Teaching a Robot to Draw

This project demonstrates how to design and build a custom, 3D-printed End-of-Arm Tool (EOAT) for the Fanuc ER-4iA industrial robot. Our goal was to create a rigid, dual-position tool that can hold a standard pencil either perpendicular (0°) or at a 45-degree angle.

To realise this project we need:

1. Fanuc ER-4iA Robot
2. Creo Parametric
3. 3D Printer
4. PLA Filament for 3D Printer
5. Screws for flange
6. Screws for clamping
7. Pencil

The critical decision-making point came during the pencil-clamping phase.

Our original design called for a split clamp, this would use a slit in the plastic to flex and grip the pencil. However, our analysis indicated that the PLA filament could easily crack at the stress concentration point of the slit.

Instead, we designed a single, solid block for the 0° and 45° holders. We kept the pencil holes rigid and added a perpendicular hole for a standard set screw. This screw applies direct pressure to the pencil, locking it against the opposite wall.

It's time to slice the model and send it to the 3D printer. This tool will be mounted on an industrial robot subject that deals with rapid accelerations and decelerations, therefore we cannot use standard print settings. The tool needs to be tough, lightweight, and dimensionally accurate.

Total Print Time: 4 hours and 58 minutes (roughly 5 hours).

Total Filament Used: 108.74 g

Model weight: 103.09 g

Support weight: 5,65 g

Material Choice: We used PLA for its great mechanical strength.

Based on slicing data, we used approximately 109g of filament. For a durable material like PLA (at an estimated cost of €25/kg), the pure material cost is roughly €2.72.

To support the overhanging blocks where the pencils go, we enabled Tree Supports (Organic). As you can see, they only consume a tiny amount of material (5.65 g) and are incredibly easy to break away without damaging the surface finish or clogging the pencil holes.