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1⁄2 Fractional TPI: Use any opposing number
TPI | Dial Number | Thread Dial | |
1½,2½,3½,4½, | Position |
| 3 |
5½,6½,9½,10½, | 1,3 or 2,4 | 2 | 4 |
11½,13½ |
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| 1 |
Figure 95. Example of opposing number groups
for cutting 1⁄2 thread TPI.
Important: Once a number has been selected, continue using that number or its odd/even counterpart.
For example:
•If you use 1 during the first threading pass, then you must select 1 or 3 for all following passes.
•If you use 2 during the first threading pass, then you must select 2 or 4 for all following passes.
1⁄4 or 3⁄4 Fractional TPI: Use position 1 on the thread dial (see example in Figure 96).
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1¼,1¾,2¼,2¾, | Position |
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| 3 | |
3¼,4¾,5¼,5¾, | 1 Only |
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6¾ |
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| 1 | |
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Figure 96. Example of 1⁄4 or 3⁄4 fractional TPI.
Pitch Turning
The following subsection describes how to set up the lathe for diametral or modular pitch turning. If you are unfamiliar with the process of turning pitches on a lathe, we strongly recommend that you read books, review industry trade magazines, or get formal training before attempting specific projects.
Headstock Pitch Turning Controls
The pitch turning charts on the headstock face display the settings for diametral and modular pitch turning, as shown in Figure 97.
Modular
Pitches
Diametral
Pitches
Figure 97. Location of modular and diametral
pitch charts.
Using the controls on the lathe, follow the exam- ple below to understand how to set up the lathe for the desired pitch turning operation.
To set levers and dials for 1.25 MP:
1.Configure the gears as instructed in Alternate Configuration on Page 55.
Model G0746/G0749 (Mfg. Since 3/13) |