cutting tool help

[AjohnwParticipant @ajohnw51620]

Posted by jaCK Hobson on 03/04/2016 10:01:50:

Posted by Bazyle on 02/04/2016 11:01:02:

" I must not be tempted to buy sets of tools"

Thanks for this. Just saved me from buying a set of 4mm I don't know how long I can hold out.

Edited By jaCK Hobson on 03/04/2016 10:02:30

To get what I wanted, a tool that with limitations will turn left, right and face I had to buy a set. Some of them will do some of these operations more efficiently if needed though and no need for several tool holders for the qctp as the tip height is the same on all of them.

John

–

[MWParticipant @mw27036]

Sounds like a proper insert grooving tool you wanted, John. Took me a while to find a decent one too, i ended up buying one from cromwell's in the end.

Michael W

[matthew shayParticipant @matthewshay62229]

hi again the 8 pc high speed steel turning set that people have said on here go from 4mm to 8mm is that the thickness of the tool is the thicker ones better

[IanTParticipant @iant]

Mathew,

I've never used the HSS tool 'sets' referred to above but I certainly do use HSS tooling, simply grinding my own profiles "as required" – a better and more cost effective approach in my view..

In terms of the "best" size – that will depend to some extent on the size of lathe and type of work you want to do. However, in general I am a great believer in small tooling and on my lathes, I generally use 3/16th HSS.

The main reason is that it is much easier/quicker to 'shape' a smaller section HSS tool than a larger one (there is less metal to grind away) and also to keep it sharp – especially if you hone them. I should add that I don't generally take huge cuts (which is more about being kind to my old machines) but it is quite possible to do so with 'smaller' tooling provided they are not overly extended. Of course, there may be times when a heavier tool is useful but generally the advantages of smaller section tooling outweigh other considerations in my view – so they normally get used in preference to the larger sections (which I do have if needed)

Regards,

IanT

[MWParticipant @mw27036]

Hi Ian,

I have some 3/16th HSS and i understand how small that is, i haven't used it though. I've never done an experiment to see which is better for small and finishing cuts, like you said, much easier to reach a sharp point. Most of my tooling is 1/2 inch.

The main reason i bought it was for grinding boring bar/internal shouldering inserts.

Michael W

[Neil WyattModerator @neilwyatt]

Posted by Ady1 on 02/04/2016 09:54:34:

https://www.machinemart.co.uk/p/6-point-metal-turning-set/

I have one of these sets.

They will probably make you want to sling your lathe in a skip. I don't blame Machine Mart as everyone sells these sets and they are all near useless on a small lathe as they are badly sharpened and have poor angles.

If you have bought them, keep them for when you have a casting that glints like silver when you try and machine it. They will manage a cut in almost anything, but the finish resembles corduroy.

Neil

[MWParticipant @mw27036]

You're quite right Neil, I have a set and i took one look at the tips and knew they were going to be bad, i've only cut 1 or 2 things as a trial but what do you expect for like £7? (i think thats how much i paid for it).

Luckily i had alot of, superbly made i might add, sherline tooling which seemed to work wonders on my old miniature machine. So i wasn't that dissapointed, i just waited til i could afford some decent bigger HSS.

So i'm just holding onto them til i can be bothered to re-grind them one day. 

Michael W

Edited By Michael Walters on 04/04/2016 12:21:04

[VicParticipant @vic]

I normally use the largest tooling that I have to hand that will fit in my tool post on the basis that it will be more rigid. In practice much of the HSS I have accumulated is 1/2" square although I have bought smaller stuff for special jobs. My Tangential tools take 1/4" square HSS which makes it very economical to use. Perhaps a bit unfair to generalise but the old English made HSS seems to last longer than the cheap imported stuff. I have bought some high grade branded HSS when it was on offer at Cromwell tools but not had chance to try it yet.

[matthew shayParticipant @matthewshay62229]

I am going to use only aluminium nylon and maybe brass and only going to make things a max 40mm round and 100mm long will the 8pc high speed steel 6mm tools

[Ady1Participant @ady1]

Carbide can be great once your hobby lathe is set up properly and you sharpen the tips up.

I created a bit more stiffness by tightening my thrust washer a bit more and no longer have any chipping issues, now I need more power and am after a better motor

This is a 2.3 mm cut on a 50mm bar so I can hack off nearly 5mm with each pass(8mm shank carbide tools), you can see the step in picture 2

The great thing is they can do a huge amount of work between sharpening, I am cutting from the back so the roughing down mess doesn't spray all over me (well most of the time anyway), the lathe is a 70 year old Drummond M series

Once you get it sorted out, carbide is fabby, so don't ever write the stuff off

Edited By Ady1 on 04/04/2016 14:59:06

[JasonBModerator @jasonb]

I also find those tools useful and they are quite capable. The Minnie in my avitar had a lot of the turning done on that using a left and right hand tool like the one at the top of the photo and that was on a smaller lathe than I have now.

