Unit Process Life Cycle Inventory  
Dr. Devi Kalla, Dr. Janet Twomey, and Dr. Michael Overcash
Reaming Process Summary
Reaming is a frequent unit process in manufacturing as a mass reduction step, used for enlarging and accurately sized existing hole by means of multifluted cutting tool. Reaming removes a minimal amount of material and is often performed after drilling to obtain both a more accurate diameter and a smoother internal finish. Hence this life cycle heuristic is to establish representative estimates of the energy and mass loss from the reaming unit process in the context of manufacturing operations for products. The reaming unit process life cycle inventory (uplci) profile is for a high production manufacturing operation, defined as the use of processes that generally have high automation and are at the medium to high throughput production compared to all other machines that perform a similar operation. This is consistent with the life cycle goal of estimating energy use and mass losses representative of efficient product manufacturing.
Reaming is a machining process in which a light cut to improve the accuracy of a round hole and enlarges an existing hole to the diameter of the tool by means of a rotary multifluted cutting tool typically aided by cutting fluids. As the reamer is rotated and advanced axially into the workpiece, material is removed in the form of chips. Chips are produced within the workpiece and move in direction opposite to axial movement of the reamer. For soft metals, a reamer typically removes a minimum of 0.2 mm (0.008 in.) on the diameter of a drilled hole; for harder metals, about 0.13 mm (0.005 in.) is removed. Consequently, chip disposal in reaming and the effectiveness of cutting fluids are important. Generally, reaming is done using a drill press. However, lathes, machining centers and similar machines can be used as well. The workpiece is firmly held in place by either a vice, chuck or fixture while the reamer advances. An example CNC machine is given in Figure MR6.1, while the reaming mechanism is illustrated in Figure MR6.2.
Figure MR6.3 shows an overview of the developed environmental-based factors for reaming operations. For a given workpiece (illustrated in Figure MR6.2) the life cycle analysis yields energy use and mass losses as byproducts or wastes.

 

Figure MR6.1. Computer numerical control (CNC) machine with 3-axis control (Photograph from Haas Automation, Inc. California, USA)

Figure MR6.2. Process Schematic (Todd et al., 1994)

 

Figure MR6.3. LCI data for reaming process

Methodology for Unit Process Life Cycle Inventory Model

In order to assess a manufacturing process efficiently in terms of environmental impact, the concept of a unit operation is applied. The unit process consists of the inputs, process, and outputs of an operation. Each unit process is converting material/chemical inputs into a transformed material/chemical output. The unit process diagram of a reaming process is shown Figure MR6.4.

The transformation of input to output in this report generates five lci characteristics,

1. Input materials
2. Energy required
3. Losses of materials (that may be subsequently recycled or declared waste)
4. Major machine and material variables relating inputs to outputs
5. Resulting characteristics of the output product that often enters the next unit process.

 

Figure MR6.4. Input-Output diagram of a reaming process

Reaming Process Energy Characteristics

Because high production reaming is a semi-continuous process. Many of these automated CNC machines have more than three axes. One of the axes is often designed as a rotary table to position the work-piece at some specified angle relative to the spindle. The rotary table permits the cutter to perform reaming on four sides of the part. These machines are classified as horizontal, vertical or universal based on the spindle orientation. The uplci is based on a representative operational sequence, in which

1. Work set-up generally occurs once at the start of a batch in production. Set-up is made on the machine tool as the work piece is introduced into the machine. The work piece is positioned, all drawings and instructions are consulted, and the resulting program is loaded. Typical set-up times are given in Table MR6.1 (Fridriksson, 1979). The total set-up time must be divided by the size of the batch in order to obtain the set-up time per component. The energy consumed during this set-up period is divided by all the parts processed in that batch and is assumed to be negligible and is discussed in the example below.
2. The power consumption during a campaign for positioning or loading each new piece into the CNC machine, with respect to tool axis is low. Time is required to load the workpiece into the CNC machine and secure it to the fixture. The load time can depend on the size, weight, and complexity of the workpiece, as well as the type of fixture. This is at the level of Basic energy and is labeled Loading.
3. Relative movement of the cutting tool and the workpiece occurs without changing the shape of the part body, referred to as Idle Energy and is labeled Handling. This is the time required for any tasks that occur during the process cycle that do not engage the workpiece. This idle time includes the tool approaching and retracting from the workpiece, tool movements between features, adjusting machine settings, and changing the tools.
4. Reaming of a hole occurs and is labeled Tip Energy.
5. The piece is repositioned for subsequent holes, thus the energy and mass loss per hole is repeated. (Idle Energy for Handling and then Tip Energy for Reaming)
6. When all holes are finished, the piece is unloaded and typically sent forward to another manufacturing unit process. This is at the level of Basic Energy and is labeled Unloading.         

