Hss or Carbide Tooling?

[Chris FarbraceParticipant @chrisfarbrace]

[Chris FarbraceParticipant @chrisfarbrace]

Hello everybody,I am taking my first tentative steps into your engineering world.Ihave obtained (at  very resonable cost) a sieg c4 lathe which is bigger than the minilathes at about 8×17(see Chesters Comet model).I couldnt afford the apparrent “holy grail” of a myford but this machine does not appear to be rough or thrown together but as they say “the proof of the pudding”.Iam at the moment trying to get together all the other bits required,tailstock chuck,4 jaw chuck,etc etc etc.you know how it goes! but really do need some advice on cutting tools,Ive seen the previous discussions on carbide tooling but still not sure if they would be the right choice for me.Does anybody have experience of the Glanze type indexable carbide turning and facing tools from people like chronos they seem to be promoted as being very good or is Hss the way to go?Would love to hear any comments from you more experienced guys,many thanks.

[ChrisParticipant @chris16039]

Hi

I am using the glanze parting tool from Chronos and find is to be very good. I also us similar cutting tools and for general work find them unbeatable. Generally I find the indexable bits don’t have a ‘sharp corner’ which is sometimes required.

A tool you can grind to shape for special aplications is always needed but for general use my money is with the replacable bits.

Hope that made some sense. I’m just a novice myself but took the advice of a miller and turner and have had no regrets.

Chris.

[DugsonParticipant @dugson]

Carbide tooling is very usefull on small machines for machining hard materials eg. the skin on cast iron.

 

It is not possible to obtain the benefits of carbide tooling on small lathes because generally they don’t have sufficient power to run at the speeds required for efficient cutting with carbide.

 

Most carbide bits don’t have a sharp corner because carbide is very brittle and a sharp corner is therefore easy to break, tools are designed with minimal front clearance for the same reason.

 

For general machining in a home workshop on a small lathe HSS is hard to beat, but you will have to do a bit of study/trial and error, to learn how to sharpen tools made from it.

 

For a Myford Super Seven most of my work is done with HSS I have a few carbide tools which are rarely used, for a beginner take a look at the Diamond toolholder from Eccentric Engineering advertised in MEW it is very versatile, easy to sharpen and the toolbits are cheap. 

[Ian AbbottParticipant @ianabbott31222]

HSS generally can be given a much better edge than carbide tips.  Unfortunately, the edge dulls way faster, so sharpening frequently is essential.  For wood working, carbide is only good for fast work and lengthy periods between tool maintenance.

For metal, I only use carbide tips for castings and a useful supply if one knows someone is a workshop where auto brake drum and disc turning is done.

I picked up a blue diamond, bell shaped  tool from a workshop getting on for thirty years ago and I’m still using it.  It was past its best for production work, but works well for me.  Come to think about it, most of my stuff is cast offs.

The one thing for a beginner sharpening HSS to watch out for is to avoid overheating the tip when sharpening, so as not to lose the temper.  Ultra cool, much coolant.   I use a nice open white wheel for HSS run dry.  Another cast off.  The hole is way to big for any arbour, so I carefully mount it on the three jaw chuck in the Randa at about 500 rpm.  There isn’t much dust, but a piece of rag draped over the bed keeps any stray grit away.  One advantage here is that a tool can be mounted on the top slide for consistent, accurate passes.

 

Ian 

[Chris FarbraceParticipant @chrisfarbrace]

Hello,many thanks to all who replied to my question definately food for thought,will probably go  down the route of grinding up some Hss  but also re Chris’s reply might try one good quality carbide tool see how it goes,anybody else using the Diamond toolholder as suggested by Dugson with any success?  looks like this forum will be a great asset regards Chris.

[DugsonParticipant @dugson]

Chris

I have used a diamond toolholder for years they are excellent and easy to sharpen look at their web site and the video

Dugson

[mgjParticipant @mgj]

It has to be said that grinding HSS is not that easy – to get consistently sharp – and consistent is probably the operative word – without some sort of grinding jig or cutter grinder.

