Harrods February Window Display

Finishing and brief spray painting and metalwork I did for models going into Harrod's London store.

V for Vendetta Mask Mould

Fibreglass mould I made from a plastic Guy Fawkes/V for Vendetta mask. Ivory pigment in the gel coat. Nice colour, wish I'd used it on the lay up instead. I had already applied blue PVA and wax to the mould when I took this picture.

Hot Wire PWM Test

Testing the ability to pulse the hot wire on and off via a potentiometer (dial).

In this circuit the heated wire has been substituted for a bulb to allow for an easier visual test.

In the video, the PWM (pulse width modulation) signal is sent via an oscilloscope. As can be seen, the signal being sent is flat on or flat off. This is the same signal I need to send from my Arduino. It is important this signal is precisely square or flat, as opposed to slightly curved because unwanted heat will be generated from the mosfet.

Also the rate at which the hot wire will pulse will also be changed. I just need to relate the dial's value (0-1023) to the amount of time the wire will be delayed on and off. This relation all depends on how hot the wire gets, so I will play around with this once the other components have been  implemented.

Hot Wire Cutter PWM Circuit Board

A circuit board for my hot wire cutter to provide a pulsing function, so that different lengths and thicknesses of nichrome wire can be used.

The circuit allows me to control the power supply, constantly turning it off and on varying the current, depending on the type of wire used, as not to melt it.

This is a prototype board to test whether the function will work in conjunction with providing the cutting wire ample heat.

It uses a mosfet with  4.5v gate drive eliminating the need to power the arduino chip separately.

For the final circuit board, I will implement a standalone arduino chip and a potentiometer to control the pulsing function.