 

Table MR6.1. Set-up times for machining operations (Fridriksson, 1979)

In this representative unit process, the life cycle characteristics can be determined on a per reamed hole basis or on a full piece (with one or more holes) basis. Since this is a high production process, the startup (at the beginning of a batch or shift) is deemed to be small and not included. In this uplci, there are three typical power levels that will be used, Figure MR6.5. Each power level, kw, is the incremental power not the absolute total power.  Thus if electrical measurements are made, the kw during the tip measurement must have the idle and basic power (kw) values subtracted to obtain this tip power (kw). Correspondingly, there are times within the reaming sequence from which these three power levels are used, Figure MR6.5. The overall time per piece is referred to as cycle time and is generally consistent in a batch. Each power level (basic, idle, and reaming) is a reflection of the use of various components or sub-operations, of the CNC machine, Figure MR6.6. The steps 2), 3), 5), and 6) are estimated as representative values for use in this unit process lci and energy required of removing material by reaming, step 4), is measured using specific cutting energy values.

 

The system boundaries are set to include only the use phase of the machine tool, disregarding production, maintenance and disposal of the machine. Moreover, the functioning of the manufacturing machines is isolated, with the influence of the other elements of the manufacturing system, such as material handling systems, feeding robots, etc. are covered in other uplci reports.
The energy consumption of reaming is calculated as follows:

Etotal = Pbasic * (tbasic )  +  Pidle * (tidle) + Preaming * (treaming )                                                 

Parameters Affecting the Energy Required for Reaming

An approximate importance of the many variables in determining the reaming energy requirements was used to rank parameters from most important to lower importance as follows:

 

1. Workpiece Material properties
2. Feed rate
3. Cutting speed
4. Reamer diameter
5. Hole depth (Reaming time)
6. Number of cutting edges
7. Coolant
8. Tool wear
9. Geometry and set-up

From this parameter list, only the top 5 were selected for use in this unit process life cycle with the others having lower influence on energy. Energy required for the overall reaming process is also highly dependent on the time taken for idle and basic operations.

 

Reaming Energy

Reaming time (treaming) and power (Preaming) must be determined for the reaming energy and are calculated from the more important parameters given above. The calculations are illustrated in Figure MR6.7. Feed for reaming is the axial advance in one revolution of the spindle, f (mm/revolution). The rotational cutting speed, V (m/min), is the rotational speed difference between the cutting tool and the surface of the workpiece it is operating on. Reamer is used to enlarge an existing hole which is done by drilling operation. So speed and feed can be estimated from the drilling process data. Reaming is done at half the speed and twice the feed as drilling. This rule still applies on the milling machine as it does on the drill press or the lathe.

V and f are estimated from the material properties, Table MR6.2(a) and MR6.2(b). The rotational speed of the spindle, N, (rev/min), N = V/ (π*D). Where V = rotational cutting speed, mm/min and D = reamer diameter, mm. Reamers generally have more than one cutting edge – introducing the concept of tooth loading, or table feed per tooth. Feed per tooth, ft (mm/tooth) is the thickness of chip material that each cutting edge of a tool removes with one pass. The feed per tooth is roughly proportional to ream diameter, higher feeds for larger diameter.                      

The feed rate, fr (mm/min) is the rate at which the cutting tool and the workpiece move in relation to one another. The rate of tool advance (feed rate), fr (mm/min) is the product of f*N. The volume removal rate has been defined as the uncut area multiplied by the rate at which the material is removed perpendicular to the area. For a hole of diameter D, the volume material removal rate (VRR) is (0.25π (D-D­c) 2)* (fr ), mm3/min. Difference between the initial and final diameter is the depth of cut which is referred as ‘l’ in mm.

