I made a studless Technic to SG90 mini-servo adapter. These things are $18/10 on Amazon right now. I'm going to build a hexapod. Link to STEP and STL files in comments. :
HS311 RC Servo (43 grams) with mounting kit for Lego Mindstorms
Non Lego RC Motors - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums
LEGO Adapter, 3mm Shaft, Pololu 1011
Lego Servo Adapter by Nick | Download free STL model | Printables.com
Plastic Micro Servo Adapter for LEGO Cross - 16mm long - Boutique Semageek
Adapting Servos to LEGO – Brown Dog Gadgets
MOC servomotor con funciones de potencia mejoradas, Motor M L XL, rojo, 7,4 V, para grupo de potencia, bloques de construcción técnicos, ladrillos, 8882, 88003| | - AliExpress
Adapter & extension cables by PV-Productions for LEGO Powered Up - Power Functions - YouTube
lego servo" 3D Models to Print - yeggi
M5Stack on Twitter: "How about this? SG90 LEGO adapter https://t.co/TYrU7jqwKr" / Twitter