B-63324EN/03 APPENDIX D.NOMOGRAPHS
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The lead at the beginning of thread cutting is shorter than the specified
lead L, and the allowable lead error is DL. Then as follows.
When the value of HaI is determined, the time lapse until the thread
accuracy is attained. The time HtI is substituted in (2) to determine δ
Constants V and T
are determined in the same way as for δ
. Since the
calculation of d1 is rather complex, a nomography is provided on the
- How to use nomograph
First specify the class and the lead of a thread. The thread accuracy, a,
will be obtained at (1), and depending on the time constant of cutting
feed acceleration/ deceleration, the d1 value when V = 10mm / s will be
obtained at (2). Then, depending on the speed of thread cutting, d1 for
speed other than 10mm/ s can be obtained at (3).
The equations for δ
, and δ
are for when the
acceleration/ deceleration time constant for cutting
feed is 0.
See the graph in reference later in the
manual for an actual example.
Time constant of
Fig. D.1(b) Nomograph