          
FigureMR6.7. Schematic Diagram of reaming Process

Reaming time (treaming) is
Time for reaming a through hole tream = (d)/f*N = d/fr                                                     (2)
Where d = depth of the hole, mm.
f – Feed mm/rev.
N- Spindle speed rpm
fr – feed rate, mm/min

The reaming energy is thus E (Joule/hole) = Reaming time*Preaming,                       
E = ream time*(volume removal rate)*(specific cutting energy, Up, W/mm3/sec)  
Eream (Joule/hole) = tream *VRR*Up = tream * Preaming                                                  (3)

With a given material to be reamed, the specific cutting energy, Up, is given in Table MR6.2(a). Then for that material a representative cutting speed, V is selected from Table MR6.2(a). Then using the hole diameter, D (final diameter), the spindle speed, N, is calculated = V/ (π*D). From Table MR6.2 (a and b) for the material being reamed the feed, f is also specified. Then the time for reaming, tream , is d/(f*N) or d/fr . The volume removal rate (VRR) is fr *(0.25π*(D-Dc)2). Where Dc is the initial diameter of the hole. 
The reaming energy is then calculated from equation 3. Thus with only the material to be reamed, the depth of the hole, initial diameter and the final diameter of the hole, one can calculate the lci reaming energy for one hole.  This then must be added to the idle and basic energies, see below.
Table MR6.2(a) Average values of energy per unit material removal rate and recommended speeds and feeds ( Erik, 2000; Hoffman, 2001; Joseph, 1989; Kalpakjian, 2008; 9, 10)

Material	Hardness [Brinell hardness number]	Specific cutting energy, Up [W/ mm3 per sec] (Hp/ in3 per min)	Cutting Speed, V (m/min, ft/min)	Feed, f	Density (kg/m3)
Aluminum Alloys(Wrought)	30 – 80	0.76 (0.28)	50 - 120, 175 - 400	Z	2712
	75 – 150	0.76 (0.28)	50 - 120, 175 - 400	Z
Aluminum (Cast)	40 – 100	0.84 (0.31)	50 - 120, 175 - 400	Z	2560-2640
	70-125	0.84 (0.31)	50 - 120, 175 - 400	Z
Aluminum (Unalloyed)	80	0.3 (0.11)	50 - 120, 175 - 400	Z	7700-8700
High Silicon Aluminum (10-14% Si)		0.84 (0.31)	50 - 120, 175 - 400	Z	2700-2750
High Silicon Aluminum (14-16% Si)		1.48 (0.55)	50 - 120, 175 - 400	Z
Malleable Cast Iron (Short Chipping)	110 – 145	1.21 (0.45)	25 - 30, 75 - 100	Z	6800-7800
Malleable Cast Iron (Long Chipping)	200 – 230	1.3 (0.48)	12 - 30, 40 - 75	Y	6800-7800
Grey Cast Iron	180	1.3 (0.48)	20 - 60, 60 - 200	Y	6800-7800
	260	1.48 (0.55)		X
Nodular Cast Iron	160	1.21 (0.45)	20 – 60, 60 - 200	Y
	250	2.10 (0.78)		X	6800-7800
Cast Steel (Unalloyed)	150	2.16 (0.8)	20 - 30, 60 - 100	Y	6800-7800
Cast Steel (Low Alloy)	150 – 250	2.51 (0.93)	20 - 30, 60 - 100	Y	6800-7800
Cast Steel (High Alloy)	160 – 200	2.94 (1.09)	20 - 30, 60 - 100	X	6800-7800
Unalloyed Steel	110	1.35 (0.5)	50 - 120, 175 - 400	Z	7850
	150	1.89 (0.81)	20 – 60, 60 - 200	Y
	310	2.92 (1.08)	15 - 30, 50 -100	X
Low Alloy Steel	125 – 225	2.51 (0.93)	15 - 20, 50 - 60	Y	7850
	220 – 420	3.29 (1.22)	12 - 15, 40 - 50	X
High Alloy Steel	150 – 300	2.94 (1.09)	8 - 12, 25 - 40	X
	250 – 350	4.56 (1.69)	8 - 12, 25 - 40	W
Hardened Steel	450	4.56 (1.69)	25 - 30, 75 -100	W
Stainless Steel (Ferritic, Martensitic)	150 – 270	2.81 (1.04)	15 - 24, 50 - 70	X	7480-8000
Stainless Steel (Austenitic)	150 – 275	2.94 (1.09)	24 – 28, 70 - 90	X	7480-8000
Stainless Steel (Quenched and Tempered Martensitic)	275 – 425	2.59 (0.96)	10 – 12, 30 - 40	X
Stainless Steel	150 – 450	3.46 (1.28)	15 – 24, 50 - 70	X	7480-8000
Iron Based Heat Resistant Super Alloy	180 – 230	3.7 (1.37)			7850
	250 – 320	3.86 (1.43)
Nickel Based Heat Resistant Super Alloy	140 – 300	3.46 (1.28)	6 – 8, 20 - 25	X	8800
	300 – 475	4.21 (1.56)	5 – 6, 15 - 20	W
Nickel Based Heat Resistant Super Alloy(Cast)	200 – 425	4.21 (1.56)	16 – 18, 55 - 65	W	8800
Cobalt Based Heat Resistant Super Alloy	180 – 230	3.46 (1.28)	5 - 7, 15 - 25	W	8746
	270 – 320	4.21 (1.56)	5 - 7, 15 - 25	W
Cobalt Based Heat Resistant Super Alloy(Cast)	220 – 425	4.27 (1.58)	5 - 7, 15 - 25	W	8746
Titanium Alloys (Commercially Pure)	110-200	1.51 (0.56)	5 - 6, 15 - 20	X	4500
Titanium Alloys	300-360	1.65 (0.61)	5 - 6, 15 - 20	Y	4500
	275-350	1.67 (0.62)	5 - 6, 15 - 20	W	4500
Copper	125-140	2.70 (1.00)	30 - 80, 100 - 250	Z	8930
Copper alloys	100-150	2.20 (0.80	30 - 80, 100 - 250	Z	8930
Leaded brass	60-120	1.90 (0.70)	30 - 80, 100 - 250		7700-8700
Unleaded brass	50	2.70 (1.00)	30 - 80, 100 - 250
Magnesium alloys	40-70	0.55 (0.20)	50 - 110, 150 - 350	Z
	70-160	1.10 (0.40)	50 - 110, 150 - 350	Z
Refractory alloys(Tantalum, columbium, Molybdenum)	210-230	5.50 (2.00)			10188
Tungsten	320	8.00 (3.00)			19600
Plastics	hard		30, 100

