Process Improvement for Drill Bit Blanks

For MN Twist Drill

The Three OrienteersScott Anderson – Project LeaderAndy Johnson – Mechanical EngineerTony Niemczyk – Industrial Engineer

Department of Mechanical and Industrial Engineering

University of Minnesota Duluth

Report Number UMDMIE-CD-2006WPDK12

Problem Statement

• Blanks are coming off of machine without orientation

• Manually sorted to bins• Blanks manually moved

approximately 10 feet to coning machine

• Manually loaded into coning machine

Problem Statement

Scope of Project

• Orientate drill bit blanks from cut-off machine

• Directly feed blanks into coning machine

• Increase throughput• Reduce work in progress

Functional Requirements

• Require little maintenance, less then $2,000/year• Reduces manual handling labor• Simple in design • Utilizes gravity as much as possible• Maintains or improves throughput • Adaptable to varying lengths and diameters• Efficient• Implemented with little risk due to offline testing

Constraints & Limitations

• The speed of the cutting and coning machines which for the cuttingmachine is 200 parts per minute

• Budget is a 2 year payback on a $20,000 a year salary based on the reallocation of labor

• Material type being cut which includes cobalt and various types of steel.

• Drill bit diameter and length varying from 1/4” to 1/2” and 2 ½” to 6” respectively

Constraints & Limitations

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

• Control Systems which include a PLC and relays• Space available• Factors that involve the safety of the workers and

the plant.• Type of power supplied (AC/DC, Mechanical, etc)• Weight of the drill bits

Project Organization

• Scott Anderson – Project Leader• Andy Johnson – Mechanical Engineer• Tony Niemczyk – Industrial Engineer• Work in parallel whenever possible• Crucial decisions made as group• Frequent group meetings

Design Concepts & AlternativesAlternative 1: Vibratory Feeder

• Ability to orientate blanks • Remove blanks that do not meet

specifications• Can Handle up to 200 parts per minute • Automatic feed of blanks into coning

machine

Design Concepts & AlternativesAlternative 1: Vibratory Feeder

Design of Alternative 1

Design Concepts & AlternativesAlternative 2: Vibratory Table

• Slight vibration from a vibratory motor would break binding

• Vibration agitates the drill bits so that gravity brings them into alignment

• Would not allow relocation of labor

Design Concepts & AlternativesAlternative 2: Vibratory Table

Design of Alternative 2

Design Concepts & AlternativesAlternative 3: Vibratory Table + Rail System

• A vibratory table aligns and feeds blanks into a movable transport hopper

• Transport hopper feeds directly into the coning machine

• Eliminates the handling of blanks• Many possibilities for automation

Design Concepts & AlternativesAlternative 3: Vibratory Table + Rail System

Design of Alternative 3

Design Concepts & AlternativesAlternative 4: Conveyor Methods

• Conveyor takes blanks directly off cut-off machine or from vibratory hopper

• Allows for automatic rejection of parts • Provides blanks sequential order of

alignment• Requires little operator interface

Design Concepts & AlternativesAlternative 4: Conveyor Methods

Design of Alternative 4

Design Concepts & AlternativesAlternative 5: Chute & Hopper

• Blanks orientate on vibratory hopper and slide down channels to coning hopper

• Coning hopper uses rake mechanism• Logic senses when blanks are in hopper

waiting to be fed into coning machine

Design Concepts & AlternativesAlternative 5: Roofing & Hopper

Design of Alternative 5

Preliminary Design Recommendations

• Preliminary recommendation was the hopper and rail system

• Met all functional requirements and was simple in concept and design

• Reduced labor intensity but did not enable relocation of personnel

• Blanks still needed to be loaded into hoppers and hoppers removed when emptied

Design Evaluation

• Previous concepts were broken down into features

• Features were given a quantitative value and weight

• Feature values and weights of each alternative were summarized and options were compared

• Hopper and chute was determined to be the best option

Evaluation Scores

  CostSimple Design Maintenance

Reallocation of

Manual laborUtilizesGravity Adaptable

Maintains or

improvesthroughput Total

Weighted Score

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

Economics

• Installed Cost: $10,297.55 • Annual Benefits of:

– System by itself: $37,070.00 – System with reduced setup time: $747,070.00

• Annual Maintenance (10% of installed cost): $1,029.76

• Payback Period of:– System by itself: 108 working days– System with reduced setup time: 5 working days

Mechanisms

• Vibratory Hopper– The first step in aligning the blanks from the existing

conveyor– Half cylinder shaped hopper attached to a base plate

that has a vibratory motor attached – The shape of the hopper and the vibrations from the

motor will force the blanks to align– The hopper will align the bits – Hopper serves as a place for the blanks to build up if

the coning machine stops

Mechanisms:Vibratory Hopper

Mechanisms

• Chute– Provides channels for the blanks to slide down– Provide further alignment of the blanks – The optimized angle of the chute was

experimentally determined to be 30°

Mechanisms:Chute

Mechanisms

• Coning Hopper– Aligns blanks for feeding to the coning

machine – When blanks enter the hopper they need to be

aligned by pneumatic actuator and “rake.”– Allows for full range of blanks without any

insert in the hopper – Gates on bottom regulated by the PLC slide

open and shut

Mechanisms:Coning Hopper

Procedures

• Setup procedures for when:– Both coner and cut-off are off– Cut-off machine is running– Both coner and cut-off are running– Cut-off machine has completed coil– Both machines have completed coil

Procedures

• Programmable Logic Controller Procedure– Sensors in the system check the system for

out of control circumstances – Ensure that the hoppers never overflow with

material – Determine the operation of the slider plates

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

PLC Flowchart

No

Setup

EnableSensors

All SensorsDisabled

Yes NO

TMRPart In top of

Vibratory HopperYes

Part?

TMR

Yes

Part?

Turn offConveyor

Yes

No

No

No

TMRPart In top of

Conning HopperYes

Part?

TMR

Yes

Part?

Turn offVibratory

Motor

Yes

No

No

TMR

Part In ConningHopper

Yes

Part?

TMR

Yes

Part?

Move Plate

Yes

No

No

No

Testing Procedure

• Build the physical components one at a time starting with the coning hopper

• Test the coning hopper• Build the chute and the vibratory hopper• Send blanks through the system

Testing Procedure

• Attach the system to the coning machine itself

• Test the feeding of the blanks into the coning machine

• Connect the PLC and the sensors to the system

• Check that the correct timings occur • Check that Out of boundary conditions do

not occur

Implementation Procedure

• Build all support structures for the system • Make modifications to the coning machine • Remove all connections to the coning

machine • Move coning machine to its new location

Implementation Procedure

• Reestablish all connections to the coning machine

• New system should be attached and powered up for use

• All elements should be tested for proper running conditions and for proper safety precautions

Setup Improvements

• A standard process for setup would be very beneficial to process flow

• Identify external operations • Identify internal operations

Acknowledgments• 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 giving Matt Mattson the capabilities to go to the University and finance the project

• Finally we would like to thank our professor’s 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 to help us learn new skills on our own

MN Twist Drill

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