Wooden hydraulic excavator model

Material: wood
Principle:
Hydraulic transmission is a transmission mode which uses pressurized liquid in closed system to transfer motion and power. It converts the mechanical energy into the pressure energy of the liquid, and then the pressure energy of the liquid into the mechanical energy.
[Bottom plate length]: about 18cm.
[Bottom plate width]: Approximately 11cm
[Overall height]: about 26cm
[Power source]: Manual