University of Minnesota Duluth

Department of Mechanical and Industrial Engineering

Process Improvement for Drill Bit Blanks - Final Report

for

Minnesota Twist Drill

The Three Orienteers

Andy Johnson Tony Niemczyk Scott Andersen

Final Report for IE 4255 / ME 4255 Senior Design Fall Semester, 2006

Report Number UMDMIE-CD-2006WPDK12 ACKNOWLEDGMENTS...... 1 EXECUTIVE SUMMARY...... 2 1.0 PROBLEM STATEMENT...... 3 2.0 PROJECT DEFINITION AND SCOPE...... 4

2.1 PROJECT SCOPE...... 4 2.2 FUNCTIONAL REQUIREMENTS...... 4 2.3 CONSTRAINTS AND LIMITATIONS...... 5 3.0 PROJECT ORGANIZATION...... 6

3.1 TIMELINE...... 6 4.0 DESIGN CONCEPTS AND ALTERNATIVES...... 8

4.1 VIBRATORY BOWL...... 8 4.2 VIBRATORY TABLE...... 9 4.3 VIBRATORY TABLE + RAIL SYSTEM...... 10 4.4 CONVEYOR METHODS...... 12 4.5 VIBRATORY HOPPER AND SLIDE ALIGNMENT...... 13 5.0 PRELIMINARY DESIGN RECOMMENDATIONS...... 15 6.0 DESIGN EVALUATION...... 16

6.1 QUALITATIVE ANALYSIS...... 17 6.2 QUANTITATIVE ANALYSIS...... 18 6.3 ECONOMICS ANALYSIS...... 19 7.0 FINAL RECOMMENDATION...... 23

7.1 MECHANISMS...... 23 7.1.1 Vibratory Hopper...... 23 7.1.2 Chute...... 24 7.1.3 Coning hopper...... 25 7.2 PROCEDURE...... 26 7.3 PLC FUNCTIONS...... 28 7.4 TESTING AND IMPLEMENTATION PROCEDURE...... 29 7.2.1 Testing...... 29 7.4.2 Implementation...... 31 7.5 SETUP IMPROVEMENTS...... 32 7.5.1 External Improvements:...... 33 7.5.2 Internal Improvements:...... 33 8.0 POST PRESENTATION REVISIONS...... 33

8.1 LOGIC REVISIONS...... 33 8.2 ECONOMIC REVISIONS...... 35 8.3 FUTURE MECHANICAL DESIGN RECOMMENDATIONS...... 35 REFERENCES...... 37 The Three Orienteers 4/6/2018

Acknowledgments

The Three Orienteers Engineering would like to thank the following people for their help and support in the progress and completion of this project. We would like to thank Matt Mattson for contacting the University of Minnesota Duluth with a senior design project and for accommodating all of the needs of the group in a respectful and timely manner. We would like to thank Scott Allison for his support and financing.

Finally we would like to thank our professors Dave Keranen and Bill Pedersen for all of their help and advice in the development of the project, and for guiding us to not only get the project to completion, but also in a manner which helped us learn new skills.

The Three Orienteers 4/6/2018

Executive Summary

Minnesota Twist Drill based in Chisholm, Minnesota produces twist drill bits.

The first process of this is to cut the blanks to size from a large coil. Then the blanks go to a machine that puts a cone on one end to identify the hardened end after the heat treatment process. This project stemmed from this problematic station that was requiring repetitive, inefficient operator motion. Triple Twisters Engineering’s efforts were focused on solving these issues.

The recommendation for Minnesota Twist Drill is to reallocate the manual labor in this area of the factory by implementing the design presented in this document. The final design consists of a vibratory hopper, a channeled slide and a modified hopper on the coning machine. The vibratory hopper is the first step toward aligning the blanks after they have been cut. Once the parts have been mostly aligned, they are sent down a slide.

This slide contains channels for the blanks to slide down and become completely parallel.

Finally, the blanks are received in a modified hopper on the coning machine. This hopper has a “rake” to push the blanks to one side and give a final alignment. The feed to the coning machine is then operated by a Programmable Logic Device (PLC) device that uses sensors to detect parts and open up the slot in the bottom of the coning hopper to allow the blanks to fall into the conveyor belt of the coning machine.

This final design reduces the WIP of the factory, specifically between the machines, and reallocates the manual labor involved in the process. It is simple, easy to maintain, and relatively inexpensive. This alternative saves time and money, increases the amount of blanks produced, and reduces repetitive movements for operators.

The Three Orienteers 4/6/2018 1.0 Problem Statement

The current situation lends itself to several problems. There is no orientation to the blanks that are coming off the cutoff machine and thus they need to be sorted manually. This manual sort is both inefficient and ergonomically unsafe, potentially creating repetitive motion and back injuries. After sorting, the blanks are transported approximately 10 feet to a coning machine. This transportation and sorting reduces efficiency of this station and raises the work in progress in this area.

The Three Orienteers 4/6/2018

2.0 Project Definition and Scope

2.1 Project Scope To produce a design to orient drill bit blanks (1/4” to 1/2” diameter) off a Lewis cutoff machine and directly feed them into a drill bit coning machine. This material handling improvement shall increase throughput between the machines while reducing work in progress and increasing floor space.

