Indexable tooling

[patgasParticipant @patgas]

I’m looking for decent set of indexable tooling for my ml7, any recommendations that won’t break the bank.

 

[Andrew TinsleyParticipant @andrewtinsley63637]

I would buy individual items as and when you need them. Most of mine came from Arc.

Andrew.

[Martin of WickParticipant @martinofwick]

Don’t bother with a set, most of which you are unlikely to use. Without knowing what  what you intend to cut, difficult to give recommendations on tool type, insert type size etc. More info needed. For that machine I have 10mm shank tools and try to keep the insert size small.

SCLCR 101006 or SDJCR 101007 to start with and if you are planning to do a lot of facing or work on the left get a get an xxxCL version of your choice or even xxxCN where the tool is set centrally and you position as you wish to suit the cut.

If you set tools only on the top slide with conventional tool clamp, the 12mm shank tools require less packing up.

S12K to S06K scmt boring bars according to choice of size. I’m sure they make the equivalent for dcmt. Where possible, try to get scgt or dcgt depending upon your preferred shape (these are ground and polished non ferrous type inserts).

I have had parting off success with MGEHR 150 using a 1.5mm carbide blade, but it is quite small. The wider 2 and 3mm tool blade equivalents are a bit hard work for the Myford.

All available at various on line markets. Generally, the holders from those sources are not the best, not even hardened in most cases but they do the job OK. purchase other tools individually as you require.

 

[Nigel Graham 2Participant @nigelgraham2]

Almost all of mine are from JB Tooling.

A point that catches me out sometimes on my ML7, is if using a Quick-Change Tool Post, consider the height of the tool itself.

On some settings, particularly when I need partially rotate the top-slide then the QCTP itself on that in order to reach the end of the work when turning between centres, the tool can’t be lowered enough to put the tip edge on centre height.

It also happens with the slides all-square, at least with my QCTP.

The problem is the size of the tool bar itself, and of course applies similarly to HSS tooling as well.

Having typed that, it’s just occurred to me to try using the 4-way toolpost instead!

…

A matter of choice but I am still not convinced indexable tools are always the way to go, and I use HSS tools about as often as carbide, but they do come into their own for screw-cutting and profiling to large root radii.

For screw-cutting I treated myself to a second tool-bar so one carries a 55º (Whitworth-form), the other a 60º (UNF and Metric), tips

[JohnFParticipant @johnf59703]

I do most of my work with HSS but do have some tipped tools and favour DCMT11 or DCGT11 tips — the M [for steel] are tougher and more robust but the G [for alloy] are much better for small machines IMO you can get a better finish and its possible to take small finishing cuts whereas the M type do not like small cuts !

As Nigel says most of the tool holders are 12mm or larger so I mill or grind off as close as practical to the tip location to 3/8″ and use in my Dickson tool post.   Any tools I have are bought as needed rather than sets but I do have two of the DCMT tools so I can have one with each type of tip ready for use.

John

[JasonBModerator @jasonb]

Glanze (Chronos) or APT are others to consider.

As said sets often have tools you won’t use much or maybe never and can be made up with various obscure insert shapes.

I mostly use CCMT/CCGT 06 inserts which fit both left and right turning tools as well as my boring bars so the same inserts can be used in all which saves having to keep a number of shapes. I think those three types and a 2mm parting tool would be a good starting point. Something like these.

Right Hand

left Hand

Boring

Parting subject to height check

You can then add things like a DC** holder to get in to tight spaces, holders to make use of the other two corners of the inserts and threading tools as needed.

Watch the tool height if using QCTPs as you may ony be able to use 6 or possibly 8mm square shanks, a 6mm shank will do for the type of cuts a Myford can take and also fits in better if using tailstock support.

All will tend to come with **MT inserts which are “blunt” and you may find you get better results with a **GT insert which are the usually bright ones intended for non ferrous metals but will also work on steel, iron and stainless. 0.2mm corner radius

[Nigel Graham 2]

On Nigel Graham 2 Said:

Almost all of mine are from JB Tooling.

