Vortex Mixer

Overview

A vortex mixer swirls the liquid inside a single tube into a spinning vortex so reagents blend, cells resuspend, or samples dissolve in a few seconds. The user presses a capped tube against a rubber cup, the cup whips through a tight circular orbit, and the liquid climbs the tube wall and folds back on itself. It is one of the most-used instruments on a lab bench, and its whole job is to turn steady motor rotation into a controlled orbital shake.

The instrument is built around a heavy Base & Housing. The Cast Base is mass-loaded and the four Rubber Feet grip the bench, because the orbiting head throws a real reaction force; without that mass and grip the mixer would walk across the bench at speed. The base also carries the controls and frames the opening where the cup head sits.

The working head is the Cup Head. Its platform is suspended on three Coil Spring springs and topped by a concave Rubber Cup Insert that grips one tube. The springs let the platform travel in a small circle while stopping it from spinning, so the motion stays an orbit rather than a rotation.

How it works

Drive comes from the Drive Motor, a brushless DC unit that reuses a standard stator and rotor on radial bearings. Its shaft turns the Eccentric Drive: an Eccentric Hub bored off-centre, a Counterweight that balances the offset mass, and a Ball Bearing whose outer race rides the offset. As the shaft spins, that bearing traces a small circle and pushes the cup platform around the same orbit, while the suspension springs return it each revolution, giving a fixed-diameter orbit at whatever speed the motor runs.

The Control Board sets that speed. Its microcontroller reads a front-panel speed dial and drives the motor to match, so the user trims from a gentle stir up to a full vortex. Two modes share the same drive: in touch-start, the Touch-Start Microswitch under the cup runs the motor only while a tube is pressed down, giving a quick burst with hands-free stop; in continuous, set by the Mode Selector, the head runs unattended for longer mixing or for holding a microplate. Swapping the cup for a head from the Attachment Kit adapts the same orbit to single tubes, racks, or plates.