Hardware Engineering

Design Specifications

Circuit Diagram and Code






The Pill Packer: iGEM Guelph's innovative solution to the expensive outourcing of pill packaging for small startups and research laboratories.




Design Specifications


Figure 1: SolidWorks model of the overall final system, including the combination separator/filler subsystems and the presser subsystem


The pill packer consists of a hybrid capsule orienter-filler-presser system, a rotating wood circular plate, and a handmade wooden frame. The system itself uses two of the pneumatic linear actuator mechanisms. The first is placed horizontally to be used in the capsule orienter and filler subsystems. This mechanism is attached to a piece of wood under the openings of the container, and is used to open and close the holes of the filler system, controlling the amount of powder that enters the pill. The second mechanism, placed vertically, is used in the presser subsystem. This mechanism is attached to the presser head and is used to push the presser head into the pill, compressing the powder. The pill filling machine is very easy to use, as the capsule tray will rotate, passing through all the subsystems until each row contains 4 fully filled and pressed pills.


The first part of the pill filling process involves filling the pill hopper with capsules and allowing them to fall into the designated funnel extrusions. Ensuring that the holes are aligned, the pills will fall into the pill plate, which will then complete a one eighth turn to align with the pill slots in the next row. This process is then repeated until all the slots are filled. At this point, the filler hopper is filled with powder and the actuator- spring system shifts the hopper into alignment with the holes. The plate then rotates as the filler packs each pill, with every cycle rotating to place each pill in alignment with the presser system that compacts the powder. The cycle of filling and pressing is repeated until all the slots are filled with pills containing the compacted powder.


Figure 2: Physical Final design subassembly 1) Presser 2) Filler

Photo Step Description
Rotating Base Set Up The rotating base allows for precise rotation of the capsule tray
4 ball bearings are used to allow for the rotating base to rotate in a smooth manner A small gear is attached to the 28BYJ-48 Stepper motor to allow for precise rotation
The top of the rotating base fits snugly onto the central ball bearing Gear teeth on the internal edge of the top of the rotating base align with the small gear to control the rotation of the base
The top and bottom of the rotating base fit together, allowing the top to rotate with control of the stepper motor
The rotating base has two holes on top which align with holes in the capsule tray. Two pegs are used to fit the capsule tray and the top of the rotating base together.
Loading of Capsules into the Capsule Tray The first step in the process is to fill the capsule tray with empty capsules
The plastic container connected to the frame of the capsule filling machine is filled with empty capsules
The empty capsules are funneled through four funnel tips
As the linear actuator is turned on 4 capsules are transferred to a hole in the bottom of the supporting base, while the spring compresses
The 4 capsules fall through the hole and onto the pill flipper mechanism which orients the capsules with the body underneath the cap in the capsule tray The linear actuator is turned off and the compressed spring returns the mechanism to its original state
Separation of Capsules The next step is to separate the body and cap of the capsules
A thin squeeze plate is layered on top of the tray containing the empty capsules
An identical capsule tray and squeezeplay set-up is layered on top, with all plates being connected through two pegs
The bottom capsule tray and squeeze plate surround the capsule bodies, while the stop capsule tray and squeeze plate surround the capsule caps
Compression springs between the capsule trays and squeeze plates are kept in compression by the pegs
When the pegs are removed the capsule trays and squeeze plates move in opposing directions due to the force of the spring squeezing both the caps and bodies of the empty capsules
With the caps and bodies of the capsules are being squeezed the two capsule trays can be separated while separating the capsules
Filling of Capsules The most important step is filling the capsules with powder
The filling of capsules used the same mechanism as the loading of capsules into the tray to create a volumetric filler with two main differences First of all the moving piece contains smaller holes which have a volume designed to hold the precise amount of powder to fill a capsule Secondly the capsule flipper mechanism is exchanged for a filler mechanism containing 4 small funnels which direct the powder directly into the capsules
Pressing of the Capsules For formulas with high compressibility, pressing is required to fit as much powder into the capsules as possible
The presser system uses the same linear actuator mechanism as the filler and capsule loader. It used linear motion ball bearings to allows for smooth and precise linear motion It contains a presser platform which moves directly with the syringe linear actuator, and a presser head which moves with the presser platform unit it encounters resistance
The pill plate containing the filled lower halves of the pills is aligned with the 4 presser heads in a concentric manner
Once the 4 presser heads are aligned with the filled pills, the presser system lowers moving both the presser head and the presser platform together
The presser head makes contact with the powder, and it begins to recoil while compacting the powder into the capsules
Closing of Capsules The final step is to close the capsules
The capsule caps which are still held by the capsule tray and squeeze plate are carefully lowered onto the capsule tray with the filled capsule bodies
With the plates aligned, the capsule bodies and caps can be pressed together and sealed The top plate can then be lifted up and the sealed pills may be released.

Circuit Diagram and Code


Figure 24: Circuit for Pill Packer Machine


Figure 25: Circuit Diagram

Components used in circuit: ArduinoUNO, ULN2003 Motor Driver, 5V Relay, 28BYJ-48 Stepper Motor, JYZ3 - N/C 3 Way 12V DC Solenoid Valve, 12V DC Air Pump, 3x 9V Battery, Breadboard


To power the linear actuator and the stepper motor the circuit seen above was used. The stepper motor was controlled using a ULN2003 motor driver. This motor driver was connected to pins 8,9,10,11 on the Arduino Uno, and to the ground and voltage input ports of the arduino, then directly to the stepper motor. Pin 12 on the Arduino Uno was connected to a 5V relay. The relay was also connected to the voltage input and ground ports of the arduino. When power is supplied to the relay by pin 12, this closes the circuit with the air pump and solenoid valve. The air pump and solenoid valve are connected in parallel to a 27V source.


Figure 26: Code for Pill Packer Machine


The above code was used to control the entire capsule filling machine system. The main loop of the code begins with setting pin 12 on the Arduino Uno to high. This causes the relay to close the circuit that supplies power to the air pump and solenoid valve, which in turn moves the syringe linear actuator. This works regardless if the actuator is being used for filling, capsule loading, or pressing. After a few seconds pin 12 on the Arduino Uno turns off. There is a one second delay then the stepper motor is programmed to turn. This rotates the capsule tray to the next row of capsules whether the system is being used for filling, capsule loading, or pressing.