I modified the TrainServos8.ino sketch in this thread on the Arduino forum. If you want a copy of my sketch, send me a PM.
https://forum.arduino.cc/index.php?topic=315457.0
There is this one that I want to try that lets you control the speed of the servo. If you go the post #6 in this thread, it has a sketch for that. For this sketch, you'll need to include the "<VarSpeedServo.h>" in your libary to make it work.
https://forum.arduino.cc/index.php?topic=419492.0
I also have 4 Tam Valley Octopus III's that are super nice for controlling servos and have a very nice speed.
Mine are about as noisy as the tortoise with 5 volts running the servos. I think it's more the servo than the PWM.
Thanks for all the info. The Tam Valley Octopus IIIs look like a suitable (i.e. lazy) option for me!
Thanks also for the 3D printing offer, unfortunately I don't have many photos of ex-SP switch and derail targets that are appropriate for my 1999 Tehachapi era. I will dig some up.
However, I think etched options will be more robust — I'm concerned about track cleaning and other logistics that will put these in peril!
This is a great thread, and really inspires me to try some more innovative switch/derail operations.