CHAPTER 9: TROUBLESHOOTING 9-25
ALPHA ST320 S2
3.5. Clamping method
3.5.1. Collets
There are different kinds of collets that are more or less effective:
A) Simple cone collet
The bar is held over about 350 degrees, over a length
from 0.5 to 7 times the diameter.
Efficiency: good to very good
B) Bi-conical collet
Clamping over 1 or 2 x 360 degrees, over an
approximate length of 1.2 times the diameter.
Efficiency: very good to excellent
C) Double cone collet
The double cone clamp has the great advantage of
holding the bar at two points separated by about 1.5
the diameter, with a clamping 2 times 350 degrees
over about 0.5 times the diameter.
Efficiency: excellent
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