Yes the tool should be exactly on centre

easiest way is to trap a strip of metal about 6” long between tool and work. It should be vertical Use strips of flat, shim or even cut up tin cans to bring it up to height. I

it looks very low opin your photo

keep the questions coming

> the tools I got with the machine, are they ok or should I buy some new one, also what’s the round one for

The material they are made out of will be just fine, but they will need to be sharpened – even if they happen to be sharp now, they won't stay that way for long. Sharpening can be a bit of an intimidating topic to start off with, but watch a few videos and read a few books and then get your hands dirty and it will make sense. A basic bench grinder is all you need – there are usually loads on Gumtree and Facebook Marketplace for not very much.

Round tools are generally used when you want to be able to fine tune the orientation of the cutting point, such as in a boring bar. Not quite sure what this particular one is ground to do, but people do all sorts of things with HSS cutters.

> is it the tool I used or me or maybe the metal

It could be a bit of all three. The biggest problem is that the tool does indeed need to be at centre height – one easy way to text this is by almost touching the tooltip and a centre in the tailstock. People will say to be a tiny bit over or under for different applications but the basic principle is it has to be on the centre, or your tool is at the wrong angle to the material it's cutting. Your tool there is quite low so the material itself is trying to "climb" over the tool – that's why the finish is worst at the tip, where it's most slender.

The tool could be not-sharp, and your tool-holding might not be rigid – everything has to be tight all the way from the tool-tip down into the carriage, through the bed and back into the headstock. And the metal you are cutting might not be ideal, though it looks like you've chewed it up pretty well! In general though having material of a known standard and thus properties means you have one less thing to second-guess.

It's difficult to see, but it looks from the first picture like you're using a slotting/parting tool on it's side? This would explain the poor finish and low tool height.

Looking at your selection, the tools all seem still serviceable, perhaps with some judicious re-grinding.

The shiny ones are of High-Speed Steel (HSS).

It's not entirely clear to me if some are lying on their sides; so the clearance angle, if that is what it is, on the fourth down is a bit large but that should not matter. For steel and phosphor-bronze, the top of the tool should slope 2-3º or slightly more, diagonally down away from the very cutting-corner. Aluminium – the slightly more. Brass – flat (0º ), giving more scraping than shearing. In all, the flank and front face below the cutting-edge is angled back below itself for clearance.

The top one was perhaps of special purpose, and being round bar, unless there is a flat along its underside it needs to be held in a shallow V-groove pad or a clamp-block, in the tool-post . It might cut neat chamfers.

The dark ones: high-carbon steel (like cold-chisels etc.). Fine, but they will not withstand much heat without losing the temper, spoiling them. That with the long slender "neck" will work into the corner of a wide groove. Next down; a general, and very much used, knife tool for straightforwards turning including facing. No.3's semicircular end may have been for profiling grooves for, e.g., sealing- or oil-retaining rings. Don't try to use it as a parting-tool: it will jam in the cut.

The tool in the middle may be another "special". Hard to see its geometry properly but it might turn the right-hand face of wide grooves, cutting towards the tailstock.

.

Height:

I usually set my lathe tools by pointing them at a centre or scribing-block, then fine-adjust if an initial facing leaves any centre-pip on the metal.

A properly-set tool leaves no pip, but by shaving it down, not shearing the last bit by force (tool too high). If the tool obstinately refuses to remove the pip, it is too low.

A tool-post without height adjustment of its own, such as your 4-way one, needs a good assortment of shims for packing the tools to height. Save expensive "shim stock" for its intended use, aligning machine parts. Instead, off-cuts from ordinary strip or sheet metal, including from food tins, etc.

Even semi-rigid plastic. Some of my shims are from expired plastic bank or club membership cards – a fairly tough, precisely-finished material, so ideal shim where it won't become hot.

Many model-engineers make a simple height-gauge for tool-setting.

.