 

 

Idle Energy

Energy-consuming peripheral equipments included in idle power (Pidle) are shown in Figure MR6.6. In the machining praxis it is known as “run-time mode” (Abele et al., 2005). The average idle power (Pidle) of automated CNC machines is between 1,200 and 15,000 watt*. (* This information is from the CNC manufacturing companies, see Appendix 1). The handling power characterizes the load case when there is relative movement of the tool and the work-piece without changing the shape of the body (e.g. rapid axis movement, spindle motor, coolant, tool changer) - Handling.
The idle time (tidle) is the sum of the handling time (thandling) and the reaming time (calculated above as tream, equation 2), see Figure MR6.5. For CNC machines, the handling times are the air time of tool moving from home position to approach point, approach, overtravel, retraction after reaming, and traverse, if needed to other holes in the same work piece. Approximate Handling time will vary from 0.1 to 10 min. We can calculate the handling times and energy as follows.

Idle time = [timehandling + timeream]                                                                                (4)

Reaming tool moves from the home position to the approach point at vertical traverse rate, VTR and it can be defined as the air time1. This distance would be in the range of 10 to 30 mm. During the reaming process, the tool is considered to be at an offset of 0.3 times the hole diameter above the work piece and so the approach distance is 0.3D. We also assume the overtravel below the hole is 0.3D. These forward distances are at the feed rate, fr. After reaching the overtravel point, the reaming tool retraces back to an offset position, but at a faster rate called the vertical traverse rate, VTR. The retraction time is estimated from the sum of the approach, overtravel, and distances, d, and the traverse rate, VTR.

Time for handling is
Air time1 + Approach/overtravel times + retraction times = timehandling                       (5)                     

The reaming time (for distance d) was previously calculated and is not included in the handling time.

