You can still buy the proper "upgrade kit" to get the fire monitors to elevate and rotate, but a lot of work and the nylon thread is prone to wearing and breakage. if you can live with the monitors just rotating, then just use some robbe pulley wheels and cord and link to a servo unit for each monitor. then link up the 3 using "Y" leads, remembering to reverse the thread around the forward drum, so all the monitors rotate same direction!

HI there, I'm currently building the same boat and have just got to that stage. I'm hoping that a 'Y' lead to both sets of servo's should have the desired result.

Barry

what water cannons are you using ?