Machine Tool Genome Project

Transcription

1 Milling models enable pre-process parameter selection and optimization, but the results are specific to the tool-holder-spindle-machine combination. For example, stability lobe diagrams offer selection of chatter-free process parameters. The necessary information includes the tool point FRF and the cutting force model. F F t Machine Tool Genome Project Real (X/F) F n f h Imag (X/F) f Depth Unstable Spindle speed The FRF for each machinespindle-holder-tool combination is required. Impact testing is the typical experimental choice.

2 Machine Tool Genome Project What is the scope of the required testing? There are 353 models of CNC machining centers from 229 builders 1. These machines are used to cut over 375 different work piece materials 2. Milling tools from 11 manufacturers and milling tool holders from 72 manufacturers are available 1. Assuming an average of 5 stock keeping units (SKUs) from each cutting tool manufacturer and 1 SKUs from each tool holder company, there are over potential tool-holder-machine-material combinations, where each toolholder-machine assembly has its own unique tool point FRF. This scenario calls for an approach that can predict the tool point FRF for arbitrary tool-holder-spindle-machine combinations using minimum input information. 4,5,,,, dynamic fingerprints 1 accessed June 2, CUTDATA, TechSolve, Cincinnati, OH (

3 This problem is analogous to the Human Genome Project: international scientific research effort determine the sequence of chemical base pairs which make up DNA identifying and mapping the 2, to 25, genes of the human genome launched in 199 completed in 23 3,4. Machine Tool Genome Project In the Machine Tool Genome Project: the genes are the tool, holder, and spindle-machine the mapping is performed using Receptance Coupling Substructure Analysis (RCSA) to predict the tool point frequency response, i.e., the body characteristics. the spindle-machine genes are measured once and archived the desired tool and holder genes are modeled (Timoshenko beams). Based on the predicted tool point FRF, preferred operating parameters are selected which respect the limitations imposed by the process dynamics. 3 Barnhart, B.J., 1989, DOE Human Genome Program, Human Genome Quarterly, 1:1. 4 DeLisi, C., 21, Genomes: 15 Years Later A Perspective by Charles DeLisi, HGP Pioneer, Human Genome News 11:3-4.

4 Machine Tool Genome Project 1. Determine spindle-machine FRF using inverse RCSA and a standard holder 5. F X 2. Model tool and holder. + Archive spindlemachine FRF = 3. Couple tool-holder model to spindle response and predict tool point FRF. + 5 Schmitz, T., and Duncan, G.S., 25, Three-Component Receptance Coupling Substructure Analysis for Tool Point Dynamics Prediction, Journal of Manufacturing Science and Engineering, 127/4:

5 Machine Tool Genome Project Measurements were performed on a Cincinnati FTV5-25 CNC milling machine (HSK-63A holder-spindle connection). Using spindle receptances, tool point FRFs were calculated. Haimer A63.14 shrink fit chuck for 12.7 mm diameter endmills Data Flute three-flute solid carbide endmills HVM-35 - overall length of 76.2 mm, flute length of 22.2 mm, relieved neck diameter of 12. mm, length below shank of 34.9 mm overhang lengths of 38.1 mm and 5.8 mm HVM-M-35 - overall length of 11.6 mm, flute length of 28.6 mm, relieved neck diameter of 12. mm, length below shank of 54. mm overhang length of 63.5 mm.

6 Machine Tool Genome Project Carbide Hollow Steel OD ID mm φ8.8 Equivalent diameter for fluted section HVM-35 with 38.1 mm overhang OD ID HVM-35 with 5.8 mm overhang OD ID HVM-M-35 with 63.5 mm overhang

7 Tool point predicted and measured FRFs. Machine Tool Genome Project HVM-35 with 38.1 mm overhang 5 x 1-7 x: H 11 Finite diff x x 1-7 y: H x 1-7 Finite diff. Spindle modes

8 Tool point predicted and measured FRFs. Machine Tool Genome Project HVM-35 with 5.8 mm overhang x 1-7 x: H 11 x 1-7 y: H Finite 5 diff Finite 5 diff. 5 x x Spindle modes and 22 Hz spindle mode interact

9 Tool point predicted and measured FRFs. Machine Tool Genome Project HVM-M-35 with 63.5 mm overhang x x x: H Finite diff x x 1-6 y: H 11 Finite diff and 22 Hz spindle mode interact again

10 Machine Tool Genome Project Join the Machine Tool Genome Project now! Contact: Mr. David Barton BlueSwarf LLC (888) Dr. Tony Schmitz University of North Carolina at Charlotte (74) Join the MTGP LinkedIn group.