To this idle time must be added the time to traverse to the next hole (if needed) and this is (hole spacing)/traverse speed, as given by the CNC manufacturer. The example given later in this uplci lists such traverse speed data for use in any representative reaming scenarios.

From these calculations the idle energy for a single hole is

E (Joule/hole)idle = [thandling + tream]* Pidle                                                                       (6)

            Thus with just the hole diameter, the information used in calculating tream, and the representative idle power (1,200 – 15,000 watts), one can calculate the idle energy for this reaming unit process.

Basic Energy

The basic power of a machine tool is the demand under running conditions in “stand-by mode”. Energy-consuming peripheral equipments included in basic power are shown in Figure MR6.6. There is no relative movement between the tool and the work-piece, but all components that accomplish the readiness for operation (e.g. Machine control unit (MCU), unloaded motors, servo motors, pumps) are still running at no load power consumption. Most of the automated CNC machine tools are not switched off when not reaming and have a constant basic power. The average basic power Pbasic of automated CNC machines is between 800 and 8,000 watt* (* From CNC manufacturing companies the basic power ranges from 1/8th to 1/4th of the maximum machine power, (see Manufacturers Reference Data in Appendix). The largest consumer is the hydraulic power unit. Hydraulic power units are the driving force for motors, which includes chiller system, way lube system and unloaded motors.

From Figure MR 5.5, the basic time is given by
Tbasic = tload/unload + thandling + tream                                                                                                           (7)
where   thandling + tream = tidle as determined in equation 4.

An exhaustive study of loading and unloading times has been made by Fridriksson, 1979; it is found that these times can be estimated quite accurately for a particular machine tool and work-holding device if the weight of the workpiece is known. Some of Fridriksson, 1979 results are showed in Table MR6.3, which can be used to estimate machine loading and unloading times. For reaming representative work-holding devices are vise, jigs, parallels, V-blocks and rotary table. To these times must be added the times for cleaning the workholding devices etc.

Thus the energy for loading and unloading is given by

Basic energy, tbasic = [timeload/unload + timeidle ]*Pbasic                                                  (8)

Where timeidle is given in earlier sections and timeload/unload is from Table MR6.3. Pbasic is in the range of 800 to 8,000 watts.

            Thus the uplci user must add some reasonable value from Table MR6.3 for the load/unload times and can then use the timeidle to determine the Basic energy

 

Method of Quantification for Mass Loss

            The waste streams in reaming process, identified with the associated process performance measures, are depicted in the Figure MR6.8 below.

		Reaming
Waste Stream	Gas/Aerosol	Cutting fluid mist Dust (dry machining)
	Solid	Chips, worn tools
	Liquid	Spent cutting fluids

 

Figure MR6.8. Waste Streams in reaming process

Lci for Material Mass Loss Calculations

            The workpiece material loss after reaming a hole can be specified as chip mass (ms). Metal chips are accumulated, and cutting fluid is separated from these. The chip mass (ms) can be calculated by multiplying the volume of material removed (Vremoval) by the density of the workpiece material ρ.
Density of the material can be attained from the material property list as shown in Table MR6.2(a) and its unit is kg/m3.
Volume of the material removed for a hole =  [mm3]            (10)
Where
D = Final hole diameter in mm,
Dc = Initial hole diameter in mm,
d = depth of the hole in mm.
Chip mass (ms) = Vremoval * ρ * (1 m3/1 D+09 mm3)    [kg]                                         (11)

Lci for Cutting Fluid Waste Calculations

For reaming operations, cutting fluids can be used to allow higher cutting speeds, to prolong the cutting tool life, and to some extent reduce the tool - work surface friction during machining. The fluid is used as a coolant and also lubricates the cutting surfaces and the most common method is referred to as flooding (23). Table MR6.4 shows the recommended cutting fluid for reaming operation. Cutting fluid is constantly recycled within the CNC machine until the properties become inadequate. The dilution fluid (water) is also supplied at regular intervals due to loss through evaporation and spillage.

