Plasma Cutter Employs Motor For Gantry Control

Plasma Cutters

Most welding professionals may be aware that when electricity and gas combine, plasma is created and it is sufficiently hot to melt through sheet metal. It will continue to be hot and move rapidly to blast molten metal away from the cut. Thus, to cut through metal and other materials, a plasma cutter creates an arc of electricity that passes through a high-speed jet of an inert gas.

Dynatorch Research

When research engineers at Dynatorch designed a line of plasma and oxy-acetylene cutting machines, they utilized the SM2315D SmartMotor from Animatics of Santa Clara, CA to operate the gantry, where the torch is mounted. To obviate warping, kinking, or scorching, the gantry and torch are placed at a fixed distance from the material that is being cut.

The small size, relatively light weight, and intelligent functioning of the motor are the attractive features that prompted the Dynatorch engineers to use it to the gantry’s integrated arc voltage height control system. It was found that if a gantry is huge-sized and too unwieldy, it will be both expensive and perform below par.

One more factor in favor of a lightweight gantry was servomotors will not need as much torque. As a result of Dynatorch’s in-house researched software, the motors are made to operate from a single micro-controller. This micro-controller manages all processing functions including the PID loop, trajectory generator, I/O control, and three high-speed serial channels all at once. As the operation is performed by a software routine, no additional hardware is needed between the command PC and the motors.

CNC Plasma Cutting Machine

The Gantry type CNC plasma cutting machine from SteelTailor - (SteelTailorTM B-2) is a Bench CNC Plasma cutter capable of cutting flat parts out of metal sheets with rare accuracy and high speed. The bench is made of re-enforced aluminum, aimed at making the Bench CNC Plasma cutter both sturdy and light weight. The bench has a water table and a cross track, with an effective cutting area of 1500 mm x 3000 mm. This is of course further expandable.

The water level of the cutting table is adjustable by an electromagnetic valve. The cross track is supporting the high control and the plasma torch is designed to accept any sort of plasma torch. The attraction is the high quality servomotors with reliable reducers provide accurate, high-speed motion.

The three axis gantry from PRO TABLE uses a four-stepper drive motor - one is on the x-axis, one is on the z-axis, and the remaining two are on the heavier y-axis. Most other systems use a single motor to power the y-axis that will transfer power to the other side using a jack shaft, belts, and/or similar components.

There is an inherent defect in this design as the gantry changes direction often during a full workday putting the whole stress on a small rubber belt and one motor. The belts will understandably give way, leading to frequent replacements. PRO TABLES whereas transfers power through a direct drive rack and pinion gear set. This eliminates the need for pulleys, rubber belts, gear box and jack shafts. Besides, this design and is far more reliable and thus more economical.