Nucor Tap-Hole Drill

Neda Safaeian, William Rogers-Durham, Peng Chith, Matthew Poppe, Thusitha Galhenage

Key Specifications

Customer Attributes

Shaft and Square End

Bearings and Couplings

Motor

Base Frame

Shroud

Power 480 Volts 3 Phase 60 Hz

Weight: design needed to weigh less then 4000 pounds

Torque: the design should produce 1000 ft-lbs

Motor Power: motor needs to produce 20 horsepower

Operation Time: needs to be less then 30 min

Axial Force: withstand a peak axial force of 9,000 pounds

Radial Force: withstand a peak radial force of 10,000 pounds

Safe to Use

Input Power 480 volts

3 phase

60 Hz

Nucor/American Made

Easy to Build

Operation Time < 30 min

Portable via Zoom Boom

Dead Man Switch

Easy to Operate

Axial load: 10000 Ib

Radial load: 9000 Ib

Torque: 12000 Ib.in

Material Used: Steel 1045 cold drawn

Yield Strength: 77 Kpsi

Tensile Strength: 91 Kpsi

•Six 1045 cold drawn steel plates welded together•Thickness ½’’•Length 5’’, width 3’’, height 4’’ •Pin Diameter 1’’•Chamfer wields

•Torque 12000 in-lb•Axial force 9000lb•Radial force 10000lb

The first bearings to be considered were pillow block bearings

Bearings were chosen with respect to the main shaft diameter and loadings on the shaft

The couplings served as a connector for the main shaft and motor shaft

A key slot will be machined on the inside diameter to connect the shafts

The bearings chosen were a pair of Dodge Type E Tapered Roller Bearings

This will accommodate the 2-7/16th inch shaft.

The Kop Flex KD4 Single Flex Size 153 was chosen to join the main shaft with the motor shaft

Features:

Two sized stepped shaft

Large portion hollow

Thin outer wall to thick wall at end

Welded Drill Bit

Hole on side for material removal

Features

Similar to first concept but with pinned drill bits for easy replacement

Stepped drill head to shaft connection

Features:

Single plate for end of drill head

Welded on drill bits

Pin or bolt attachment to drill head

Drill head Weight ~750lbTorque 12000 in-lbAxial forces 9000lbRadial forces 10000lb

Initial : Motor and no gearbox Simple Easier to build In line design Did not produce a sufficient

amount of torque for the weight

Secondary: Motor and build a gearbox Complicated Time consuming

Designing Manufacturing

Lack of quality Allowed for our own

configuration

Final Selection

COMPARISON OF MATERIALS

Tap Hole Material

High Strength Concrete

Low Strength Concrete

Composition(18%

Porous)(Hibbler 7th

Edition)(Hibbler 7th

Ed)

Al2O3 (%) 74.4 - -

SiO2 (%) 18.8 - -

Cu (%) 0 - -

Density (lb/ft^3) 165 148.608 148.608

UTS (Mpa) - - -

TYS (Mpa) - - -

USS (Mpa) 38 38 12

Comparison of ceramic materials made

Used material properties of a similar material to determine the torque necessary for drilling

Determined that 808 ft-lbs was necessary

Final Design: Purchase Motor/Gearbox combination

Power: 20 horsepower

RPM: 105 RPM

Torque: 1000 ft-lbs

Weight: 347lbs

Decided to use a motor and gearbox combination that produced 1000 ft-lbs to make up for any mechanical loses during drilling

The following designs show our preliminary concepts and our current design we have chosen and built

Version 1 Beta

Advantages: Relatively small and light frame. Simple design, easy to build, plates could be optional and motor assembly could be mounted between supports, multiple bolt mounting locations can be supplemented to have an adjustable drill angle

Disadvantages: Could have clearance issues with zoom boom due to short height,

Version 1

Advantages: Relative light weight, Easy to model, Vertical mountings to make assembly simple

Disadvantages: Difficult to build and maintain, Strength depends on the quality of the welding, multiple points of high stress concentrations

Version 2

Advantages: Easier to build, Simpler design, Angled for aligning with tap hole

Disadvantages: Heavy, Multiple areas with very small stress, Could have clearance issues with furnace

Version 3

This version is nearly the same as the previous version except that the mounting position is on the vertical side of the base

Advantages: Easier to build, Simpler design, Vertical to avoid furnace clearance issues

Disadvantages: Heavy, Multiple areas with very small stress

Version 4

Advantages: Eliminate many weight issues with previous designs at 550 lbs for only the base

Disadvantages: Bearing mount design is just a block of metal, Strength highly depend on quality and placement of welds

Version 5

Advantages: Better bearing mount design than the previous version, Comparably lightweight at 450 lbs of only the base, Easy to build

Disadvantages: Strength highly depend on quality and placement of welds, Not adjustable

Final Version

Final Design approved by Chuck Minter

FEA simulation in SolidWorks

Axial force: 9000 lbs

Torque: 12000lb-in

Radial force on square end: 10000lb in the X direction

Weight of the frame ~741 lb

Weight of the whole assembly ~ 1900 lb

FOS: 1.5 in worst case scenario

Prevent all the dust and debris from getting into the motor and the bearing.

Material Used: sheet Metal (Thick: 0.035)

Exposure to Real World Situations

Utilizing Skills Learned in the Classroom

Solid Works, Design Classes, Lab Classes

Consulting Experienced Individuals

Manage Time and Work as a Team

Learn from Mistakes

Design Process is a Learning Process