Cutting Parameters and Machining

Cutting Parameters and Machining

This assignment has two sections. The first section is a practicum related to reinforcing basic
calculations and knowledge with respect to simple machining. The calculations and discussion
questions are to be done independently. Show all your calculations, and your formulae. You will have
to find the necessary information on the Internet or using library resources. Clearly indicate your
reference material on the last sheet. See the on-line spreadsheet on the course site for the material
assigned to you. The second part of the assignment focuses on general principles.
(Up to -5 Marks) – if the work is not neat, calculations are not shown, and not properly
referenced
? The work piece material to be cut is ________________ for calculations for M10x1.50 mm
and ¼-20 tapped hole and a 0.500 reamed hole.
Calculate the feeds and speeds for HSS & Carbide cutting tools where appropriate.
Calculate a speed and feed rate for the drill, reamer and a boring bar (one insert) with the same
diameter as the reamer. Show the calculations on the last sheet (neatly). Clearly state the units.
Assume a depth (min. 10 mm) to calculate the cutting time. Hint: draw a detailed sketch prior to
calculating the cutting time. (12)
Drill Speed/Feed parameters (assume 31/64 inch)
Drill parameters HSS Carbide
Drill rpm:
Drill feed rate:
Drill cutting time:
Drill material removal rate
Reamer Speed/Feed parameters (assume 0.500 inch)
Reamer parameters HSS Carbide
Reamer rpm:
Reamer feed rate:
Reamer cutting time:
Reamer material removal rate
Boring Speed/Feed parameters (assume 0.500 inch)
Boring parameters HSS Carbide
Boring rpm:
Boring feed rate:
Boring cutting time:
Boring material removal rate
06-91-321-01 Fall 2015
University of Windsor
Manufacturing Process Design
Instructors:
Dr. Jill Urbanic, e-mail: [email protected]
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When would you use a reamer versus a boring bar? Discuss. (1)
Tapping: M10x1.50 mm & ¼-20 tapped hole (2)
What is the drill diameter of your drills?
______________.
______________.
What is the percentage thread engagement for this diameter? (1.5)
______________.
______________.
What are the speed and feed values of these drills and taps? Clearly state your cutting speed data
along with the references, and the appropriate units. (4)
List three typical tap types, and when they are used (1.5).
Reaming: For an 8F7 hole: (5)
What is the diameter of your drill you would use? ______________.
What reamer would you use and why? ______________.
Drill Reamer
Material
Feeds
Speeds
Time
Other characteristics:
06-91-321-01 Fall 2015
University of Windsor
Manufacturing Process Design
Instructors:
Dr. Jill Urbanic, e-mail: [email protected]
3 of 5
Quickies (3)
Which of the following statements is not correct?
a) core drills have 3 or 4 flutes.
b) high helix drills help in chip removal.
c) straight fluted drills are used for sheet metal.
d) centre drills are for long holes, such as gun barrels.
If we want a hole with a 1/2-13-UNC thread, what size of tap drill should be used? (1)
If we want a hole with a 6 x 1.0 thread, what size of tap drill should be used? (1/2)
What size is an F drill? (1/2)
List three reasons that machining operations may be required, and provide an example for each. Do
not provide duplicate information. (3)
What special precautions are needed when cutting magnesium, and thermoplastic materials (such as
ABS plastic)? (3)
When considering the basic metal-cutting process, what are the important physical and chemical
properties of a cutting tool? (2)
Tool materials can have conflicting properties when used for machining operations. Discuss. Use
numerical examples to justify your answer, and reference appropriately. (Hint: consider tool costs, tool
life, processing time, potential failure modes). (8)
Explain whether it is desirable to have a high or low (a) n value and (b) C value in the Taylor tool-life
equation. You may develop an example to assist with your explanation. (2)
Describe the difficulties that may be encountered in clamping a workpiece made of a soft metal in a
three-jaw chuck or a vise. (1)
It has been stated that titanium-nitride coatings allow cutting speeds and feeds to be higher than
those for uncoated tools. Survey the technical literature and prepare a table showing the percentage
increase of speeds and feeds that would be made possible by coating the tools. (4)
List the concerns you would have if you needed to economically machine carbon-fiber reinforced
polymers or metal-matrix composites with graphite fibers in an aluminum matrix. (5)
Contact several different suppliers of cutting tools, or search their websites. Make a list of the costs of
typical cutting tools as a function of various sizes, shapes, and features. (5)
06-91-321-01 Fall 2015
University of Windsor
Manufacturing Process Design
Instructors:
Dr. Jill Urbanic, e-mail: [email protected]
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Hint: Good sources for such a literature search are trade magazines, and cutting-tool vendors whose
product specifications will include data on speeds and feeds – Kennametal, Iscar, Sandvik, Carboloy,
and Valenite, Precision Twist Drill, ….
Practice Quantitative Questions from the Text Book:
21.48, 21.61, 23.42
06-91-321-01 Fall 2015
University of Windsor
Manufacturing Process Design
Instructors:
Dr. Jill Urbanic, e-mail: [email protected]
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Calculation Worksheet