2.2 Functional Requirements The solution to the existing problem shall increase productivity, reduce intensity and amount of labor, while not adding an excessive amount of overhead cost to the company.

. Require little maintenance, less than $2,000/year based on 10% installed

cost

. Reduces manual handling labor

. Simple in design

. Maintains or improves throughput defined by the amount of blanks that

have been coned in a shift

. Adaptable to varying lengths and diameters of the drill bit blanks

. Efficient as defined by the usage of power and of manual labor

. Safe for operators

. Can be implemented with little or no risk due to offline testing

The Three Orienteers 4/6/2018 2.3 Constraints and Limitations A major constraint to the project is the high flow rate of blanks produced by the cutoff machine and the blanks needed to keep the coning machine running as much as possible. The large volume of parts creates a weight constraint. The design will have to handle the weight of the blanks that are produced by the cutoff machine. A solution has to be financially feasible, and have the ability to process the dimensional variety of the blanks it handles. Along with the specific requirements are the given special constraints of the neighboring machines and the plant itself. Specifics are summarized below.

. The feed rate of the cutting and coning machines, the cutting machine is at

200 parts per minute

. Budget is a two year payback on a $20,000 a year salary based on

reallocation of labor from this station.

. Space available around existing machines and work areas

. Drill bit diameter and length varying from 1/4”-1/2” and2 ½ to 6”

respectively.

. Factors that involve the safety of the workers and the plant, including

ergonomics, maintenance procedures, and regular operations.

. Weight of accumulated drill bits during system operation.

. AC/DC power availability

. Set up time as it relates to throughput for the entire system

. Control Systems including a PLC, relays, actuators, motors, etc…

The Three Orienteers 4/6/2018

3.0 Project Organization

To complete the project, many organizational techniques were applied to aid in accomplishing our goal of orienting drill bit blanks and streamlining the process between the cutoff machine and the coning machine. Scott Anderson was found to be best suited for the position of Project Leader due to his administrative and management qualifications. Tony Niemczyk was named Industrial Engineer considering his education and knowledge of process flow. Andy Johnson was named Mechanical Engineer due to his skills and qualifications in design.

3.1 Timeline A timeline, shown in Table 1, shows the progress of the project and defined important tasks, goals and events that were undertaken in the past fifteen weeks. Tasks were assigned to specific group members to allow the group to work in parallel and accomplish as much as possible in the time given. Other tasks required full group participation due to the significance of these tasks on the outcome of the project. When working in parallel group members worked solo on assigned tasks which were completed and submitted for approval among other members during the frequent group meetings.

The Three Orienteers 4/6/2018 Table 1: Timeline Task Name Duration Start Finish Project Scope 0 days 9/26/2006 9/26/2006 Visit MN Twist Drill 1 day 9/14/2006 9/14/2006 Call Contact (Matt Mattson) 0 days 9/7/2006 9/7/2006 Research and Data Collection 16 days 9/7/2006 9/28/2006 Sketch and Research Idea 1-Tony 5 days 9/27/2006 10/3/2006 Sketch and Research Idea 2-Andy 5 days 9/27/2006 10/3/2006 Sketch and Research Idea 3-Scott 5 days 9/27/2006 10/3/2006 Developing Alternatives 68 days 9/21/2006 11/28/2006 Designing on Computer- Andy 65 days 10/11/2006 12/14/2006 Developing Baseline Presentation-Scott 1 day 10/12/2006 10/12/2006 Designing of best alternative 19 days 11/26/2006 12/14/2006 Generating a Finished BOM - Andy 20 days 11/26/2006 12/14/2006 Researching materials needed -Andy 8 days 11/7/2006 11/16/2006 Baseline 0 days 10/12/2006 10/12/2006 Project Update Document- Tony 0 days 10/10/2006 10/10/2006 Updates 62 days 9/12/2006 12/5/2006 Project Update and Final Design Project 0 days 11/7/2006 11/7/2006 Making Power Point for final presentation - Scott 3 days 12/11/2006 12/13/2006 Writing Final Report - ALL 18 days 11/27/2006 12/20/2006 Introduction - Tony 18 days 11/27/2006 12/20/2006 Diagrams/ Designs/ Layouts - Andy 18 days 11/27/2006 12/20/2006 Project Development - Scott 18 days 11/27/2006 12/20/2006 Programming PLC- Tony 11 days 12/01/2006 12/11/2006 Wiring/Procedure/Implementation - Tony 17 days 11/28/2006 12/20/2006 Final Presentation 0 days 12/14/2006 12/14/2006 Final Reports 0 days 12/20/2006 12/20/2006

Final mechanical design of the best alternative was undertaken by Andy Johnson by developing CAD drawings with the assistance of SolidWorks. Andy also engaged in creating the bill of materials. Creation and testing of different design concepts were done by Andy Johnson and Scott Anderson. Scott Anderson worked on formulating the cost of the project and completed the economic analysis as well as writing project updates and status reports. Requirements of logic controls for the apparatus were researched and determined by Tony Niemczyk. Tony also wrote and outlined the final project report.