High-speed steel tools are fine, and have advantages over carbide inserts, not only by being much cheaper. (I use both.). They are relatively easy to sharpen many times to a standard that will give you decent results; and are less fussy than inserts which are really made for quite specific materials and cutting conditions. Some aver insert-tooling can only work at very high speeds, but that is not quite so. They work like that in industry for rapid production at very high repeatability. The HSS tools sometimes give a better finish, especially on steel not of free-cutting grade.

[If the work-piece is to be welded, especially for anything critical, it must not be of a free-cutting steel anyway. Their additives, usually lead, embrittle the weld.]

.

Grinding:

As Calum says, a simple bench-grinder is fine for HSS tools. In fact it is necessary!. It takes some practice but you can grind a tool free-hand to give good results, even on the crude rest usually fitted to these grinders.

A final honing by oil-stone or lapping-plate will help give even better finish, but the finish is mainly dependent on tool geometry, speed, feed and material. The very tip should have at least a tiny radius in plan, even for turning into a shoulder as on your sample.

Hence another caution. If the part is to be heavily-loaded (e.g., a crankshaft, a locomotive driving-axle), internal corners need a little root radius for stress-distribution.

It's worth examining industrially-made parts to see how such principles are applied.

.

I would recommend Harold Hall's Tool & Cutter Sharpening – lathe-tools, drills and in a limited way, milling-cutters; No. 38 in the Workshop Practice Series by Special Interest Model Books. (www.specialinterestmodelbooks.co.uk). Buy from them, or as as I did, from TEE Publishing. Mr. Hall's book gives designs for attachments to turn a simple bench-grinder into a moderately comprehensive tool-&-cutter grinder – useful exercises as a bonus. Just a simple plate adjustable for angle in both directions, on brackets screwed to the bench in front of a grinder itself screwed down, will greatly facilitate sharpening lathe-tools.

It goes without saying the grinder should be well away from any machine tools!

Also note that with perhaps some specific, controlled exceptions (see the book's cover photograph!) the side of a grinding wheel should not be used. The concave radius from the wheel's rim does not normally matter.

.

Cutting Fluid:

A cutting fluid is a coolant and lubricates the cutting action, for steel, phosphor-bronze and aluminium; and can help maintain a decent quality of finish (with all other criteria met). Cut brass and cast-iron dry – note as another thread here discusses, cast-iron chips are abrasive.

Steel and bronze: one of the water-soluble oils, pumped or gravity-fed to the tool tip; or applied with an old paint-brush. For Aluminum: paraffin, white spirit or WD-40 (which is mainly white spirit); but note that these will wash out lubricating oil from the lathe. (WD-40 is not a lu

Edited By Nigel Graham 2 on 31/05/2

Agree with what has already been said.

In your picture, the tool is well below centre height. That tool, or any other, will, not cut properly.

It MUST be on centre height. Don't go above. The tool will not cut, just rub.

If the tool is off centre height, when you face across the end of the bar, it will, leave a pip in the middle.

As I said earlier, make yourself a Centre Height Gauge (But fit some more clamping screws into that 4 way toolpost.) Rigidity is important, so clamp the tool securely, and keep tool, overhang as short as possible.

If you want to know how, PM me with an E mail address, and I'll send a picture of one or two that I have made, with a few notes.

Until then, as said, trap a piece of thin steel between tool and work. If the steel is vertical, the tool tip is on centre height. Ifv it not it will not be vertical If it leans away from you, the tool is too high, towards you it is too low.,.

Don't worry about all the different tools, at this stage.

Just learn how to grind a plain knife tool and start learning with that. The fewer variations that you have, the better you will learn the effect of any change that you make.

One of the first techniques that you need to learn is how to hand feed at a steady and consistent rate.

For roughing, you can feed REASONABLY quickly, but. for finishing cuts, tghe feed rate needs to be small, of the order of 0.004" – 0.002" per rev.

No longer have a ML7, but the thread will, or should, be 1/4 BSF, (Probably., unless a previous owner has departed from the original specification )

My preference is for a 4 way toolpost, as opposed to the standard Myford clamp, or the Quick Change Toolposts advocated by others.

