What causes excessive dross (slag) on the bottom of a plasma cut?

Dross is primarily caused by either cutting too slowly (low-speed dross, heavy and easily chipped off) or cutting too quickly (high-speed dross, tenacious and hard to remove). Low dynamic air pressure and worn nozzle orifices are also primary culprits.

How do I calculate CNC kerf offset for CAD/CAM parts?

The kerf offset in your CAM software (SheetCAM, Fusion 360, Torchmate) should be exactly half of the total kerf width. For example, if your 45A tip produces a 1.2mm kerf, set your tool kerf offset to 0.6mm.

Can I use a 20-gallon 2 HP hobby air compressor for plasma cutting?

A 2 HP compressor delivers around 5.5 to 6 SCFM at 90 PSI. While it can run a 30A-45A plasma cutter for short bursts, the small tank will cause pressure to drop below dynamic cut thresholds within 30 to 45 seconds of continuous cutting, causing the torch to sputter.

Why does my cut have a severe bevel angle on one side?

Plasma swirl rings introduce a clockwise vortex to the gas, creating one square edge (the right side of torch forward motion) and one beveled edge (the left side). Additionally, an out-of-round nozzle orifice, improper torch height, or incorrect torch standoff angle will cause angular bevel.

What is pierce delay and why is it critical on CNC tables?

When initiating an arc in the middle of a plate (rather than edge starting), the molten metal blows directly upward into the torch shield cup. A pierce delay allows the torch to pause at an elevated pierce height until the arc punches through the plate before lowering to cut height and moving forward.

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🔥 Cutting Parameters & Metal

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Operation Type

Supply Hose Length (ft) Air line from compressor to machine

⚡ Torch Pressures, Nozzle & Speeds

Recommended Nozzle Orifice -- Tip diameter (mm & inch)

Dynamic Air Pressure -- Flowing pressure at torch

Air Volume Consumption --

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Expected Kerf Width --

Pierce Delay (CNC) --

Static Regulator Setpoint --

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The Critical Physics of Air Pressure, Flow, and Plasma Arc Constriction

Plasma cutting utilizes an ionized gas vortex (thermal plasma exceeding 20,000°C / 36,000°F) to melt metal and instantly blow molten dross away from the cut kerf. The quality, bevel angle, dross formation, and life of consumable electrodes depend on the balance between three factors: electrical current (amperage), swirl air flow rate (SCFM), and nozzle orifice geometry.

Dynamic vs. Static Air Pressure

One of the most frequent mistakes in plasma cutting is adjusting compressor regulators based on static pressure (the pressure shown when the torch is off). When the trigger is depressed and gas flows through the torch solenoid and restrictive swirl ring, line friction causes a 10 to 20 PSI drop.

Dynamic Pressure (Operating): The actual pressure at the plasma machine inlet while air is actively discharging through the consumables (typically 70 to 85 PSI).
Static Pressure (Supply): The idle pressure set on the shop air regulator (typically 90 to 110 PSI) to compensate for hose line friction and filter resistance.

Clean, Dry Air: The Consumable Life Factor

Standard shop compressed air contains atomized compressor oil and water vapor. Water vapor in a 20,000°C plasma arc disassociates into hydrogen and oxygen, aggressively eroding the hafnium electrode emitter and creating irregular bevel angles and dross. Running a multi-stage desiccant air dryer or coalescing oil filter is mandatory for high-precision CNC cutting.