The Three Orienteers 4/6/2018 4.0 Design Concepts and Alternatives

4.1 Vibratory Bowl One solution that was considered was the use of a vibratory or a centrifugal feeder bowl to orient the blanks as seen in Figure 1. It was found that many companies manufacture these bowls and that they are custom engineered to the length specifications of the parts for which they would be used. They provide a good orientating machine and many have sensors that could detect blanks that were not to the specifications. The bowl could also handle the volume of 200 parts per minute off the cutoff machine that is required. Many of the bowls also came with powered feeders that could have been hooked up directly to the coning machine for an automatic feed into this machine. The major drawback of this system is the cost which varied from $5-50,000 10 years ago.

The cost of eliminating everything that currently exists at the cutoff machine and buying a new piece of equipment for the factory would be unreasonable. Upon a visit to

Minnesota Twist Drill it was found that they had been exploring this type of machine for some time, but never acted on it, probably due to the cost. Many estimates were well over budget for the project and overall the machinery would be costly.

Figure 1: Vibratory Feeder from Feeding Concepts, Inc. www.feedingconcepts.com

The Three Orienteers 4/6/2018

4.2 Vibratory Table

Figure 2: Vibratory Table circular cross section.

Another potential solution to manual orientation and handling of the drill bit blanks is a circular cross section vibratory table as shown in Figure 2. The idea stemmed from the shape of the hoppers used at most of the machines at Minnesota Twist Drill.

Nearly every machine has a circular cross section basket used to catch the drill bits after they have been processed. The baskets for the most part align the drill bit so that they are parallel. Since the blanks exiting the cutoff machine have no end orientation, this shape is a logical choice. Once the baskets get some materials into them, or if the drop to the baskets from the machine is too far, they don’t align very well. The solution to this would be to agitate the drill bits so that gravity will bring them down to a resting place in alignment with each other. It is believed that this slight vibration from a pneumatic or electrical vibratory motor would break binding that prevents alignment, as a similar

The Three Orienteers 4/6/2018 system was tested experimentally. Also, electric and pneumatic motors are adjustable so that a proper amount of vibration is achieved. Vibratory tables are a commonly used piece of equipment in industry and could be sourced readily. Another alternative to buying a vibratory table would be to build one. A vibratory motor can be sourced from several manufacturers and the table built at a local fabrication shop. Motors range from

$150-$2000, depending on application.

4.3 Vibratory Table + Rail System

Figure 3: Vibratory table and transport hopper

This option starts by using the existing conveyor belt that blanks travel on after exiting the cutoff machine. The blanks fall off the conveyor belt into a vibratory hopper with a specified angle at the bottom that matches the angle of a transport hopper to the side of the vibratory hopper. The blanks are fed manually or automatically from the vibratory hopper to the transport hopper as shown in Figure 3. When the transport hopper

The Three Orienteers 4/6/2018 reaches the desired volume of blanks it is moved on the wheels attached to the transport hopper along a transport track that leads to the coning machine. The transport hopper will travel directly into the space currently filled by the coning machine input hopper, thus becoming a coning machine interchangeable hopper. A slot on the front of the transport hopper is opened and blanks feed into the coning machine. When the transport hopper has emptied into the coning machine it can be taken off the track and the next filled transport hopper is positioned into place with coning machine and is emptied.

The design is simple in nature and has limited maintenance needs and low design and assembly costs. The parts needed could all be manufactured and assembled using simple and cost effective techniques such as machining and welding or bolting the parts together. This alternative would eliminate the handling of the blanks into bins, loading the bins onto dollies, transport of the bins between machines on dollies, unloading of the bins on to the lift table, and the need for the coning machine operator to manually feed blanks from the filled hopper into the coning machine input hopper. This alternative leaves the possibility for future development to automatically fill and feed the transport hopper to further reallocate labor. Multiple transport hoppers would have to be manufactured to accommodate the blanks that would travel between the two machines.

Transport hoppers are able to accommodate different lengths of blanks by inserting gauged spacers in the transport hoppers. This alternative would have little effect on the volume of product produced due to limiting factors such as cutoff machine setup time and coning machine feed rate. Under the current design of this alternative there is no method for removing blanks of incorrect dimensions produced during cutoff machine setup without operator intervention as is currently done with the existing setup.

The Three Orienteers 4/6/2018 4.4 Conveyor Methods

Figure 4: Conveyor methods

Further alternatives were conceived that included differing types of conveyors, which would take the part either directly off the cut-off machine or would take them after they were aligned by some sort of vibratory hopper. It was thought that this would allow for the automatic rejection of bad parts by a visual recognition system. This system could look for the correct size and then either by magnetic means or air pressure the rejected blanks could be sent off the line. This alternative provided the benefits of a sequential order of alignment and very little operator interface. The option also contained many problems because of the uncertainty of total alignment onto the conveyor and because of the complexity of the vision system and the automatic rejection system. It was also uncertain how the blanks would act on a simple rubber belt and so further research was done on using conveyors.

Cleated conveyors were researched to ensure that the blanks would make it completely down the belt and roll down the incline. This however led to problems with designing the automatic rejection system and in the requirement of the belt. The size of

The Three Orienteers 4/6/2018 cleats that was to be needed did not come standard and would have to be specially ordered which significantly increased cost. Another alternative that was researched was the use of an angled conveyor with cleats to individually pick up the blanks. It was thought that if a vibratory table similar to the one already designed was used to align the blanks. Then if they were fed into a hopper then an angled cleated belt could pick them up one by one and then check for defective parts. This option again ran into the problem of a custom belt and problems with the transfer from the belt to the coning machine.

