ER collet chuck runout

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John,

To be more specific ... it was the information on the Centaur page that I thought would interest you [see hyperlink in the quote below]

MichaelG.

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Edit: Apologies for the 'width' prolem ... I copied and pasted from the other thread, but sometimes things don't behave quite as expected.

Edited By Michael Gilligan on 27/04/2016 10:40:00

It does Michael. I took a screen shot of the spec. I was aware of the other aspects. I mentioned the contact aspect with diffenerent diameter in the same collet in this thread but in usability terms at home I don't think it means a jot and not that much elsewhere either as the collets would be chosen to fit standard tool shanks.

Just add that I think people will find that the Vertex collet spec's are about on the web.

John

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Edited By Ajohnw on 27/04/2016 10:46:01

On the subject of collets; I had problems with run out last year which I couldn't get resolved so put it on the back burner, until yesterday, when I was machining the cross head for my S50 I was attempting to use a slitting saw to cut out the slot for the con rod connection & talk about wobbling all over the place...​ ! ... closer inspection revealed a anomaly that I would never have expected... the spindle on my WM250 is cracked... ​ !! specifically the end where the MT2 taper is... so now I now why it hasn't run concentric for some time now. Don't ask how it got cracked, I have never ever tightened any MT tooling into the taper with any undo force, normally push the tooling in with a slight twist to engage both tapers then snug the draw bar up, so how it cracked is beyond me, ?? it beggars belief !

I wrote a long post in forum last year on subject...

http://www.model-engineer.co.uk/forums/postings.asp?th=120208​

I now have the problem of getting a new spindle; I have sent e mail to Warco for price & availability of new spindle, plus a query if the two original spindle bearings are angular contact. I recall way back that some one had stripped their Warco lathe & changed the bearings but cannot locate the post, maybe when there was a thread titled 'Warco WM250 & family' or words to that effect. If some one can remember & put me in the right direction ( Link ? ) along with any procedures / hiccups it would be appreciated, also, at the bottom of the quill there is a collar that has two holes that require a 'pin' spanner to remove/adjust, does anyone have dimensional sketch for this as a quick ref, TIA.

​In the interim, as the spindle is still useable to a certain degree, I am looking at making a clamp type collar of some description to keep the taper closed tightly until repairs are sorted, but would appreciate any info from members / WM owners who have had similar issues.
Ho hum, so much for posting about not having any probs with my Warco machines in previous posts... eventually comes back & bites you in the arse don't it...... Ce la vie! ...

pic... cracked spindle.



TIA.
George.

George, what are we talking about here the WM250 lathe has an MT4 spindle! Is this a WM16 milling machine?

John

Well it is a hardened spindle and It looks like a WM16 spindle nose, and whilst this would suffice to suffer far more stress than an unhardened one without bending, if a force large enough attacks it, it will just go all at once.

I normally don't have any problems getting hold of the warco spares department by their telephone ext. They seem to respond better to this and they do call me if something was out of stock but has come back in.

Michael W

Edited By mechman48 on 16/04/2017 13:43:38

Hi George,

The "WM250 & lathe family.." is here.

Thor

Just to clarify...

​It is the spindle on my WM16 mill that is cracked & am looking for any advice on spindle removal, disassembly, bearing change out ( angular contact, info, alternative ? ) etc. from anyone who has had similar problem with their Warco mill, plus any specific things to look out for. Being Easter not had anything back from Warco's, maybe tomorrow.

TIA.

​George

p.s. thanks Thor.

Edited By mechman48 on 17/04/2017 23:25:03

Spoke to Warco; bit the bullet & ordered a new spindle, + 2 bearings, according to Warco's spares dept. the bearings for the WM16 they stock for todays machines are tapered roller so...

George.

