Collet Chuck for my CL250M?

[Ian MellorsParticipant @ianmellors72388]

Thinking about getting a collet chuck for my lathe. I have been looking on RDG Tools website and am currently undecide on an ER20 or ER25 set, not sure if I need the extra capacity of the ER25, or if the lathe has enough oomph to cope with the larger sizes available.

I have heard though that there can be problems with smaller lathes with MT2 spindles where the taper is too far inside the spindle and the chuck will not lock in place. Is this common, should I be concerned?

[Ian MellorsParticipant @ianmellors72388]

[Bo’sunParticipant @bosun58570]

Hi Ian,

If you're looking at a morse taper mounted collet chuck, bare in mind that it won't be through bored, and will consequently limit the length of stock it can hold. If so, a collet chuck on a backplate might be worth considering.

[not done it yetParticipant @notdoneityet]

my lathe

Is it a secret? You might get better responses if you included the lathe type/model? Or maybe the power? Are you just drilling, or end-milling as well?

[Ian MellorsParticipant @ianmellors72388]

Posted by not done it yet on 23/02/2021 14:19:29:

my lathe

Is it a secret? You might get better responses if you included the lathe type/model? Or maybe the power? Are you just drilling, or end-milling as well?

CL250M – Clarke 250mm bed mini lathe, I did put the model number in the thread subject.

Turning, mainly toy train wheels

[John HaineParticipant @johnhaine32865]

See title – CL250M.

Not a good idea to get a collet chuck on a taper for a lathe headstock- for the reasons that Bo'sun states and also the overhang. Much better is one on a backplate as he says. ARC have suitable chucks and may also have a backplate that fits the spindle – however you do have to machine the register carefully.

[Ian MellorsParticipant @ianmellors72388]

Posted by Bo'sun on 23/02/2021 13:48:28:

Hi Ian,

If you're looking at a morse taper mounted collet chuck, bare in mind that it won't be through bored, and will consequently limit the length of stock it can hold. If so, a collet chuck on a backplate might be worth considering.

Thanks, food for thought, although as I said above, I'll mainly be using it for turning model train wheels, so length of stock will not be an issue. Thinking about this the larger collet sizes available in ER25 would be less likely to be used with shorter lengths of stock, maybe …

I'm leaning towards an ER20 set

[EmgeeParticipant @emgee]

Hi Ian

Does the 3j chuck screw on and off the spindle or does the spindle have a flange for fixing the chuck to ?

Emgee

[Ian MellorsParticipant @ianmellors72388]

Posted by John Haine on 23/02/2021 14:24:21:

See title – CL250M.

Not a good idea to get a collet chuck on a taper for a lathe headstock- for the reasons that Bo'sun states and also the overhang. Much better is one on a backplate as he says. ARC have suitable chucks and may also have a backplate that fits the spindle – however you do have to machine the register carefully.

Interesting that you site overhang as a problem, I have heard the opposite as my original post, in that the chuck hits the spindle before the tapers bind. Food for thought though, thanks

[Ian MellorsParticipant @ianmellors72388]

Posted by Emgee on 23/02/2021 14:29:48:

Hi Ian

Does the 3j chuck screw on and off the spindle or does the spindle have a flange for fixing the chuck to ?

Emgee

Chuck bolts to a spindle adaptor, adaptor is bolted to the spindle with hex head screws, so I'm told. Will take the chuck off this evening to confirm

[Ketan SwaliParticipant @ketanswali79440]

Hello Ian,

Your CL250M is a SIEG C1 lathe.

Consider getting one of these from ARC or from whoever you prefer.

The hole through your headstock spindle is 10mm diameter I think. So, this will allow you to hold stock up to 9.99mm through the spindle. Stock from 10mm to 16mm diameter can be held in the front (as cannot go through the spindle) using the appropriate ER25 collet….. Hope my explanation makes sense.

If you have an MT2 taper mill, then the MT2 milling collet chuck ER20 or ER25 would make sense, as it can be used in both the lathe and mill spindle.

Ketan at ARC.

[Ian MellorsParticipant @ianmellors72388]

Posted by Ketan Swali on 23/02/2021 15:14:40:

Hello Ian,

Your CL250M is a SIEG C1 lathe.

Consider getting one of these from ARC or from whoever you prefer.

The hole through your headstock spindle is 10mm diameter I think. So, this will allow you to hold stock up to 9.99mm through the spindle. Stock from 10mm to 16mm diameter can be held in the front (as cannot go through the spindle) using the appropriate ER25 collet….. Hope my explanation makes sense.

If you have an MT2 taper mill, then the MT2 milling collet chuck ER20 or ER25 would make sense, as it can be used in both the lathe and mill spindle.