4.5 Vibratory hopper and Slide Alignment

Figure 5: Vibratory hopper and Slide alignment The final iteration of the designs combined some of the previous alternatives as shown in Figure 5. It reduced the complexity of some while solving some of the problems that were brought forward with others. The design uses the basic vibratory table presented earlier and adds to it a simple slide with channels on it. This slide increases the velocity of the part so that it will align when it reaches the bottom of the slide. It also helps in the alignment process as the blanks will fall into the channels and

The Three Orienteers 4/6/2018 be directed to align along them. They then fall into a hopper that has been attached directly to the coning machine. This hopper is the most complex part of the system as it contains an actuator which is connected to “rake” mechanism. This mechanism will continually align the parts for their drop to the coning machine. It will also contain logic that will sense when there are parts in the hopper waiting to be fed into the coning machine.

The Three Orienteers 4/6/2018 5.0 Preliminary Design Recommendations

The team’s preliminary recommendation to Minnesota Twist Drill was the

Hopper and Rail System Figure 3 in section 4.3. This early conception appeared to meet the all the functional requirements of the project and appeared to be simple enough in concept to design and operate. Labor was reduced in intensity, but was not reduced enough to allow relocation of personnel. The blanks still had to be loaded into hoppers at the end of the cut-off process and then the hoppers had to be removed at the beginning of the coning process. Therefore the combined process still required that two operators be present while in progress. Future revisions of the design were decided to reduce the required labor of the system to allow for labor reallocation.

The Three Orienteers 4/6/2018

6.0 Design Evaluation

In order to develop a final recommendation, the previous concepts were analyzed to pick out the best option and the best feature of each option. Each option had pros and cons that were evaluated on both a qualitative and quantitative basis. The qualitative measures were supportive in organizing the features and capabilities of each option as shown in Table 2. This was helpful in determining not only what the final design should be, but what features were the most important to the project. These features were then taken to the quantitative level and given a value and weight based on how important the option was to the final design as shown in Table 3 and 4. The quantitative analysis showed that doing nothing produced the smallest weighted value of the all the alternatives which was a weighted value of 270. The next smallest was the vibratory feeder with a weighted value of 273. The next best was the vibratory table and the rail system alternative which produced a weighted result of 295. Next were the conveyor methods and the vibratory table at 318 and 319. Finally the hopper and chute alternative came in as the leader at 400. This means that the hopper and chute alternative was determined to be the best option considering a value set to each feature it contained weighted by the importance of that feature to the overall design.

The Three Orienteers 4/6/2018

6.1 Qualitative Analysis

Table 2: Pros and Cons

Design Concept Pros Cons

Vibratory Feeder Automated Complex Reduces Labor Expensive Can check for defects Power requirements Orients Blanks Has “one –at-a-time” capabilities Direct feed to coning machine Vibratory Table Inexpensive Does not reduce amount of people Orients Blanks No direct feed to coning machine Reduces manual operations Vibratory Table + Rail System Inexpensive Manual operations still necessary Orients Blanks May have some power requirements Reduces manual operations May require movement of Coner Direct feed to Coning machine Requires some manual operations Possibility of reducing labor needs at stations Conveyor Methods Orients Blanks Expensive Reduces manual operations May have some power requirements Direct feed to Coning machine May require movement of Coner Possibility of reducing labor needs at Complex vision system required stations Automatic rejection of shorts Uncertain how blanks will act on belts Roofing/ Hopper Orients Blanks Logic system required Reduces manual operations Will have some power requirements Direct feed to Coning machine Will require movement of Coner Inexpensive Uses multiple means to orient blanks

The Three Orienteers 4/6/2018

6.2 Quantitative Analysis

Table 3: Index of values Score Importance Score Importance Cost 10 Simple Design 7 High 1 Complex 1 Medium 5 Medium 5 Low 10 Simple 10

Maintenance 5 Reallocation of Manual labor 10 High 1 Low 1 Medium 5 Medium 5 Low 10 High 10

Utilizes Gravity 6 Adaptable 9 Low 1 Low 1 Medium 5 Medium 5 High 10 High 10

Maintains or improves throughput 10 Maintains 5 Improves 10

Table 4: Weighted Analysis

f r o

o e r y n b n t i o o

a g i l v c e i r t t

l c s a o S a u r s

a n e c e p s l e d u a G o D h

n v l b e

n i n l t g s o a e a e a a t r l h u t t e l e t p p p g M z o n n i i a i i r s l a t R i e m m a a h o t i i d o t C S M U A M T W Vibratory Table 10 10 10 1 5 1 5 42 319 Vibratory Feeder 1 1 1 10 1 5 10 29 273 Vibratory Table + Rail System 10 5 5 1 5 5 5 36 295 Conveyor Methods 1 1 1 10 1 10 10 34 318 Vibratory hopper/Slide/Modified Coning Hopper 5 10 5 10 10 5 5 50 400 Do Nothing 10 10 5 1 1 1 5 33 270

The Three Orienteers 4/6/2018

6.3 Economics Analysis The economic analysis proves that alternative 5, Vibratory hopper and Slide

Alignment, is economically feasible and would be of great benefit to MN Twist Drill if implemented. Two economic analyses were completed, one for the economic benefit of the installed system alone and one including the proposed reduced setup time. The calculated installed cost for both alternatives is $10,300 with annual benefits of $34,826 for the system by itself and annual benefits of $114,826 for alternative 5 in conjunction with the proposed reduced setup time. The complete economic analysis of the system using a three year Modified Accelerated Cost Recovery System (MACRS) has a payback of 114 working days or 0.44 years for the system alone and 35 working days or .14 years if the system is in conjunction with the reduced setup time as shown in Table 5.

