As a part of the development of our own industrial 3D printer, we required a filament feeder that could keep a constant upward pressure on the filament entering the tube to reduce strain on the printhead motor. In addition to this, we wanted continuous filament monitoring, run-out detection, and the ability to load 2 reels into each extruder with automatic reel changeover. A lot to fit in a box only 200mm wide!
This project was a ground-up development, right from concept through to end product.
[this is an internal project, so costs and lead times indicated above are for customer reference]
This novel device was tricky to design in a condensed space. In order to provide constant upward spring force, multiple floating extruder assemblies were required, separated into pairs to feed the primary and secondary nozzles of the printhead. The feeder also needed to know where the filament is at several points throughout the system in order to successfully perform a reel changeover.
This dense mechanical and electrical system consisted of:
– 14 microswitches
– 4 stepper motors
– 4 independent LED’s
– 4 fans
– 2 encoders
2 custom printed circuitboards were designed to consolidate all 56 connections into FPC ribbon cables. These allow us to drive the unit with our in-house developed FPGA control board, situated away from the heated environment.
To survive the 80deg heated environment it is exposed to, extruder parts were printed from polycarbonate- able to withstand 120deg before softening. Again, no machining required as our industrial 3D printed thermoplastics can handle the application with ease.