 

From that point of view, the Eccentric tools holder looks very good, because even with a proper tool and cutter grinder, it does take a few minutes to set up before grinding. That thing looks as if it will work of a plain offhand grinding wheel rest.  – and you get easy set up screwcutting tools out of it as well.

 

I think, for the model engineer, the advantages of carbide are somewhat misrepresented. Everyone goes on about speed of cutting etc. That’s not it for me – its the fact that you can have, quickly, conveniently and easily, sharp tools with no hassle (at a price!), which will consistently produce a good to excellent finish. Are they sharp – yes – very. But the radiused tip means that often they are reluctant to do a shaving cut, so hitting a diameter to say +/-.0002″ is a matter of good technique.

 

The only disadvantage perhaps, is the rake. With HSS you can grind in quite a steep rake angle which generates an “inwards” pull. That greatly reduces the load on the feed mechanism (Don’t go overboard!). You don’t get that with tips. That is quite a help with the smaller ME type of lathe

 

So you pays your money and takes your choice. I use tips almost entirely, but I do keep a selection of Quorn sharpened HSS for particular tasks. Also with  an adaptor for ER25 collets, the Quorn is just brilliant for sharpening drills, slots drills, and spiral cutters like endmills – paid for itself hands down.

 

Oh and the one tipped tool that is just the must have – can’t be without, won’t jam –  is a proper parting tool. I have a Glanze sliding blade type with a 2mm wide tip. And one from Greenwood which uses the Sandvik 2.5mm tip. The Kit Q cut from Greenwood is the more expensive, and cuts much more freely and to a better finish, even though it is broader. Probably the tip geometry. The Greenwood is, for my money not only superior, but can also be fitted with a greater variety of tips.

Edited By meyrick griffith-jones on 09/08/2009 09:45:01

Edited By meyrick griffith-jones on 09/08/2009 09:46:26

Edited By meyrick griffith-jones on 09/08/2009 09:55:08

[Peter GainParticipant @petergain89847]

Hi Chris,

Refer to “Milling – A Complete Course” By Harold Hall. Construct the simple grinding rest fully described there-in. This will provide good machining practice & enable you to sharpen HSS toolsteel. Then use indexable tips for fast, rough turning follwed by HSS for fine finish. HSS will remove the merest whisper of material unlike indexable tips which do not like removing much less than a couple of thou.

Regards,

Peter Gain.

[mgjParticipant @mgj]

Taking whispers?

 

Does one actually need to?

 

 

I’d rough to .010 oversize. Measure. Split the difference and cut – measure. So you now have a final cut that will be, to all intents a purposes offering the same conditions as the last measured cut – spring in the material, feed rate etc. If the lathe is halfway reasonable you will hit diameter. In general its only if the last measured cut is significantly different from the final one that diameters go awry. You might just have to polish up a touch with emery and oil just to get all running absolutely smoothly, but if one has a micrometer one is only talking a tenth or so …

 

Taking whispers off is, for my money, an easy way to get the tool to rub, or to run the risk of it anyway.  Especially if one is turning to a good finish and so one has just broken the tip of the tool with a stone, which is, I understand standard practise. Not least because a very small radius reduces the stress raiser at a shoulder. Which is exactly why these carbide tips have a radius in the first place – its partly about finish and nose strength, but mostly its about that stress raiser or sharp notch which is the great engineering no-no. .

 

I think too that a lot of these troublesome shaving cuts can be eliminated by avoiding trial and error. For instance in The Engineers Handbook, all the classes of fit are listed. So if one wants a precision running fit, (or whatever) and one actualy applies that data given, thats what one will get, and the odd thenth or two becomes irrelevant. It may seem a counsel of perfection – perhaps it is! But it don’t half save a lot of hassle and wasted time.