To complete the economic analysis there were cost assumptions that had to be estimated. Some of the shipping costs were free if sent through regular USPS ground mail, and unknown shipping costs were estimated to be $25. The tax rate used was the

MN tax rate of 0.075%. The cost for metal fabrication was estimated to be $5,000 based on the complexity of the design. The cost of labor to relocate the coning machine was estimated as $270 based on 12 hours of labor at $22.50 an hour for all electrical, water and air connections to be disconnected, relocated and reconnected in the new location.

Materials necessary for relocation such as pipes and fittings for the water, air and electrical were estimated to be $200. The installation labor for the system was estimated to cost $540 based on an estimated 24 hours of labor at $22.50 an hour. Installation materials such as supports for the system and hardware to attach the system were estimated to be $200. The annual maintenance for the system was estimated to be $1,030

The Three Orienteers 4/6/2018 or 10% of the installed cost. The work in progress reduction was estimated to be $660 or a 10% increase of the value of one coil due to added value from being straightened and cut. The workman’s compensation reduction was estimated as one employee’s salary for one half year due to the ergonomic advantages of the new system. The value of the floor space gained was calculated as $100 per square foot and space gained was the width of coning machine, 4.16 ft, multiplied by the 10 feet it is moved. Setup labor reduction was estimated by calculating 250 work days per year multiplied by 3 setups per day multiplied by 10 minutes gained per setup and a $10 per hour salary. Production increase was estimated by 2.5 blanks per second multiplied by 600 seconds gained per setup multiplied by an average of 3 setups per day multiplied by 250 work days per year multiplied by net profit of 7 cents per finished blank since the cutoff machine was determined to be a bottleneck.

The Three Orienteers 4/6/2018 Table 5: Economic Analysis First Cost $10,297.55 $ Annual Benefit 34,826.00 Annual Maintenance $1,029.76 Property Class 3 yrs Tax Rate 0.34 System By Itself Untaxed Year BTCF Taxed BTCF MACRS % MACRS Taxable Income Tax ATCF 0 -$10,297.55 -$10,297.55 - 1 $33,796.24 0.3333 $3,432.17 $30,364.07 $10,323.78 $23,472.46 2 $33,796.24 0.4445 $4,577.26 $29,218.98 -$9,934.45 $23,861.79 - 3 $33,796.24 0.1481 $1,525.07 $32,271.18 $10,972.20 $22,824.04 4 $33,796.24 0.741 $7,630.49 $26,165.76 -$8,896.36 $24,899.89

Payback Period 0.44 years First Cost $10,297.55 114 days $ Annual Benefit 114,826.00 Annual Maintenance $1,029.76 System With Reduced Setup Property Class 3 yrs Tax Rate 0.34 Time Untaxed Year BTCF Taxed BTCF MACRS % MACRS Taxable Income Tax ATCF 0 -$10,297.55 -$10,297.55 - 1 $113,796.24 0.3333 $3,432.17 $110,364.07 $37,523.78 $76,272.46 - 2 $113,796.24 0.4445 $4,577.26 $109,218.98 $37,134.45 $76,661.79 - 3 $113,796.24 0.1481 $1,525.07 $112,271.18 $38,172.20 $75,624.04 - 4 $113,796.24 0.741 $7,630.49 $106,165.76 $36,096.36 $77,699.89

Payback Period 0.14 years 35 days

In the economic analysis table above the untaxed BTCF is the untaxed before tax cash

flow which is the initial cost of the system. The taxed BTCF is the taxable before cash tax

flow which is the annual benefit minus the annual maintenance. The MACRS percentage

is the modified accelerated cost recovery system percentage of depletion of the first cost

in that year. MACRS is the modified accelerated cost recovery system amount of

The Three Orienteers 4/6/2018 depletion in that year. The taxable income is calculated as the taxed before tax cash flow minus the depletion of investment in that year. The tax is the amount paid in taxes in that year on the system calculated as the taxable income from the system multiplied by the tax rate of 34%. ATCF is the after tax cash flow calculated as the taxed before tax cash flow minus the tax paid in that year.

The Three Orienteers 4/6/2018

7.0 Final Recommendation

The final recommendation for Minnesota Twist Drill is the Vibratory Hopper and

Chute system. This system was shown to be the best alternative economically, qualitatively and quantitatively. This section details the how the system operates and how it will interface with the existing operation.

