Lathe Leveling

[MattM]

It is a 12" Starrett level that I dialed in before use. I watched that video about a fortnight ago.

 

[Tolerent]

I'm a Navy veteran with 12 years in a shipyard engineering department. Lathes do not need to be precision leveled. They do prefer to be level but it is not important. What lathes do need is for the ways to be aligned in relation to each other and for the bed to not be twisted. A bubble level is going to be a lot less helpful than a straight edge.

If it were me I would be inclined to level it first, then align the ways by removing stress imbalances, then verify the headstock and tailstock are aligned, in that order.

 

[Dabbler]

'leveling' is just the easiest (and fastest) way to get to 'rough aligned'. Final alignment is always done using the 2 collar test...

 

[eeler1]

What Tolerent and Dabbler and the rest of them said.

As I understand it, before the lathe leaves the factory, it is tested for alignment. But the manufacturer first levels the lathe using the same procedure that is outlined in the lathe owner manual. Then if it passes the tests, they send it out for sale. You may even get a test card that shows you the tests and that the lathe passed.

So, theoretically, if you achieve level as outlined in the manual, then you have put the lathe back to the same position as when it was tested and passed at the factory. It should be properly aligned, and it gives you the best starting point when you set it up in your shop. But, recognize that things may change during shipping and handling and jostling to get it into position. So after leveling, we take additional test cuts and make adjustments to get it properly aligned and cutting straight. This is also part of the set up procedure set forth in most owner manuals; they tell you to do the two collar test after you have leveled the bed.

I don't know if any of this applies to the asian imports, but it should. Badly worn lathes are another story altogether.

And I don't know how they do it on ships, although clearly the lathe need not be level in use. There must be some tricks in setting it up. But most of us aren't on ships, and have the ability to set the machine up as the manufacturer intended. Is there really any resistance to doing that?

 

[Tolerent]

I don't know how they do it on ships, although clearly the lathe need not be level in use. There must be some tricks in setting it up. But most of us aren't on ships, and have the ability to set the machine up as the manufacturer intended. Is there really any resistance to doing that?

99% of ship based lathes are set while the ship is in drydock sitting on Keel Blocks.

When a commissioned submarine was docked the shipyard had a responsibility to get it within 1 degree of plumb. no challenge with pitch but roll could require a few attempts. The foundation for the lathe would then be set to match gravity rather than the hull misalignment.

Surface ships do not generally have radial hulls so they are easier to dock square to the world.

There might be more lathes on tenders and perhaps Aircraft Carriers than all other ships in the fleet combined. I do not know for example whether or not a submarine or a destroyer has a lathe at all. I have seen numerous lathes on a single sub tender.

 

[matthewsx]

I'm a Navy veteran with 12 years in a shipyard engineering department. <snip>

Thank you for your service

My dad was a Navy vet and might have been career if he hadn't gotten hurt....


John

 

[Tolerent]

Thank you for your service

My dad was a Navy vet and might have been career if he hadn't gotten hurt....


John

So, Your father was career. Just a shorter career that got derailed and pushed him in another direction due to things not within his control. Bless him for that service as well.

When someone's commitment to a cause exceeds their resources or capacity they should never feel like their contribution fell short

Mark 12:41–44 wasn't only about her.

Thank your father for me.