SOUTH BEND LATHE MODEL 9C ( 1937-1940 ) 127/100 METRIC TRANSLATION RING GEAR

This is a Metric Translation gear for cutting metric threads on an imperial leadscrew lathe this was designed for a South Bend lathe model 9C.

photo is of 80/63 translation gear as I don't think this 127/100 would fit my present set up need to make another banjo to make it fit.

The teeth have 14.5 degree pressure angle

The gear has a DP of 18

The module is 1.411

True involute form

The 127 tooth has an designed inside dia of 165mm but ends up about 164mm

The 100 tooth has a designed inside dia of 127mm but ends up about 126mm

The 100 tooth ring has 1mm step so it give a gap between the gears so it is 3/8" wide + 1mm

The 127 tooth ring is 3/8" wide which is the width of the standard South Bend gears

It's mainly a space problem that dictates which of the translation gears you use, there may be others but these are the common ones that I know of.

The 127/100 metric translation gear which gives no errors in the generated pitches.

The 80/63 gives an error of 0.0125%

The another gear set 47/37 gives an error of -0.0212%

Print Settings

Rafts:

No

Supports:

Resolution:

I used a 0.3

Infill:

Notes:

The centre I made is of hardwood as that is what I had laying around, but form board or marine ply would probably be a better option.

I turned the timber so that the ABS ring just slipped over then cover with super glue and made sure it ran true before the glue set