I still often use the cranked ones with a rounded tip as they are ideal where you want a small fillet rather than a sharp internal corner.

Seem to work on aluminium

Bronze

Cast Iron

Steel

So don't be in too much of a hurry to banish them to the back of a cupboard.

Edited By JasonB on 04/04/2016 15:30:15

[Dinosaur EngineerParticipant @dinosaurengineer]

It's a sign of the times that quality HSS ( USA/ British) is often cheaper in the larger sizes than the small sizes. Most Industry now uses inserted tools and the larger HSS tool sections can be had at bargain prices.

[VicParticipant @vic]

Posted by matthew shay on 04/04/2016 13:52:55:

I am going to use only aluminium nylon and maybe brass and only going to make things a max 40mm round and 100mm long will the 8pc high speed steel 6mm tools

Bigger the better but we don't know what size lathe you have. 10mm would be good if your lathe can take them.

[matthew shayParticipant @matthewshay62229]

chester conquest from new

[MWParticipant @mw27036]

I have to agree that carbide is very useful, especially if you're new to machining harder materials like cast iron, at first, i often ran my lathe at high speed and found HSS just sparked and eroded. So i switched to carbide and found it worked out.

Now that i have more experience with cast iron, I often tend to prefer slower speeds, i rarely find the need to use any of my machines at high speed except for maybe small drills and linishing.

Alot of hobby machines seem to be trying too hard to get as high a speed as possible when really it's quite unnecessary. You can quite satisfactorily work at lower speed and as the late Joe Martin once said "i never knew anyone who ruined a part from taking too light a cut". If you visit the swindon rail museum, you'd be surprised just how slow the victorian lathes were operated at; these were not intended to be ran fast. 

Only last week, on a post about grinding, someone asked if it was possible to use a slower (1200rpm) speed for grinding, only for a number of people to tell him(or her) it was not possible. I remained quiet, but the image conjured in my head was that of a medieval blacksmith using a treadle operated grinding wheel, so i'm pretty sure his foot couldn't keep up with 4000rpm, so it must be possible. 

Michael W

 

Edited By Michael Walters on 05/04/2016 00:15:57

[IanTParticipant @iant]

Matthew (and any other "beginners" reading this thread)

As you will see there is a range of opinions here on this subject (as there always is). Everyone has their personal preference – sometimes this is simply because of habit (I've always done it like that) and sometimes it's a view that has 'evolved' over time.

The "turning" set that you originally asked about, could be seen as a convenient starting point for a beginner but it's not one that I would recommend. When you first start turning, there are always problems that will stop you getting a good result. I certainly mangled a lot of metal before I gradually understood the various factors that effected my work finish. One of them was having a sharp tool with the correct clearances. So even if you buy one of these sets (and I'm assuming the tools are 'sharp' to begin with) you will eventually still have to sharpen them – and in the beginning you are much more likely to chip and damage the cutting edge – so will be doing this quite often (at least I did).

So unless you intend to always used tipped tooling, learning to correctly grind your own cutting tools is something you will need to do sooner or later. A tangential tool is very useful (I have one) and is easy to keep sharp but it will not do everything. I have different tool sets for steel and non-ferrous for instance, as well boring, parting/grooving, fly-cutting and form cutters. They all need to be kept sharp.

As to the size of this tooling – well I started with large chunks of HSS (1/2" and larger) purchased S/H at shows believing it was stronger, more rigid, more 'professional' (etc etc). But when I started to re-sharpen and re-shape it, I discovered what a complete PITA it was. So here is what I would recommend anyone wanting to learn how to make their own HSS tooling do.

Get a new length of 3/16th (or 1/8th) HSS and another length of 1/2". Shape them both to cut mild steel (read a book for the clearances) and see which one is quicker/easier to do. Now imagine that you are going to want/need multiple tools and to keep them sharp. Your choice will I think be obvious.

But will the smaller tool be any good? My turning diameters usually range between about 3mm and 60mm in both ferrous and non-ferrous materials. Correctly supported, my 3/16th HSS tooling will give just a good a result as any larger section tooling (even on heavier cuts) and in fact (because it's easier to maintain them) probably better over time, as I am less tempted to work on with a blunt tool. In my experience, the limits are not set by the tooling but by the tool-holding and machine rigidity.

Now other folk will have very different ideas about this subject but if I had to name just a half dozen things that make my machining life easier/better – then using small section HSS tooling would be up there with ER collets. I am of course a complete amateur (and not working in an industrial or commercial environment). But for anyone who is using larger section HSS routinely – then try the 3/16th versus 1/2" HSS test and you might well be pleasantly surprised.

Regards,

IanT

[Author]

Posts