[Lathe] Need to Replace Nylon Reversing Gear(?) in Vevor 7 x 12 Lathe

[Growley Monster]

If you have access to a 3D printer you could print a gear which would work OK, at least until you got a 'nylon' gear.
The gear plugin for OnShape is really easy to use (even I could produce a usable file); probably other CAD software has something similar.

I got a 3D printer and one of these days I will get it working again. Meanwhile, when the dryer isn't working it is a great place to dry a few tshirts if it is raining outside. My CAD software is FreeCAD, over Debian. There is probably a gear plugin for that, yeah.

 

[Growley Monster]

Sometimes called a "tumbler reverse gear"

Nice. Now I have a name for it! Thanks a whole lot!

 

[Growley Monster]

They also have a metal “upgrade” p/n 3455. They usually have someone in the technical side available, but make sure you have all of the nameplate info ready. It looks like all of the 7x lathes use the same two gears in the reversing group: a 20T & 25T. I would replace both, and get a set of spares. With the exception of the change gears, I believe all of the other gears are metal.

I suggest you also get the three plastic gear-sets/gears in the High/Low train unless your lathe does not have these (eventually one of these will fail).

Before you reassemble the lathe, check the fully engaged locations for the forward/reverse lever and either deepen the existing detents or drill new ones. The factory detents aren’t very deep and can allow the lever to shift unintentionally causing the damage you have.

Thanks. I was thinking about metal gears there, but wasn't sure if I wanted that gear to be the weak link or not. Definitely I will want a spare set, yeah. If one set can break, the replacement can break, too.

And now I can blame the lathe for chewing up its own gear. Wasn't me! I feel better now.

 

[Growley Monster]

If you can buy the gear, get it, especially since it won't be all that expensive. That kind of gear is quite printable, bet I could whip up an stl file in under 5 minutes. M1 gear, 20T, 10mm bore, 7mm thick. Well I lied, it took me 4 minutes. If you can't buy one, see if you can print this.

Nice! Thanks for the file. And I bet someone else will need it sooner or later on this board. My only 3D printer is kaput right now. Too many things going on, haven't had time to mess with it. I will check LMS now that I know what it is called.

 

[WobblyHand]

I got a 3D printer and one of these days I will get it working again. Meanwhile, when the dryer isn't working it is a great place to dry a few tshirts if it is raining outside. My CAD software is FreeCAD, over Debian. There is probably a gear plugin for that, yeah.

I designed the gear using FreeCAD and the gear plug in. Took me very little time to design it. If you have FreeCAD and have questions, post in the CAD forum. We have a FreeCAD sub forum there.

 

[WobblyHand]

Nice! Thanks for the file. And I bet someone else will need it sooner or later on this board. My only 3D printer is kaput right now. Too many things going on, haven't had time to mess with it. I will check LMS now that I know what it is called.

The 3d printers can be a time sink. If you are time strapped, just buy the gear.

 

[Growley Monster]

The 3d printers can be a time sink. If you are time strapped, just buy the gear.

Yeah that was my plan and I ordered one last night.

 

[ttabbal]

Yeah that was my plan and I ordered one last night.

If you end up wanting printed parts, post on the forum. There are a bunch of us with printers that don't mind running a small part here and there for people. Glad you found something. That will probably be a bit tougher than most prints would be, even in similar material. However, I have been surprised a couple of times how well printed replacement parts will hold up.