A point that catches me out sometimes on my ML7, is if using a Quick-Change Tool Post, consider the height of the tool itself.

On some settings, particularly when I need partially rotate the top-slide then the QCTP itself on that in order to reach the end of the work when turning between centres, the tool can’t be lowered enough to put the tip edge on centre height.

It also happens with the slides all-square, at least with my QCTP.

The problem is the size of the tool bar itself, and of course applies similarly to HSS tooling as well.

Having typed that, it’s just occurred to me to try using the 4-way toolpost instead!

…

A matter of choice but I am still not convinced indexable tools are always the way to go, and I use HSS tools about as often as carbide, but they do come into their own for screw-cutting and profiling to large root radii.

For screw-cutting I treated myself to a second tool-bar so one carries a 55º (Whitworth-form), the other a 60º (UNF and Metric), tips

Rather than use the 4-way tool post when the QC won’t do I suggest you look into using two way posts for the indexable tooling. You will need to devise some way of accurate positional repeatability so you can rapidly interchange pre-loaded two ways and the QC post as necessary and be confident of positional repeatability. Being inherently much slimmer than a 4-way its much easier to get a tool into position on these tricky jobs when you just run out of room. In my experience that is most likely to occur on a tailstock supported task.

Perfectly satisfactory two way posts can be built up using stock steel plate sections for top and bottom with a solid spacer in between. light alloy does just fine for the spacer. In a perfect world you’d find just the right thickness of plate for the bottom so the tip height comes out just so. In practice it will almost certainly need to be shimmed but its a one and done process as the tool will most likely never need to come out of the post.

In 50 or so years of metal mangling I’ve rarely regretted taking time out to properly sort a fix for tricky stuff. But frequently, with 20-20 hindsight, wished I’d done it properly straight out rather than wasted considerable time bullying a less than ideal ad hoc semi solution into working. Don’t want to even contemplate the (possibly) years of workshop time wasted wrestling with the barely workable!

Clive

[JasonBModerator @jasonb]

Or choose a QCTP that has extended holders😊 Though these days it seldom gets used as I find a DCGT gets in just as well in most cases.

 

[derek hall 1Participant @derekhall1]

Morning Jason,

Can I ask how are you holding those spacers between the webs of your crankshaft?

I always wonder if it’s best to normalise BMS before machining a crankshaft out of it. Or rough out the shape first, as there are lots of locked up stresses in BMS.

I realise you have done lots of crank shafts before, do you get much movement between the webs after removing the spacers? Do you then skim the crankshaft after the spacers have been removed?

Regards

Derek

[Martin of WickParticipant @martinofwick]

For consideration later, bear in mind that dcgt inserts have a tip angle of 55 degrees and tcgt have 60 degrees, useful for threading.

Otherwise you can go down the thread specific insert route if you do a lot of threading work.

[JasonBModerator @jasonb]

Spacers were turned using teh gap to gauge their fit and are held in with hot melt glue, sometimes I will add wire as well. They should slip in with minimal clearance but not force the webs apart

I mostly use black (hot rolled bar) for crankshafts but in that case did mill it from bright.  I let it settle for a couple of weeks between roughing out and final machining. This black bar was left to settle for a couple of weeks after stitch driling out the waste

 

They mostly run true, the odd one that has had a bit of a bow can be cold set back into place. I did have one on a part finishe dengine where th eprevious builder made a big point of the cranks being cut from EN24 and that needed quite forceful cold setting to get it running how I wanted

 

[SillyOldDufferModerator @sillyoldduffer]

Conventional wisdom is against buying sets, but my advice is give them the benefit of the doubt.   Those who don’t like sets, I think, are those who already have tooling, perhaps using indexed inserts to supplement HSS, or already have a good understanding of what they need.   They are in the happy position of being able to save a few bob!  Beginners are different.

Beginners benefit more from sets because the tools provided become part of the learning experience.   I was told I would never use some of the tools, which turned out to be wrong, though it took me 5 years in one case!   It is true that a few tools get used far more than others.  Another major beginner advantage is sets allow newbies to get on with exploring what’s what.  A weekend spent playing with a new lathe, some free-cutting Steel, Aluminium, Brass and a box set of cutters won’t be wasted.

