Machinery's Handbook, 31st Edition
MICROFABRICATION PROCESSES AND PARAMETERS 1187 • Tool vibration. Avoid unnecessary disengaging then engaging of microtool and workpiece in a milling program when programing the tool path. Vibration and bending of a microtool when starting and ending a cut could fatigue and shorten the tool life of the microtool (Fig. 32). Positioning of a Micromist Nozzle in Micromilling
Micromill flute diameter
Axial depth Micromill
Radial depth Micromill
60–70°
Micromist nozzle
Micromist nozzle
Workpiece
The nozzle should move with the microtool during machining
Workpiece
Fig. 31a. Top View.
Fig. 31b. Side View.
20
10
0
–10
Start
End
–20
0
1
2
3
4
5
Machining Time (s)
Fig. 32. Vibration of a Micromill When Engaging and Disengaging a Workpiece. Carbide mill Ø1 mm (Ø0.040 inch), 316L stainless steel, 25000 rpm, 10 m m/tooth feed, 0.348 mm axial depth, 0.558 mm radial depth.
Mill diameter
Shank diameter
Flute length
Overall length
Fig. 33. Micromill Nomenclature.
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