Table MR6.4. Cutting fluid recommendations for reaming operation
(Hoffman et al., 2001)

Material	Reaming (most of these cutting fluids are aqueous suspensions)
Aluminum	Soluble Oil (75 to 90 percent water). Or 10 Percent Lard oil with 90 percent mineral oil.
Alloy Steels	Soluble oil
Brass	Soluble oil (75 to 90 percent water). Or 30 percent Lard oil with 70 percent Mineral oil.
Tool steels and Low carbon Steels	Soluble Oil
Copper	Soluble Oil
Monel Metal	Soluble oil
Cast iron	Dry
Malleable Iron	Soluble Oil
Bronze	Soluble oil
Magnesium	60-second Mineral Oil

The service of a cutting fluid provided to one CNC machine tool for one year was considered as the functional unit. It is assumed that the number of parts produced per unit time will not vary depending on the cutting fluid replacement. The reaming time associated with one year of production was based on the schedule of 102 hr of reaming/week for 42 weeks/year from one of the most comprehensive cooling fluid machining studies (Andres et al., 2008). From (Andres et al., 2008) a single CNC machine using cutting fluid required an individual pump to circulate the fluid from a 55 gallon (208L) tank to the cutting zone. The 208L/machine is recycled within process until it is disposed of after two weeks. Assuming cutting fluid is used 204 hr/ 2 weeks, then the cutting fluid loss is 208L/ (204*60) per minute. Which is 0.017 L/min or about 17 g/min as the effective loss of cutting fluid due to degradation.  The coolant is about 70wt% - 95 wt% water, so at 85wt% water, the coolant oil loss is 15wt% or 2.5 g cutting oil/min. With the machining time for reaming a hole the mass loss of coolant oil can be calculated.
There is also be a fugitive emissions factor here that could account for aerosol losses. Wlaschitz and Hoflinger (2007) measured aerosolized loss of cutting fluid from a rotating machining tool under flooding conditions. For a cutting fluid use of 5,700 g/min, the aerosol oil loss was about 0.0053 g/min and water loss of 0.1 g/min. Other losses from spills and carry off (drag-out) on workpieces were not included at this time.

Lci for Lubricant Oil Waste Calculations

            Lubricant oil is mainly used for a spindle and a slide way. Minute amount of oil is infused to the spindle part and the slide way at fixed intervals. From the CNC manufacturing companies it is found that lubricant oil is replaced only 2-3 times of the life of the machine. It is assumed that the life of the machine is around 20 years. Since it is negligible lubricant oil loss is not considered for this study.

 

Cutting Tool usage

Reaming processes often require regular replacement of cutting tools. The tool life is a time for a newly sharpened tool that cuts satisfactorily before it becomes necessary to remove it for regrinding or replacement. Worn tools contribute significantly to the waste in the form of wear particles and a worn tool at the end of tool life. The wear particles usually are carried away by the cutting fluid. From an environmental perspective the cutting tools remaining at the end of the tool life are of importance as they are often disposed off and hence are a burden to the environment. The worn tool can be identified by the process performance in terms of the cutting forces, energy consumed, and surface finish. For simplification regrinding of the tools are not considered.

Case Study on Reaming

            In this report we analyze the detailed energy consumption calculations in reaming process. The machining process is performed on Jeenxi Technology 4-axis CNC machine (JHV – 1500) in a high production mode. The machine specifications are listed below:

Table MR6.5.  Specifications of JHV – 1500 CNC Machine

 

Product Details:

            For this example we are assuming a grey cast iron (BHN 180) as the work piece. The work piece is a square block of dimensions 100 mm x 100 mm x 50 mm (L x H x B). The objective of the study is to analyze the energy consumption in reaming 4 symmetrical holes of 25.4 mm diameter through the thickness of the work piece. Initial hole diameter is 25 mm. The part dimensions are shown in Figure MR6.9. From the dimensions and the density from Table MR6.2(a), the weight of the workpiece is 3.6 kg.

 

Summary:

This report presented the models, approaches, and measures used to represent the environmental life cycle of reaming unit operations referred to as the unit process life cycle inventory. The five major environmental-based results are energy consumption, metal chips removed, cutting fluid, lubricant oil, and cutting tool. With only the following information the unit process life cycle energy for reaming can be estimated.