I think rejecting sets on principle is too simple.   The value of a set depends on how good a fit the tools are to the needs of the purchaser.  So look at what’s in the set and engage brain.   My example is from Warco chosen because it’s typical, and because I’ve not had a problem with Warco tooling!  The contents suit me fairly well, but aren’t for everyone.   I’ve colour coded and numbered the tools for reference.  Let’s pick this innocent set apart.

The tools ringed in blue are for threading inserts.   Probably metric if the set is bought anywhere in the world apart from North America, but check.    Fairly obviously, a pair of metric threading tools won’t be valuable in an Imperial only workshop.  And likewise, a pair of unified thread cutters aren’t much cop in a metric shop.   Good or bad?  It depends on what your workshop needs.

The tools boxed in Green are for internal use – 3 boring bars and an internal threader.  Of the boring bars, I mostly use type 2, with a dash of #1.   Again, whether the set selection is good or bad, depends.  In my case, I don’t do much internal work, so the set is slightly over-provisioned.  I wasted a few quid, so what.

The tools boxed in Red are for external cutting.  They’re all useful in my workshop.   My criticism is that a tool is missing – I need Right and Left hand versions of #2.

The unringed tool in the centre is a front-mounting parting-off tool.  Even though I prefer parting-off with a rear-mounted blade because it’s idiot proof, its often quicker to part-off from the front because set-up time is much reduced.   Unfortunatetly trouble-free parting-off from the front requires more rigidity than most small lathes have, and the machine having a powered cross-slide helps enormously.   This tool works well on my WM280, but would be hopeless on a mini-lathe.  Anyone use this type on a Myford?  My gut feel is their rigidity is borderline for parting-off with carbide, especially with the tool held in a QCTP.   I have no experience though!

Whether or not the inserts provided with a set are ideal depends on the type of work too.  Though golden coated inserts cut well-enough for me on a relatively fast powerful Chinese hobby lathe, I like the sharp silver type intended for non-ferrous work.   Easier to get good finish.   Choice is difficult because a huge range of insert shapes are available, Sandvik’s website is helpful.

I hope it’s obvious that others doing the same analysis on a set could come to entirely different conclusions.  That’s expected:  choosing tools is rarely black-and-white because so much depends on the job in hand.   Fortunately stuff is rarely critical in a home-workshop though, so we usually manage.

Finally, if analysing a few sets identifies your list of essential tools, they can be ordered individually.

Dave

 

[not done it yetParticipant @notdoneityet]

Dave, he’s a beginner?  Maybe needs to know about that red box (‘cos you duplicated the green box and omitted the red one🙂).

[Nigel Graham 2Participant @nigelgraham2]

Clive –

Thankyou for the hint: I have always used my Myford’s rear tool-post just for the parting tools but there is no reason I can’t use it for other tools.

 

Jason –

I’d be wary of extended tool-holders. Sometimes we have to push the tool forwards but it does increase the cantilever effect, and on a small lathe the less overhang the better.

 

Sorry Dave –

-but why are Unified thread cutters unsuitable for an all-metric workshop? The thread angle – 60º – is the same for both systems.

There is point we need remember with Whitworth-form threads (55º). Even if we use all-metric dimensions for everything else, the standard pipe thread outside of the USA and fittings made to US standards, is still BSP (the ISO calls it “G”), and that is of Whitworth form.

.

Regarding crankshaft material, I would go for hot-rolled material, not BMS at all. I don’t know if round may be better than rectangular section if you do use BMS, though a bit wasteful of metal and taking a lot more machining.

I cut my steam-wagon’s crankshaft cut from a scrap of old quarry tramway wagon axle – so I have no idea of the steel grade, but it has had many decades of outdoor life to normalise it… sort of. I would blame any run-out on my machining rather than its metallurgy.

I milled it to an ‘L’-section, chain-drilled it, so it looked a bit like that stage on Jason’s. Then milled it further to remove the “teeth” and edges, to be kind to the lathe.

