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The Robotic Filament Dispenser for Arduino

Why a motorized filament support?

3D printers filament - usually almost robust - is pulled by the extruder while the roll is placed nearby to the printer, free to rotate. I have observed meaningful differences in the material behavior depending on the usage level, based on 1Kg filament rolls. A new (full) filament spool flows almost well but the force applied by the extruder should be relatively relevant: the weight is at least 1Kg. The extruder motor (most of the cases a Nema17 stepper) is not damaged by the effort but the two gears of the extruder collect particles of the plastic material due the applied force; this requires frequent extruder maintenance to avoid the nozzle clogging in the hot end. These particles tends to detach and mix with the clean filament while it is feeding increasing nozzle problems and a more frequent nozzle wear; this occurs more frequently with 0.3 mm diameter nozzles.

When the filament roll is half used or more its spirals become smaller and in some environmental conditions the filament tend to break too frequently. Long print jobs become less reliable and stressful; I can't leave the printer working alone for an entire night without controlling it. Thus controlling the filament feed by motor figures solving a series of issues.

• Make the automated engine almost simple and easy to reproduce
• Reduce as much as possible the number of non-3D printable components to make it
• Reduce as much as possible the stress applied to the extruder while printing
• Use a low cost and easy to program micro controller board
• Use the weight load sensor to keep under control che filament consumption and filament feeding
• Manage the environmental noise interfering with the filament weight measures

What's included in the kit

• All the 3D printed parts refined and tested
• N.6 bearings 8 mm internal diameter (22x8x7 mm)
• N.1 M5 Threaded bar and locking nuts
• N.1 Weight load sensor 5 Kg max
• N.1 HX711 AD IC board load sensor amplifier
• Needed assembly nuts and Allen screws

Optional parts

You can buy or not the geared motor. We offer a High quality 12 V McLennan geared brushed motor (what is shown in the video). If you already own a geared motor depending on the reduction speed maybe some constants should be updated in the software before flashing it on the Arduino board.

This tool has been developed for the Infineon TLE94112LE Shield for Arduino. You can use a different motor controller shield but some parts of the software may not works and need to be updated.

The assembly instructions can be found on Instructables