 

With aplologies to grannies, and those who use metric. (Your time will come, but it isn’t here yet. Mercifully. )

Edited By meyrick griffith-jones on 09/08/2009 13:43:17

[Geoff TheasbyParticipant @geofftheasby]

Hi,

 

I too am just a beginner, and I haven’t made much, yet.

However, I use HSS bits from Chronos and have broken one or two (my fault).   I reground them by hand on a bench grinder, and they seemed to work OK afterwards.   I also regrind twist drills by hand on the grinder, and they seem to work OK, too.

 

I wonder if we don’t make too much of getting all the angles right, I know how to put rake on, and am not looking for a mirror finish, so maybe I am just building up a list of bad habits?   Ho Ho.

 

Regards

Geoff

[mgjParticipant @mgj]

Perhaps you are doing what we all did when we started. Grinding offhand – which is OK in so far as it goes.It works, mostly, but sometimes you get a great finish, sometimes less good and so on.

 

But I promise you (said he unintentionally pompously) the difference between a hand sharpened tool and a properly Quorned one (or I expect any other jig sharpened one), is chalk and cheese. Also to sharpen up, I can just set my angles, skim a thou or 2 off which is only a couple of passes, plus one more on the fine stone to polish, and away I go sharp all along the whole edge. I don’t waste metal or time, and good high grade HSS is not to be wasted these days given its price. (Eclipse, Cleveland or Sandvik, as opposed to the far eastern unspecified monkey metal)

 

Drills – sorry – no comaprison. Once you have a means of holding drills properly along the flutes (and the ER collets will do just that), then you can (4 facet) sharpen drills that cut so fast you simply cannot keep up with them – and they will cut straight and to dead size, and don’t wander on startup -(they have a built in centring action) – nor do they  leave a burr on break through like a new one does. And you can back one off for brass, bronze and copper to stop it grabbing, and then resharpen easily.  Chalk and cheese.

 

Not looking for a mirror finish? With respect, that comes naturally when the tool is properly sharp and radiused. There’s no need to look for it.

 

Its a moot point IMHO, whether the first tool you build is Quorn/Kennet or Hemingway equivalent, or the GHT Versatile Dividing head, but both are things I wouldn’t be without.

 

 

[Ian AbbottParticipant @ianabbott31222]

I used to sharpen all my drills freehand and they were dead on.   Now I can’t see the end of the drill, so I bought a sharpener a couple of years ago, makes as good a job as i ever did.  I think I paid about $120 when I was in Canada, ’bout sixty five quid.

 

On finishing cuts.  If I even thought about not shaving a thou off on the final cut, a big hand from my apprenticeship would appear and slap me round the ear.  It’s one of those things that decades can’t erase.  I still can’t pick up a hacksaw or file without hearing the voices… “… and don’t rock the saw!”  ”… keep that file flat!”  The neuroses that I’m packing around from then are scary.

 

Ian 

[mgjParticipant @mgj]

Well there’s obviously more than one way to skin a cat.

 

I was taught never to take a shaving cut, and got into the habit of doing so, because a lot of the materials I have used Ti, 13/18 aluminium armour, RHA and stainless all workharden like fury. So one just learned not to.

 

I know I have fouled up a surface by taking a shaving cut, so ……actually my real point was that if you set up the final 2 cutts correctly, you never need to take a shaving cut.

[ChrisHParticipant @chrish]

This is another interesting thread to someone used to using just mainly HSS tool bits for turning, all hand ground.

 

I have no doubt at all that both a Quorn/Kennet or  Hemingway tool grinder/jig and a DHT Versatile Dividing Head would be considered very desirable or even essential items of kit in the workshop.  But setting up a workshop from scratch is an expensive business.  I was lucky in obtaining a lathe a few years ago, together with a modest drill press, a grinder and numerous power and hand tools, but now adding to it is a major item of cost for each item, be it a vertical mill or band saw or whatever is next deemed to be essential.  Plus the cost justification necessary in persuading SWHBO of it’s essentialness has to be considered!