(Purely my opinions, but in my view, most of the the time, you can change tools as quickly with a 4 way as with a QCTP, and the 4 way is slightly or rigid, since there is less overhang and fewer mating faces. This is based upon the tool heights having been set previously. You will need to be ingenious to fit more than 3 tools into a 4 way post, though )

The books that I recommended will show the angles at which to grind the tool.

As a personal note, I use a Tangential Turning Tool for a lot of my work. You can buy from Eccentric Engineering (There is an agent in UK ) Probably too soon to suggest that you make your own.

There is only one face to grind, and the "Diamond" tool should come with a grinding jig.

Don't worry about what coolant, if any, to use, for the moment.

Just learn the basics first of all..As you learn, you will be able to try new things and learn more.

Where are you located? In addition to reading up on how to set up and operate a lathe, you can do with some face to face guidance.. Possibly, there is someone near to you who would be prepared to visit and advise you.

Howard

That photo of the cut reminds me of a broken tip, but you will hear the difference between a sharp cutting tip on right height versus a broken tip or a tip sharpened unable of cutting, it will not sound good.

Edited By Chris Mate on 31/05/2022 21:26:36

As much as all these observations, suggestions, recommendations, etc might be helpful, my advice would be to locate your nearest model engineering society and find help from a local, experienced user. It”s a steep learning curve, starting from close to zero.

NDIY –

A good point. I agree that Chris is best finding a welcoming model-engineering club near him.

Really, skills such as metal-working are best taught in person. A forum can be valuable but risks creating a lot of well-meaning but confusing information as different contributors put forwards what may be valid but seem different approaches to the same things.

Andrew –

Oh, I know that problem only too well! I can work round it by trying the best approaches to some bit of rusty steel; so if it proves not suitable for one application it may prove suitable for another. Fine if you've machined lots of bits of pre-loved steel so have some judgement to draw on; but not the best route for a beginner less likely to know if the fault is material, tool or machine-settings.

For example, I have some 18mm diameter steel bars that were big cable-drum tie-rods. It is grotty stuff, and a carbide tool just tears it. It will cut fairly well with a suitably-ground HSS tool, so I know I can use it for static parts not needing a bearing-surface or attractive display finish – but I would certainly not give it to someone learning to use a lathe.

I noticed a couple of references to EN1A and Pb – but I don't think it was made clear that this is a free machining grade of STEEL.

Oldiron –

With respect I think there is a bit of confusion there.

Looking back from your quote, shows Speelwerk is talking about the lathe levelling-studs, not the tool-post screws.

Very sorry for the misunderstanding, only behind a lathe since 1971 and Myford since 1979, therefore will leave it to the UK experts to comment. Niko.

It was my preferred way on a mini-lathe, where the minimum speed was too high for comfort! As it had an ordinary DC motor, I didn't bother to take the belt off – with the power off, turning the motor with a hand-crank, didn't add significant resistance.

Is the SC3 brushless? If so the motor might be harder to turn. Another concern is the possibility of damaging the electronics because the motor will act as a generator when it's spun. I've not tried it, but I think damage is unlikely because hand cranking is slow, and because lathe control electronics don't pop when the emergency stop is pressed at high-speed. Doing that means the chuck will drive the motor as a generator until the energy is absorbed by the bearings, gears, and belt. Much faster at first than a hand-crank.

A good alternative on lathes that can run in reverse without the chuck unscrewing is to screw-cut away from the headstock rather than towards it, so that there's no risk of colliding with the chuck. This can be done at high-speed, might not need a hand-crank at all. At 30rpm minimum speed my WM280 is a perhaps just a tad fast for super-safe screw-cutting, so I often reverse cut considerably faster. One day I might experiment to see how fast threads can be cut, I guess hundreds of rpm are do-able.

Dave

Edited By SillyOldDuffer on 25/05/2023 11:47:27