Magnetic Field Apparatus Design

Post date: Feb 15, 2012 12:4:41 PM

Presented here is our final design. We used a permanent magnet and funneled the magnetic field to a small gap where the freeze-casting sample will be. The magnet will be rotated by a stepper motor coupled to the magnet.

Caption: High Resolution Render of the Final Design of the Magnetic Field Apparatus

This design utilizes one permanent magnet one large 4in X 4in X 1in magnet which is rated at 1.32 Tesla, a pull force of over 700 lbs. Using the concept of flux funneling the magetic field , we will apply about a magnetic field strength of 2.3 Tesla at the surface of the magnet closest to the sample in the PVC tube. The magnetic field strength at the location of the sample can be adjusted simply by rotating the threaded blocks on the cylindrical screw on the magnet.

Caption: High Resolution Render of Magnet

To mount the magnet to the entire frame, we will mount a non-ferouss aluminum block to the magnet and run a non-ferrous aluminum rod from this block through the frame, a thrust bearing, and a shaft coupler which will attach the shaft to the stepper motor. The stepper motor will be mounted to a laser-cut motor mount.

Caption: High Resolution Render Displaying Stepper Motor Setup

One large issue was supporting the weight of the magnet due to the weight of it. The stepper motor could not support the 12 kg magnet. In order to work around this, our magnet is held by a coupler resting on a thrust bearing. The coupler then connects to the motor on the other side which can now rotate the magnet without any weight on the motor. As a safety if the magnet slips out of the coupler, we have a safety clip which runs around a notched out area of the aluminum rod attached to the magnet.

Caption: High Resolution Render of Thrust-Load Mechanism and Safety Clip Cross Section

In order to drive the stepper motor, we will be using an Arduino UNO with a stepper motor shield. With a given knob, we will be able adjust the rotation speed of the stepper motor.

Build Of Materials for Final Design

CAD for Machining and Cutting Acrylic

Instruction Manual *When we create Manual

Describe Controller, and arduino

Code for Arduino LINK