I am assembling a Gimbal controller that needs "Ferrite rings". Can I use Ferrite clamps instead? Do they do the same thing?
It should make no difference either way, as long as it is only a single pass through the center of the core. This filters out-of-band HF harmonics. Multiple passes through the same or 2 cores may start to affect signal strength.
Note that at very low bit rates (Kbps) you could add extra turns (better filtering) through the core but you would be locked out of a shift to a much higher bit rate. Mbps is only possible with just a single turn (pass) through the ferrite toroid or clamp-on.
The clamps are better for raising the CM impedance thus reducing the EMI interference so that forward and return currents can cancel out better from a distance.
They offer higher inductance for a feedthru. This becomes important when sensors pick up the stray current flux from current spikes from emitters like motor drivers. Since sensors are already high impedance, they benefit more from twisted pairs and/or shield pairs.
Unlike inductors where X reduces the Rs rises so this means it also becomes an absorption loss to noise in the bands where the load does not need this energy but can interfere with logic and analog signals.
A better design will include CM chokes on the board where CM chokes can increase the uH in a smaller size with lower cost and smaller size but depend on the max motor surge current.