I have used the following Servo Control Boards. All have their strengths and weaknesses: I believe there are other offerings but I haven’t used them as yet. These are just my own personal opinions as a user.
GF Controls Dual Servo Controller:
easy to set up
Cons: You have to be careful how you mount the servo to operate the signal, as you cannot reverse pull and release. You can “invert” but that just seems to move the section over which the servo moves.
Cannot alter the characteristics independently
Cannot alter speed separately
Cost about £25.00 plus P&P
Everything is configurable except for the amount of bounce
Operation by push button
Costs :about £65.00 plus P&P Controls up to 12 servos
Controls 4 servos , has bounce option, DCC only, easy to set up with DecoderPro
Perhaps difficult to get hold of these days. Pre-
Single servo controller, bounce models available -
MERG (Membership required)
Cost of a Servo4 is less than £10.00
The cost of a Servo 1 to members is approx £4.00 and setting box less than £10.00 (You only ever need one of these)
Of course you have to build them!
Which do I personally prefer? Servo4 but am tinkering with Servo 1 at the moment.