lathe tool help

Good morning Lee, can I add my thoughts for you and family. I only met John once, but corresponded with him freely over this forum and I valued his advice and expertise more than I can say.

To your question as to carbide or HSS lathe tools, my advice is HSS and a bench grinder all the way. It would be even if it was the more expensive option, as the results you will get will be much better. Here's my take on why.

Sweeping generalisation it may be, but in general carbide replaceable insert type tooling has been designed for optimum metal removal, with a completely rigid (at least by an amateur's view) machine and effectively unlimited power at the spindle. For a hobby lathe - or indeed anything available through the second-hand market and which hasn't had a major refit - both this conditions are way off. I know there are nice examples of Triumph 2000's say which are stiff and heavy and have got plenty of power, but by the time you graduate to one of these you'll be able to decide what tooling works for you on your own experience. A chap starting out on a hobby lathe has to put up with the built in limitations of his machine in terms of shaft horsepower and flexiness.

Carbide tools don't like un-rigid set ups. They chip and chatter, and now all the advantages of a replaceable tip tool are null and void. Sure, it's dead easy to replace the tool tip and wreck another one, but at a fiver a kick this makes for a expensive hobby. Moreover most (not all, but we'll come back to that) insert tools are not made with a sharp edge, as the cutting action is to cause the metal to flow over the tool edge and meet the chip breaker. The carbide material is strong in compression but intolerant to tension, so the edge of the insert is made intentionally blunt to make it stronger and last longer. As a rule of thumb if the chips are coming off the tool as a birds nest the feed and speed aren't high enough. You need power and therefore rigidity to make this happen.

Jenny at JB Tools sells a range of inserts without chip breakers, and with sharp edges for small lathe use. You might like to investigate these, but I still think that HSS is the way to go at least to begin with.

OK, so you have to buy a grinder, and some HSS blanks. How were you going to sharpen twist drills without the grinder?

Sharpening HSS blanks is only an exercise in metal sculpture. The shapes of the tool you want are simple enough, and the cutting action is remarkably tolerant of the actual angles you use. So long as the edge presented to the revolving work has got some clearance and some rake, it'll cut fine. You'll soon learn how to tune the tool geometry for good results, it's not a black art whatever anyone says.

HSS tools can be ground to be really evilly sharp so they cut freely, the material is easy to grind with a little bit of patience, and the whole system is very adaptable. But the big, big advantage HSS has over carbide is that it's very difficult to chip an HSS tool. You can concentrate on shaping the work piece without having to worry about all the variables of edge geometry and profile that are built into inserted carbide by the manufacturers. Not to mention different grades of carbide, having to get to grips with the insert coding system (there are two, a European system and an American system and it isn't always straightforward to see which is being used), and also the range of mounting configurations.

HSS? Easy Peasy. Just watch your surface speed and you'll get on fine.

Good luck, let us know how you get on.

Best rgds Simon

Lee,

PM sent to you, please check your in-box.

Ketan at ARC.

Listen to Ketan, I don't know him personally, but he seems to know what he's talking about, and he worked with your Uncle(or was it the other way round).

My suggestion is, start with HSS, get to know your lathe, then you will be able to decide for your self if you need Tungsten Carbide tools.

Ian S C

Hi Lee,

When I bought my lathe,I bought a set of those cheap turning tools,to begin with. I used two of them,the others are still in the box. I also bought a few tools with replacement tips,and broke some of them. I then turned to HSS,and never looked back. This material will do all you need and is both cheap and easy to grind to correct profiles [even I can do it !} A 3" or 4" length goes a long way,and even if you do break or chip it,so what,it,s easy to regrind and away you go. One way or the other,you will need a bench grinder,even a cheap one,since your drills wont stay sharp forever. Tipped tools are great for some jobs or materials,but for most of the stuff you are likely to be dealing with,I doubt if you will go far wrong with HSS.

Give it a try,you might be surprised !

Hello Lee,

My sympathies for the loss of John, he was a good friend.

I'd echo Ian's suggestion - start with an HSS set. They are more forgiving than tungsten carbide and easy to resharpen.

The TCT brazed tools are great for taking heavy cuts but are rarely a good option for precision work out of the box.

Tipped tools are great, once you have the confidence to use them properly, but few beginners will want to use the sorts of speeds and feeds that get the most out of them.