Vibratory Hopper

Chute

Coning Hopper

Figure 6: Complete Assembly

7.1 Mechanisms

7.1.1 Vibratory Hopper

Figure 7: Vibratory Hopper

The Three Orienteers 4/6/2018 The vibratory hopper will be the first step in aligning the blanks from the existing conveyor that currently transports the blanks from the cut-off machine to a table. The vibratory hopper will be a half cylinder shaped hopper that is attached to a base plate. The base plate has a vibratory motor attached to it to shake the hopper. The combination of the shape of the hopper and the vibrations from the motor will force the blanks to align so that the axis of the blanks and the hopper are parallel. The primary function of this hopper is to align the blanks. A secondary function of the hopper will be to serve as a place for the blanks to build up if the coning machine has to stop momentarily and prevent a shut down of the cut-off machine. The vibratory hopper is to be made of fourteen gauge cold rolled steel. Cold rolled because of the finer finish, and fourteen gauge because it will flexible enough to form, but not so thick that it will have a lot of mass, the vibratory motor has to vibrate the mass of the hopper as well as the blanks within it as seen in Figure 7.

7.1.2 Chute The secondary process of alignment is a steel chute. The chute will provide channels for the blanks to slide down after being aligned in the previous process. It will also provide further alignment of the blanks as they will naturally want to enter the channels in an aligned manner. The angle that has optimized flow in the current system will be 30o. This angle, experimentally determined, will allow for the proper material flow and will still fit within the space requirements. The lubrication used in the cut-off process remains on the blanks,

The Three Orienteers 4/6/2018 so as a by product the blanks will lubricate the slide to reduce the coefficient of friction.

7.1.3 Coning hopper This is the most complicated mechanism in the assembly (see Figure 6) because it has to attach to the coning machine in a specific area and it has to have all the blanks aligned for feeding to the coning machine. At this point in the operation all blanks should be aligned with parallel axes and falling into the hopper. When they enter this hopper; however, they need to be all pushed to one side in order for the coning machine to take the parts onto its track. This also has to be compatible in the range of 2.5”-6” in length. This is accomplished with a pneumatic actuator and “rake” that extends to push all the blanks to one side and then retracts with an internal spring and slide. This will finish the alignment process and will force the coning machine to take the full range of blanks without any insert to the hopper. This entire actuator will be mounted on a linear lead screw mechanism for a movement of the “rake” so that all lengths of blanks can be fed into the hopper.

To ensure that the blanks do not drop down directly onto the coning machine’s belt there are plates located beneath the hopper. These plates will slide in and out depending on volume of blanks in the hopper to ensure proper alignment. These plates are being regulated by the logic programmed into the

PLC, detailed in section 7.3. This hopper will be made from sheet metal and will contain pneumatic actuators and the moving parts associated with aligning the blanks in the hopper as seen in Figure 8.

The Three Orienteers 4/6/2018

Rake

Linear Positioning Stage

Figure 8: Coning Hopper

7.2 Procedure Detailed in this section is the procedure for the combination of the cut-off and coning machines. This procedure is designed to give the operator a detailed account of how the machines will work and how they need to interact with them. The operator will have to perform a set of operations in a specific sequence for the entire system to work properly.

The operator will have to setup both machines before any operations can be performed.

They will then have to make sure all components of the alignment system are working properly. Then the operator should turn on the vibratory hopper in order to make the parts currently in the system fall to the coning hopper. In the coning hopper the operator can take out the “defect” parts and then continue with the operation of the system.

1. Setup Cut-off and Coner

1.1. Setup both the cut off and coning machines as directed by the work order 1.2. Test the sensors and motors for proper performance 1.3. Set motor for the appropriate size and diameter of coil 1.4. Clear any debris from chute and hoppers 1.5. Move plastic bins to receiving end of coner 1.6. Raise platform to appropriate height

The Three Orienteers 4/6/2018 1.6.1. Ensure that there are enough bins for entire coil 1.7. Turn on cut-off machine

2. Cut-off machine is running

2.1. Turn on vibratory motor 2.2. Walk to coning hopper and when all “reject” part have entered remove them 2.3. Push end of Setup Button 2.4. Turn on alignment actuator 2.5. Turn on coning machine

3. Both machines are running

3.1. Sort out “rejects” and place good parts back into coning hopper 3.2. Observe coning hopper and machine to ensure proper feeding 3.3. Observe the alignment process for jams 3.4. Walk to receiving end of coner 3.5. Unload coner as needed

4. Cut-off machine has completed coil

4.1. Turn off cut-off machine 4.2. Let all parts to enter coner 4.3. Turn off Vibratory and alignment motors 4.4. Unload coner a final time 4.5. Shut off coner 4.6. Press Setup Button

5. Both machines have completed a coil

5.1. Lower platform 5.2. Move bins to appropriate WIP storage area 5.3. Repeat Steps 1-4

The Three Orienteers 4/6/2018 7.3 PLC Functions

Yes Setup NO

All Sensors Enable Disabled Sensors No

No Part In Conning Hopper No Yes Part In top of TMR Yes Conning Hopper TMR Part In top of TMR Yes Vibratory Hopper

No Part? No Part? Part? No Yes Yes Yes TMR No TMR TMR No

No Part? Part?

Part? Yes Yes

Move Plate Yes Turn off Vibratory Turn off Motor Conveyor

Figure 9: Flow Chart of Logic

An essential part of the current process is the implementation of a Programmable

Logic Controller (PLC) to the system. A PLC is used to make logic based decisions to power a motor or turn on a light based on an input received from a sensor or a button.