[JasonBModerator @jasonb]

Oh dear I feel I don’t agree with Dave again.

lets take those 3 boring bars. All of similar size, to me if you are going to buy three boring bars then get them in three different sizes to cover a range of holes say 6, 10 and 16 mm shank.

Now look at the position of the inserts, All are for through holes, ones that can do blind holes and also face the bottom of a hole are far more useful. (EDIT, just looked at a bigger image, one will do blind/bottoms)

Lastly two or possibly 3 insert shapes which means you need to keep a larger range of spares.

Red external tools. Only one that allows machining to an edge or shoulder, again a mix of insert shapes and as Dave says no LH tool though the right will do most work.

09 size inserts on most of them except the 6mm square means cost of inserts will be higher and you are unlikely to make much us eof teh additional length of cutting edge the bigger inserts offer.

Someone above mentioned using the MEGH type tool on their Myford though they do have a more limited range of diameter than the blade type as well as more frontal overhang as you can’t adjust the stick out.

That is why I don’t suggest beginners buy sets. Though there are worse sets out there.

[JasonBModerator @jasonb]

Nigel, the extended holder offers more support for those occions when a tool ha sto be extended a long way from the tool post, otherwise as you say keep overhang to a minimum.

UN and Metric inserts are different, angles may be the same but radii are different and particularly with full form they are made to a specific pitch so you could not use a 1mm to cut 24tpi for example without mashing the crests due to the topping action of the insert.

[Martin of WickParticipant @martinofwick]

Dave, I am afraid you have rather proved the point regarding sets – rarely use all you have provided, don’t have the one you need! Additionally, apart from the wnxx, the angle of inserts on your set just seems a bit odd to me (I’m sure they work fine, just odd).

My alternative would be a commonly available left and a right  ccxx holder with 95 degree insert set, ditto boring bar (s) possibly a neutral set ccxx for chamfering . If you deal with a lot of tight spaces, substitute ccxx insert tooling for dcxx inserts (or purchase in addition).  Four tools, 1 insert type.

Agree with comments regarding 2mm part off tools and Myfords. Not impossible with 2mm bits, but not easy either so best avoided, hence go for 1.5mm tools not commonly available in sets or stick with HSS.

Threading – decide if how much you do justifies extra tooling and insert cost.

[not done it yet]

On not done it yet Said:

Dave, he’s a beginner?  Maybe needs to know about that red box (‘cos you duplicated the green box and omitted the red one🙂).

What are you seeing NDIY?  Can you publish a screenshot?  Looks OK to me, but we might have a variant of the image posting bug.

Just had a thought. Colour blindness!  Apologies if that’s the case – highlighting with green and red boxes was a poor choice on my part, because colour blindness is a well-known problem.  I do know better!

Ooops – late edit. Just spotted a silly typo – thanks NDIY.

Dave

[Nigel Graham 2]

On Nigel Graham 2 Said:

…
 

Sorry Dave –

-but why are Unified thread cutters unsuitable for an all-metric workshop? The thread angle – 60º – is the same for both systems.

…

Good question, and either will be fine for both in most circumstances.  This explains why it might matter.

The ISO inch thread series form, (the Unified thread) is defined in the standard ISO 68-2. Originally, the metric and Unified design profiles were identical. The minimum root radius of both threads being 0.108P. In 1975 it was proposed that for the metric thread the minimum root radius be increased to 0.125P, except for property classes less than 8.8. This was to improve the thread’s fatigue performance. Accordingly, the design forms of the inch and metric thread differ in regard to the minimum allowable root radius.

So a full-form metric insert is slightly different to a full-form Unified insert.   Does it matter – probably not!

Thanks for questioning it, and mentioning Whitworth.

Dave

 

[Nigel Graham 2]

On Nigel Graham 2 Said:

Almost all of mine are from JB Tooling.

A point that catches me out sometimes on my ML7, is if using a Quick-Change Tool Post, consider the height of the tool itself.

On some settings, particularly when I need partially rotate the top-slide then the QCTP itself on that in order to reach the end of the work when turning between centres, the tool can’t be lowered enough to put the tip edge on centre height.