Neil

Choosing between HSS and Carbide is an old-chestnut. As a cack-handed beginner myself here's my take:

• HSS vs Carbide may not matter much to a beginner - they both cut metal.
• The downside of HSS is that it has to be kept sharp. This means buying a grinder and learning how to use it. Grinding is a skill that some find easier than others. I'm not very good at it. I'm afraid that chaps good at grinding 'it's easy' often forget that beginners struggle with it.
• The downside of carbide is that the start up cost is more than HSS because you have to buy holders. Also, carbide works best at high-speed, not ideal if you are a slow worker with old equipment.
• With experience you can change your mind. It doesn't mean much but I use HSS about 25% of the time, mainly because carbide on my machine doing the sort of work I do is usually more convenient. If I could only have one system, it would be HSS. Fortunately I'm allowed to use either!
  

If your lathe has a maximum spindle speed less than, say, 1800 rpm, then go HSS. Buy a grinder and learn how to use it. You can simplify sharpening and learn about common tip shapes by starting with an HSS toolset like this:

The photo is from the ArcEuroTrade website. They will be delighted to sell you one, other vendors are available.

If your lathe can do more than 1800rpm then Carbide is probably a better choice for rank beginners. All you have to do is mount the tool at centre height and away you go. Using carbide has the important advantage of removing the need to learn a new skill at a time when a beginner is already overloaded with workshop mysteries! ArcEuroTrade are worth a look because they carry a simplified range of holders and inserts suitable for most hobby purposes. In contrast a general search of carbide inserts on the web is liable to leave the beginner feeling like a rabbit caught in headlights!

The important thing is to make a start.

Dave

Lee

I've also sent you a PM. The not always obviously flashing envelope symbol at the top left of the page.

David

Another vote for HSS Lee - I started out with a set similar to the ARC offering pictured in Dave (SillyOldDuffer's) post because the whole thing about tool geometry was too much to get my head round when trying to learn so much other stuff. Eventually I realised that you don't actually need those fancy hollow ground bits - but it was a good place to start and get to know my first lathe.

Now I mostly grind my own stuff - your uncle John gave me a hands-on tutorial once, bish-bosh, job done in about 3 minutes, can't claim to be as fast or confident as he was, but he showed me that there wasn't anything mysterious about the process.

No one has mentioned the carbide inserts designed for cutting aluminium - sharp by carbide standards, a steep positive top rake - but weirdly OK for brass and MS as well, at least for me at sub-industrial feeds/speeds.

Rob

I also reckon HSS is good for starting out. I personally wouldn’t touch brazed carbide tooling. I also like Tangential tool holders as they do 90% of what I do and are cheap to run. The polished carbide inserts Robin mentioned are also good though for some jobs.

Buy two cheapish basic sets of HSS. Also some HSS blanks later or at the same time.

Use one set, and retain the other to compare the sharpening profile while you practise sharpening. Buy other cutters as and when you need, if the need arises.

Progress to carbide as and when you feel the need to experiment, or for very hard steels.

Having two (or a few) unused cutters and persevering with sharpening the used set is better than several blunt/broken cutters and still no idea of what the profile should be. A small angle checking device is good for a beginner, so the new grind can be compared with a factory item.

Experience only comes with practising ... and quite quickly if you persevere. Some means of honing the edges is an important aspect, to retain a keen cutting edge for longer.

Hello,

I'd like to add my experience on this, I was shown replacable carbide tip tools cutting and they worked superbly, can't fault them, but this was on a large machine. I own a myford ML4, a much,Much smaller lathe. I have chosen early on to go down the route of HSS, as mentioned above it's resharpened and shaped to any form easily, it really is not a black art, the key is the wheel on the grinder, it's gotta be clean, free of dirt and balanced. When the HSS is sharpened the diamonds (grit) in the wheels becomes clogged with dust, they dull and don't cut so well. A clean bright wheel (it'll almost sparkle in different lights) produces a happy tool. Also a small plastic cup of water to the side helps to keep the tool cool, dip in the water after every few passes.

The tool angles aren't too critical to begin with, the wheel will form most of the clearance angle, turn the tool face 90° to the wheel and take a grind, lightly across the face of the wheel from left to right, or right to left, (your preference but alternating will help keep the wheel square and balanced), until you see red sparks from the top surface of the tool, once you see those red sparks cresting the top surface then you can stop grinding the clearance.

Next rotate the HSS on the rest to about 6°, (look at a cheap stationay set, it' not much of an angle), take a few passed as before, don't forget to keep it cool with the plastic beaker of water.

The above two grinding operations form clearance from the cylindrical work, meaning it won't rub and "chatter" (looking at the chuck from the tailstock), the second forms a clearance from the cut cylindrical piece of work, slightly angled away from the cutting point, again to prevent rub and chatter.

If your just planning on turning brass or Ali, this is as far as you need to go to get a tool ready for the lathe, oh apart from honing...come to that in a min.