 

So, playing devils advocate, given that for certain jobs a Dividing Head of some description is essential, at what stage does forking out 3-400 quid for a Quorn/Kennet or  Hemingway tool grinder/jig become one?  Yes, repeatability and precision of grinding tool bits is an advantage and a Good Thing, as is not wasting more HSS than is necessary, but you can buy a lot of HSS tool steel for 400 quid.

 

Any thoughts on this anyone please?  I would like to be persuaded!

 

ChrisH 

[CirclipParticipant @circlip]

ChrisH, go back to Peter Gain’s reply re the H. Hall book. (Buy BOTH of them and get another FREE). You’ve already got a bench grinder and if you make the ADVANCED H. Hall fittings, you’re Going to have at LEAST £350 change.

 

  If you have any Yorkshire blood in you it’s a no brainer.

 

   Regards  Ian.

[Barry QParticipant @barryq]

Circlip,
I’ve not a scrap of Yorkshire blood in me but I’m going to look at H Hall’s books. Thanks for directing me to Peter Gain’s reply. Also thank you Peter for the initial info that I didn’t notice first time round. This is what forums are about – helping each other and assisting beginners like me to learn fast.

Best regards

Barry Q.

[mgjParticipant @mgj]

Depends on how you view it !

 

The tool and cutter grinder doesn’t have to be a Quorn – that was one of the few around at the time. 

 

However, what became clear to me was that decent tooling was a must and I was never able to offhand grind a good tool every time.

 

I built the Quorn so I could sharpen tool accurately so I could build an accurate mill (the Dore Westbury.)

 

Any sharpening jig is worth the investment. Where a proper cutter grinder paid ( and this cam as a sort of accidental discovery) was in the sharpening of drills, making radius cutters that worked first time and so on.

 

You don’t have to sharpen many  1/2 drill bits, or slot drills, or 3/4 3MT shank drills to make your money back.

 

I know also that some say they can sharpen these drills free hand. Well there is sharpened and sharpened. And there is also cutting dead straight and to dimension. If that is important to you, Ok, build a Quorn or Stent or Worden. If its not, well thats fine too.

 

It’s just two different points of view – but I wouldn’t sell that Quorn!.(And since I have one, I don’t need to make another)

 

 

 

 

Edited By meyrick griffith-jones on 18/08/2009 18:38:27

[CirclipParticipant @circlip]

Meyrick, I have total respect for your posting re Prof DH’s exellent piece of tooling and the “Lesser” but not inferior tool and cutter grinders, but for the beginners, getting them to at least aknowledge they need a method of repeatably grinding a tool (Rather than going down the chuck away bits of industrial rejects) is a start. Must admit, that although brought up with the propper “Gear” when a “Child” in the toolroom, the only piece of equipment I would have sold my soul to own was the Christensen Drill grinder, oh to be able to sharpen No.80 drills again.

 

  Given that the Jigs sold for a few quid are good for use as a paper weight in the workshop, Harold has made quite a good fist of basically re-inventing, with improvements, a bit of jiggery work started by Duplex in 1948. If some of the newbies have the tenacity to stick out the foibles of weird and not to scale or erronious drawings, super, but with the best will in the world, without making tooling to make tooling to make tooling, a Quorn is a long way down the must have list.

 

  Regards  Ian.

Edited By Circlip on 19/08/2009 13:36:23

Edited By Circlip on 19/08/2009 13:37:05

[mgjParticipant @mgj]

Ian – I agree totally.

 

A Quorn, for most (including me) is total overkill. Like I said, back in the early 80s a Quorn or a Stent was about all you could get. But, having got one, I find I use most of its capabilities(including oh cheapskate!!) resharpening carbide tips with a green grit wheel!!! So I’m very glad of it and I wouldn’t get rid of it.