See Figure 9 and Table 6. This logic has been programmed into the PLC for use with the system. The sensors that are incorporated in the design of the system both check the system for out of control circumstances and for situations for the flow of the system.

They ensure that the hoppers in the system never overflow with material causing not only a mess but damage to the product. They also determine the operation of the slider plates located on the bottom of the new coning hopper. Without these monitors, it would be

The Three Orienteers 4/6/2018 impossible to guard against a dangerous situation and to properly observe the flow of the

system.

Table 6: Inputs and Outputs Inputs Outputs Sensor in coning hopper to detect height Turn off vibratory motor Sensors in coning hopper to move plates Move plates in and out to prevent damage to coning belt Sensor in Vibratory hopper to detect height Turn off conveyor Pushbutton to determine if setup is happening Sensors are not used until pushed

7.4 Testing and Implementation Procedure

7.2.1 Testing To test the validity of the assumptions that were made on this design a

certain procedure could be followed. This procedure would allow for the testing

of the system without the entire movement and construction of the full solution.

The first step in testing would be to build the physical components one at a time

starting with the coning hopper as seen in Table 7.

Table 7: Coning Hopper Coning Hopper Components Part Numbers 1. Hopper ends, and cylinders 206, 207, 208 2. Pneumatic cylinders 105 3. Guide Tubes 605 4. Rake 604 5. Fasteners See Drawings and BOM

This hopper would need to be built in its entirety as it is the most crucial part of

the entire system. Once this was built it could be tested by either sliding blanks

into the hopper or by having blanks in the hopper when the “rake” is turned on.

This will allow the testing of the hopper for throughput, operating speed, ease of

use, and frequency of jams. Have both an engineer and the operator test the

machine and use any feedback to improve the hopper for use. The next step

The Three Orienteers 4/6/2018 would be to build the chute and the vibratory hopper and all of the components related to them. See Table 8.

Table 8: Vibratory Hopper Vibratory Hopper and Slide Components: Part Numbers 1. Hopper 605 2. Chute 205 3. Vibratory Motor 102 4. Supports 106, 107, 108

With these items built the system could be tested for ease of flow, throughput and frequency of alignment at the end of the system. Blanks should be sent down the system at all ranges of frequency, from zero to more than the capacity of the hoppers. This will give a better representation as the blanks are now being better aligned and it give a good representation of how the system will work as a whole. The next process to test would be to attach the system to the coning machine itself. This is the only way to accurately test the feeding of the blanks into the coning machine and to the see the feed rate of the coning hopper to the coning machine. There should be caution taken at this point as the PLC is not connected to the system and therefore one has to be concerned with a blank hitting the coning belt straight on. This testing should only be done with blanks already in the hopper. The next step would be to connect the PLC and the sensors to the system to check that the correct timings occur and the out of boundary conditions do not occur as seen in Table 9.

The Three Orienteers 4/6/2018 Table 9: PLC Components

PLC Components 1. PLC 2. Sensors 3. Mounting Brackets for Sensors 4. Relays 5. Push Buttons 6. Mounting Bracket for PLC 7. End Brackets, Covers 8. Cable 9. Wires 10. Terminal Block

This will allow for accurate testing of the feed rate of the coning hopper and of the control of the entire system. This will also test most of the procedure involved with the two machines. When this testing is complete and the system is working to its specifications then the implementation procedures should be followed.

7.4.2 Implementation The first step in implementation would be to build all support structures for the system and make any modifications to the coning machine that are necessary for attachment. Next, the coning machine should be prepped for movement by removing and/or detaching all water pipes, air ducts, and electrical connections. Now the coning machine should be moved to its new location. Once in the new location all water, air, and electrical connections should be reestablished and checked for proper function. Finally, the new system should be attached and powered up for use. All elements should then be tested for proper running conditions and for proper safety precautions. Special care should be taken to ensure that all electrical connections are made and correct so as not to damage

The Three Orienteers 4/6/2018 any of the electrical components. Pneumatics are to be assembled according to the

manufacturer’s specifications. Specification sheets can be found in the Appendix.

7.5 Setup Improvements This recommendation can only improve the process to a certain point, but

the entire operation is currently being bottlenecked by setup time. The Lewis

Cut-off machine, specifically, can take up to 2 hours if the complete setup is done.

It has also been brought to our attention that there is only a limited amount of

people who know how to setup this machine efficiently. To effectively decrease

the setup time overall and to train new people on a standard process that has been

laid out would be the ideal situation for this machine. A standard procedure

would ensure that all operators could effectively do the setup in an expedited

time. A detailed time study analysis could be done to determine the actions that

could be changed or improved upon to decrease the time of the setup. In addition

to this the implementation of Single Minute Exchange of Dies (SMED) operations

could drastically improve the time on this machine (Productivity Press

Development Team, 1996). Below is a list of some of the improvements that

could be made based on the first step in the SMED process, which is to identify

the operations can be completed while the machine is running (defined as external

processes) and what has to be done while the machine is not running (defined as

internal processes). All setup is now done while the machine is not running but

many operations could be done while the machine is running. There are also

some areas that could be improved so that the time where the machine is down is

further reduced.

