Bulb the Social Robot Companion

Introduction: Bulb the Social Robot Companion


Bulb is a social companion robot that helps to create moments throughout the day to optimise your work life balance. Bulb does this by going through the day just like his owner had planned, e.g. waking up by wiggling and lighting up slowly, and looking at spots in the room to indicate the current planned activity (such as studying by looking at the laptop). Through these physical social cues, changing its gaze and light, bulb takes on the role of a social companion that guides his owner in separating work and free time activities in a non-intrusive way.

Step 1: Base Structure

To begin check out the parts list and the 3d print files: https://drive.google.com/drive/folders/1YwkcT9HWp6geCt046Cwyokc3NLiRov8p?usp=sharing

We start by making the main structure of the robot. Bolt the three linear bearings onto the triangular base of the pillar, then push the 8mm rods into the holes of the triangular base plate, then slide 2 springs over each rod and then slide the three bearings over the rods.

Step 2: Head Mount

Push the circular bearing into the 3d printed beam, it should fit in snugly. Then bolt the other bearing on top of the beam. Position the beam in the circular head mount and bolt them together. At last align the hole of the bearing in the beam with the hole in the pillar from the previous step, and join them by inserting another 8mm rod.

Step 3: The ''wiggle'' Servo

slide the the attachment holes of the servo in the slot of the pillar and bolt it tight. The assemble the crank mechanism by bolting the 3d printed arm to the servo attachment piece using a bolt, nut and 2 washers to allow for rotation. Press the attachment piece onto the servo and attach it to the beam with one bolt, a nut, 2 washers and a spring that acts as a spacer.

Step 4: Head Rotation Actuation

Press the bearing into the 3D printed servo holder and carefully screw the pulley into the servo output wheel. Attach the servo to the 3D printed servo holder, two bolts will be enough. Then take 4 70mm bolts and push them through the holes in the side of the servo holder. Then slide 4 springs over the bolts and attach the servo holder to the main beam, the springs will act as a tensioner for the timing belt. Attach another pulley to an 8mm rod and slide it into the bearing on top of the main beam together with te timing belt, make sure to tighten the pulley as well as the bearing on the beam using the set screws.

Step 5: The Eyes

The eye contraption is made to be adjustable so you can find the perfect angle and distance for the magnets to be attracted well enough, without creating too much drag resistance. To begin bolt both T-arms together with a piece of rubber in between, this piece of rubber creates the necessary grip to position the two pieces in the desired angle. Then glue the magnet into place on the long slotted magnet holder piece, before doing this make sure you are glueing the the magnet in the correct orientation. Then add the slanted piece on top of the magnet holder, it should fit in snugly between the raised edges while still allowing for linear adjustment. Next crew the led ring onto the slanted piece using a single screw and a rubber spacer, this rubber spacer will make sure the led ring will stay in the correct orientation (these rubber spacers come with your servo). Do this for both eyes and then it is time to bolt the eyes onto the larger T-arm. If tightened right the eyes can be twisted and pushed forwards and backward on the T-arm. Now to bolt the entire eye contraption to the circular plate. At last it is time to make ''pupils'' of the eyes by glueing in the magnets (in the correct orientation so it attracts to the other magnets in the eye contraption) and painting the pupils black.

Step 6: Calibrating the Eyes

Place the plastic dome onto the ring and make sure it does not touch the eye contraption. If the dome does touch the eye contraption take it of and adjust the eyes until it doesn't. You can adjust the eyes by either mounting the entire eye contraption further backwards on the circular mounting plate or by pulling the eyes backwards through loosening the bolts that join the magnet holder to the T-arm and retightening them after finding the correct position. While doing this make sure the magnets are are as close to the dome as possible without touching it (around 3-ish mm). When the eye contraption is adjusted correctly the pupils can be added on the outside of the dome and should stay put.

Step 7: Mold Assembly and Silicone Cast

To prepare to cast the silicone skin of the robot make sure that all 3D printed parts are dust free and then grease the inside of the mold(olive oil will suffice), this will make the process of taking the mold apart after casting easier. Then assemble the parts as shown on the pictures. Begin by assembling the inside mold; take the bottom part(depicted as the grey part on the 1st picture) and slide it over the neck of the main body inner mold(the green part). If these parts do not stay put on their own apply a layer of tape over neck of the main body inner mold and try again until it fits snugly. Then take both halves of the outer mold and slide it over the parts you just assembled, the arms of the inner mold should fit snugly in the fittings of the outer mold as shown on the pictures. Now take 6 m6 bolts and bolt both halves tightly together, to be sure tape of the seems of the mold to prevent any leaks. After preparing your silicone it can now be poured into the mold trough the gap at the top. To make sure that the silicone reaches the bottom a slightly unorthodox method is recommended: take the entire mold and place it in a sturdy bag, make sure it stays up straight when you grab the handles of the bag and centrifuge it by swinging the bag in circles. Do this every now and then throughout pouring. Allow the silicone to dry as long as is recommended by the manufacturer of your silicone of choice. When enough time passed remove the bolts and your cast should be ready to go.

Step 8: Finishing Touches

Take the ''base cup'' and drill 3 8mm holes approximately 2 cm up from the bottom, each at a quarter of the circumference. The middle hole will be an outlet for the wires and must be positioned at the back of the robot, therefore check beforehand that you drill the holes at the correct orientation by looking at the triangular fitting in the base cup. Next fit the triangular base of the entire contraption into the triangular fitting on the bottom the 'base cup, it should fit in snugly and can be tightened down using a single screw. Now place the entire contraption in the silicone housing, now using a sharp knife make three small cuts in the silicone where it overlays the holes in the base cup, when this is done you can pull the wires through the hole in the back. Now you can pull the entire silicone housing up to and over the ring where it should stay put. Now push in the bottom legs through the bottom holes in the silicone, they should fit in snugly. Then take your knife again and make two small cuts in between the first and the second ''wobble'' of the silicone skin where the main beam is joined to the ring piece that holds the dome. Now push through the arms and bolt them to the the main arm. Take the plastic dome piece and apply a thin layer of white spray paint to the inside of the dome. The dome can now be placed back on the ring and the pupils can be placed back as well. At last bundle the wires in a cable eater for protection and glue together the laser cut suitcase to fit the Arduino and breadboard and hurray! Your robot is complete!

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    Penolopy Bulnick
    Penolopy Bulnick

    7 weeks ago

    Fun little robot :) What made you decide to make it?

    Jay Kolvenbag
    Jay Kolvenbag

    Reply 6 weeks ago

    Hi Penelopy! This robot was made for an Industrial Design project at the Technical University of Eindhoven, to explore human robot interaction