To build a model of a windlass 

Cork

Sosatie sticks

Sellotape

Paper clips

Thin string 

Small bucket (plant pots or small pie dishes)

Make a hole through the cork

Push the sosatie stick through the hole

Use the paper clip to make a handle and stick it on with sellotape

Put another paper clip through the sides of the bucket to create a handle

Wind the string to create the differential pulley.  Wind it around the cork then pass it through the bucket handle and attach to the sosatie stick.