The Three Orienteers 4/6/2018 7.5.1 External Improvements: . Getting coil of steel could be done the shift before while machine was running

and there should always be at least one waiting for operation.

. Getting cart with tools and dies could be done the shift before or while

machine is running. Cart should contain ALL tools needed for setup in a

specified order.

. Cleaning of dies should be done while the machine is running

. Fill oil while the machine is running

. Set standardized position for adjustments related to feeding the steel through

the machine – end screws in bend area - tension on rollers

. Make sure all dies are in good quality

7.5.2 Internal Improvements: . Change bolts to functional clamps if possible – specifically in cutter portion

and die exchange portion

. Have automatic light turn on when cutter door is opened

. Centering method for cutter die

. Some sort of jig for bend area – put on a typical bend with a tolerance –

include measurements for amount of turns to put into position

8.0 Post Presentation Revisions

8.1 Logic Revisions It was determined from the final presentation that some areas needed to be addressed concerning the logic of the PLC. The concern was raised that at the when the final blanks reached the conning hopper and there were not enough of them to be sensed by the sensors, there was no way to open the restrictor plates. The current setup also had

The Three Orienteers 4/6/2018 a problem in that it was easily used by the operator and a maintenance person, but didn’t provide any direct information to the engineer. These problems were addressed and the following changes were made to the PLC program.

Changes made to PLC program 1. Override Switch was added 2. Logic was added to add the time that the system is not in setup mode.

An override switch was added to the coding of the program that puts the switch in parallel with the sensors that detect the blanks in the bin. This will allow the operator to hit this switch, wait out the timing, and then the slides will open. This timing will allow the operator to get the parts in the desired position for easy feeding into the coning machine. The switch will be a GCX1310 Selector Switch from Automationdirect.com which is a spring return from the right selector switch. This will ensure that the operator will always have the override off unless they are holding it on.

The second change that was made was to add coding that allows the engineer to gather data from the PLC. The code that was added was found in an example code from

Automationdirect.com and their technical support. The code with start counting time when the setup button is pushed and the machine is in operation. It will accumulate this time until the setup button in unselected. When the button is unselected then the PLC will write the time accumulated to a table and then automatically reset itself to write to a different location on the table for the next run. This table will then be the time of operation for the machine and it will be easy to find the time of setup from this time.

This will provide the engineer with valuable data about the performance of the system without having to be on the factory floor all day.

The Three Orienteers 4/6/2018 8.2 Economic Revisions It was found that there were errors in the economic analysis. The errors were caused by calculating the production increase due to reduced setup time using the value of a finished drill bit instead of the net profit from a drill bit. To fix this, the net profit of a drill bit was found and used in the new economic analysis making the economic analysis more accurate.

8.3 Future Mechanical Design Recommendations Another suggestion from the presentation from the client was to add a section making a recommendation for future work. This section would document the changes that the group would make to the design if there were more time.

As with every design, there are design aspects that would be revised after the first complete design. A concern is that the chute has a ridge that the blanks would dump onto and create an area where the chute will eventually fail. Possible solutions to this area of concern would be to shape the vibratory hopper with a ridge inside of it that matches the shape of the chute. This though would create a ridge for the blanks to damage inside of the vibratory hopper. A better solution would be to add a piece of sheet metal to the end of the vibratory hopper that gradually separates the blanks into two sides and preventing them from falling directly onto the ridge of the chute.

Another area of concern is the restrictor plate control. The actuators were used instead of electromagnetic solenoids because of spatial uncertainty around the coning machine. More accurate measurements should be taken around the mounting area of the coning hopper and space allowing use electromagnetic solenoids to control the restrictor plates on the bottom of the coning hopper.

The Three Orienteers 4/6/2018 As designed, the new modified coning hopper will use the mounting points and adjustment features of the existing coning hopper. This adjustment ensures that the bottom of the hopper be close enough to the coning belt to prevent the blanks from pouring out uncontrolled. Future modifications would be desired to automatically control this distance from the coning belt. One design concept would be to have the hopper float on its mounts and have wheels similar to rollerblade or skateboard wheels roll along the coning machine’s belt. The wheels axis would be fixed to the hopper and the hopper travel up and down in the mounting slots. This modification would automatically adjust the hopper position and allow for varying depth belts that are used on the coning machine. With operator maintenance in mind, the hopper would have a locking mechanism that would hold it in a fixed position above the belt for belt changing procedures.

The Three Orienteers 4/6/2018

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"MSC Industrial Supply Co." Fall 2006 .

Oberg, Erik, Franklin D. Jones, Holbrook L. Horton, and Henry H. Ryffel. Machinery's Handbook. 26th ed. New York: Industrial P Inc, 2000.

The Productivity Press Development Team. Quick Changeover for operators: The SMED System. Oregon: Productivity Press, 1996.

Sclater, Neil, and Nicholas P. Chironis. Mechanisms and Mechanical Devices. 3rd ed. New York: McGraw Hill, 2001.

"SMC Corporation of America." Fall 2006 .

"South St. Paul Steel Supply." 21 Feb. 2006. Fall 2006 .

"The Way to Buy Industrial Supplies." Automation Direct. Fall 2006 .