Interference from Stepper Motors

I am getting real interferance as the stepper motors are pulsing.
I have tried decoupling the lines that power the motors with 0.1 microfarad capacitors and screen the stepper motor wires with an outer screen that is earthed. This has reduced the noise about half of what it was but there is still a lot there. This is on the 2 metre amateur radio band using FM.

Stepper motors give a lot of interference. We had major problems getting the ultimaker original within CE norms. My electical engineering is a bit rusty, but this makes sense; you are sending a lot of power over a wire, which is basicly an antenna. Shortening the length of the stepper motors should also decrease the interference.

We think that the best way to deal with that is to separate the RF electronics from the high power (voltage regulator because is switching regulator is generating lot of noise to) and place them in a shielded box we will come up with a plan very soon.

My suggestion would be also to put all electronics, in individual metal boxes. The switching power supply will kill the SDR otherwise.
I.e. like:

Found this site:

http://motion.schneider-electric.com/support/general/wiring_noise_shielding_bp.html

Google indicates that this is a common issue.

Ferrite beads could also work right? I remember that we considered those for a while, but we managed to lower the RF influence without using them (which was cheaper).

Hi, I’m testing with the motors and it worked pretty well, use a shiel of aluminum tape on the wires of the motors.