Choosing a heater

(Backdated: Oct 24, 2016)

I started this sprint out strong with some research into heaters. Basically, we saw two different options for heating up the barrel of our extruder: ceramic heating elements or a coil of nichrome wire.

The differences between a ceramic and coil heating element

Ceramic Heating Element:

• Pro: Prepackaged with known impedance. Super easy to implement
• Pro: Commercially manufactured
• Pro: Already electrically insulated
• Pro: We’ve seen it implemented in a hot glue gun.
• Pro: We already have one!
• Con: Small concentrated heater (won’t heat evenly without proper heat conductor design)

Nichrome Wire:

• Pro: Customizable length, heat output, resistance, power consumption
• Pro: We have control over more variable
• Pro: We can wrap it around
• Con: Totally custom setup takes more engineering effort
• Con: Have to manage electrical insulation

In the end, I decided we’d go with nichrome wire, because it’s more easily customizable to our application and would take less mechanical design effort to implement. I bought some 1 ohm-per-foot nichrome wire, which should provide us 120 watts of heat (the same as our hot-glue gun prototype) if we put 12 volts across 1 foot of it (P = IV, 10A * 12V = 120W).