P18391: Grinder Gizmo
/public/

Preliminary Detailed Design

Table of Contents

Project Statement: Automated burger machine with custom imaging to reduce cost and attract customers.

Team Vision for Preliminary Detailed Design Phase

PRI: Katie Berus

Rev: 1

Date: 11/4

Planned Tasks:

Accomplished Tasks:

Engineering Analysis

Zachary Gastin Last Edited: 11/14/17

Cook Hamburger Patty

Two-sided conduction heater: This was tested by using a standard George Foreman grill as an empirical model. Power consumption was measured through a Kill-A-Watt device while time to reach an internal temperature of 170°F was recorded. When compared to similar testing of alternative methods, such as one-sided conduction and electrical resistance heating, this was shown to be the fastest, efficient and maintained a high level of safety.

Prototype: measure internal temperature of burger with meat thermometer

Prototype: Measure entire power consumption with Kill-O-Watt

Place Top and Bottom Buns

Vacuum pickup. This method is chosen by thought model. Hamburger buns are lightweight, soft, and are not uniform. Vacuum is an industry standard for pick and place operations. By having a large surface the vacuum chuck will apply low pressure and prevent deformation of the bun, and allow lifting force to be generated when the shape is irregular. This assumption will be tested by attempting to lift hamburger buns with standard vacuum systems. Bun deformation will be recorded as well as repeatability.

Measure the center point of each ingredient

Image Generation

Heated Element: This was tested by using a soldering iron to sketch an image on a hamburger bun. When tested against other proposed methods, this method was chosen for line width, speed and image appeal. This testing confirmed that using a heated element to toast the top of the bun can generate a discernible image.

Prototype: Measure final designs

Prototype: Measure time of printing

Check Placement of printer Make sure printer enclosure is clear

Assembly Location

Assembly nest

Run models with individual times Once prototype complete: time entire process

Measure the center point of each ingredient

Estimate burger rate by time for each step Prototype: Monitor burgers output for selected time

Store Solid Ingredients

Water-cooled hopper: Ice bath.

Estimate temperature with calculations Prototype: Monitor temperature variation with thermocouple

Place Cooked Patty on Assembly

Place with vacuum pickup system. This is a standard solution.

Measure the center point of each ingredient

Receive Customer Orders

Web Interface: This is a standard Solution

Put in many different orders to the system and check for correctness

Estimate with calculations Complete testing with live subjects Prototype: Monitor and measure interaction time

Estimate with calculations Prototype: Measure time

Estimate with calculations Prototype: Measure time

Estimate with calculations

Estimate with calculations Prototype: Measure time

Estimate with calculations Prototype: Check with many different tickets

Live Document

Feasibility Testing

Scott Eisele

Last Update: 11/8/17

Note: The burger cooking tests and bun etching tests were conducted during the previous cycle, but the results are shown again here.

Burger Cooking Tests

Three techniques were tested in our burger cooking test. These methods are outlined in the table below:
Cooking Method Description Initial Predictions
Two-Sided Press Two heated surfaces press into the burger from either side Fast cook time & high power consumption
One-Sided Press The burger is placed on a hot surface, then flipped halfway through cooking Medium power consumption & automated flip would be challenging
Direct Electrocution Two electrodes are placed on either side of the patty, to cook the patty with the electric current Uncertain cook time & power consumption

The three variables we tested for were total cook time, energy consumption, and preheat time. All burgers were cooked to approximately 170 deg Farhenheit, as per industry health standards. The table below demonstrates the results across the various cooking methods:

Cooking Method Cook Time Preheat Time Total Power Consumption Other Comments
Two-Sided Press 2:13 3:30 0.040 kWh Quick grease buildup
One-Sided Press 11:02 3:30 0.065 kWh Flip at 3:30
Direct Electrocution 5:00 0:00 0.020 kWh Horrible smell

The linked video below shows the outcome of our "electrocution" method test: Electrocution Test Video

Bun Etching Tests

To test the capabilities of our various image generation methods, we tested them by hand to establish a baseline for the effectiveness. The table below describes the various methods tested:

Imaging Method Description Initial Predictions
Laser Etching Use a laser to burn the image into the top of the bun. Fast & effective
Soldering Iron Use a soldering iron to burn the image into the top of the bun. Potential to damage bun
Butane Torch Use a butane torch to burn the image into the top of the bun. Potential to burn bun excessively
Adhesive & Sesame Seeds Apply an adhesive layer to the top of the bun, then sprinkle sesame seeds onto the adhesive. Excess seeds will fall off, but seeds will stick where the adhesive is placed. Adhesive recipe may be complex
Flammable Liquid (Alcohol) Drip alcohol onto the top of the bun in the desired pattern, then ignite to burn the image into the top of the bun. Alcohol may absorb into bun
Flammable Liquid (Oil) Drip oil onto the top of the bun in the desired pattern, then ignite to burn the image into the top of the bun. Oil may absorb into bun
Food-Safe Marker Use a food safe marker to draw the image on top of the bun. Marker may be off-putting
Knife Use a knife to carve the image into the bun. Potential to damage bun

