Preliminary Detailed Design
Team Vision for Preliminary Detailed Design Phase
Goals for this Phase
- Create a more detailed floor plan.
- Obtain setup process data.
- Create a CAD model for the current glue well design. In addition, create CAD models for the neckband dispenser legs, the improved glue well design, and the rolling tray.
- Complete an experimental feasibility analysis for the torque required to turn the rollers.
- Write a preliminary standard operating procedure document.
- Select a motor, battery, and push button to recommend to the client.
- Perform feasibility analysis' for the improved layout and table designs.
- Used different masses in conjunction with the current glue well and determined a relationship between rotations per minute and torque.
- Performed a detailed analysis to determine the optimum angle at which the glue well should rest.
- Obtained time study data relating to the time required for morning setup, the material handlers idle time, and the time required to correct errors.
- Created a detailed preliminary standard operating procedure document.
- Performed simulations of the work table layout as well as the floor plan layout.
- Determined the battery, push button, and motor that will be used for the remainder of this project.
- Created a preliminary build of materials (BOM).
- Formulated a more detailed and comprehensive budget.
- Created CAD models for the neckband dispenser legs, the current glue well, the improved glue well design, and the rolling tray.
Setup Time StudiesTime studies were conducted on both disabled and non-disabled operators to determine the average setup times for the glue well. It was noted a large portion of time that influenced the results was the operators walking to the far sink to wet their towels. Time studies were also conducted on a few operators pre-stamping their labels. The following table displays the results.
Current Material Handler Travel TimesTime studies were conducted to determine the time Material Handlers spend re-stocking operators and transporting finished cases to packaging. The round-trip times are based on Material Handlers transporting two cases at a time, and re-stocking operators with six cases. The overall time is based on having 16 operators. The following table shows the approximate average times to travel between the pallets and rows of workstations.
Ideas Concerning Possible Conveyor Implementation
- 7-10 Seconds for Case to Travel Down Conveyor Depending on Start Location
- Case Does Not Always Travel To the Bottom
- Only Potentially Utilized by 8 Operators
- 1 Material Handler Devoted to Conveyor
- Interrupts Flow of Area
- Potential Quality Problems
- Bottles Rattling & Breaking
- Case Fall Off Conveyor
- Money Invested to Ensure High Quality
- Maintenance and Upkeep Needed
Prototyping & Engineering Analysis
Room Layouts Performed at RITBased on the selected work layout design from the Systems Design Review, the group re-arranged a classroom at RIT to simulate the proposed design. Preliminary time studies were run during this. However, this simulation displayed there were concerns with the flow and proposed design. The following photos display the simulation.
Simulated Future Material Handler Travel TimesAfter the work area layout was re-designed to improve the flow, a simulation was conducted using the dimensions and implementation of the cart. This simulation shows the possible improvement opportunities of the new work area layout combined with the implementation of the cart. This simulated re-stocking four operators with four cases each. The results are in the following table.
Here is the link to the Standard Operating Procedure(SOP) document: Standard Operating Procedure
Drawings & Schematics
Improved Floor LayoutAfter simulating our initial selected work area layout from our systems design review, we re-designed the layout to improve the flow of the area. Here are the following two options, we determined would be better suited for the area.
Option #1 with 9 work benches, which can accommodate 18 bottle-wrapping associates:
Option #2 with 8 work benches, which can accommodate 16 bottle-wrapping associates:
Improved Desk LayoutStandardization of Desk
- Implementation of Rule: No boxes on the floor
- Operators Receive 4 Cases at a time
- "Incoming" and "Outgoing" sections taped off on desk for easy tracking of WIP at each work station
Additional GraphicsFlags will be used to signal to material handlers when a bottle-wrapping associate needs more boxes, has a complete batch or needs more glue which will be kept on the material handler carts.
Cart Implementation for Material HandlersWith the implementation of the cart, Material Handlers will be exposed to less stress bending down and lifting cases. It will also help to decrease motion waste and decrease their energy expenditure throughout the day. The following are the different types of carts and their associated costs.
Additional Possible Ergonomic ImprovementsBoth ergonomic chairs and scissor lifts are possible ergonomic improvements that if implemented would reduce the stress of employees and increase productivity at ArcWorks.
- Part 4517T311 from McMaster
- $2000-3000 depending on amount of weight it needs to hold
- Available at McMaster
Mechanical Engineering Improvements
Feasibility: Prototyping, Analysis, Simulation
Feasibility Analysis for MotorTo determine the appropriate motor to purchase we created a theoretical model to predict the required torque. This analysis is presented on the systems design page of EDGE. This theoretical model was then implemented in MATLAB and used to create a relationship between required torque and rotations per minute (RPM). In addition, we used different masses in conjunction with the existing glue roller to determine the required torque and RPM.
The above code was used to create a relationship between RPM and torque. The following graph depicts the theoretically required torque at different RPM speeds.
