Mill chuck advice needed

[Alex MasonParticipant @alexmason47486]

Hello all, new to the forum but have been enjoying the veritable treasure trove of info available here for a while.

I’ve recently (yesterday) acquired a new Warco wm14 mill. With it came what I’m told is a posilock style chuck all in imperial sizing (I’ve been brought up on metric). I’ve had a bit of experience with small size ER chucks in the past but never these. I understand that these need a threaded end mill but can’t find any info on what particular threads are used on this chuck or on available end mills I’ve seen on eBay. Is this a standard of some sort or am I likely to run into issues? Can they be used with unthreaded end mills?

I’m very tempted to buy an ER25 chuck and switch back to what I know with unthreaded tooling. As yet I’ve got no end mills of sufficient size so can jump in either direction relatively easily. The added benefit here is my emco compact 8 mill can also use these with an adapter plate.

I think my question is would I be better off selling this chuck and switching to an ER setup or even MT2 direct collets or sticking with this chuck and probably getting some metric collets for it?

Thanks, Alex

[Alex MasonParticipant @alexmason47486]

[Brian WoodParticipant @brianwood45127]

Hello Alex,

The threads are standardised at 20 tpi and no, you can't grip non threaded cutters as the screwed end is essential to the fitting onto an internal cone for reacting to the outer collar pressure when tightening..

So, perhaps stay with what you know and sell the Posilock on. I find ER chucks will grip all cutters as well as or better than a Posilock and they can be used for drill holding as well.

Regards

Brian

[not done it yetParticipant @notdoneityet]

The only really important imperial part of it will be the draw bar threads. The downside of this type of holder is mainly that a specific collet for each size of cutter is required.

ER collets work over a prescribed range of sizes, so within that range any one collet it will accommodate any diameter you choose – whether metric or imperial.

Don’t buy a holder from a cheap chinese supplier, is my advice. One from banggood was most certainly not a fit in a 2MT socket. It rattled! I still have the evidence! Unadulterated carp – and their customer service is on the same scalein my experience.

[Thor 🇳🇴Participant @thor]

Hi Alex,

I use ER collet chucks for both my milling machine and my Compact 8 lathe as milling cutters with a threaded end is very difficult to find where I live, Weldon shanks are the norm here. As Brian says, you might want to sell the Posilock and buy an ER chuck. The ER collets can be used both for holding milling cutters, twist drills or round stock in your lathe (with a suitable ER chuck).

Thor

[JourneymanParticipant @journeyman]

Alex, I have the WM14 and use an ER25 chuck all the time, in fact it hardly ever comes off the machine. I use it for drilling, countersinking and milling saves changing chucks. Grips very well using plain shank end-mills or threaded. The threaded part just sticks out the top of the collet. I can recommend ball bearing nuts for the chuck. Makes it a bit easier to torque up when you have to close a collet down. All my collets are metric as are my end-mills but I have a few old imperial slot drills which are fine but usually involve a bit of grunt to grip properly. Might invest in a couple of imperial collets in the smaller sizes.

John

Edited By Journeyman on 25/03/2018 15:29:13

[Clive FosterParticipant @clivefoster55965]

To me the ER collet approach only makes sense if, like John, you use it all the time for pretty much everything. Then the wide gripping range and coverage of "every" size are useful.

Odds are you will only use 3 or maybe 4 sizes pf milling cutter shank so ER versatility is wasted on milling only duties.

You have the Posilock already and say you need to get end mills so its probably less costly all round just to go with what you have. Threaded shanks are standard and still easy enough to get hold of.

My Posilock has done me fine for around 25 years, got the full set one with both imperial and metric holders, whilst the ER set bought at same show has been used about 4 times. Just remember that the nose piece is screwed up decently hand tight first and the cutter screwed in until the collet comes as hard up against the nose piece as you can manage by hand. After mounting in the mill I always slot the spanner on the nose piece and bump it with the heel of my hand. Was told to do this years ago by "one who showed every evidence of knowing". Allegedly it tightens things up a touch more.

Worth getting some Weldon style holders and putting a flat on some plain shank cutters to suit. Weldon holders are much more compact than collet systems which can be very handy when doing small work or when trying to get round a job thats on the big size for your mill.

Clive.

[JasonBModerator @jasonb]

Big question is why did you not order the mill with a set of metric collets for the Posi chuck if you prefer to work in metric? may be worth asking Warco if they can swap them over.

[Roderick JenkinsParticipant @roderickjenkins93242]

Worth bearing in mind that solid carbide cutters tend to have shank sizes the same as the nominal diameter. Not sure either whether threaded versions are available. ER seems to be a much more versatile option allowing pretty much any milling cutter, including inset tips, to be used.

Rod

[Alex MasonParticipant @alexmason47486]

Hi all,

Thanks for the many replies. To clarify the mill is bought used, I should have said new (to me). It looks like I’ll be making the switch over to ER then in this case, I think the compatibility with the lathe, the lack of a threaded insert requirement and the fact I could also use it for drilling makes it the ideal choice. I don’t have a pillar drill so this would also be my main method of doing accurate drilling work.