The results of our testing are demonstrated in the table below:

Imaging Method Time to complete [s] Other comments
Laser Etching 192 Poor image contrast, laser could not focus
Soldering Iron 26 High contrast, high resolution image
Butane Torch 18 Poor resolution, surrounding areas of bun were burned
Adhesive & Sesame Seeds 15 Good image contrast, low resolution
Flammable Liquid (Alcohol) N/a Did not work
Flammable Liquid (Oil) N/a Did not work
Food-Safe Marker N/a Did not work
Knife 14 Damaged bun
Bun Imaging Test Via Laser Etching

Bun Imaging Test Via Laser Etching

Bun Imaging Test Via Soldering Iron

Bun Imaging Test Via Soldering Iron

3D Printed Sprocket

To test the feasibility of using 3D printed parts for the complex geometries which will be required by some of our actuation mechanisms, we printed out sample sprockets at The Construct. These sprockets were based off of a CAD model for a sprocket on McMaster Carr.

3D Printed Sprocket

3D Printed Sprocket

The 3D printed sprockets surpassed our expectations for quality and rigidity from the 3D printer. It demonstrated that utilizing 3D printed parts for generic sprockets, gears, gear racks, and bushings could provide sufficient quality to be utilized in our final device. Considering the 3D printed sprockets costed only $0.18, and the cost of one sprocket from McMaster Carr costs $7.40, there is opportunity for significant cost savings in printing many of our parts. 3D printed parts appearing in our BOM are currently planned on being printed at The Construct.

Bun Vacuum Testing

To test the feasibility of using a vacuum to pick and place the buns, a quick test was performed using a shop-vac and a pair of hamburger buns. The expectation was that the shop-vac would create enough suction to lift the buns. The test demonstrated that the shop-vac was easily able to pick up the buns, however, after the vacuum was turned off, the bun still remained stuck to the vacuum for a few seconds. We believe this is due to the inertia in the vacuum mechanism continuing to generate vacuum even after it has been turned off.

The linked video here demonstrates the test: https://drive.google.com/file/d/0B_Sv6sWokmLAc2RZSUtJbFJNQTA/view?usp=sharing

As a result of this test, we plan on using a shop-vac as our source of vacuum for bun pickup. A shop-vac from WalMart will cost only ~$20, and provide sufficient suction to pick up our buns.

Drawings, Schematics, Flow Charts, Simulations

Mechanical Modeling

Burger Elevator

Scott Eisele

Last Update: 11/11/17

A specialized "burger elevator" has been designed to store and dispense burger patties onto the grill. The image below shows a CAD model of the current elevator design.

Burger Elevator Isometric View

Burger Elevator Isometric View

The elevator will be actuated via a linear electric actuator taken from an electric wheelchair. The linear actuator has a 7" stroke, and requires a 24V power supply. Since the actuator was a pre-used part, it was tested in the CE labs, which verified its usability.

The elevator's position will be monitored via cutoff sensors and a series of flags on either side. On one side of the assembly, the flags will be solid, and on the other side the flags will have a 1/16" slot cut into it. This will enable positioning accuracy of 1/16".

Flag Sensors for Burger Elevator Positioning

Flag Sensors for Burger Elevator Positioning

The burgers will be loaded into the elevator on stackable plates, ideally made of stainless steel for food-safety. However, the plates could hypothetically be made of any material, and the elevator will still function properly, enabling flexibility in usage. The plates rest on M4 screws spaced 1" apart on the elevator. Since the plates will be removable, cleanup of the device will be simple, and access to all the corners and crevices of the elevator will be easy.

Removable, Stackable Plates for Burger Loading and Storage

Removable, Stackable Plates for Burger Loading and Storage

The patties will be pushed off of the elevator and onto the grill via a spatula controlled with a pneumatic actuator. The pneumatic actuator will enable precise control over the travel speed of the spatula in both the forward and backward stroke. This will enable us to quickly slide out the spatula from underneath the patties to drop them onto the grill.

Pneumatic Actuator With Spatula for Burger Unloading

Pneumatic Actuator With Spatula for Burger Unloading

Vacuum Transfer

Zachary Gastin Last Update: 11/14/17

A vacuum pickup system will be used to move ingredients through the assembly process. This will be accomplished with a a vacuum cup mounted to a vertical linear actuator, on a horizontal rail system. This allows the vacuum cup to locate over each assembly or ingredient station and then raise or lower to the appropriate height for object pickup or placement. The horizontal rails will be constructed from aluminum extrusion for rigidity. Horizontal actuation will be provided by a stepper motor and toothed belt to allow for repeatable positioning over the entire 2ft horizontal travel. Vertical actuation will be provided by a stepper motor turning a balls screw. The vacuum cup will ride on a carriage with a captured nut and bushing, sliding on a guide rail parallel to the ball screw.

