Minimum Time Trajectory Planning Along Specified Tool Path With Consideration of Cutting Force Constraint and Feed Drive Dynamics

Manufacturing ◽  
2002 ◽  
Author(s):  
Nejah Tounsi ◽  
Trevor E. Bailey ◽  
Mohamed A. Elbestawi
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
Tool Path ◽  
End Milling ◽  
Low Frequency ◽  
Minimum Time ◽  
Force Model ◽  
Modeling And Analysis ◽  
Feed Drive ◽  
Drive Dynamics

This paper proposes an Optimized Feed Scheduling Strategy (OFSS). This strategy integrates the feed drive dynamics with the minimum-time trajectory planing to achieve the desired feed rate at the appropriate tool position along specified tool path. It optimizes the use of the feed drive capabilities and provides good tracking of the cutting geometry variations. The feed scheduling is applied to maintain near-constant cutting force magnitude. An integrated geometric and mechanistic force model is used to estimate the in-cut geometry and the cutting force. A methodology based on time series modeling and analysis is proposed to identify the low frequency feed drive dynamics. The resulting model is applied as an acceleration/deceleration processor (Acc/Dec) to relate the actual feed rate to the commanded feed rate specified in the G-Code file. The effectiveness of the OFSS is analyzed using ball end milling operations. Its performance in terms of productivity and machining safety is assessed based on comparison with other feed scheduling techniques where the trajectory planing does not consider the feed drive dynamics.

scholarly journals Off-Line Feed Rate Scheduling Based on a Mechanistic Cutting Force on Discrete Segments during End Milling

2013 ◽  
Vol 774-776 ◽  
pp. 1174-1180
Author(s):  
M. N. Islam ◽  
A. Pramanik ◽  
A. K. Basak
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
End Milling ◽  
Force Model ◽  
Cutting Force Model ◽  
Analysis Software ◽  
Machining Time ◽  
Milling Operation ◽  
Rate Scheduling ◽  
Number Of Segments

This paper describes the development of an off-line feed rate scheduling technique based on a mechanistic cutting force model. The proposed technique was developed for an end milling operation. The surface area of the workpiece was divided into a number of segments, and the resultant cutting force at each discrete segment was determined using One Path Analysis software. The calculated resultant cutting force was applied to the feed rate scheduling. Experimental results clearly showed that the implementation of feed rate scheduling reduces machining time considerably and that as the number of segments increases, the effectiveness of the feed rate scheduling increases.

Micro Flat End Milling Simulation Model With Instantaneous Plowing Area Prediction

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Abdolreza Bayesteh ◽  
Junghyuk Ko ◽  
Martin Byung-Guk Jun
Keyword(s):  
Feed Rate ◽  
Tool Path ◽  
End Milling ◽  
Chip Thickness ◽  
Depth Of Cut ◽  
Uncut Chip Thickness ◽  
Chip Area ◽  
Edge Radius ◽  
Wide Range ◽  
Radial Depth

There is an increasing demand for product miniaturization and parts with features as low as few microns. Micromilling is one of the promising methods to fabricate miniature parts in a wide range of sectors including biomedical, electronic, and aerospace. Due to the large edge radius relative to uncut chip thickness, plowing is a dominant cutting mechanism in micromilling for low feed rates and has adverse effects on the surface quality, and thus, for a given tool path, it is important to be able to predict the amount of plowing. This paper presents a new method to calculate plowing volume for a given tool path in micromilling. For an incremental feed rate movement of a micro end mill along a given tool path, the uncut chip thickness at a given feed rate is determined, and based on the minimum chip thickness value compared to the uncut chip thickness, the areas of plowing and shearing are calculated. The workpiece is represented by a dual-Dexel model, and the simulation properties are initialized with real cutting parameters. During real-time simulation, the plowed volume is calculated using the algorithm developed. The simulated chip area results are qualitatively compared with measured resultant forces for verification of the model and using the model, effects of cutting conditions such as feed rate, edge radius, and radial depth of cut on the amount of shearing and plowing are investigated.

Statistical Cutting Force Model for Orthogonal Cutting of Polytetrafluoroethylene (PTFE) Composites

2013 ◽  
Author(s):  
Felicia Stan ◽  
Daniel Vlad ◽  
Catalin Fetecau
Keyword(s):  
Friction Coefficient ◽  
Cutting Force ◽  
Feed Rate ◽  
Normal Force ◽  
Polynomial Regression ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Tool Geometry ◽  
Force Model

This paper presents an experimental investigation of the cutting forces response during the orthogonal cutting of polytetrafluoroethylene (PTFE) and PTFE-based composites using the Taguchi method. Cutting experiments were conducted using the L27 orthogonal array and the effects of the cutting parameters (feed rate, cutting speed and rake angle) on the cutting force were analyzed using the S/N ratio response and the analysis of variance (ANOVA). Statistical models that correlate the cutting force with process variables were developed using ANOVA and polynomial regression. The variation of the apparent friction coefficient was analyzed with respect to tool geometry and the cutting process. The results indicated that cutting and thrust forces increase with increasing feed rate, and decrease with increasing rake angles from negative to positive values and increasing cutting speed. A power law relationship between the apparent friction coefficient and the normal force exerted by the chip on the tool-rake face was identified, the former decreasing with an increasing normal force.

