Imperial Thread on a Metric Sheraton Challenger

[TroyB]

Hi all, I have a metric Sheraton Challenger and wondering if anyone can help me with converting it to be able to cut 14, 16TPI and 24TPI. The lathe is apparently a copy of the Leblond Regal. I have Photos of the gear tooth counts. Wondering if it would be just a matter of sourcing or making some other gears?

 

[technocrat]

127 tooth gear in the gear train gives you a direct conversion. A 63 tooth gear will come close, so it depends on the accuracy required. There are tables and calculators on the web to work out the gearing.

 

[TroyB]

Cheers mate so I take it that I need to replace the 120 with a 127 with and retain a 75 on the back of it? thanks for the help, appreciate it

 

[technocrat]

yes, but it depends on the other gears as well. Where there is enough space a typical metric/imperial will use a 120/127 that you flip, but quick change gearbox charts and indicator may not be as shown. Likely you will have to leave the half nuts engaged to stay in thread sync.