Vacuum Rails iso View
Isometric View of the Vacuum Rails
Vacuum Rails Top View
Side View of the Vacuum Rails

Bun Storage

Zachary Gastin Last Update: 11/14/17

Buns will be stacked in a vertical tube with a vertical actuation to lift them to the pickup zone. This will be provided by a stepper motor controlling ball screw.

Bun Tube iso View
Isometric View of the Bun Storage
Bun Tube Top View
Side View of the Bun Storage

Bun Etcher

The Bun Etcher base is a borrowed 3D Printer that will allow us to get the x and y axes movement that we need in order to draw images on top of the buns. The heating element that we are using is a soldering iron which will allow the bun to be toasted with limited time of the bun and iron in contact. To help us position the soldering iron at the right location without drawing on the bun where it is not supposed to, we are attaching the soldering iron to solenoids in order to get the lift we need. The solenoids will lift the soldering iron when it is not putting an image on the bun and will lower when the soldering iron is in position to draw. The holder for the solenoids and soldering iron has not yet been developed, but will be shortly after the soldering iron is received.

Isometric Bun Etcher
Isometric View of the Bun Etcher
Top Bun Etcher
Top View
Front Bun Etcher
Front View

CAD Files

To test the feasibility of the soldering iron bought, we will attempt to make recognizable images on the top of the bun with the soldering iron once it is relieved. This process will be the same as the feasibility testing we did to figure out which way we wanted to make the images, this will just check the specific soldering iron we purchased.

To test the feasibility of the solenoids lifting the soldering iron, we will create a temporary holder for them, must likely using tape, and attempt to lift the soldering iron up using only the force of the solenoids. The soldering iron does not need to lift up very high, just enough that it will not be touching the bun when moved into position for creating the image.

Assembly Station

Jacky Ho

Last Update: 11/15/17

The assembly station will receive the ingredients(Bottom bun, cooked patty & etched top bum), assemble and deliver the finish burger. This station will be controlled by a DC motor with a rack and gear system at the back to move the push plate to deliver the burger with the ramp at the front of the station.

Isometric View of the Assembly Station

Isometric View of the Assembly Station

Side View of the Assembly Station

Side View of the Assembly Station

Electrical Diagrams

Electrical Schematic

Electrical Schematic

Click Here For The Full Electrical Schematic

Click Here For The Full Electrical Schematic

Software Diagrams

Bun Etcher Software Flowchart

Bun Etcher Software Flowchart

Burger Cooker Software Flowchart

Burger Cooker Software Flowchart

Vaccuum Transport Software Flowchart

Vaccuum Transport Software Flowchart

Bill of Material (BOM)

PRI: Jacky Ho

Rev: 1

Date: 11/01/17

Bill of Material (BOM)

Bun Etcher Bill of Materials

Bun Etcher Bill of Materials

Burger Cooker Bill of Materials

Burger Cooker Bill of Materials

Burger Assembler Bill of Materials

Burger Assembler Bill of Materials

General Items Bill of Materials

General Items Bill of Materials

Budget

Sub-System Cost
Bun Etcher $42.92
Burger Cooker $98.23
Burger Assembler $136.65
General Items $62.40
Total $ 340.20
Cost Distribution

Cost Distribution

Bill of Materials & Budget Live Document:

Bill of Materials & Budget Live Document

Test Plans

PRI: Katie Berus

Rev: 1

Date: 11/4

Test Plans

Example of Component Test Plan

Test Plans2

Example of Complete Prototype Test Plan

Test Plans

Design and Flowcharts

System Architecture

PRI: Murali Srinivasan

Rev: 2

Date:11/09/2017

High Level Subsystems

High Level Subsystems

High Level Subsystems

Architecture Flow

Architecture Flow

Architecture Flow

Risk Assessment

PRI: Jacky Ho

Rev: 4

Date of Last Revision: 11/07/17

Risk Index and Prediction Chart

Risk Index and Prediction Chart

Revision 1 2 3 4 5 6
Risk Index 99 164 157 127 - -
Prediction 99 150 140 120 100 100
Risk List

Risk List

Risk Management Live Document:

Risk List

Design Review Materials

Presentation

Agenda

Plans for next phase

PRI: Katie Berus

Rev: 1

Date: 11/4

PDF

Plan


Home | Planning & Execution | Imagine RIT

Problem Definition | Systems Design | Preliminary Detailed Design | Detailed Design

Build & Test Prep | Subsystem Build & Test | Integrated System Build & Test | Customer Handoff & Final Project Documentation