Characterizing the Effect of Cutting Condition, Tool Path, and Heat Treatment on Cutting Forces of Selective Laser Melting Spherical Component in Five-Axis Milling

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Amir Mahyar Khorasani ◽  
Ian Gibson ◽  
Moshe Goldberg ◽  
Guy Littlefair
Keyword(s):  
Heat Treatment ◽  
Production Process ◽  
Cutting Force ◽  
Feed Rate ◽  
Cutting Forces ◽  
Tool Path ◽  
Annealing Temperature ◽  
Spindle Speed ◽  
Cutting Condition ◽  
Scallop Height

Additive manufacturing (AM), partly due to its compatibility with computer-aided design (CAD) and fabrication of intricate shapes, is an emerging production process. Postprocessing, such as machining, is particularly necessary for metal AM due to the lack of surface quality for as-built parts being a problem when using as a production process. In this paper, a predictive model for cutting forces has been developed by using artificial neural networks (ANNs). The effect of tool path and cutting condition, including cutting speed, feed rate, machining allowance, and scallop height, on the generated force during machining of spherical components such as prosthetic acetabular shell was investigated. Also, different annealing processes like stress relieving, mill annealing and β annealing have been carried out on the samples to better understand the effect of brittleness, strength, and hardness on machining. The results of this study showed that ANN can accurately apply to model cutting force when using ball nose cutters. Scallop height has the highest impact on cutting forces followed by spindle speed, finishing allowance, heat treatment/annealing temperature, tool path, and feed rate. The results illustrate that using linear tool path and increasing annealing temperature can result in lower cutting force. Higher cutting force was observed with greater scallop height and feed rate while for higher finishing allowance, cutting forces decreased. For spindle speed, the trend of cutting force was increasing up to a critical point and then decreasing due to thermal softening.

Analytical Convolution Model of Cutting Forces in 3-D Ball End Milling

2001 ◽  
Author(s):  
Richard Y. Chiou ◽  
Bing Zhao
Keyword(s):  
Cutting Force ◽  
Frequency Domain ◽  
Cutting Forces ◽  
End Milling ◽  
Force Model ◽  
Three Dimensional Model ◽  
Calculation Algorithm ◽  
Ball End Milling ◽  
Convolution Model ◽  
Force Calculation

Abstract This paper presents an analytical convolution model of dynamic cutting forces in ball end milling of 3-D plane surfaces. The model takes into account the instantaneous slope on a sculptured surface to establish the chip geometry in cutting force calculation algorithm. A three-dimensional model of cutting forces in ball end milling is presented in terms of material properties, cutting parameters, machining configuration, and tool/work geometry. Based on the relationship of the local cutting force, chip load and engaged boundary, the total cutting force model is established via the angle domain convolution integration of the local forces in the feed, cross feed, axial direction, and inclination angle. The convolution integral leads to a periodic function of cutting forces in the angle domain and an explicit expression of the dynamic cutting force components in the frequency domain. Following the theoretical analysis, experimental study is discussed to illustrate the implementation procedure for force identification, and frequency domain data are presented to verify the analytical results.

Analysis of Cutting Force in Elastomer End-Milling

2017 ◽  
Vol 11 (6) ◽  
pp. 958-963
Author(s):  
Koji Teramoto ◽  
◽  
Takahiro Kunishima ◽  
Hiroki Matsumoto
Keyword(s):  
Parameter Identification ◽  
Cutting Force ◽  
Cutting Forces ◽  
End Milling ◽  
Process Models ◽  
Force Model ◽  
Cutting Force Model ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
The Stability

Elastomer end-milling is attracting attention for its role in the small-lot production of elastomeric parts. In order to apply end-milling to the production of elastomeric parts, it is important that the workpiece be held stably to avoid deformation. To evaluate the stability of workholding, it is necessary to predict cutting forces in elastomer end-milling. Cutting force prediction for metal workpiece end-milling has been investigated for many years, and many process models for end-milling have been proposed. However, the applicability of these models to elastomer end-milling has not been discussed. In this paper, the characteristics of the cutting force in elastomer end-milling are evaluated experimentally. A standard cutting force model and its parameter identification method are introduced. By using this cutting force model, measured cutting forces are compared against the calculated results. The comparison makes it clear that the standard cutting force model for metal end-milling can be applied to down milling for a rough evaluation.

Voxel Based Cutting Force Simulation of Ball End Milling Considering Cutting Edge Around Center Web

2018 ◽  
Author(s):  
Isamu Nishida ◽  
Takaya Nakamura ◽  
Ryuta Sato ◽  
Keiichi Shirase
Keyword(s):  
Cutting Force ◽  
End Milling ◽  
Chip Thickness ◽  
Previous Method ◽  
Cutting Edge ◽  
Force Model ◽  
End Mill ◽  
Uncut Chip Thickness ◽  
Ball End Mill ◽  
Tool Rotation

A new method, which accurately predicts cutting force in ball end milling considering cutting edge around center web, has been proposed. The new method accurately calculates the uncut chip thickness, which is required to estimate the cutting force by the instantaneous rigid force model. In the instantaneous rigid force model, the uncut chip thickness is generally calculated on the cutting edge in each minute disk element piled up along the tool axis. However, the orientation of tool cutting edge of ball end mill is different from that of square end mill. Therefore, for the ball end mill, the uncut chip thickness cannot be calculated accurately in the minute disk element, especially around the center web. Then, this study proposes a method to calculate the uncut chip thickness along the vector connecting the center of the ball and the cutting edge. The proposed method can reduce the estimation error of the uncut chip thickness especially around the center web compared with the previous method. Our study also realizes to calculate the uncut chip thickness discretely by using voxel model and detecting the removal voxels in each minute tool rotation angle, in which the relative relationship between a cutting edge and a workpiece, which changes dynamically during tool rotation. A cutting experiment with the ball end mill was conducted in order to validate the proposed method. The results showed that the error between the measured and predicted cutting forces can be reduced by the proposed method compared with the previous method.

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