Vevor 8x14 tailstock headache

[Inferno]

I'm just going to say this again.
RETURN IT.
Mini lathes are hard enough and they sent you a bad one. There's no reason why you shouldn't return it. No reason why you should keep it.
It's JUNK as it is. Wouldn't even make a good boat anchor.

 

[WobblyHand]

Here's a picture of my tail stock (LMS7350). 7x16.

Only contact is on the prism on the left and the flat on the right. Maybe it is slightly tilted, hard to say. The flat on the right is in contact for about 1/4" (6mm). Sorry about the dirt on the end of the lathe. Even this unit isn't all that well machined, but it works for the most part.

To the right is my tail stock adjuster, with a differential screw.

 

[NervesofSteel]

Here's a pic I found online that shows what I'm talking about: note that the tailstock rests on the (backside) vee, and on the front way, but it there are no other bearing surfaces. This makes sense if I "do the math": more bearing surfaces would make it much harder to keep it all in alignment, while providing essentially no value.
The problem with mine is not the vee-plus-single-way-bearing: I think that's normal (PLEASE send me pics if you've got something else, I'm just not seeing it). The problem is that the way bearing surface was never milled, so it sat on a single edge, which would likely wear a groove in the way eventually (unless the way is hardened and all the wear occurs on the tailstock: I have heard that these mini-lathes typically do come with induction-hardened ways, though I don't know how well that's done: I'll try to test mine against some known materials soon).

 

[WobblyHand]

The problem is that the way bearing surface was never milled, so it sat on a single edge, which would likely wear a groove in the way eventually (unless the way is hardened and all the wear occurs on the tailstock:

This is my concern as well. There's no reason to have high contact force there - it will wear the way. My G0752Z has a similar arrangement as your figure above. Pyramid on the right and flat contact on the left (front) way.

If you can, return this unit or get an incredible discount. (Like almost free.) If you don't get satisfaction, get your CC company involved - say it is defective equipment.

 

[NervesofSteel]

This is a fascinating journey already.
If I look closely at the Grizzly G0602, a $2000 10x22 lathe, the tailstock is supported on a vee and an opposite bed way, although the vee is in the back and the way is in the front.
Very interestingly, the carriage sits on a separate front vee and the back bed way. So they each have the one-vee plus one flat bearing surface configuration, but flipped around. The center support on this lathe is configured like the tailstock, so you can see both versions in this photo:

I can imagine flipping them like that would somewhat decouple the carriage and tailstock (and the carriage and center support) with respect to vibration: I would expect a vibrational modality longitudinally along the (different) bed ways in each case (pivoting on the vee, sort of), and by setting them up on different sides they would swing in opposite arcs, somewhat cancelling out each other's vibration. I'm not describing that terribly well, hopefully it makes sense to people (if anyone cares about this kind of analysis). My cheaper lathe doesn't come with two vee's (nor do any of the really cheap mini-lathes that I see: sub-$1000).
All this careful consideration is making me look at lathes in an entirely different way, and I've barely turned it on yet! I'm not sure it's worth the $700 yet, but it might get there! Education is expensive!
Meanwhile, I've reached out to Vevor to explore options.
Keith

 

[NervesofSteel]

So when I look at a big expensive Colchester lathe, it has the same double-vee carriage on one set and steady rest on the other:

You can see how it skips over the back vee to rest on the back way (the front is on the left). Okay, so I see this is how Bridgeports are configured too. I'll stop gushing about my kindergarten-level machining insights. Well, for now. This all may cause me to approach my tailstock repair differently...
keith

 

[WobblyHand]

Did your lathe come with dead centers? One for the head stock spindle taper and one for the tail stock? If you put in the dead centers, and slide the tail stock to the head stock, do the points of the dead centers align? Can you adjust them to get closer? What is the closest distance between the points?

Not recommending you keep it, but should things not work out, just seeing how far off things are.

 

[Headhunter Pipe Co]

Makes me never want to buy anything made by Vevor

 

[Inferno]

Makes me never want to buy anything made by Vevor

Their stuff has worked for me so far.

 

[Headhunter Pipe Co]

Their stuff has worked for me so far.

Maybe you got lucky ?

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