It's grossly excessive. If you bought the lathe new then don't attempt any rectification yourself, reject it as not fit for purpose and get a refund. Vevor have a mixed reputation, for obvious reasons!

Doesn't sound good, but:

How straight and round is the Aluminium rod? I guess it's extrusion stock rather than an accurate test bar. If so, a better test is put a short length of the rod in the chuck, no longer than 3x diameter, and turn it down by a millimetre or so. Then see what the DTI makes of the turned diameter. Measure how the lathe cuts, not the accuracy or otherwise of stock metal.

Next suspect is the chuck. Might be faulty, but If the rod isn't round, the best 3-jaw chuck in the world won't hold it straight. Take the turned rod made above and put the machined end into the jaws, leaving enough of the turned diameter protruding to test it with the DTI. It won't be perfect, but 0.05mm isn't unreasonable.

Have you removed and replaced the jaws? For accuracy they go into particular slots, and the chuck body is usually stamped with a zero, 1 or dot to identify the first slot (the jaws are also numbered 1,2,3)

If unsatisfactory, take the chuck off and make sure the back and spindle flange are clean – no paint or burrs etc.

With the chuck off, use the DTI to test about 10mm inside the spindle. The spindle hole should be accurately ground to take a machine taper, and bad readings here indicate bearing problems.

Put the chuck back on carefully, making sure it stays properly seated in the register as the nuts are tightened.

Don't jump too quickly to conclusions. Measuring at the 0.02mm level seems straightforward, but is actually difficult. For example, a DTI applied to a rod is only good for measuring rotating error, and running it lengthwise is untrustworthy.

Beginners often start by measuring their new toy, but I don't recommend it. Instead, measure the work it produces, and only when that's wrong look for causes. It's much easier to measure small work accurately with a micrometer than a big machine with a wobbly DTI.

Noting that mini-lathes aren't high-precision tools, working to about 0.02mm in capable hands, with luck the machine and chuck are 'good enough'. However, lemons do occasionally reach customers. What happens then depends on where you live and who it was bought from. In the UK, the supplier would normally replace or money-back a faulty machine. There's always a negotiation, sometimes painless, sometimes difficult.

Fingers crossed, your new lathe cuts metal as well as it should.

Dave

Peter, can you confirm if this 15mm either way is RUNOUT when the chuck is rotated or PLAY when pressure is applied to the end of the bar

Aha.

Vevor Australia

Interesting that it claims to be direct drive "no belt" with motor on spindle and shows a graphic of a outrunner type brushless DC motor. I guess it is geared. Not what I'd call direct drive.
I can't find a manual online.
Looks like your consumer rights are similar to UK/EU. I'd ask for my money back…

Robert.

Edited By Robert Atkinson 2 on 02/05/2023 12:33:58

I regard all the product descriptions given on Banggood, Aliexpress, Vevor and Amazon as purely a 'guide' rather than an exact and true definition of what is being sold. Amazon seem to get away largely by just showing as little as possible rather than a full description.

The Australian Vevor lathe linked to by the OP has a 'Main material' of HT200 Cast iron with a lifespan of 3 years! what on Earth is that meant to mean?

Regarding the drive/motor arrangement. They do stress the 'no belt' drive and I find it unlikely they would use a geared drive, it would be nice to think that the direct drive motor has a large hollow spindle but its probably my wishful thinking.

If it is a direct drive motor then one would hope that the spindle design and the bearings its mounted on are in keeping with it being a lathe headstock rather than just a general purpose brushless motor.

Ian P