To validate the theoretical model, a physical experiment was conducted. Different masses were hung off the knob attached to the end of the top roller. The masses were used to calculate the applied torque. For a range of masses, the RPM was recorded. The following table details the results of this experiment.
For the majority of the masses, three trials were conducted. The following graph was created from this experimental data.
The following graph depicts the average values of the experimental data. From the trendline, you can see that there is a linear relationship between torque applied and RPM.
Feasibility Analysis for AngleWe have determined that we can not determine the optimal angle through theoretical calculations but we can determine the minimum angle we need to exceed. We will determine the optimal angle through experimental testing in the detailed design phase.
Benchmarking of MotorsFrom the feasibility analysis, we can conclude that the required torque and RPM need to be very small. The following table details the motors we considered.
From our benchmarking, we recommend the Phidgets 3255 motor. It is a 12 V gear motor. It generates 0.26 lb-in of torque and 127 RPM. The cost is $10.00 not including shipping.
Benchmarking of Push ButtonThere are two possible types of push buttons that are feasible for this project; they are momentary or latching. A momentary push button requires the user to hold the push button down in order for it to actuate. The latching push button can be pressed down once to turn on and has to be pressed again to be turned off.
We decided to only explore momentary push buttons. The reason for this is twofold. First off, if you are required to hold the button down, less battery power will be used because you can not leave the motor running continuously. Secondly, the fewer times you push the button the longer the button will last.
The following table details the benchmarking of momentary push buttons. The cost estimates in the table do not include the shipping costs.
Our recommendation is for the EAO Series 45 push button. This choice was made because of the large rating for voltage and current. Additionally, it has 10x, at a minimum, the lifespan of the other buttons.
Benchmarking of BatteryFrom the motor we selected, we determined that we require a 12V battery. We investigated three different types of batteries. The first were large rechargeable lead-acid batteries. These weigh around 5 lbs and can range from $15 to $100. This cost estimate does not include shipping or the cost of the charger. With this type of battery, you can expect them to run for around 100 hours without having to charge them. We decided not to pursue this type of battery because:
- lifespan in comparison to other options
There are two other options for 12V batteries. Small battery packs or placing eight AA batteries placed in series. The small battery packs are all rechargeable and range in cost from $20 to $100. Again, these prices do not account for shipping or the cost of the charger. They will typically run, on average, for 34 hours. The following is a chart detailing multiple small battery pack options, though we have decided not to recommend them.
In our opinion, the best option is to purchase AA batteries and place them in series. This means an added purchase of the container to place them in, but the overall lifespan of the batteries is worth the added cost.
We investigated C, D, AAA, and AA batteries and found that there was not a great enough difference in lifespan to warrant the cost of the larger (C,D) batteries. Focusing in on AA batteries you can purchase either rechargeable or not rechargeable batteries. For all of the batteries listed in the following chart, the lifespan in comparison to the cost is well worth it. We recommend choosing the Duracell DX1500H Rechargeable AA batteries. These batteries are rechargeable, with Duracell estimating they can be recharged 400 times without the battery lifespan decreasing. The cost of these batteries are around $4 per and can be easily picked up at a local store.
To see the entire excel spreadsheet detailing this analysis click here: Battery Assessment
Current Glue Well
Impoved Glue Well DesignSince the last review, we have decided to move the angle to the outside of the glue well. This change will ensure that the volume of glue in the glue well remains the same. Instead, we have decided to add two small angle pieces to the side edges. This angle will not cover the back. Also of note, there is a small box attached to the right side of the glue well. This is the space holder for the motor.
Rolling Tray Design
Neckband Dispenser LegsThe following is the CAD model for the new neckband dispenser legs. Four legs will be needed for each neckband dispenser. These will be 3D printed at RIT at no cost to ArcWorks.
We will print four of these legs and test them to ensure that they work properly before printing the remainder of the legs.
The following figure is the schematic drawing for the neckband dispenser legs.
Bill of Material (BOM)
Test PlansThe following two documents were created to detail the test plans for the process and mechanical improvements. These two documents will be refined in the detailed design phase.
Risk AssessmentThe new risks we have identified are as follows:
To see the entire risk management assessment click here: Entire Risk Assessment
Design Review Materials
- The Systems Design review was presented using the EDGE website on 4/20/2017 at ArcWorks.
- The agenda for this presentation: Agenda
- The notes from the review can be found here.
- The following action items were recorded during this review:
Plans for next phaseThe plan for the detailed design phase is as follows:
Detailed Design Phase Preview: Detailed Design Phase Review
Personal Goals for Next PhaseTroy Bailey's Three Week Plan: Troy's Plan
Cassie Kaczmarek's Three Week Plan: Cassie's Plan
Emily Hebert's Three Week Plan: Emily's Plan
Kyle Chrysler's Three Week Plan: Kyle's Plan
Lachlan Newcomb's Three Week Plan: Lachlan's Plan
Justin Cook's Three Week Plan: Justin's Plan