Gear Cutting News Today : Breaking News, Live Updates & Top Stories | Vimarsana

Asked a similar question some time ago but forgotten the answer.....doh! Could some kind soul take 5 minutes and enlighten me on how to calculate lathe gear changes required for selective pitches please? I can see on machine what gears I need but how exactly does this work out eg. my machine has 8tpi leadscrew, I have 20,30,40,50,55,60,63,70,75 + 80 gears. For a 26tpi thread I would need 70, 65, 30 + 60 gears but how does the maths work here exactly? My previous thread a gentlemen mentioned the 127/100 rule, what does that mean and what bearing does it have on change gears? Many thanks onc...

Having just replaced the headstock bearings and the hi - lo gears in there with metal ones, i guess this was bound to happen, The toothed drive gear that the motor drives exploded on me when i accidentily dug in whilst parting. Now i was thinking of changing that gear anyway for a slightly larger one, so i can get a little more torque at the low end. I'm thinking if i go for a metal one, the weak link will then be the belt or the motor drive gear, so would i be best going with a plastic gear here and having this is the 'fusable link'