Leveling the lathe - not sure if I'm "doing it right"

[Jake M]

Thanks Jake,

So others don't have to search...

That is awesome. I know it's out there, there's clear evidence that it's been out there since shortly after time began, but to search for it... It's a dirt simple, yet very powerful technique.

 

[Dabbler]

acing a large disc and checking it for flatness across the whole diameter is the easiest way.

if you face a disk, a properly set up lathe will have a few tenths dip in the centre. Or at least that what Connely said.

Almost everybody seems to skip the first step in aligning a lathe. You have to align the headstock to the lathe bed. Even on lathes with the headstock sitting on a veeway. My leBlond 15" sits on a veeway, but it still needed aligning after putting it back on. Imperfections or small bumps on the veeways, a mote of dust (or metal) or the oil being a little too thick can misalign the head by up to .002 at 6". (From my experience). It took me 3 tries, a little stoning and re-cleaning the veeways to get the headstock to 0.0001 in both horizontal and vertical. (technically X and Y).

 

[verbotenwhisky]

this is what i am struggling to get my head around. if i get the lathe bed level to a plane and the headstock is out i have to shim the headstock but by doing so i am altering (spoiling) the level plane of the bed.

the second thing is where does one draw a line for arguments sake lets say i get 0.001 over 12" im never going to be turning anything of that length as my interest lies in making model hot air engines (maybe steam if i progress enough) i only have 10" swing so most parts i make are going to be less than an inch long

No that isn't correct. If the head stock is out it isn't a shimming adjustment, it's because it isn't lined up on a machine where the headstock is bolted to the base rather than integral to the base. You have to align it by loosening it then using the jack bolts rotate it until it is aligned. I do not think this is a problem in 99.8% of these machines but it deserves to be checked and you have an issue checking it if the bed isn't level and if you are checking the bed using a test bar and the head is off......

 

[SouthernChap]

You have to align it by loosening it then using the jack bolts rotate it until it is aligned.

Not all lathes have headstocks that have intrinsic adjustment.

Mini lathe headstocks for example tend to be adjusted by shimming.

Alternatively one could use some kind of epoxy filler with high compressive strength but all the "liquid shim" products seem a little expensive for use on a Chinese mini lathe!

 

[verbotenwhisky]

Not all lathes have headstocks that have intrinsic adjustment.

Mini lathe headstocks for example tend to be adjusted by shimming.

Alternatively one could use some kind of epoxy filler with high compressive strength but all the "liquid shim" products seem a little expensive for use on a Chinese mini lathe!

Typically the head stock is off through rotation, not up and down, i.e. the horizontal plan of the lathe ways with horizontal plan of the spindle are not parallel as opposed to the vertical plan of the headstock, not certain how you would shim that but I do not have a mini lathe so I will take your word on it.