SOUTH BEND LATHE MODEL 9C ( 1937-1940 ) 127/100 METRIC TRANSLATI

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This Metric Translation gear is designed for cutting metric threads on an imperial leadscrew lathe. It was specifically created for a South Bend lathe model 9C. The provided photo showcases the 80/63 translation gear, as the 127/100 version may not fit the present setup, necessitating another banjo to accommodate it. The teeth feature a 14.5 degree pressure angle, while the gear boasts a DP of 18 and a module of 1.411. Its true involute form ensures precise performance. The 127 tooth has a designed inside diameter of 165mm but ends up about 164mm due to manufacturing tolerances. Similarly, the 100 tooth has a designed inside diameter of 127mm but ends up about 126mm. A 1mm step between the gears is incorporated in the 100 tooth ring to create a 3/8" wide gap, further enhanced by an additional 1mm. This width matches the standard South Bend gear dimensions. Space constraints are primarily responsible for determining which translation gear to use; these two options (127/100 and 80/63) are commonly employed. The 127/100 metric translation gear produces no errors in generated pitches. In contrast, the 80/63 gear results in an error of 0.0125%, while another option, 47/37, yields an error of -0.0212%. Print settings: Rafts: No Supports: No Resolution: A 0.3 resolution was used. Infill: 100% Notes: The center I created is made from hardwood due to availability; however, form board or marine ply would be a better choice. The timber was turned so that the ABS ring could easily slip over it before being covered with super glue. Ensuring the center ran true before the glue set prevented any potential issues.