1. material of part being manufactured
2. diameter, number of holes, and location
3. hole depth to be reamed
4. Table MR6.4

The life cycle of reaming is based on a typical high production scenario (on a CNC Reaming machine) to reflect industrial manufacturing practices.

References Cited

 

1. Abele, E.; Anderl, R.; and Birkhofer, H. (2005) Environmentally-friendly product development, Springer-Verlag London Limited.
2. Clarens, A.; Zimmerman, J.; Keoleian, G.; and Skerlos, S. (2008) Comparison of Life Cycle Emissions and Energy Consumption for Environmentally adapted Metalworking Fluid Systems, Environmental Science Technology, 10.1021/es800791z.
3. Dahmus, J.; and Gutowski, T. (2004) An environmental analysis of machining, Proceedings of IMECE2004, ASME International Mechanical Engineering Congress and RD&D Expo, November 13-19, Anaheim, California USA.
4. Erik Oberg. (2000) Machinery’s Handbook, 26th Edition, Industrial Press.
5. Fridriksson, L. Non-productive Time in Conventional Metal Cutting, Report No. 3, Design for Manufacturability Program, University of Massachusetts, Amherst, February 1979.
6. George, F.S; and Ahmad, K. E. (2000) Manufacturing Processes & Materials, 4th Edition, Society of Manufacturing Engineers.
7. Groover, M.P. (2003) Fundamentals of Modern Manufacturing, Prentice Hall.
8. Hoffman, E.; McCauley, C.; and Iqbal Hussain, M. (2001) Shop reference for students and apprentice, Industrial Press Inc.
9. http://www.engineeringtoolbox.com/metal-alloys-densities-d_50.html
10. http://www.mapal.us/calculators/Reaming/CalculatorReaming.htm
11. Joseph R. Davis. (1989) Machining Handbook, Vol. 16, American Society for Metals international.
12. Kalpakjian, S.; and Schmid, S. (2008) Manufacturing Processes for Engineering Materials, 5th Edition, Prentice Hall.
13. Piacitelli, W.; Sieber, et. al. (2000) Metalworking fluid exposures in small machine shops: an overview, AIHAJ, 62:356-370.
14. Schrader, G.; and Elshennawy, A. (2000) Manufacturing Processes & Materials, 4th Edition, Society of Manufacturing Engineers.
15. Terry, R.; and Erik, L. (2003) Industrial Plastics: Theory and Applications, 4th Edition, Cengage Learning.
16. Todd, R.; Allen, D.; and Alting, L. (1994) Manufacturing processes reference guide, Industrial Press, New York.
17. Wlaschitz, P. and W. Hoflinger. (2007) A new measuring method to detect the emissions of metal working fluid mist, Journal for Hazardous Materials, 144:736-741.

Appendices

Manufacturers Reference Data

 

The methodology that has been followed for collecting technical information on CNC machines has been largely based in the following:

The documentation of the CNC machine and the technical assistances collected from the manufacturing companies through internet. Several interviews with the service personnel of the different CNC manufacturing companies have been carried out. After collecting the information from the different companies it has been put together in the relevant document that describes the different approaches the different companies have regarding the technical information on the CNC machines. Telephone conversations allowed us to learn more about basic power and idle power. Companies that involved in our telephone conversations are Bridge port, Fadal, Hass and Jeenxi. These companies’ manufactures different sizes of CNC machines, but this report shows the lower, mid and highest level of sizes. For our case study we picked machine at the highest-level.

