He had the old gear in his hand but the teeth were very badly worn. He also had a smaller gear that he said matched the gear on the machine perfectly but it was to small and the number of teeth were wrong
The small gear was 12 dp, I don't remember how many teeth.
The gear he wanted meshes with a very large internal tooth ring gear (30")
The gear he wanted and I measured was 1.75" 18 tooth and I assume 12dp because the smaller gear was 12dp
But the math doesn't work a 18 tooth 12dp gear should be 1.667"
What am I doing wrong?
Did they use to make gears different?