Machine Tool Genome Project

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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 Real ( X /F ) Im ag (X /F) f F_t F h₀ F_n Spindle speed Depth

The FRF for each

machine-spindle-holder-tool combination is required. Impact testing is the typical experimental choice.

Unstable

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What is the scope of the required testing?

• There are 3053 models of CNC machining centers from 229 builders1_.

• These machines are used to cut over 3750 different work piece materials2_.

• Milling tools from 110 manufacturers and milling tool holders from 72 manufacturers are available1_.

• Assuming an average of 500 stock keeping units (SKUs) from each cutting tool manufacturer and 100 SKUs from each tool holder company, there are over

4.5×1015_{potential holder-machine-material combinations, where each}

tool-holder-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.

4,500,000,000,000,000

dynamic “fingerprints”

1_{http://www.techspex.com, accessed June 2, 2010.}

2_{CUTDATA, TechSolve, Cincinnati, OH (http://www.cutdata.com/).}

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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 20,000 to 25,000 genes of the human genome • launched in 1990

• completed in 20033,4_.

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., 2001, Genomes: 15 Years Later A Perspective by Charles DeLisi, HGP Pioneer, Human Genome News 11:3-4.}

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Machine Tool Genome Project

1. Determine spindle-machine FRF using inverse RCSA and a standard holder5_.

5_{Schmitz, T., and Duncan, G.S., 2005, Three-Component Receptance Coupling Substructure Analysis for Tool Point Dynamics}

Prediction, Journal of Manufacturing Science and Engineering, 127/4: 781-790. +

F

X

2. Model tool and holder.

3. Couple tool-holder model to spindle response and predict tool point FRF.

+

Archive spindle-machine FRF.

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Machine Tool Genome Project

Measurements were performed on a Cincinnati FTV5-2500 CNC milling machine (HSK-63A holder-spindle connection). Using spindle receptances, tool point FRFs were calculated.

• Haimer A63.140 shrink fit chuck for 12.7 mm diameter endmills • Data Flute three-flute solid carbide endmills

• HVM-30500 - overall length of 76.2 mm, flute length of 22.2 mm, relieved neck diameter of 12.0 mm, length below shank of 34.9 mm

• overhang lengths of 38.1 mm and 50.8 mm

• HVM-M-30500 - overall length of 101.6 mm, flute length of 28.6 mm, relieved neck diameter of 12.0 mm, length below shank of 54.0 mm

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Machine Tool Genome Project

Carbide Hollow Steel 13 12.9 _38.1 3.2 12.7 22.2 mm OD 32 ID 10 32 32 30 30 24 12.7 12 φ8.8 12.7 12.7 13 25.6 _25.4 15.9 12.7 22.2 OD 32 ID 10 32 32 28 28 24 12.7 12 8.8 12.7 12.7 13 12.9 _38.1 9.5 25.4 28.6 OD 32 32 32 30 30 24 12.7 12 9.6 ID 10 12.7 12.7 HVM-30500 with 50.8 mm overhang Equivalent diameter for fluted section

HVM-30500 with 38.1 mm overhang

HVM-M-30500 with 63.5 mm overhang

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x: H₁₁

Tool point predicted and measured FRFs.

y: H₁₁ HVM-30500 with 38.1 mm overhang 0 1000 2000 3000 4000 5000 -5 0 5x 10 -7 Re a l ( m /N) Measured Finite diff. E-B 0 1000 2000 3000 4000 5000 -10 -5 0 x 10-7 Frequency (Hz) Im a g ( m /N ) 0 1000 2000 3000 4000 5000 -5 0 5x 10 -7 Re a l ( m /N) Measured Finite diff. E-B 0 1000 2000 3000 4000 5000 -10 -5 0 x 10-7 Frequency (Hz) Im a g ( m /N )

Tool mode Tool mode

Spindle modes

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Machine Tool Genome Project

0 1000 2000 3000 4000 5000 -5 0 5 x 10-7 Re a l ( m /N) Measured Finite diff. E-B 0 1000 2000 3000 4000 5000 -10 -5 0 5x 10 -7 Frequency (Hz) Im a g ( m /N ) 0 1000 2000 3000 4000 5000 -5 0 5 x 10-7 Re a l ( m /N) Measured Finite diff. E-B 0 1000 2000 3000 4000 5000 -10 -5 0 5x 10 -7 Frequency (Hz) Im a g ( m /N ) x: H₁₁

y: H₁₁

HVM-30500 with 50.8 mm overhang

Tool mode Spindle modes

Tool mode and 2200 Hz spindle mode interact

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Machine Tool Genome Project

1000 2000 3000 4000 -1 0 1 2 x 10-6 Re a l ( m /N) Measured Finite diff. E-B 1000 2000 3000 4000 5000 -3 -2 -1 0 x 10-6 Frequency (Hz) Im a g ( m /N ) 0 1000 2000 3000 4000 5000 -2 0 2 x 10-6 Re a l ( m /N) 0 1000 2000 3000 4000 5000 -3 -2 -1 0 x 10-6 Frequency (Hz) Im a g ( m /N ) Measured Finite diff. E-B x: H₁₁

y: H₁₁

HVM-M-30500 with 63.5 mm overhang

Tool mode and 2200 Hz spindle mode interact again

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Machine Tool Genome Project

Join the Machine Tool Genome Project now! Contact: Mr. David Barton BlueSwarf LLC [email protected] (888) 811-3260 Dr. Tony Schmitz

University of North Carolina at Charlotte

[email protected]

(704) 687-8421