Web4Deb extruder

Introduction

The Web4Deb Extruder is a functional auger based granular extruder that produces perforated HDPE strips for use in aquaponics. A video of the extruder in action can be found [here]. The blog of the creator (Web4Deb) can be found [here].

Specifications

• The barrel is heated with a length of Nichrome wire and and insulated with what appears to be polyimide tape.
• The auger is a standard 3/4" wood auger bit (bought a set from Harbor Freight) and cut it down to length.
• The auger is driven by a wind shield wiper motor which is geared down with a bicycle chain and sprocket.
• The heating element draws around 16A at 12V (192W) from a computer power supply.
• The temperature for the extruder barrel is controlled with a Teensy AVR micro-controller.
• The die is appears to be interchangeable.
• The extruded HDPE is forced through a set of fan cooled rollers.
• Two individual temperature sensors are located on the extrusion barrel.
• The Teensy AVR micro-controller appears to be used to switch one or more relays through a transistor array.

Questions

• How far does the auger drill bit extend into the extruder barrel?
• what is the RPM of the auger while extruding?
• What type of thermistor is used for the temperature sensing?
• Is it really required that the temperature be measured in two places?
• Is there two separate windings of nichrome wire that are individually controllable?
• What RPM is are the pinch wheels running at?
• How are the pinch wheels powered?

Further information

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