Servo crawler with Arduino Nano

this is a crawler that uses 3 continuous servos, it doesn't work with limited, i tried. It uses an arduino nano with a shield from Amazon, link
(link)
with a 9V battery. It is a tight fit but it fits OK with a little force. It also has a slot for an Ultrasonic sensor

Feel free to comment, I'd love to hear more about what I can fix.