Cutting tools - what type is most suitable?

Hi. I picked up a pre-owned Clarke lathe today in exceptional condition.. Unfortunately the seller suffered a fall in the week, so his son was there to handover the lathe. The lathe is variable speed, with compound slide, power feed and screwcutting capabilities. This is my first 'proper' lathe.

Okay - to the point. There were these five tools in the parts box that have seen better days so I need to get some more. My primary use of the lathe will be turning jewellery items from materials as soft as wax (investment casting) epoxy resins, aluminium for prototyping, brass, bronze and at some stage stainless steel. I will be both turning including putting bevels on and when I get a tailstock chuck in place boring up to 22mm on 25mm rod.

Based on the above, would you guys recommend getting a set of regular tool steel cutters or those cutters I have seen with the carbide inserts? I am only intending to get a cheap set to begin with until I get more experienced with the lathe, for obvious reasons. I do stress that I have zero experience of sharpening cutting tools and limited experience of using a lathe.

All help, suggestions and guidance would be gratefully received.

Thanks...

I suspect you are currently having the thought of 'how do I post photographs'..........

You need to create an album, put your photographs in it, and post them from there.

I wouldn't get a set of any sort of cutters. There'll be some you never use and quality isn't a given. That's another mistake, buying cheap because you're a beginner. That way lies frustration. Personally I'd buy some HSS blanks, a cheap bench grinder, and experiment. Grinding a basic lathe tool is simple, just three angles and you don't need to hone it within an inch of its life for it to work.

For aluminium the CCGT polished inserts are useful as they reduce the likehood of aluminium building up on the tool. Likewise inserts may be good for stainless steel. But both can be turned with HSS tooling.

You don't say what size the lathe is, but drilling 22mm holes, certainly in stainless, going to require a lathe with some grunt. At those sorts of diameters you're much more likely to be using a boring bar after drilling a smaller hole.

It also helps to say where you are, a lot can be achieved by a short face to face meeting and practical demo.

Andrew

These are the five tools that came with the lathe (thanks to David for telling me how to get photos on here.

I am guessing the left hand two are parting tools. The centre tool is unknown but with a 13mm square it going to be too big for the toolpost. The two right hand cutters have a tiny cutter at a ninety degree angle to the shaft so presume they for thread cutting.

Yep will be using a boring bar Andrew.

I do have a sturdy bench grinder as well as decent files including diamond. Would need a few tools to see what I was l was aiming for to be able to create my own tools at this stage though, as would hate to cause damage to the lathe.

Your middle tool is a boring bar. The one to the left of it looks like a fine external threading tool, the one to the right a fine internal threading tool.

Far left possibly parting and far right possible small internal groove cutter.

Hi Will,

The middle tool looks like a boring bar, you are probably right that the tool to the left is for parting (or grooving) and the two rightmost for cutting internal threads. A few tools made from HSS blanks should get you started. For advice on grinding HSS lathe tools look here or here.

Thor

Thanks for the info on what the existing tools are guys. I have found a 6th tool in there now, which I initially thought was one with a broken tip but on closer inspection it is perhaps a regular turning tool, as appears to have three ground surfaces on there akin to the pictures in the link that Thor has kindly provided.

Not the silly question that it may sound, but are all HSS blanks suitable that are the right size to fir your toolpost, or are there different hardnesses with some more suitable for lathes or different materials. Do bear in mind I am a complete novice as regards lathe tools..

The problem with HSS is you also need a grinder and then have learn how to use it! Some take to grinding better than others, you won't know until you try. Practice, practice, practice...

Inserts make life easy but aren't ideal on small lathes. Personally I prefer the convenience of inserts and use them at least 80% of the time. Others swear by HSS and they're not wrong.

There are several different grades of HSS but I don't worry about it. For general purpose cutting the differences probably don't matter much.

Dave

Don't worry about the grade of hss it's not that important. Personally I think grinding is a bit of a hassle. I'd rather be turning than grinding.

If it was me I would go with a tipped tool and inserts. An sclcr tool will do 90% of turning jobs. You would want an 8mm or possibly 10mm shank and ccgt tips.

