0
TECHNICAL PAPERS

# Dynamic Analysis of a Mesoscale Machine Tool

[+] Author and Article Information
Sang Won Lee1

S. M. Wu Manufacturing Research Center, University of Michigan, Ann Arbor, MI 48109sangwonl@umich.edu

Rhett Mayor

Powerix Technologies, Ann Arbor, MI 48105

Jun Ni

S. M. Wu Manufacturing Research Center, University of Michigan, Ann Arbor, MI 48109

1

To whom correspondence should be addressed.

J. Manuf. Sci. Eng 128(1), 194-203 (Jun 21, 2005) (10 pages) doi:10.1115/1.2123007 History: Received November 11, 2004; Revised June 21, 2005

## Abstract

Miniaturized machine tools, referred to as mesoscale machine tools (mMTs) henceforth, have been proposed as a way to manufacture micro/mesoscale mechanical components. A thorough study of the dynamic behavior of the mMT is required for the successful development of its machine structure. This paper demonstrates the development of an mMT, the performance evaluation of its mesoscale milling process, and the characterization of its dynamic behavior. The mMT is developed by using an air turbine spindle and three piezoelectric linear stages, and its volumetric size is $150×70×140mm$. A series of micro/mesoscale milling experiments are conducted, and the performances in the developed mMT testbed are evaluated. The dynamic characteristics of the mMT can be different from those of conventional machine tools because the mMT is a miniaturized structure and comprises different machine components. Therefore, the effect of the miniaturization of a structure on the change of its dynamic behavior, called scaling law of the structural dynamics, is studied numerically and experimentally. The dynamic characteristics of the developed mMT that are estimated from the scaling law of the structural dynamics are much different from those obtained from an experimental modal analysis, and the flexible joints of the developed mMT are mainly responsible for this significant difference. Therefore, the joint dynamics of the mMT are studied by introducing an equivalent lumped parameter model, thus enabling simple identification of the joint dynamics and the effective modification of its critical joints to enhance a machining performance.

<>

## Figures

Figure 11

Mode shapes of the conventional vertical milling machine; experimental results

Figure 1

The mMT testbed

Figure 2

Microscopic photos of the milled slot; tool diameter ϕ=635μm

Figure 3

Schematic and SEM photo of micro endmill (ϕ=508μm)

Figure 4

Impulse excitation and acceleration measurement points of the mMT testbed

Figure 5

Inertance FRFs of the mMT testbed

Figure 6

SEM photos of milled slots

Figure 7

Surface roughnesses (Ra) of milled slots versus cutting frequencies

Figure 8

Photo of the conventional vertical milling machine and map for experimental modal analysis

Figure 9

FE mesh model of the conventional vertical milling machine structure

Figure 10

Measured receptance FRFs of the conventional vertical milling machine

Figure 12

Mode shapes of the conventional vertical milling machine; FE analysis results

Figure 13

Measured receptance FRFs of the mMT testbed

Figure 14

Photo of the coupled structure of the mMT testbed

Figure 15

5-DOF lumped parameter model of the coupled system

Figure 16

Measured and estimated receptance FRFs of the base-plate substructure

Figure 17

Measured and estimated receptance FRFs of the XY stage unit with free boundary condition

Figure 18

Measured and estimated receptance FRFs of the base plate–XY stage substructure

Figure 19

Measured and estimated receptance FRFs of the adapter with free boundary condition

Figure 20

Measured and estimated receptance FRFs (G41) of the entire coupled structure–Case 1: Four-screw bolting

Figure 21

Measured and estimated receptance FRFs (G41) of the entire coupled structure–Case 2: Two-screw bolting

## Discussions

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections