SMA Test

The SMA I use : Flexinol Wire 0.010″ LT / data sheet

The main point of the test have been aim at the whole configuration of my lighting unit design:

- the balanced movement of four corners

- control the tilt angle and distance between the surface panel and the mechanism base

- regulate the length of the SMA and the angle that fit in between top surface and the base

- stabilise and place the SMA ( enhance the strength make it able to stand)

- try out a way to embed the SMA with the material

- find out the right material which could active by the SMA perfectly and provide a better performance

- calculate  the length of the SMA and the max. voltage and the right current

 

Structure One

First I tried with this structure which is able to active the corner and create the bendy / folding motion.

Materials:

- SMA / I60mm *2 

- pvc tube / Ø2mm

- foam / 150 * 150 *3mm

- wooden base / as the above diagram

Method:

- use the pvc tubes to hold and fix the SMA

- test with two diagonal corners

Problems:

- the motion is limited in bendy corner ( not bad)

- without any external support the top surface panel is not balanced when moving

- the SMA need space to move / now fix with the plc tubes which is too easy melted by the heat of the SMA

- the foam is a bit too thick

Structure Two

After the Structure One, I tried to solve the problems before and build a new structure which include a central support. Also I narrowed down the size of the base that provide more space for the movement.

Materials:

- SMA / 220mm *2 

- pvc tube / Ø2mm

- foam / 150 * 150 *3mm

- wooden base / as the above diagram

- universal joint

- soft sides support

Method:

- Universal joint to balance the panel when moving

- longer distance between surface and the base

- build the supports for fixing the SMA / made out by foam

Improvement:

- the motion is more stable

- central support increase the strength of the whole structure

- increase the movement 

Problems:

- still need to find out a better way to fix and support the SMA

- to think about what kind of motion is better/ bendy corner or average tilt