to cut sheets down into manageable chunks please take advantage! Other Metals: Admiral Metals 781-933-8300. Delivery minimum unknown Special Note: You must be present to accept deliveries, or you must notify if you can't be present. A fee may be charged for accepting material deliveries CNC Plasma cutting Tuneable Settings Current (Power Unit).
7 Cut Feed/Speed (Torchmate cutting Software). Nozzle Type (Consumables). Cut Height (Height Control Unit). Voltage (Height Control Unit). Material Type (You). Preparing To Cut Reserve time for cutting at Screen off Plasma cutting area with welding curtains Check slats for high spots and grind down where appropriate Place sheet on cutting surface Fill water table to within of bottom of sheet Attach grounding clamp to material, or to the closest slat to the power unit that's under the material Put on gloves and carefully check torch consumables for damage, replace if necessary Turn on Plasma power unit, gantry controller, height controller, and control computer Set appropriate amperage on the Plasma cutter power unit Set appropriate pierce delay, pierce height, cut height.
8 And touchdown torque on height controller Open Torchmate 4 software and connect to the gantry controller Plasma cutting Add lead-ins, lead-outs, arrays of parts, and offset cutting paths in Torchmate CAD software (optional). Import a DXF into the Torchmate 4 cutting software, setting cutting speed and scale in the import dialog box Jog the torch head to the desired zero position, and set program coordinates to zero Ensure that all bystanders are aware of your cutting , and are behind safety screens Run the cut, keeping the cursor over the Hold command in case of a crash Inspect the first piece for dimensional accuracy and straight edges Repeat as needed Teardown and Cleanup Log total cut time rounded to the 5 minute mark on the cutter log sheet Wipe down and dry all rails, gear racks and machine components.
9 Mop floor if necessary Jog the head of the machine to the corner closest to the operator station Turn off the gantry controller, height controller, and Plasma power unit Disconnect Plasma cutter ground clamp and place it next to the power unit Remove the cut sheet from the table and store it or recycle it Drain the water into the water accumulator until there's of slat above the water level Grind the dross off the slats in the area in which you were cutting In Case of Crash Stop the program with Hold . Turn Cut light off on height controller Turn off power unit Reset torch head Inspect Plasma consumables File Formats Torchmate cutting software only reads DXF or G- code files Solidworks can generate DXFs from sketch view or drawing view ALL LINES WILL BE CUT INCLUDING.
10 ANNOTATIONS, DASHED CENTERLINES AND. CONSTRUCTION LINES. Inkscape and Gimp have DXF plugins Torchmate CAD program can generate DXFs Mechanical Design for Plasma cutting Mechanical Design Considerations Plasma cuts start with a pierce that can ruin straight lines or features Torchmate CAD can lead-in and lead-out to minimize pierce effects Plasma cuts have a beam width that depends on amperage and material thickness That width can be offset by you in the design of your piece, or by Torchmate's CAD program Repeatability is within .015 across a foot;. accuracy seems to be . across a foot Mechanical Design Considerations Very thin features (or material near edges) will bow, sometimes interfering with the torch Thin sheet will warp if heavily cut into, sometimes interfering with the torch Very large features on thin sheets will be difficult to cut successfully due to sheet warpage Dross will build up on the back of your parts, and will need to be cleaned in some way Kerf-Width: Mild Steel Kerf-Width: Stainless Steel Kerf-Width: Aluminum Asylum Electronic Infrastructure Asylum Infrastructure All cuts must be reserved and logged on the log sheet.
