force feedback on Vive controller


i’m trying to add a rumble effect on the controller depending on the distance the controller travels.
I want to fire a single “knock” each time the controller travels 5 cm.

Here is my setup (pawn blueprint) :

Press a button opens a gate setting the distance traveled since the button is pressed as a variable.
This distance is divided by a value corresponding to the segment I setup (5 cm), giving me an incremental number of “knocks” (or sort of).
The difficult part comes here : I had to compare this value to its truncate value, to find when it changes - this condition should make the event fire each time the value is near to an int and changes from 1 to 1.
However if it worls well sometimes, it appears that during some periods the comparative nodes returns (oddly) false and the force feedback doesn’t appear.

Is ther another way to achieve this ?
Is there an error in my setup ?

Thanks a lot for your help !