For what it's worth, jmo.
When I converted my 12 x 37 belt drive lathe to gear head I used stock gears (I think "MartinSprocket" were the cheapest). I cut my own gears from Delrin plastic so that each gear mating would be from metal to plastic or plastic to metal. The reasoning was economy and lubricity. Converting the headstock to a leakproof sump would have been impossible.
This was done almost 20 years ago and I have not had a failure yet.
About 8 years ago I replaced the 1½ hp original motor with a 3 hp motor (from "inventory") and haven't "stressed" the gears further.
The primary drive is via single "B" section belt so there's a "torque limiting" factor there.
There has been some lubricant applied so it's hard to tell the plastic ones from the steel.
When I converted my 12 x 37 belt drive lathe to gear head I used stock gears (I think "MartinSprocket" were the cheapest). I cut my own gears from Delrin plastic so that each gear mating would be from metal to plastic or plastic to metal. The reasoning was economy and lubricity. Converting the headstock to a leakproof sump would have been impossible.This was done almost 20 years ago and I have not had a failure yet.
About 8 years ago I replaced the 1½ hp original motor with a 3 hp motor (from "inventory") and haven't "stressed" the gears further.
The primary drive is via single "B" section belt so there's a "torque limiting" factor there.
There has been some lubricant applied so it's hard to tell the plastic ones from the steel.
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.