Tiberius the Tootsie Roll Dispenser was created for the LVL1 Hackerspace Halloween Party.
Step 1: Starting Point
We begin with a fully assembled plastic dog skeleton. And a number of electronic components.
4 watt speaker
Adafruit Audio FX Sound Board + 2x2W Amp - WAV/OGG Trigger -16MB
4 watt speaker
Adafruit 16-Channel Servo Driver with Arduino
MG90S Micro Servo and horns
Servo Cable Extender
Geeetech Arduino Prototyping Shield
Not included in photo
Battery Packs and connectors
4 Momentary Button Switches
Step 2: Disassemble Dog
Several modifications to the dog skeleton are necessary.
Step 3: Jaw
The only moving part is the jaw. In order to drive the jaw via servo, two holes were made to act as anchors for a wire lever to be installed.
Step 4: Jaw Servo
Install small servo. Servo horn attached via wire to lower jaw. Servo attached by wire and glue to internal surface of mouth roof.
Step 5: Dog Eye Installation
The eye sockets pierced with a drill for the insertion of RGB LEDs. The LEDs are wired for connection to the PWM controller.
Step 6: Skull Base Servo
A servo is installed at the neck opening of the skull.
Step 7: Head Assembled
Once the two head sections are completed, they are joined together.
Step 8: Neck Modifications
The original connection of the head to skeleton was a nub that allowed limited motion. This nub was cut away. Over the resulting hole, a servo horn was attached.
Step 9: Hip Alteration
The hips are altered to hold servos for each leg. The blue servos seen were later replaced by black metal geared servos due to weight. The tabs on the servo were also removed to allow insertion of servos for adjustment of leg orientation.
Step 10: Hind Leg Attachment
The original lags consisted of a front and back half shell. The shell were separated and a servo horn is attached to one half. The attachment to one half will allow the servo horn to be attached to the servo via a screw which must be accessible while the leg is split. The construction images show a blue servo which was discarded due to plastic gear failure. The black replacement metal geared servos are shown with a different servo horn and a metal wire that keeps the horn fixed since only one screw could be used to affix the horn.
Step 11: Dividing the Knee
The legs are then divided into front and back halves. The halves are then cut at the knee below the knee cap. These cuts allow for the creation of a bending knee.
Step 12: Creating a Knee
Several combinations of rubber bands and springs were tried. The basic plan for a spring is shown in the blue background image. Finally, two nested strings were found to provide adequate support and return force. The springs are threaded by a tie-wrap segment. They are then anchored to the internal posts of the leg halves.
Step 13: Tail
The original tail has a hook at the end to attach to the skeleton. This hook is removed and a servo horn is attached. The original skeleton spinal column base needed to be removed to make room to install a servo. A servo is then installed. The tail is attached via the servo horn.
Step 14: Above and Beyond
Just animating this skeleton isn't enough. Two additional surprises await. After all, why is it called a Tootsie roll dispenser?
Step 15: Dispencer Begin
The dispenser is made of three materials. A PVC tube of sufficient diameter for tootsie rolls. A sheet of plastic (a piece of scrap was used here). And a servo (servo horn not shown).
Step 16: Tube Preparation
The OVC tube is marked for removing a notch. This notch is along the diameter and just larger than a Tooties Roll length. Once the notch is removed, a second cut is made to the extending section. This cut "splits" the section remaining after the notch. Several cuts are needed to get the desired width. A file was used to even up the cuts.
Step 17: Dispencer Mechanism
The dispenser mechanism consists of two pieces cut from the plastic sheet, a servo horn and a servo. The servo horn is attached to the pie cut disk. The disk is then attached, via the horn, to the servo.
Step 18: Dispencer Plate
The servo and disk assembly is attached to the slotted plate.
Step 19: Attaching Tube
The disc, plate, servo assembly is attached to the plate and aligned.
Step 20: Dispensing Action
When assembled, the dispenser operates as shown in the pictures. An incline to the tube allows the Tooties Rolls to be gravity fed.
Step 21: Attach Dispenser
The dispenser tube is cut to the needed length and installed inside the rib cage along the spine.
Step 22: Fluid Dispensing
A tube is installed along the length of the dispenser. A pump and motor controller assembly is prepared.
Step 23: Switches
Four switches are wired into the base. The switches share a common ground and will be connected to arduino pins 4 thru 7 with pull up resistors.
Step 24: PWM Controller
The PWM controller is wired with servo cable extenders with the ends removed. Servo channels 0 thru 3 are wired for connection to servos. Channels 4 thru 6, 8 thru 10 signal leads are connected to the RGB LED leads. Channel 7 and 11 signal lines is wired to the common anode of the LED. This requires channel 7 and 11 signal lines be high to supply power while lines 4 thru 6 and 8 thru 10 are kept low to allow them to light up. Next time I'll use common cathode LEDs and not tie up two PWM channels. Channels 12,13 and 15 are wired for servos. Channel 14 is no used (for now).
Step 25: Arduino Prototyping Shield
The arduino shield is wired with four sets of wires. The five on the left go to their color's buttons installed into the base with blue for the common ground. The set at the bottom are four trigger lines to the FX Sound board. The four on the right are for power and I2C to the PWM controller. The two lines on the top are power for the FX Sound board. The switch and FX Sound trigger lines are pulled high by resistors soldered to the shield.
Step 26: Disorganized Whole
With all parts collected, the whole is wired together.
0 Left Leg
1 Right Leg
4-6 Left Eye RGB LED
7 Left Eye LED Anode
8-10 Right Eye RGB LED
11 Right LED LED Anode
12 Head Twist
Step 27: Demo Video
Demonstration of Head Functions
Dispensing Function Below:
Step 28: Time Running Out
The dispensing of Tootsie Rolls is in the linked video.
The Head and Eyes are demo-ed.
Next would be the FX sounds and liquid dispensing.
Updates to follow.....
Second Prize in the
Halloween Decor Contest 2015