Operating the Harmonizer MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. General Procedure Record background noise with machine operating at some high spindle speed. Determine a threshold. Record machining operation. Analyze for chatter. When chatter occurs, change speed and feed rate (constant chip load) per suggested values. Execute new machining operation and record results. Chatter? Yes, then repeat with new speed and feed values. No, then adjust feed rate with limits of machine, spindle, holder and cutting tool. Alternatively, can attempt to go deeper. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Basic Steps Hook-up microphone and make sure it is turned on. Enter: Maximum permissible speed (1); Commanded spindle speed (2); Number of cutting edges (3). Run machine at idle no cutting. Record Sample (4). Use “Fine Tune” (5) to determine spindle speed. Set threshold, estimate (6) or manually (7). Record cutting signal (4). Fine Tune (5) again to detect any speed changes. If chatter indicated (8), click on Analyze button (9). Repeat as necessary. 8 4 9 1 2 3 7 5 6 MetalMAX Training Manufacturing Laboratories, Inc.

Detection of Chatter (Analyze Button) Lists: Starting Speed; Suggested Spindle Speed (Harmonizer Spindle Speed); Detected Chatter Frequencies. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Ready for Next Cut Suggested “Harmonized” spindle speed and feed rate (constant chip load) are entered automatically for next cut. Repeat procedure by recording new cut to determine if chatter is eliminated. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Next Cut Results If cut is now stable, then done or can adjust feed up or down with no danger of chatter. Alternatively can try deeper cut. If cut is unstable can continue doing analysis, making suggested speed changes until stable or Harmonizer reports that no spindle speed is available. MetalMAX Training Manufacturing Laboratories, Inc.

Two Main Screens (F1 and F2) Plot Screen Main screen with time and frequency plots. Activated by Hot Key (F1) History Screen Provides detailed history of recorded cuts. Hot Key (F2) MetalMAX Training Manufacturing Laboratories, Inc.

Detailed Setup/Display (F3) 7 Setup/Display Options F1: Main screen with frequency and time displays. F2: History of spindle speed adjustments. F3: Project description settings. F4: Cutting parameters. F5: Chatter Detection parameters. F6: Preferences, data directories. F7: Recording Preferences. MetalMAX Training Manufacturing Laboratories, Inc.

SETUP: Cutting Parameters (F4) Defines Cut. Necessary parameters number of teeth and spindle speed accessible on front screen. Other parameters optional and mostly for documentation purposes. Material selection necessary for process damping. MetalMAX Training Manufacturing Laboratories, Inc.

SETUP: Chatter Detection (F5) Chatter Detection Refinements. Critical parameters shown on right side menu. Other parameters refine settings. Target speed ranges limit set by “lobe size”. Highest lobe determines number of potential available speed ranges. Chatter frequency range focuses detection frequencies. Spindle speed filter width for harmonic filter set in terms of speed range. Can eliminate specific unwanted frequencies with background filters. MetalMAX Training Manufacturing Laboratories, Inc.

SETUP: Chatter Detection (cont.) Machine Limits Only maximum speed is critical and can be set by spindle speed range as well as maximum surface velocity. MetalMAX Training Manufacturing Laboratories, Inc.

SETUP: Preferences (F6) File locations, units and language. MetalMAX Training Manufacturing Laboratories, Inc.

SETUP: Recording Preferences (F7). Set data collection source and sample times. Mostly use microphone but can use accelerometers. Default minimum sample is 2 seconds. Can record up to 600 seconds. Can do continuous recording but must set sampling window to none or rectangular in F5 chatter detection specs. Direct access to Windows Multimedia properties window to set recording levels. Our example again from start to finish. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Recording Background Setup parameters: maximum allowable speed; commanded Speed; number of cutting edges. Operate spindle at desired speed and record. Use fine tune to more precisely determine spindle speed and adjust filters. Can set threshold two ways. Manually adjust making sure that chatter indicator stays off. Use computer’s “Estimate” function to set threshold (sometimes very conservative) MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Record Cut If chatter present, user will see red chatter indicator. For long recording times, may need to adjust FFT window. Fine tune of spindle speed may be necessary on heavy cuts where speed may change. If chatter detected use Analyze button. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Analyze A spindle speed and feed will be suggested. New speed will be automatically updated on main screen for next sample. New feed recommendation based on chip load input on cutting parameters setup screen (F4). Detected chatter frequencies will also be shown and recorded on history screen (F2). MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Run and Record New Cut If new cut is not stable repeat Analyze step. Otherwise you are done (stable) and can adjust feed rate based on other limitations (tool limits, spindle bending moment, chip evacuation, etc.), or go deeper. Can now check for resonance. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Resonance Check Turn off Harmonic Filters. If “suspected “ resonance is present it will be indicated and the analyze function can suggest a minor speed change range. Markers indicate: once per revolution; tooth frequency; and harmonics. Note: Absolute detection of resonance not possible without measurement of dynamics, just an indication. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Resonance Analysis Suggests slight reduction in speed. Provides values for tooth passing and largest harmonic frequencies. Additionally supplies ratios to indicate size of suspected resonance and harmonic number of spindle rotation value. MetalMAX Training Manufacturing Laboratories, Inc.

Manufacturing Laboratories, Inc. Reselecting Speed Can use back button to reselect spindle speed. Can reset any preference or setting, usually maximum speed to permit reselection of alternative spindle speed. Can select any maximum speed, even below current spindle speed. MetalMAX Training Manufacturing Laboratories, Inc.