 

I’ve got Harold Halls book and his sharpening jig looks pretty good.

 

Were I to go the HSS route again, I think I’d get the Eccentric tool holder because that gives you a good turning tool and  both  55 and 60deg threading, and the appropriate sharpening jig. Next some kind of reasonable drill sharpener. Pretty much anything else is likely to be a one off and one can hand gind, unless you have very specific purposes in mind.

 

That would do 95% of any model engineers sharpening to a good standard.

 

Like all these things, its 90% of the result for 50% of the effort. If you want to be able to make reamers, or proper radiused cutters, or sharpen the edges of endmills then one has to think again. (and I do because it saves money and I can – but only because I can).

 

I also think that a lot of the need for a Quorn type cutter grinder has disappeared – if you want to pay the price. We have inserted tip milling cutters, threading tools. FC3 throwaway cutters etc. Of them all, the only one which is IMO a must have, is a tipped parting tool, because Quorn or not, I have never met a parting tool which matches the Sandvik tipped jobs (Greenwood, Sandvik etc)

 

However,  I would disagree with  those who reckon one can offhand grind HSS really effectively. Because one simply cannot.. And once one has used one of these decent grinders/jigs you know that to be true.

 

So its just a matter of how far down the route you want to go – but for sure, some way down it is essential.

 

 

Edited By meyrick griffith-jones on 19/08/2009 18:20:24

[ChrisHParticipant @chrish]

Thanks everybody for the replies so far on the grinder/grinding jigs topic.  As BarryQ said – this is what forums are about and how they can help by spreading other peoples hard won experience around, so all the comments have been well appreciated whilst giving me much to think about.

 

I too will get the H.Hall books, and have looked at the diamond toolholder with considerable interest and added it to the “would like to have” list, along with aforesaid Hemingway kits and Sandvik tipped parting tool.  If only one had a bottomless pot of money……….! Still, slowly, slowly catchee monkey as they say!  Will get there one day, but at least I am convinced of the need to go down that road now – thanks fella’s.

 

ChrisH 

[jomacParticipant @jomac]

Oh!!! for a decent Tool & Cutter Grinder.

I looked at a few designs and ideas in ME & MEW also H Halls, all seem to have some limitations and easy of manufacture.

So  Graham Howe, was good enough to point me in the direction of MaryPoppinBag on the E/bay site, where they sell all sorts of goodies,One of these is the CD on tool& cutter grinders, which has the complete manuals of many industrial tool sharpeners, More importantley it also has 65 pages of drawings and instructions for the Bonnelle T&CG, the photo’s show a very interesting machine that can sharpen lathe tools, drills, milling cutters, reamers etc etc. By the way I am in no way connected to the above people.

The Bonnelle looks complicated, but not as much as the Quorn, so when I can get some spare time, I will look in the scrap box and harrass my local steel merchant, and see what eventuates, Maybe Harold Halls grinding tool holder could be a start , then the Bonnelle or a variation on all of them.

As for sharpening by free hand, I can do it reasonable proficentley, but its a real hassle cause when my fingers get  hot I know the tool is probabley way overheated and I need to start again.

Which reminds me, that years ago while working on site, 30 miles away from  the workshop, and trying to sharpen drills up to 30mm diameter, that we had worn,  broken, or chipped, and were doing this on the side of a 9″ angle grinder, or the side of the portable steel drop saw,  now that was a pain in the butt, Why they chipped, was mainley because the holes that were punched in the beams or brackets were usually undersize, maybe the chap punching the holes in the workshop was useing worn imperial size punches and not the metric equivalent, who knows  ??? We  should have had more backups or at least a decent grinder.

 

 

[CirclipParticipant @circlip]

Isn’t the Bonnelle a Quorn without castings?? The site you mention also sells other goodies to suit us, Reliable and TRUSTWORTHY too.

 

   Regards  Ian.

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