I bought a Grizzly G4000 in 2006. At the time, I had a ball modifying it in many ways. For instance, I replaced AC motor with a DC motor and variable speed control. I installed a tumbler reverse, added a QCTP and several other mods. I think it's a pretty decent little lathe.... except for one big problem. In the apron, there's a worm gear that slides along the lead screw and provides for the carriage power feed. This worm gear EATS it's neighboring 41 tooth gear for breakfast. They rarely last even one job before the teeth are ground to powder. And it doesn't matter if I take a very light cut or even no cut. At least one of the problems was that the apron casting held the worm gear so sloppily that the 41T gear was hardly mated to the worm gear. Also, the worm gear appears to be a much harder material than the 41T gear. Maybe it's even powered metal, at least if grinds up like powder.
While I should have complained to Grizzly back then, I didn't. Instead, being the a DIY kinda guy, I tried boring the apron out and installing bronze inserts. That certainly took the slop out of the worm gear. Still the 41T gear turns to sludge. One hope I have, 15 years later, is that Grizzly found this to be a recurring issue with the G4000 and have remedied it with a better version of the apron. And indeed, if I look up the parts, I see that the description for the apron says Grizzly P4000701 - APRON CASTING V2.01.06 (notice the V2.01.06). I have no idea what version of apron casting my 2006 G4000 had. I wrote to Grizzly to see if maybe their support folks know the history of the castings and can confirm that my problem can be remedied by the purchase of this version. Even if this is so, I still worry that the 41T gears from Grizzly are made of butter.
My other option is to hob my own 41T gear from decent material and with a concave & helical profile that will have a chance to mate better with the worm gear. I wish the ghosts of my grandfather and father, both toolmakers, could help me out here.
A third, and exciting option would be to buy a new/better lathe. But I don't think I could sneak a new lathe past SWMBO. If anyone has ideas or advice I'd sure appreciate hearing from you.
While I should have complained to Grizzly back then, I didn't. Instead, being the a DIY kinda guy, I tried boring the apron out and installing bronze inserts. That certainly took the slop out of the worm gear. Still the 41T gear turns to sludge. One hope I have, 15 years later, is that Grizzly found this to be a recurring issue with the G4000 and have remedied it with a better version of the apron. And indeed, if I look up the parts, I see that the description for the apron says Grizzly P4000701 - APRON CASTING V2.01.06 (notice the V2.01.06). I have no idea what version of apron casting my 2006 G4000 had. I wrote to Grizzly to see if maybe their support folks know the history of the castings and can confirm that my problem can be remedied by the purchase of this version. Even if this is so, I still worry that the 41T gears from Grizzly are made of butter.
My other option is to hob my own 41T gear from decent material and with a concave & helical profile that will have a chance to mate better with the worm gear. I wish the ghosts of my grandfather and father, both toolmakers, could help me out here.
A third, and exciting option would be to buy a new/better lathe. But I don't think I could sneak a new lathe past SWMBO. If anyone has ideas or advice I'd sure appreciate hearing from you.