The purpose of this work is to present an investigation of the force system generated during spade drill-bit drilling processes that is a prerequisite for the design of spade-drills with improved performance. The technical literature offers no references to this type of bit and process; hence an approach based on the well-established mechanistic force prediction methods will be used. The force and torque prediction models are based on a complete analytical model of a generalized spade bit that takes into account the cutting action of all the characteristic cutting edges of the spade bit, namely of its chisel edge, tip and major cutting edges. In conjunction with the model an efficient model calibration method is also introduced and experimentally verified.

1.
Zhao, H., 2000, “Geometry and Mechanics of Spade Drilling Operations,” Ph.D. Thesis, Northwestern University, Evanston, Illinois.
2.
Zhao, H., and Ehmann, K. F., 2001 (Under review), “Topology of Spade Drills for Wood Drilling Operations-Part 1: Spade Drill Point Geometry Definition and Part 2: Spade Drill Point Cutting Geometry Analysis,” ASME J. Manuf. Sci. Eng. .
3.
Kline
,
W. A.
,
DeVor
,
R. E.
, and
Lindberg
,
J. R.
,
1982
, “
The Prediction of Cutting Force in End Milling with Application to Cornering Cuts
,”
Int. J. Mach. Tool Des. Res.
,
22
(
1
), pp.
7
22
.
4.
Yucesan, G., and Altintas, Y., 1993, “Mechanics of the Ball End Milling Process,” ASME Winter Annual Meeting, PED-64, pp. 543–552.
5.
Williams
,
R. A.
,
1974
, “
A Study of the Drilling Process
,”
ASME J. Eng. Ind.
,
106
(
4
), pp.
1207
1215
.
6.
Watson
,
A. R.
,
1985
, “
Drilling Model for Cutting Lip and Chisel Edge and Comparison of Experimental and Predicted Results. I—Initial Cutting Lip Model, II—Revised Cutting Lip Model, III—Drilling Model for Chisel Edge and IV—Drilling Tests to Determine Chisel Edge Contribution to Torque and Thrust
,”
Int. J. Mach. Tool Des. Res.
,
25
(
4
), pp.
347
406
.
7.
Watson
,
A. R.
,
1985
, “
Geometry of Drill Elements
,”
Int. J. Mach. Tool Des. Res.
,
25
(
3
), pp.
209
227
.
8.
Chandrasekharan
,
V.
,
Kapoor
,
S. G.
, and
DeVor
,
R. E.
,
1995
, “
A Mechanistic Approach to Predicting the Cutting Forces in Drilling: With Application to Fiber-Reinforced Composite Materials
,”
ASME J. Eng. Ind.
,
117
(
4
) pp.
559
570
.
9.
Chandrasekharan
,
V.
,
Kapoor
,
S. G.
, and
DeVor
,
R. E.
,
1997
, “
A Calibration Procedure for Fundamental Oblique-Cutting Model Coefficients Based on A Three-Dimensional Mechanistic Drilling Force Model
,”
Transactions of NAMRI/SME
,
XXV
, pp.
255
260
.
10.
Budak, E., and Altintas, Y., 1993, “Prediction of Milling Force Coefficients from Orthogonal Cutting Data,” ASME Winter Annual Meeting, PED-64, pp. 453–460.
11.
Shin
,
Y. C.
, and
Waters
,
A. J.
,
1997
, “
A New Procedure to Determine Instantaneous Cutting Force Coefficients for Machining Force Prediction
,”
Int. J. Mach. Tools Manuf.
,
37
(
9
), pp.
1337
1351
.
12.
Stephenson
,
D. A.
, and
Agapiou
,
J. S.
,
1992
, “
Calculation of Main Cutting Edge Forces and Torque for Drills with Arbitrary Point Geometries
,”
Int. J. Mach. Tools Manuf.
32
(
4
), pp.
521
538
.
13.
Armarego
,
E. J. A.
, and
Cheng
,
C. Y.
,
1972
, “
Drilling With Flat Rake Face and Conventional Twist Drill-I. Theoretical Investigation
,”
Int. J. Mach. Tool Des. Res.
,
12
, pp.
17
35
.
14.
Armarego
,
E. J. A.
, and
Wright
,
J. D.
,
1984
, “
Predictive Models for Drilling Thrust and Torque-A Comparison of Three Flank Configurations
,”
CIRP Ann.
,
33
(
1
), p.
5
5
.
15.
Merchant
,
M. E.
,
1945
, “
Basic Mechanics of the Metal-Cutting Process
,”
ASME J. Appl. Mech.
,
66
A-168–A-175
A-168–A-175
.
16.
Gu
,
F.
,
Kapoor
,
S. G.
,
DeVor
,
R. E.
, and
Bandyopadhyay
,
P.
,
1992
, “
A Cutting Force for Face Milling with a Step Cutter
,”
Transactions of NAMRI/SME
,
XX
, pp.
361
367
.
17.
Endres
,
W. J.
, and
Waldorf
,
D. J.
,
1994
, “
The Importance of Considering Size Effect Along the Cutting Edge in Predicting the Effective Lead Angle for Turning
,”
Transactions of NAMRI/SME
,
XXII
, pp.
65
72
.
18.
Stabler, G. V., 1964, “The Chip Flow Law and its Consequences,” Advances in Machine Tool Design and Research, Oxford: Pergamon Press, Ltd., p. 243.
19.
Oxford
,
C. J.
,
1955
, “
On the Drilling of Metals I-Basic Mechancis of the Process
,”
Trans. ASME
,
77
, pp.
103
114
.
You do not currently have access to this content.