Levelling the lathe
I set up the lathe by cleaning the ways with acetone and inspecting them. There should be no significant divots or projections — if there are, it’s a good idea to use a stone on them to get them flat. Ideally, it’s best to level something using just three points.
Put a jack under the midpoint of the tailstock end and then just balance the thing from the headstock end where all the weight is. I didn’t have anything small enough to do that as the best jack I have is too big to fit under, so I tried using a lifting jack that I have, but it tended to lift the end too far to be useful. Usually I select three points across the ways to find level — under the chuck, in the middle, and against the tailstock.
I set all the feet at their lowest point so they were all more or less even. Then I began the business of adjusting one foot at a time until I could get the level flat. It is a tedious business and very tiresome, especially on your own. My thigh muscles haven’t quite recovered. I
It’s not exactly precision, but it’s not bad for a small lathe, and overall I’m happy
did eventually resort to using a mirror to save the constant moving up and down. Eventually you will get all three points roughly in line and then it’s just a matter of fine-tuning. You can rarely get it perfect. To double check I also put the level on the carriage, since this is the operative bit. It’s recommended to do the longitudinal level first. The longitudinal level is the least important but it gives you a base to start from. The most important level is the latitudinal one across the ways. This is where twist will manifest and that will cause you the most issues.
Testing
Once you are happy, or when you get to the point that you can’t get it any closer, it’s time to check the effect. Lock all the feet. Put a test bar in the chuck and skim the end off. Bore a centre hole for the live centre. After making a quick skim cut, make a cut at each end of the bar, enough that you can measure with a micrometer. Measure both cuts and see how they compare. With luck they will be perfect; in practice they’re likely to be out by a greater or lesser degree.
If there is still significant variation, check that the tailstock is aligned properly. Check the amount of variance and move the tailstock by half the difference. If the taper starts at the tailstock end then move the tailstock away from you; if it’s the other way round then move it towards you.
Mine still has a small variation of .001mm over 300mm. It’s not exactly precision but it’s not bad for a small lathe, and overall I’m happy. Once the lathe is level it pays to check it regularly, but it’s always easier to level the second time around.