Robot arduino 3D print

Here you have a small robot I have done for a special holiday course for children.
In 6 week, 2h/week they have finish all the robot
The cost is around 20$ per robot of material

They can modify the top with tinkercad
they can start programming with blocklyduino or S4A and then switch to arduino IDE.

You have :
an arduino nano
https://www.aliexpress.com/item/1PCS-LOT-For-arduino-Nano-3-0-Atmel-ATmega328-Mini-USB-Board/32807152086.html
motor driver (L9110S dual H bridge)
https://www.aliexpress.com/item/H-bridge-Stepper-Motor-Dual-DC-Motor-Driver-Controller-Board-L9110S-For-Arduino/2038557946.html
9V battery holder clip
https://www.aliexpress.com/item/10Pcs-Snap-on-9V-Battery-Holder-Clip-Connector-Hard-Shell-10CM-Cable-Lead/32640215699.html
ultrasonic sensor (HC-SR04)
https://www.aliexpress.com/item/Ultrasonic-Module-HC-SR04-Distance-Measuring-Transducer-Sensor-HC-SR04-HCSR04-ultrasonic-transducer-ultrasonic-sensor/32319720974.html
2 DC motors with wheels
https://www.aliexpress.com/item/Deceleration-DC-motor-supporting-wheels-smart-car-chassis-motor-robot-car-wheels-for-arduino/32694686113.html
some cables (dupont line male/male or/and male/female)
https://www.aliexpress.com/item/Dupont-Line-120pcs-20cm-Male-to-Male-Male-to-Female-and-Female-to-Female-Jumper-Wire/32827752222.html
a remote control kit with receiver module
http://www.aliexpress.com/item/100-New-Infrared-IR-Wireless-Remote-Control-Module-Kits-For-Arduino-Wholesale/32227571338.html
and some cable ties, 9v batteries and other small part (condensateurs, switches,...)

** EDIT 28/03/2017 **
Public CAD source : https://www.tinkercad.com/users/57R4FTxF3Sq-zoilo-abad
To connect and program you have some example on github
https://github.com/drachezoil/Mindlab-robot

** EDIT 01/11/2017 **
Added schematics and new links