We sometimes take for granted the amount of work and time that goes into making the things we use. Take, for example, a chair. They can be found everywhere, yet we rarely stop to think about the processes used to make them. The designer has to first make a design, which requires calculations in order to determine the shape and what material should be used to make the object. Next, the raw materials need to be sourced and bought. The manufacturer interprets the designs and using the raw materials, the individual parts are machined. Finally, the parts are all assembled and the final product, a chair, it ready. The point of the final project for this class was to walk through all of these processes and introduce us to the tools in the EPIC (Engineering Product Innovation Center) workshop at Boston University (BU); this would be the first time in my college career where I would get to make something from start to end and use the major tools offered by EPIC (i.e. CNC mills, lathes, etc.).
Project Goals: The major goal of this project was to pick anything we wanted to and make it from start to finish. The object we choose to make was to be approved by the professor and the staff in EPIC. My group and I decided to make a juice press; the picture to the left served as our inspiration and base design.
Learning Objectives: Throughout the process of completing this project, I was introduced to what EPIC had to offer, as well as a demonstration on how everything in the workshop worked. The skills I employed included:
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The Design
The project starts with a base structure component to hold the machine stable. The base is connected with a 12’’ aluminum rod with an L-bracket. This will be the base component of our design creating a solid infrastructure to the components surrounding it. The main functionality will come from the plastic components that are attached to the aluminum rod. The plastics we used for most of the juicer were HDPE because it would be resistant to corrosion from the acidity of the fruits to be juiced. The design has a nested storage pulp control dial that has a removable reamer of a basic size. The reamer is removable making it easy to clean. The design is based on a gear and a gear rack along with a wheel to create the motion of the lowering of the press onto the reamer. The gear and rack were made of nylon plastic as it is cost efficient. The rotational motion of the user input is converted to linear motion that compresses the fruit in order to juice it. Creating a smooth motion, the press has full functionality. The top base is made out of plastic materials making it easy to clean and safe to use with food. Below is one concept of the 3D CAD model, a drawing of another concept, and an image of a drawing (NOT MINE) of the final design we choose to go with:
The project starts with a base structure component to hold the machine stable. The base is connected with a 12’’ aluminum rod with an L-bracket. This will be the base component of our design creating a solid infrastructure to the components surrounding it. The main functionality will come from the plastic components that are attached to the aluminum rod. The plastics we used for most of the juicer were HDPE because it would be resistant to corrosion from the acidity of the fruits to be juiced. The design has a nested storage pulp control dial that has a removable reamer of a basic size. The reamer is removable making it easy to clean. The design is based on a gear and a gear rack along with a wheel to create the motion of the lowering of the press onto the reamer. The gear and rack were made of nylon plastic as it is cost efficient. The rotational motion of the user input is converted to linear motion that compresses the fruit in order to juice it. Creating a smooth motion, the press has full functionality. The top base is made out of plastic materials making it easy to clean and safe to use with food. Below is one concept of the 3D CAD model, a drawing of another concept, and an image of a drawing (NOT MINE) of the final design we choose to go with:
Materials
The materials we considered for this project consisted mainly those that were safe when in use with food. Several materials are commonly used in kitchen appliances for their chemical resistance such as stainless steel. We considered using stainless steel but due to the price range for purchasing the material, it wouldn’t be convenient to use. An alternative option would have been aluminum and remains as one of our highest probable materials due to its convenient use. Both materials when exposed in environments of food would not rust therefore clean and appropriate for our project. The third material and the one we are most likely to use is plastic, specifically High Density Polyethylene (HDPE). It is cheap, easy to clean and would allow us to create a cheap alternative to juicers already out in the market. In the end, we went with a Aluminum for the structural parts and HDPE for the parts in contact with juice.
The materials we considered for this project consisted mainly those that were safe when in use with food. Several materials are commonly used in kitchen appliances for their chemical resistance such as stainless steel. We considered using stainless steel but due to the price range for purchasing the material, it wouldn’t be convenient to use. An alternative option would have been aluminum and remains as one of our highest probable materials due to its convenient use. Both materials when exposed in environments of food would not rust therefore clean and appropriate for our project. The third material and the one we are most likely to use is plastic, specifically High Density Polyethylene (HDPE). It is cheap, easy to clean and would allow us to create a cheap alternative to juicers already out in the market. In the end, we went with a Aluminum for the structural parts and HDPE for the parts in contact with juice.
