can someone tell me what servomotor to use to build the gauges for several panels
You don’t need anything exotic. Speed and torque are not an issue. You just need something that fits physically. This is a Servo that has a decent price point and nice specs. It is a HV MG Servo. HV means it will operate on voltage up to about 7.4 . The MG means it has a metal gear train. Metal gears are much better than plastic. https://hobbyking.com/en_us/corona-ds339hv-digital-metal-gear-servo-5-1kg-0-13-sec-32g.html
Great answers Roger, thank you!
I did all my Gauges with X27 for single Pointer and X40 Stepper for dual Axis.
10Pcs 18€ from Aliexpress . Those Stepper are used in Automotive for Speedometers. With an additional VID666 driver, you can drive 4 Stepper by only 8 Pins. Zero adjustment is included. Really simple to use.
If you order from Hobby king make sure you order from the USA warehouse If you are a resident of th United States.