NIck: First, welcome to the forum.

Second, the issue of poor finish crops up on a regular basis on the forum, both for turning and milling. The vast majority of finish issues are cleared up by taking care of two factors; material and tooling.

Material first; all steel is not created equal. Some types are easy to machine and some are difficult, and some manufacturers produce poor quality material of any sort. So stage one would be to dump the indeterminate steel and buy a length of steel of a known grade, preferably EN1A, as that should be easy to machine. It will be cheaper to buy a standard length from a commercial supplier, and there's also a good chance you'll get what you paid for.

As for the tooling you don't say what type you are using, HSS, brazed carbide or carbide inserts? There are two rules for cutting tools, irrespective of the type:

1. Don't bother buying cheap cutting tools, they may be cheap but they are poor value

2. See rule 1

Of course even a decent cutting tool needs to be properly ground, at the correct height and running with appropriate speeds and feedrates.

The problem is unlikely to the lathe itself, although going over to check gibs wouldn't do any harm.

Lastly if we knew roughly where you are based there might be some-one local who could assist.

Regards,

Andrew

The problem, as I see it, is that in these days of inserted and pre-ground tooling and charts of cutting speeds and feeds for each style of tooling, everyone expects to achieve a good finish because they have bought the tool for the job, so it should deliver. Back when the world was very young things were completely different, with hand ground HSS every job was different, in fact, after rough turning to 0.020'' over size, a turner would experiment with different speeds and feeds before committing to the finial cut to size, as the same machining conditions couldn't be guaranteed from one work piece to another. Taking onboard all of Andrew's points, I feel its good practice to try different approaches, but for finishing, the general rule of thumb is dead sharp tooling, light depth of cut, experiment with speeds and feeds and use plenty of soluble oil, cutting oil or paste applied with a brush brush if no machine fed coolant is available. To become an all round machinist it was expected to take a five year apprenticeship, so you have only just taken the first steps, but good luck with it all.