Multipurpose 6061 Aluminum
Aluminum was selected as the frame base bar that will hold the press together. This is due to it being a material that is easy to machine as well as strong and not complex. Aluminum is widely used in kitchen utilities due to its rust resistance and ease of cleaning, making it an approachable material for our specific product. The specific type of Aluminum is Multipurpose Aluminum 6061. |
Rigid HDPE Polyethylene
A widely used plastic throughout kitchen containers and food storage devices is Polyethylene. As a Type 2 Plastic, this classifies it safe for food handling, hence why it is commonly used in industrial food storage containers. It is to our benefit to make use of this material in all components we make removable for safe cleaning of the product. Additionally, it is the most cost efficient of the types of plastic used in food handling. |
Cost
All of the materials we choose to go with were purchased from McMaster-Carr. Originally, the price for all materials would have come up to around $85, however, by altering the design and reducing the amount of material needed for each part, we were able to reduce the final cost to around $50 without affecting the functionality or durability of the finished product.
All of the materials we choose to go with were purchased from McMaster-Carr. Originally, the price for all materials would have come up to around $85, however, by altering the design and reducing the amount of material needed for each part, we were able to reduce the final cost to around $50 without affecting the functionality or durability of the finished product.
Material |
Cost/Unit |
# of Units |
Total Costs |
Description |
Rigid HDPE Polyethylene Rod, 4” Diameter, 3” Length |
$21.10 |
1 |
$21.10 |
Used for
tank linings and industrial cutting boards. Excellent moisture resistance of
chemicals and alcohols |
Multipurpose
6061 Aluminum, Rectangular Bar, 1”, x 1’ Length |
$6.34 |
1 |
$6.34 |
The mostly
widely used aluminum, corrosion resistance |
Plastic Gear – 14 – ½ Degree
Pressure Angle, Press-Fit Mount, 32 Pitch, 62 Teeth |
$15.16 |
1 |
$15.16 |
A light duty alternative to metal, these gears have a 14 1/2° pressure
angle that maximizes contact between mating teeth for smooth operation. They're also known as spur gears. |
32 Pitch Rack for Plastic Gear - 14-1/2 Degree Pressure
Angle |
$6.46 |
1 |
$6.46 |
A light duty alternative to metal, these racks have a 14 1/2°pressure angle that maximizes contact between mating teeth
for smooth operation. They’re cut to ensure end-to-end
butting without interruption of tooth spacing. |
Total Cost |
$49.06 |
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The Final Product
The objective for this project was to build a functional, simple juice press that could be mass produced due to its simple approach to a common mechanism. A manual juice press was chosen due to its approachable design. The primary objective was to build this press in a cost effective manner, including testing stages on how to approach the handle and how to maneuver through materials to make the outcome of this whole project effective. The initial design was changed in slight ways due to the material we ended up selecting and trying to simplify the complex design we initially chose. The rack and pinion mechanism was employed due to the ease of use and could be easily adapted to any design we choose. By making the reamer removable, the design had the functionality of it being easy to remove major components to clean. All parts were machined via a CNC mill and all connections were made via screws and threaded holes. Below is an image and video of the final product:
The objective for this project was to build a functional, simple juice press that could be mass produced due to its simple approach to a common mechanism. A manual juice press was chosen due to its approachable design. The primary objective was to build this press in a cost effective manner, including testing stages on how to approach the handle and how to maneuver through materials to make the outcome of this whole project effective. The initial design was changed in slight ways due to the material we ended up selecting and trying to simplify the complex design we initially chose. The rack and pinion mechanism was employed due to the ease of use and could be easily adapted to any design we choose. By making the reamer removable, the design had the functionality of it being easy to remove major components to clean. All parts were machined via a CNC mill and all connections were made via screws and threaded holes. Below is an image and video of the final product: