Why not steel?. Get yourself some EN1A leaded and some brass/ Ali 6082 T6. You will find Delrin/Acetal quite expensive but nice to work with. Macc Models are a good supplier

If you do try aluminium, then a tiny bit of WD40 spray to keep it damp will avoid it sticking to the tools. As mentioned, brass is messy, mild steel is a better bet. Get a book on turning and milling, it will get you off to a better start.

Steel is going to be the cheapest material, by that I mean EN1A, 230M07 or EN3B, 0070M20, both in bright not black. Keep diameter down to below 25mm, this will make parting off a little less stressful. Brass is an easier material to cut with either high speed steel or carbide tools so is worth a try but the cost is greater. I would avoid aluminium unless you intend to use it in your work, it appears a lot on YouTube videos as most are from the USA and it is more prevalent there than in the UK, i don't know what the cost is in the USA but in the UK it is more than steel. By practicing on the material you intend to produce items from you are learning about the cutting tools as well as the material as there is a geometry difference at the cutting edges. Also avoid silver steel at the beginning, it is tougher than simple steels so more difficult to get a good finish.

When you do try brass, make sure it's CZ120. A lot of brasses don't machine very well at all.

I like aluminium actually and don't find the sticking so much of a problem as long as you have sharp tools, run fast, and use a machinable alloy – 6082 or T6 as recommended are good. Lot's of things are just as good made in aluminium and easier to machine.

I'm going to state the obvious here, but as a newbie you might not have considered safety too much.

I'm not a H&S nut, and often despair with some of the ridiculous rules and regs that defy common sense, but beginners really need to consider the possibilities of injury even when using relatively small low-powered machinery. I'm sure there will be postings on this site relating to sensible do's and dont's so have a search, or / and get a good book.

Machining brass for example – someone mentioned earlier about being showered with tiny chips – yes it often does, and they can be very sharp, if they get in an eye they can be a nightmare to get rid of at hospital. Safety glasses may not always be adequate – a full face visor may be prudent. (3 guesses who's speaking from experience!)

Don't want to put people off, but a timely reminder is sometimes sensible.

As others say, buy a copy of a book like Geo. Thomas'. Note the title above, not his Model Engineers' Handbook which is a valuable reference on the more theoretical side.

You'll want one that covers the basics and if it has some simple projects for making tools and machine accessories, it's a bonus. If that's now out of print there are equivalents – look on the TEE Publishing site, and I see by the side-bar ads that two of this forum's denizens have become technical authors too!

It's not just the material you need consider. Different metals and plastics need different tool geometries for best results – the reference-books will give the details.

The silver-steel you mention is tough stuff. It is not a general-purpose material but can be hardened and has a precision-ground finish, for making cutting-tools, small shafts, bearing pins and the like.

You'll also need a reasonable bench-grinder – though many use both High-Speed Steel and carbide insert tools, or inserts only, I would advise HSS at least for now. As well as cheaper (carbide tips are single-use), you can buy them already made to the main shapes, and they are relatively easy to re-sharpen to appropriate geometry for a good, accurate finish. Ordinary lathe tools don't need fine sub-degree accuracy except for precision thread-cutting, can be ground free-hand, and it's not too hard to make simple rests to guide them against the grinding-wheel. Authors such as Harold Hall have published designs for these.

Edited By Nigel Graham 2 on 25/05/2021 13:03:22

Not sure the difference is worth worrying about – for similar sizes they cost about the same. Just checked on the web and 3m x ⌀25mm Black mild steel is £51.16 compared with Aluminium at £55.56 today in the UK. (Both ex-VAT) Didn't check carriage cost, but Aluminium might be cheaper because it's lighter.

I probably use more Aluminium than any other metal because it cuts faster than steel, resists corrosion, and is strong enough for my experimental purposes. Important to get a machinable alloy – pure Aluminium and many of it's alloys are nasty squishy stuff. Steel for strength, weight, and wear resistance.

Brass is my favourite metal – machines well without fuss. The sharp needle-like swarf is a menace though.

Apparently the easiest metal to machine is Magnesium but it's rarely useful for home projects.

Generalising wildly, the preferred metal in a workshop depends on the type of work:

• Clock makers use lots of Brass
• Loco makers are into steel and cast-iron
• Experimenters get good results from Aluminium

However, all common metals get used sooner or later, and plenty of other materials are useful too. I've turned Silver steel, Bronze, Copper, Graphite, Cupro-nickel, plastics, cardboard, MDF, rubber and wood more-or-less successfully. Even attempted glass, didn't go well.

I learned a lot by building Stewart Hart's PottyMill Engine; steel, aluminium and brass, artfully combined to get a working machine by exploiting their individual virtues.

Dave

Perhaps one important facet has not been considered: What cutters do you intend using?

I am like SOD – I like aluminium. Easy to machine, doesn’t need exceedingly specialised/exotic cutters to get a reasonable finish and doesn’t blunt/chip cutting edges quite so quickly. Brass is expensive. Aluminium welding on the tip usually means it is too hot at the cutting point. Insufficient cooling/lube or a blunt cutter are the usual causes.

I’ve never particularly bothered with free-cutting steel for most things I make.

I think the HSS will serve you best. To get the most out of carbide inserts on a mini lathe get those specifically designed for aluminum.

I really like the tangential tools like those from Eccentric Engineering. I don't know if they make a holder small enough for a mini lathe.

Little Machine Shop has excellent reference material like speeds and feeds, angles for grinding HSS tools and a bunvh of other good stuff.

**LINK**

+1 for Tangential Turning Tools.

Made one from a design shown in an article in M E W. This is on the mini lathe.Then made a larger one, and eventually took up a special offer from Eccentric Engineering.

There is an agent in U K.

I had to shorten the tool holder shank, to get rid of chatter. Needing only face to grind, easy to keep sharp.

There have been several articles on modifications made to mini lathes, in M E W to improve their usefulness.

Well worth reading, for future use.

HTH

Howard