CNC Electrical Noise Problems
One of the biggest frustrations on a CNC router is noise problems. Noise can manifest itself in a variety of ways including uncommanded movements, servo encoder problems, and limit switches tripping unexpectedly.
Poorly engineered CNC machines with electrical noise may cause:
- PC not to be responsive to mouse movements or keyboard strokes. This is specially noticeable when running high power spindle at maximum RPM.
- Stepper motors to lose pulse and in turn lose coordinate , ruin material , crash and cause injuries
- Sensors, switches and even emergency stop flicker ON and OFF. This is specially dangerous if emergency stops become affected and don’t respond when pressed.
- Spindle RPM suddenly increases and decreases
These are some major affects of noise in a CNC router system. But there could be many other to watch out for.
Noise suppression is often a matter of surrounding the noise producers and/or the noise victims with a grounded metal shield.
With enough foil and grounding, you can shield anything from electrical noise:
Some Methods to reduce electric noise in your CNC controller and components :
- Using Opto-Isolated breakout board and PC power
- Using shielded cable (specially for motor encoder and sensors)
- Wiring all sensors and switches N.C (normally closed)
- Avoiding grounding loops
- Using ferrite beads
- Adding in-line noise filter
- Frame and controller bonding
