Hydraulic Arm
Water-filled syringes transmit force through tubes to move a cardboard arm — fluid power you can grip with.
Start building ↓The build
Build the arm
Cut linked cardboard segments hinged at joints.
Pair the syringes
Connect two water-filled syringes with tubing for each joint.
Mount them
Fix one syringe to the base and the other to the moving part.
Operate
Push one plunger and the other extends, moving the joint.
Water can't be compressed, so pushing one plunger forces an equal volume out the other, moving the linked joint — Pascal's principle in action.
A closer look
Pressure applied to a confined fluid transmits undiminished, letting small hand forces move larger loads through fluid links.
Variables to test
- 1 Use a fatter output syringe — more force or more motion?
- 2 Add air bubbles — why does the arm get spongy?
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