It also happens with the slides all-square, at least with my QCTP.

The problem is the size of the tool bar itself, and of course applies similarly to HSS tooling as well.

Having typed that, it’s just occurred to me to try using the 4-way toolpost instead!

…

A matter of choice but I am still not convinced indexable tools are always the way to go, and I use HSS tools about as often as carbide, but they do come into their own for screw-cutting and profiling to large root radii.

For screw-cutting I treated myself to a second tool-bar so one carries a 55º (Whitworth-form), the other a 60º (UNF and Metric), tips

I’ve also bought from Jenny, at one of the shows. The last one was double sided for both left and right hand cutting which has come in handy once or twice.

[SillyOldDuffer]

On SillyOldDuffer Said:

On Nigel Graham 2 Said:

…
Sorry Dave –

-but why are Unified thread cutters unsuitable for an all-metric workshop? The thread angle – 60º – is the same for both systems.

…

Does it matter – probably not!

 

Dave

 

Dave read my explanation as to why it matters with full form a bit further up.

Partial form inserts are sold by the angle not the thread form so are neither metric or imperial.

[patgasParticipant @patgas]

So as much as I appreciate your input, this really grew some legs and I’m none the wiser.
I’m interested in these comments and purchasing mind-

My alternative would be a commonly available left and a right  ccxx holder with 95 degree insert set, ditto boring bar (s) possibly a neutral set ccxx for chamfering . If you deal with a lot of tight spaces, substitute ccxx insert tooling for dcxx inserts (or purchase in addition).  Four tools, 1 insert type.

Agree with comments regarding 2mm part off tools and Myfords. Not impossible with 2mm bits, but not easy either so best avoided, hence go for 1.5mm tools not commonly available in sets or stick with HSS.

[Martin of WickParticipant @martinofwick]

So below is a basic 10mm shank  left, right and centre  + 10mm boring bar turning tool collection for dcxx 07 inserts available either as a set or individually from the usual markets (cheapest as a set at around twentyish). Probably can get the same sort of collection for ccxx insert if you prefer that type.

Other configurations of tools sets are available that include both ccxx and dcxx types plus threading, parting tools etc. Inevitably they have the less than stellar MGHER parting tool (also shown below). They work after a fashion but best for non ferrous (except hard bronzes). The blunt 2mm blade puts a bit of a strain on the Myford and needs a bit of courage to get started. I have a 1.5mm version which is easier to start, but with the added attraction of the thinner blade  being a bit more bendy and prone to digging in! I find really sharp HSS in the rear toolpost the most reliable.

Also avialble are boring bars sets 6/8/10/12 for ccxx 06 inserts for twentyish or less. It would be nice if you could just get a 6/10/16 as a set but will probably cost you more as you would need to get individually, so I ended up getting a set I mainly use the 6 and 8mm but that is reflective of the size of work being done.

You want to chose tools that use the smaller inserts and avoid those that require larger inserts (ccxx09 etc) as they just cost more for no benefit.

edit  As an aside, I find the ccxx inserts to be slightly more robust than the dcxx, but the dcxx type is useful to work into tight spaces.

MGEH….Aaargh!

 

[patgasParticipant @patgas]

Any specific makes brands to look out for ?

[Nigel Graham 2Participant @nigelgraham2]

Dave –

Screw-cutting tools: I agree it is not usually critical.

Strict adherence to form is right if you are finish-cutting to very fine limits, but normally even if the root radius is there the crests cannot help but be left sharp. If I want a reasonably correct profile, which I usually do, I finish cutting slightly undersize then complete with chaser, tap or die.

 

Patgas –

Brands? I don’t think I have ever really worried about brands too much, because I buy from the regular retailers to the hobby, and am confident they all sell reasonably good-quality tools. It would not be in their interest to do otherwise. The only complaint I have ever made was about a lead-screw hand-wheel whose keyway was quite badly off-centre.

Some model-engineers do buy from more general engineering stockists who are happy to sell to private as well as trade-account customers. Same goods – and the professional customers won’t want rubbish!

 

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