To use a CNC plasma table, get your part into the software (a stock shape, your own CAD drawing or a DXF from your detailer), nest it, put the plate on the table, zero the torch at the plate’s corner, run a simulation and then hit Play. Here’s each step on an STV plasma table with the Optimum CNC software, for someone who’s never cut a part before.
Safety: plasma cutting means a hot arc, UV light, fumes and heavy plate. Follow your table’s and plasma cutter’s manuals for setup, eye protection and PPE.
How do I get my part into Optimum CNC?
There are three ways. All of them start on the CAM tab at the top.
Option 1: use a stock shape
- On the CAM tab, click SHAPES. You’ll see basic shapes like circles, squares and brackets.
- Click the yellow shape you want. A window opens below it where you set the width, height, hole sizes and so on.
- Click Add to Nest. The part drops onto the cutting layout on the right.
Need more than one? Click Add to Nest once for each copy.
Option 2: draw your own shape
- On the CAM tab, switch to CAD on the left.
- Draw the part with the lines, circles, rectangles and arcs tools.
- Click Save and give the file a name you’ll recognize later.
- Click the green button with the check mark in a circle to send the drawing to CAM.
- In CAM, set the lead-ins and cut paths, then click the green button again to send it to the Optimum window.
Option 3: import a DXF from your detailer
If your detailer sends a DXF (from Tekla, Advance Steel or similar), import it directly. If you’re the detailer, here’s how I prepare and export a DXF from Advance Steel for a plasma table.
- On the CAM tab, click Import DXF and pick the file.
- Check the preview. Set the units (inches or millimeters) and the scale if you need to.
- Click Add to Nest in the bottom right, once for each copy.
- Click the green check mark button in the upper right to go back to the main Optimum window.
How do I cut the part?
Step 1: put the plate on the table
This guide assumes your table is set up, the computer is connected and Optimum CNC is running. An overhead crane is the easiest way to load plate. If you don’t have one, use any method that’s safe for the weight.
- Line the plate up as straight as you can with the slats of the water table. It makes everything else easier.
- Clean the plate first. Dust, rust and weld spatter make the arc less stable and the cut rougher.
Step 2: power up
- Switch on the control unit. It’s usually at a corner of the table, about knee height.
- Turn on the plasma cutter and the air compressor.
- Turn on the computer that runs the software.
Step 3: zero the torch on the plate
Jog the torch to the bottom-left corner of the plate, close to the plate but not touching it. Then zero X and Y in Optimum CNC. That tells the machine where the plate is.
Step 4: check the part fits the plate
Turn on the Ruler in the top ribbon. It shows the size of material the job needs. Compare that to your plate before you cut.
Step 5: run a simulation
Click Simulation, then the green Play button in the lower right. The software shows exactly how the torch will move. Watch for anything that would run off the plate or cut in the wrong order.
Here’s the STV table running in simulation mode:
Step 6: cut
Turn Simulation off and click Play again to cut for real.
What if the cut doesn’t come out right?
- Part is the wrong size. The DXF units were set wrong at import (inches vs millimeters). Check the units and the scale.
- Part runs off the plate. The torch wasn’t zeroed at the plate corner, or the plate is crooked on the slats. Re-square the plate and zero again.
- Rough or wandering cut. Clean the plate. Then check your air supply and consumables, and the cut settings in your plasma cutter’s manual.
- Nothing happens when you press Play. Simulation mode is still on.
If you’re looking at hardware or software upgrades, my toolbox page lists the tools I use and any discounts I know of.
