Economical way to level lathe

[CJ5Dave]

I have an old metal lathe that I have been tinkering with/setting up since January. Was missing some parts but now operational. It was missing the bolts and plates in the base to level it up. I made a setup this weekend and have 1/2 inch bolts setting on steel plates to level it. I used a carpenters lathe to get it as level as this will tell me. One leg of the base was not even touching the concrete floor because some previous owner welded the base to the frame. Hopefully this will stead up the rocking vibration I was getting. I just need a more precision level to get it closer. I see used Starett machinist levels in the $150 range plus shipping. I hate to pay that for a tool I will use once, for 30 minutes, and store in a toolbox. Is there a more economical way to do this?

 

[Dabbler]

yes there is: try this:

Her has an updated video from 3 years ago as well.

This one is a great video:

All the best!

 

[MrWhoopee]

I leveled mine with a plastic dollar store level. Cuts within .0003 over 14". Close enough.

 

[great white]

I use my starrett level all the time. I thought I wouldn’t use it much either, but I’m always finding uses for it.

 

[CJ5Dave]

Thanks.

 

[Flyinfool]

Level is not important to a lathe, square is. You check it my machining test parts. The lathe does not care if it is 30° off level in either direction or both, as long as everything is square and solid with no twist.

 

[great white]

Level is not important to a lathe, square is. You check it my machining test parts. The lathe does not care if it is 30° off level in either direction or both, as long as everything is square and solid with no twist.

You’re right, it doesn’t. It could be upside down for all the lathe cares (well, you’d loose a lot of oil upside-down! Lol!).

But what a precision level allows you to determine is twist in the bed.

Place it across either end of the bed and if the bubble isn’t the same, the bed has a twist in it. A simple re-shimming can remove that twist.

 

[RJSakowski]

Cutting a taper can be caused by bed twist or headstock misalignment. If the headstock is not aligned parallel to the bed, it may be possible to correct it by introducing a bed twist in the opposite direction but is is preferable to correct each as best you can.

The two collar test or the RDM * test won't parse out the problem. Leveling will identify bed twist. For that reason, I would recommend leveling as best you can as a first step in aligning a lathe. If you have eliminated bed twist as shown by the leveling process but still are cutting a taper, then it is time to look at other possible causes. Headstock alignment would be most likely. The headstock is adjustable on my G0602 and there is always a possibility that it was incorrectly adjusted some time in the past. On older lathes, wear could be another cause.

If all other options have been pursued but you are still cutting a taper, then purposely introducing a twist is the final corrective measure. In the end, the two collar test or RDM test is the definitive indicator of proper performance though and should always be done to confirm alignment.

 

[RJSakowski]

Regarding the use of a plumb bob for lathe alignment: A Starrett 199 precision level has a sensitivity of .0005"/12" per division. For a 48" plumb bob to have the same sensitivity, you would have to be able to visually detect a change of .002". Parallax, line width, flex in the supporting bar, minute oscillations in the pendulum, etc. are all working against that objective.

 

[sdelivery]

It's just a lathe people.
Mark a line around a clear drinking glass then fill with water to the line. Move slide from end to end and note readings, adjust as required.
It shows you both directions at once.