If your turning steel then you'll need top rake, this is done by tilting your grinding rest at a slight upward angle, then placing the top surface of your tool (cutting point facing upward) 90° to the face of the grinder. Grind away until the red sparks crest the surface again, remembering to cool the tool in water ever few touches to the wheel. You should now have major clearances sorted for brass, Ali, and even steel or cast iron.

To finish you need to hone the tip, this is a small radius that is put onto the sharp point of all the grinds you have done, this is done by hand on an oil stone.

Oil the stone around a 5cm dribble of 3 in 1 will do, spread with your finger tip, and coat the tool tip with oil from the stone, hold the tool top surface 90° to the top surface of the stone, or slightly less to your first relief angle. Take a long (10cm) sweep over the oil stone rotating just your wrist. You should see a small round been added to the tool tip, the greater the round the smoother the finish, however the greater the round the harder it is to get a tight corner on relief work, (a rim on a flywheel for example).

Practice and learn these basics they'll help you loads in the future and save you a fortune in carbide tools, holders and tips.

If you plan to cut stainless, you'll need carbide unfortunately. HSS will blunt really quick, and you'll need high speeds.

All the best to you and your family from another rookie

Firstly i'd like to say sorry for the delayed reply everyone i will explain why shortly.

Wow as my first thread on here i was not expecting the overwhelming positive response i have recieved .This has really brightened me up because im a self taught hobbyist and often ask questions but most go un awnsered .

It seems clear from the response hss is the way to go so thats that ! . I like "not dont it yet" comment about buyiny a set of cutters and replicating them from blanks this seems logical to me and will give this method a go.. However if my tool cutting skills match up to my drill sharpening i'm screwed . It is now time to get a bench grinder which will be nice as i only got a bench yesterday .

The reason for a late reply is whilst installing my workbench in my toolshop ( its not really a toolshop its a coal shed outside my house but i can dream) My lovely missus had left the shed unattended whilst the log burner was roaring and it caught fire All my electronics tools , my bodged up homemade cnc and drone bits are now a melted puddle of god knows what

If someone could direct me how to ill post photos of the damage

The moral of the story is dont keep all your tools in one basket

sorry to hear of the fire damage, hopefully something(s) is/are recoverable....?

Here's the link for info on posting images...

**LINK**

I'd also go with HSS. The shapes of the above kits are a bit idiosyncratic but they are sharp. I would always thin the parting tool so that the tip is about 3mm wide. Some of these kits have such a wide tip they would only be any use on a very rigid industrial size lathe with loads of power. I found the steel in the kit I bought to be very good. Tools stay sharp for a long time and mostly only need some help from a small stone.

Oh dear!

You lost a good mentor in your uncle, (as we all did) and now a lot of kit.

Having said that, as you now see, there is a LOT of experience and help available on here. So welcome aboard!

HSS will stand being knocked, (interrupted cuts and accidents) which Carbide won't. Carbide is at its best in a rigid machine, running at high speed, which is not really hobby machine territory, although many of use it.

My advice, FWITW, is to heat the shop with dry heat, rather than gas or solid fuel, and do allow some ventilation, (one vent set high and one set low to allow the damp air to exit)

If it is possible to insulate, do so, (polystyrene sheets fixed to the walls and ceiling?) Improves comfort and obviously reduces heat loss, and keeps cooler in the summer. (My wooden shop has 50mm of glass fibre on walls and ceiling, and is comfortable at all times)

From here the way is forward!

Howard

Hello Lee.

I very rarely post here but I like to read the posts of others even if just for a laugh sometimes. Truth is, you can ask ask 7 experts and get 8 different answers.

I won't presume to be any sort of expert but I can offer you some HSS steel blanks to have a play with. I would imaging that there are hundreds sitting around doing nothing and many lifetimes worth of cutting tools. If you live down south....(Essex area) I would happily make you a coffee and sort out some HHS bits for you to use or practice with.

Best regards

Gazza

Workshop fire - nightmare!

Couple of people have mentioned carbide chipping. Certainly used to be true but improvements have been made. I was responsible for this catastrophic dig-in:

I did it with the smallest and sharpest carbide index I own, a non-ferrous CCGT 060204 in a 6mm holder:

As you can see the insert was undamaged by the smash.

It's worth remembering that HSS has been at the end of the line in terms of development for many years now. It's not going to get any better. Not so carbide which, being mainstream, has steadily improved since it was first introduced. It's still being actively developed and may be tougher than you think! I certainly work carbide MUCH harder than HSS; in my workshop it's HSS that gets mollycoddled.

Dave

I'm beginning to wonder whether you have shares in carbide manufacturers, Dave.

Michael W