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Model for forces on drill bits during metal cutting operations

jscpm

Titanium
Joined
May 4, 2010
Location
Cambridge, MA
I am trying to find a good model for typical forces on drill bits during metal cutting operations. Apparently the most traditional work on this subject is the following paper:

Shaw, M.C., Oxford, C.J. (1957). On the drillings of
metals: II. The torque and thrust in drilling. Transactions
of the ASME, vol. 79, p. 139-148.

Unfortunately, it is turning out to be pretty hard to find this journal issue (or any of the ASME stuff from 1950 to 1980).

Does anybody know where I can find it?
 
I'd try an engineering university library - say MIT in your area

They are linked to all others in Canada / USA /
If someone has it, they can do inter library loan requests.

There may be some cost for copying and shipping


Or ASME directly.
 
Here are references you may wish to pursue.

von turkovitc drilling of metals - Google Search

Modeling the Drilling Process. An Analytical Model to Predict Thrust Force and Torque: C. A. Mauch, L. K. Lauderbaugh, Computer Modeling and Simulation of Manufacturing Processes, Vol MD 2�, Dallas, TX, 199�. pp. 59–65. ASME, New York, NY - Documents

"B. Von Turkovich" download free. Electronic library. Finding articles booksc

Look at articles by von Turkovick, K.J. Trigger, S. Ramalingham. Trigger is dead. You can try contacting Ramalingham.

Ramalingam [[email protected]]

Not sure where Turkovich is, I lost track of him. These are people I studied with at the UofI 1960's. All were in metalworking.

Tom
 
Another article,

63, C. A. Mauch, L. K. Lauderbaugh, "Modeling the Drilling Process. An Analytical Model to Predict Thrust Force and
Torque," Computer Modeling and Simulation of Manufacturing Processes, Vol MD 20, Dallas, TX, 1990. pp. 59-65. ASME, New
York, NY. This paper introduces an analytical model that predicts thrust and torque levels for drilling. These predictions are based on
drill geometry, yield shear stress, and chip thickness. This model is presented in contrast to previous empirical models which require
large amounts of experimental data and are of questionable use outside of the experimental range. The model is developed by
dividing the drill tip into three regions with each region having a separate metal cutting model. The chisel edge comprises two of the
three regions. The inner chisel edge region is modeled as an indentation process: while the outer chisel edge region is modeled using
orthogonal cutting theory. In this paper a new analytical expression is developed to define the transition point between these two
regions. This expression was found to be in excellent agreement with empirical results of other researchers. Finally, the lip region of
the drill is modeled by dividing the region into N cutting elements and modeling each element with oblique cutting theory. The total
force and torque are then computed by summing the contributions from each of the three regions. Currently, the model can be used
for both conventional and splitpoint high speed steel drill tip geometries. However, the model can be easily extended to include other
geometries. Thrust and torque predictions from the analytical model are compared with experimental results that were generated by
using conventional and splitpoint drills to drill 2024-T351 aluminum. 8 Refs.

Tom
 
Here are references you may wish to pursue.

von turkovitc drilling of metals - Google Search

Modeling the Drilling Process. An Analytical Model to Predict Thrust Force and Torque: C. A. Mauch, L. K. Lauderbaugh, Computer Modeling and Simulation of Manufacturing Processes, Vol MD 2�, Dallas, TX, 199�. pp. 59–65. ASME, New York, NY - Documents

"B. Von Turkovich" download free. Electronic library. Finding articles booksc

Look at articles by von Turkovick, K.J. Trigger, S. Ramalingham. Trigger is dead. You can try contacting Ramalingham.

Ramalingam [[email protected]]

Not sure where Turkovich is, I lost track of him. These are people I studied with at the UofI 1960's. All were in metalworking.

Tom

Unfortunately, all those links are just to abstracts, not the full article.

I did find this paper on drill point geometry by Turkovitch:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.23.67&rep=rep1&type=pdf#page=50
 
Abstracts are largely what you find unless you are a member of the particular society such as ASM. Find yourself a member that would willing to download some of the papers. University libraries as mentioned are another greater source. The real value is not just the paper itself but also the references and citings. Once you start pursuing the references, the world will explode with information.

Tom
 
I am trying to find a good model for typical forces on drill bits during metal cutting operations. Apparently the most traditional work on this subject is the following paper:

Shaw, M.C., Oxford, C.J. (1957). On the drillings of
metals: II. The torque and thrust in drilling. Transactions
of the ASME, vol. 79, p. 139-148.

Unfortunately, it is turning out to be pretty hard to find this journal issue (or any of the ASME stuff from 1950 to 1980).

Does anybody know where I can find it?
.
better cnc machines have torque and thrust readings for setting the automatic feed control or afc, i have often watched them while drilling
.
as drill dulls forces change, as coolant dries up cause drill deep in hole and cannot get to drill tip forces change
.
different ipt feed rates changing the machinability rate or hp requires per cubic inch metal removed per minute. that is differences between thin and thick chips made.
.
my experience is often forces are not steady but constantly changing.
.
a drill that has runout makes a bigger hole and has more clearance from side of drill to side of hole. a drill with more backtaper or smaller diameter near shank has less rubbing. the drill lands or margins width and angle clearance effects things.
.
a long drill following a pilot hole that is .002" smaller can cause high enough rubbing and drill vibration to break the drill easily. just saying drill vibration can effect forces that is forces pulsating and not holding steady
 

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a drill that has runout makes a bigger hole and has more clearance from side of drill to side of hole.

My experience is runout doesn't really matter with a twist drill/spade. The factor that effects the size hole drilled is how close or far from center the drill point is.

A twist drill will drill a hole 2 times the length of the longer side.

I have sharpened larger twist drills off center to drill oversize holes with good predictability.
 








 
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