Will stick the chuck up on here or eBay once I’ve made the switch over.

Thanks, Alex

[John HinkleyParticipant @johnhinkley26699]

Looks very much like you are being steered in the direction of ER chuck and metric collets. I'll throw my hat into the ring and advise that as well. I must say, though, unlike some posters on this forum, I've had absolutely no problems with kit from the other side of the bamboo curtain – and I've bought quite a bit, either directly or through sellers on eBay. Either I've been very lucky – or my standards are lower than other's. I've had good ER stuff from Aim Tools on eBay, CTC tools ( when you could buy direct from Hong Kong – not tried them since they moved the operation, due to the increased postage costs – but their kit is good quality IMHO ). Very much a case of you get what you pay for.

Jason's suggestion to go back to Warco for a swap would be my preferred option.

John

[Alex MasonParticipant @alexmason47486]

Next obvious question to add would be where is a good place to be looking for a set? I’ve spotted one on chronos for £54 as a full kit. Is this too cheap? What should I expect to pay for something middle of the road?

[John HaineParticipant @johnhaine32865]

I assume that the spindle is MT2? If it happens to be R8, then you could buy R8 collets which give you an extra 50mm odd headroom, and a Jacobs chuck for drilling.

[JourneymanParticipant @journeyman]

Can't comment on quality but that is not a full set. There are usually 17 or 18 collets in a full ER25 set. The larger sizes all cover a 1mm range up to 16mm some of the smaller sizes only cover .5mm depends on the make as to how many of the smaller range collets. No reason however to buy a full set in one go. Get a good chuck with the drawbar thread you need and start with the common sizes 6mm, 8mm, 10mm and 12mm then add as required.

John

[JonParticipant @jon]

Stick with the Clarkson, at least the cutters wont drop out no matter how tight ER done up.
Also a pain to change cutter, worse the collets. Had 3 types including Wabeco supplied, all the cutters drop and scrap the job. Right pain to undo as well but if you have 5 mins each time fire away.

ARC do some good MT collets, you wont look back and wonder why others are using ER. Eseentially the same as R8 with all the advantages.

[Ian PParticipant @ianp]

Posted by Jon on 27/03/2018 13:42:49:

Stick with the Clarkson, at least the cutters wont drop out no matter how tight ER done up.
Also a pain to change cutter, worse the collets. Had 3 types including Wabeco supplied, all the cutters drop and scrap the job. Right pain to undo as well but if you have 5 mins each time fire away.

ARC do some good MT collets, you wont look back and wonder why others are using ER. Eseentially the same as R8 with all the advantages.

Each of us has different ways of working and preferences for different methods and tools etc. I use MT collets very rarely nowadays, ER are much more versatile.

It is true that cutters can 'fall out' and damage themselves or the job, however if the correct size collet is used (1/4" for 1/4" cutters and 12mm for 12mm cutters etc) the cutter is a snug fit in its ER collet and does not drop out. Whilst most ER collets have a 1mm grip range (so a 12mm cutter is fine in a 1/2" collet) using a smaller than nominal shank does make loosening and tightening the ER nut a bit of a fiddle.

I mostly have the correct size collet for the cutters I use but by habit I automatically hold the cutter or drill in my gloved hand when I take out and put in cutters.

The droppy cutter syndrome does not apply to MT or R8 because the collet has to be the correct size, so using them to hold drills is less likely to happen.

Ian P

[Jon GibbsParticipant @jongibbs59756]

I agree with Jon above. Why not keep the Clarkson and perhaps start building up an ER set of collets and holders slow-time if you feel like it?

I got a Clarkson and a Pozilock with my 2nd hand mill but bought an ER32 collet chuck for it later. My Clarkson is just imperial, the Pozilock is metric and imperial and I now have a small set of ER32 collets (16mm, 1/2", 12mm, 10mm and 1/4" ) dedicated for tooling on the mill to accommodate both metric and imperial end mills with less than 0.5mm closure needed. Having 3 chucks means I can keep some tooling in chucks ready which can be an advantage sometimes but not always. I plan to add an 8mm ER32 collet to my mill set soon for carbide 8mm endmills – see Rod's comment above.

I also have a full set of ER32 collets reserved for the lathe and workholding with Stephenson blocks on the mill. Standardizing on ER32 makes sense for my work.

…and don't muck about with the plain ER collet nuts FWIW. Buy bearing ones. They are far easier to tighten properly for both workholding and toolholding.

Just some thoughts and HTH

Jon

Edited By Jon Gibbs on 27/03/2018 17:12:38

Edited By Jon Gibbs on 27/03/2018 17:12:54

[SillyOldDufferModerator @sillyoldduffer]

Posted by Jon on 27/03/2018 13:42:49:

… at least the cutters wont drop out no matter how tight ER done up.