The link that Thor supplied, also gives details of a simple jig to use with the grinder to help get the angles right. I think trying to grind those faces freehand would take an immense amount of skill.

Looking at the toolpost just, I have found it will actually accommodate all the way to to 18mm square capacity, but I am probably going to be looking at 8mm or 10mm square stock for tooling.

Following members suggestions on here, I am probably going to get just a couple of HSS blanks to try grinding my own tools initially, but will get the grinding jig sorted first. I am attracted to the inserts too though, as for things like bevels they appear they can produce repeatable angles very easily.

Thanks for everyone's input so far. It truly is appreciated.

You are going to need a big range of tools to get the best results with that range of materials.

Silver CCGT carbide inserts are probably eh nearest you will get to something that will cut all of them with a reasonable finish.

Grinding your own HSS will be good for making very sharp tools for waxes and epoxy.

Neil

Don't make the common mistake of assuming the size of the slot in the tool post is the size of cutter it will accommodate. I can almost guarantee an 18mm shank cutter would be above centre height on a mini lathe. Even 12mm is a stretch on my own mini lathe.

Edit - I'm assuming you have a CL300 as it's the most common. You may have the CL500 in which case ignore my rambling. 

Edited By Hollowpoint on 29/09/2019 22:06:51

Not really, if I can do it I'm sure you can. It's just three angles and as long as you understand why the angles are the way they are (the precise values are not critical) everything should be fine.

I've never really understood the obsession with grinding jigs. While I have the wherewithal to accurately shape HSS if needs be almost all my HSS tools are shaped freehand, not even using the piddly rest on my bench grinder. I use HSS exclusively on my repetition lathe, and that's a production machine, so the tools get run hard.

Andrew

Thanks 'Hollowpoint'. Don't worry I have no intention of using a 18mm shanked cutter. I am presuming the 13mm shanked boring bar supplied has been used successfully with this lathe, but the trouble is with the actual owner in hospital after his fall earlier this week, I have had no interaction with how the cutters have been used, as the handover was with his son, who showed the lathe working only, as he had little working knowledge of it.

Andrew, perhaps i should have said grinding faces freehand would take an immense amount of experience. Much of my work in done on cnc mills where I send the design to the machine and tell it to run.. I do appreciate that manual lathes require a lot more operator input and a different skill set, but I am always willing to have a go at things once I am pointed in the right direction.

Well said Andrew

Mike

Will,

If you are going to purchase a cutting tool, I would recommend the Diamond tool holder made by Eccentric Engineering (advertised on this site). It uses 6mm square and round tool blanks and has a jig for grinding, very easy to get the correct angles for cutting. Not the cheapest tool but well worth the money.

Paul.

Disagree.

Yes you don't need 5% Cobalt or M42 HSS, BUT... you DO WANT brand name HSS, it is not expensive. I stay clear of no name Chinese HSS.

I also disagree that grinding is a hassle, it is extremely simple, and in the smaller 1/4" and 5/16" sizes, very quick.

Plenty on YT to get you going.

I agree, the actual grade of the steel isn't that important but yes try to buy branded HSS. - Eclipse, Cleveland, Presto etc.

Hassle was probably the wrong word, inconvenient is probably better. While grinding isn't particularly difficult it's never going to be as easy as swapping a tip. Obviously you also need a grinder which can be messy to use. Thurther down the line if he ever decides to purchase a QCTP, carbide tips can be changed in place without any other adjustments. That can't be said about HSS. The tool would have to be removed from the holder for grinding, subsequently the new edge means centre hight is lost and will require readjustment.

I'm another one who thinks this is absolutely on the money.

Invest the time in developing the skill and you'll never be stymied for lack of a cutting tool - in fact the idea of buying somebody else's idea of what the tool should be like will seem like a restriction. Back in the 70s learning to grind your own tools offhand was a part of the standard Government Training Centre course in Centre Lathe Turning, and the effort spent on it has repaid itself for me more times than I can describe.