Specifications	JEENXI TECHNOLOGY
Model Number	JHV – 850	JHV – 1020	JHV – 1500
Spindle Speed	8000 rpm	8000 rpm	8000 rpm
Spindle Drive	Belt/Direct type	Belt/Direct	Belt/Direct type
Spindle Motor	5.5/7.5 kw	7.5/11 kw	7.5/ 11 kw
Rapid Traverse (X,Y)	30 m/min	30 m/min	30 m/min
Rapid Traverse (Z)	20 m/min	20 m/min	24 m/min
Cutting Feed rate	1 – 15000 mm/min	1 – 15000 mm/min	1 – 15000 mm/min
3 Axes motor output(X,Y,Z)	1.8/ 1.8/ 2.5	1.8/ 1.8/ 2.5	4.0/ 4.0/ 7.0
Power Consumption	20 KVA	20KVA	40 KVA
Specifications	HAAS
Model Number	VF- 7	VM - 2	MDC
Spindle Speed	7500 rpm	12,000 rpm	7,500 rpm
Spindle Drive	Belt/Direct type	Inline direct drive	Direct speed belt drive
Max Torque	75 ft-lb@1400	75 ft-lb@1400	75 ft-lb@1400
With Gearbox	250 ft-lb@ 450	-	-
Spindle motor max rating	20 hp	30 hp	20 hp
Axis Motor max thrust	3400 lb	3,400 lb	2,500 lb
Rapids on X-axis	600 ipm	710 ipm	1,000 ipm
Rapid on Y & Z Axes	600 ipm	710 ipm	1,000 ipm
Max Cutting	500ipm	500 ipm	833 ipm
Power Consumption(min)	200 – 250 VAC 380 – 480 VAC	200 – 250 VAC 380 – 480 VAC	200 – 250 VAC 380 – 480 VAC
Specifications	KAFO
Model Number	VMC – 850	VMC – 137	VMC - 21100
Spindle speed (Belt)	8000 rpm	8,000/10,000 rpm	6000/8000 rpm
Spindle speed (Gear)	4000/7000 rpm	4000/7000 rpm	4000/7000 rpm
Rapid Traverse (X, Y)	590.55 ipm	787.4 ipm	393.7 ipm
Rapid Traverse (Z)	472.44 ipm	787.40 ipm	393.7 ipm
Cutting feed rate	236.22 ipm	393.7 ipm	393.7 ipm
Spindle drive motor	7.5/ 10 hp	15/ 20 hp	15/20 hp
X,Y,Z axis drive motor	a12, a12, a12	a22, a22, a30	a30, a30, a30
Power consumption	20 KVA	25 KVA	35 KVA

 

Specifications	BRIDGE PORT
Model Number	XR 760	XR 1270 HP	XR 1500 HPD
Spindle Speed(Belted)	9000/15000 rpm	-	-
Fanuc Motor Power	25/25 hp	-	-
Heidenhain Motor Power	28/28 hp	-	-
Spindle Speed(Directly coupled)	15000 rpm	15000 rpm	375 – 7500 rpm (Gear Box)
Fanuc Motor Power	30 hp	40 hp	40 hp
Heidenhain Motor Power	33 hp	34 hp	40 hp
Rapid Traverse (X,Y)	1692 ipm	1417 ipm	1417 ipm
Rapid Traverse (Z)	1417 ipm	1417 ipm	1417 ipm
Cutting Feed rate	787 ipm	787 ipm	787 ipm
Power	30 KVA	40 KVA	40 KVA
Specifications	FADAL
Model Number	VMC 4020	VMC 6030	VMC 6535 HTX
Spindle Speed	10 - 10,000 rpm	10 - 10,000 rpm	6000 rpm
Spindle Drive	Automatic Mechanical Vector Drive	Automatic Mechanical Vector Drive	Automatic Electric Vector Drive
Rapid Traverse (X,Y)	900 ipm	400 ipm	900 ipm
Rapid Traverse (Z)	700 ipm	400 ipm	700 ipm
Cutting Feed rate	600 ipm	400 ipm	600 ipm
Motor Power	10 hp	14.7 hp	29.5 hp
Air Pressure Required	80 – 120 psi	80 – 120 psi	80 – 100 psi

Specifications	TTC
Model Number	TTC-630	TMC 500	XR 1500 HPD
Spindle Speed(Belted)	4000 rpm	6000	-
Spindle Motor Power	15/20 KW	5/7 KW	-
X Axis Motor Power	2.8 KW	-	-
Z Axis Motor Power	2.8 KW	15000 rpm	375 – 7500 rpm (Gear Box)
Coolant Pump Motor Power	1 KW	40 hp	40 hp
ATC Motor Power	12.6 KW	34 hp	40 hp
Rapid Traverse (X,Y)	197 mm/min	1417 ipm	1417 ipm
Rapid Traverse (Z)	630 mm/min	1417 ipm	1417 ipm
Total Driving Power	40 KW	787 ipm	787 ipm
Hydraulic Pump	1.1 KW	40 KVA	40 KVA