Although I've never had any bother with ER collets, Jon is far from alone in his criticism. I wonder what's going on? I can suggest a few things that might cause trouble:

• ER collets don't grip well at one end only. A truly parallel tool shank has to extend the full length of the collet.
• Forcing even a slightly oversized shank into a collet is likely to ruin it.
• ER collars need to be tightened firmly. It's a known problem – ball-bearing collars are recommended because they are easier to tighten than the ordinary type.
• I sometimes tighten collars by hand to adjust tool height and then forget to spanner them up properly.
• I find ER less friendly at the fully clamped end of a collet's size range. For instance a 3mm drill is much happier in a 2-3mm collet than in a 3-4mm. Awkward shank sizes can cause trouble if you mix imperial and metric tooling in the same set – for example 1/8" drills aren't a good fit to a metric collet set.
• Spinning a tool in a collet is likely to damage both.
• Other systems may be tolerant but worn and damaged ER collets should be ruthlessly replaced.

If the ER system was complete rubbish it wouldn't be so popular in Industry. Any other suggestions as to why they sometimes misbehave?

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by SillyOldDuffer on 27/03/2018 17:39:19:

If the ER system was complete rubbish it wouldn't be so popular in Industry. Any other suggestions as to why they sometimes misbehave?

.

Dave,

There was a long [and at times excellent, analytical] thread a while ago.

… hopefully I can insert a link here, before editing-time closes.

MichaelG.

.

Edit: Here we go …

http://www.model-engineer.co.uk/forums/postings.asp?th=116912&p=1

http://www.model-engineer.co.uk/forums/postings.asp?th=120333&p=1

Edit: Oops … Just noticed that you participated in that long discussion, Dave

 

Edited By Michael Gilligan on 27/03/2018 18:44:24

[VicParticipant @vic]

I bought a cheap ER32 chuck from China for my VMC mill and it’s worked very well. It was an easy decision for me as I already had a set of ER32 collets and a chuck for my Lathe. Up until this point I’d been using finger collets in the mill.

[JonParticipant @jon]

Dont get me wrong have looked at ER40 for specific work holding rather than revisit the 5C route.

For whats its worth any engineering type company that produces by the batch needs the minium of down time. ie parts or tools replaced as quick as possible needing no setup to continue.
In this respect ER just dont cut it unless for specific applications or naive to extra labour costs and downtime.

Theres masses of other work holding setups that fit the bill, Tormach, Weldon, other quick release setups along the lines of these (brilliant cutters by the way). https://www.secotools.com/#article/m_6890 Twist unlock, pull and out job done, 5 seconds to replace and no resetup. Idea is to replace a broken tool with minimal setup ie same cutter in to a stop = ready to go and repeatable.

Bottom line cnc ers take a lot of shallow depth of cuts at faster spindle and feed rates than any manual users ever would tehrefore substantially reduced risk of ER cutters dropping during a cut.

Looking back all the problems i have encountered using ER types have been down to vibration and or tool wear. ie blunt milling tool can develop a chatter at every flute which may result in felt or visible vibration. With cnc thats just programme fed with no user feel as to whats actually happening, if done manually the operator would instantly or should know and make amends.

I buy in a fair chunk of whats regarded as top quality German made high value items to modify. Each batch measures substantially different whether that be thread sizes or just general maching and bore sizes. Can be 0.22mm difference where 0.06mm would be poor and your working to less than that.
You can put that down to machine setups, programmes the same.

[John OlsenParticipant @johnolsen79199]

Seems to be a little confusion in some of the posts, a Clarkson is not the same as a Posilock, although they both take screwed shank cutters. They need a separate set of collets for metric and imperial. I've actually ended up with two Posilock chucks and a full set of Imperial and metric collets, a Clarkson with just a couple of collets, and a set of ER32. and ER16. The Posilock get the most use, mostly because that is what most of the cutters are.

The ER have the advantage of being useful on the lathe as well, if you get a suitable chuck to fit.

John

[Alex MasonParticipant @alexmason47486]

OK so I've ordered a couple of threaded imperial end mills to try out the posilock chuck that I have. Worst case I dont get on with it and will be able to use them with an ER system in the future. Will take my time and try to find a decent non chineese ER chuck in the meantime.

Like I said before, I will likely make the transition anyway to allow for dual use with the lathe. Those stevenson blocks look very useful too.

[JasonBModerator @jasonb]

Unless you buy bargain basement direct from China where you are taking pot luck then an ER chuck from one of our usual suppliers of chinese made products will be more than adequate for hobby use use.

This is my one which shows 0.0004" on the tool and 0.0003" on the socket that is about 0.01mm run out on the tool.

[Thor 🇳🇴Participant @thor]

Hi Alex,

I have an ER-32 chuck from ChesterUK, on my chuck I get the same tool runout as Jason. When using very cheap collets the runout may increase to 0.02mm.

Thor

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