About this 3D model

This is a simple adjustable-volume straw pipette. It should be very useful around any wet lab and works nicely with a relatively high range of possible volume settings. You can calibrate the volume but it is generally only good for low precision work. The pipette has two thumb nuts for adjusting upper and lower stops. To complete the build you will also need a spring (Pez dispenser) but it may work without as the membrane is elastic, a kids balloon, drinking straw, and some tape. Good luck! See a demo: http://youtu.be/N2Ax4OGokGM