Update... finally got round to fixing the cracked spindle on my WM16; was dubious about getting bearings off etc as didn't have a bench press, just a small bearing puller, anyhow set to yesterday. Getting the spindle cartridge out wasn't a major deal, just a matter of looking at the exploded drawing from the manual , just a case of covers off compress the spring with a screwdriver, remove the 'C' clip... careful you don't let go of the spring, once that's out the cartridge slides down out of the splined drive gear ... for a fuller description of bearing replacement look on YouTube... there is a nice video by Hossmachine on bearing replacement on a Grizzly G0704 which is the nearest equivalent to the WM16/18 ...

https://youtu.be/hP-XvbV7Pc4

​Following the video my self for clarity I managed to get the spindle out using the small bearing puller set, plus some 10mm screwed rod I had. I didn't take too many pics of the procedure as I wanted to get on with it & get it of my 2doit list. What I noticed on the original spindle was a heat marks around the area of the bottom bearing... what is this I ask? the bearing didn't show any heat marks... was it some form of heat treatment in manufacture, maybe hardening treatment of the MT2 taper end...? anyhow the spindle is out, a good wash out with white spirits, dry off & check over for any signs of damage.

​I refitted the new spindle with a pair of new taper roller bearings that I bought with new spindle, as per OEM, I didn't fit angular contact bearings ( ac ) as this would have meant messing about with shims to make up difference in outer race dimensions, a lot of YouTube videos show this but as part of upgrading to increase speed, which I wasn't planning on doing, so far I haven't needed to use higher than the 1200 rpm on the low range setting so no need for ac bearings. I have att. a couple of pics of the main procedure...

Bearing puller prep'...

Spindle pushed out of cartridge...



​Heat marks on spindle, no signs of overheating on bearing...spindle heat treatment ?... the blue is OEM grease...



​Old spindle out, new fitted, tools used...



​I repacked new bearings with high temperature lithium based grease rated for 4000rpm, suitable for pump shafts, wheel bearings & other high temp' applications, all it needs now is to run in for a while & check for any over temperature rise indications on casing, then it should be good to go... fingers, toes & everything else crossed

​George.

Looking good, Mechman.

Gave my WM16 a run in yesterday, checked collet run out... way less than .001"... I would estimate approx .0002" looking at the dti I used & it's running a lot quieter than previously...

Hi George,

Glad to hear you got the spindle sorted, job well done. You have less runout then I have on mine.

Thor

It might be worth sawing or grinding the old cracked spindle to reveal the full length of the crack. This would show whether there was a flaw in the bar from which it was made. If so, the device could be described as 'not of merchantable quality' and (in the UK) you could then have a serious talk with your supplier.

You might find a talk with your trading standards office helpful, too.

Cheers, Tim

Thanks Thor/Tim.
​Tim, I can see where you're coming from but I won't resort to such drastic action, what I've decided is to contact an ex work colleague in the training centre I used to teach in, ask him to ask the welding instructor to clamp the spindle tight to close the crack, grind back to half depth wall thickness, & either Tig / Mig weld the spindle. I can then dress back the surface area, check the internal MT2 for any distortion and, all being well, keep it as a emergency spare spindle. Being a Yorkshire man 'waste not want not' if you follow my reasoning... must remember in future not to brag about not having any probs with my machines, don't want my arse bitten again...

George.

So I got some ER11 collet nuts. Had a piece that needed to run quite true. When I used one of the new collet nuts, it was out by more than 0.05mm. Used the genuine ER nut and it was fine.

So I set up made a spacer and checked the original with my set up and the taper on the nut ran within 0.01mm, the new ones were out by as much as 0.1mm. So I set up and recut the 30 deg front taper using the thread and the back shoulder as a reference. Picture shows the inverted bore tool and the compound set at 30 deg. Using a Regofix ER11 collet holder with the sleeve spacer for the nut to seat against.

I also set up and trimmed the outside with it just on the thread of the mandrel 1st. Cutting the inner 30 deg taper was a second op.

Now they are just as good as the original collet nut.

Neil