Ketan at ARC.

Ah, now that's interesting. I do hope one day to get my hands on either the now discontinued CL251MH or Sealey SM2502B milli/drill attachment for the lathe, which has an MT2 taper …

[Ketan SwaliParticipant @ketanswali79440]

Posted by Ian Mellors on 23/02/2021 15:21:36:

Ah, now that's interesting. I do hope one day to get my hands on either the now discontinued CL251MH or Sealey SM2502B milli/drill attachment for the lathe, which has an MT2 taper …

Unless you are limited for space, or you find one second hand – cheap which works, you would be better off looking at saving up for a SIEG SX1LP. …. It is more cost effective and better investment than getting an attachment for the lathe. The 'muti' is limited in its use.

Ketan at ARC.

[Iain DownsParticipant @iaindowns78295]

I bought an MT3 ER32 collet chuck for my REal Bull CJ18A and it was horrid. The run out was bad. I bought another one. It was just as bad.

I then bought an ER32 collet chuck from ARC which fits on the chuck backplate (that may be the wrong word. The bit of the spindle that the chuck bolts to) and have been delighted with it.

Iain

[not done it yetParticipant @notdoneityet]

Apologies, missed the title – in a rush to get spares for my jackhammer sorted is my excuse☹️ .

[Ian MellorsParticipant @ianmellors72388]

Posted by Ketan Swali on 23/02/2021 15:28:47:

Posted by Ian Mellors on 23/02/2021 15:21:36:

Ah, now that's interesting. I do hope one day to get my hands on either the now discontinued CL251MH or Sealey SM2502B milli/drill attachment for the lathe, which has an MT2 taper …

Unless you are limited for space, or you find one second hand – cheap which works, you would be better off looking at saving up for a SIEG SX1LP. …. It is more cost effective and better investment than getting an attachment for the lathe. The 'muti' is limited in its use.

Ketan at ARC.

Pretty much convinced. If I ever lay my hands on a 251MH I'll just get an MT2 collect holder.

Seems I ordered something from ARC back in 2017, can't find out what though as the website throws and uncaught exception in the aspx code when I click on the order number (I used to be an asp developer)

anyway, I'll prob order at the end of the week for delivery to work next week

[Ian MellorsParticipant @ianmellors72388]

Couple of questions Ketan, I'd PM these but the answers may be useful to others

1. Is there any machining to be done to the collet chuck for the C1 lathe or is it a straight fit?
2. are fixing bolts/screws supplied? – it looks from the images that there are 3 tapped holes, whereas the stock 3 jaw chick comes with studs that fit through the spindle plate.

Thanks

[Nick Clarke 3Participant @nickclarke3]

Posted by Ian Mellors on 25/02/2021 09:05:58:

Couple of questions Ketan, I'd PM these but the answers may be useful to others

1. Is there any machining to be done to the collet chuck for the C1 lathe or is it a straight fit?
2. are fixing bolts/screws supplied? – it looks from the images that there are 3 tapped holes, whereas the stock 3 jaw chick comes with studs that fit through the spindle plate.

Thanks

I have bought 3 and 4 jaw chucks for my SC3 lathe which come as you describe. It is not a long job to cut the heads off some commercial bolts and loctite them into the chuck. You then use nuts to hold the chuck onto the spindle.

It is held true by the register. You cannot use bolts directly into the chuck as there is not clearance to fit them to the spindle.

[Ian MellorsParticipant @ianmellors72388]

Thanks Nick, as you say three M6 screws are not a great issue – I own an old Subaru so probably have some cap heads in stock already

I figured the clearance issue as I had to ease the 3 jaw forward away from the spindle flange after loosening the nuts just to get the nuts off, clearance to the headstock casing is that tight ….

[EmgeeParticipant @emgee]

Ian

To make changing from 3j to collet chuck a bit simpler you could drill the fixing holes in the collet chuck backplate to suit the spindle flange and then drill through and tap the spindle flange and use front fixing screws.

Emgee

[Ian MellorsParticipant @ianmellors72388]

Posted by Emgee on 25/02/2021 10:57:56:

Ian

To make changing from 3j to collet chuck a bit simpler you could drill the fixing holes in the collet chuck backplate to suit the spindle flange and then drill through and tap the spindle flange and use front fixing screws.

Emgee

Ta for that, to be honest I can see the collet chuck being the norm on the lathe and it's only 3 nuts to swap from one to another, all be it with tight clearances

[Ketan SwaliParticipant @ketanswali79440]

Posted by Ian Mellors on 25/02/2021 09:05:58:

Couple of questions Ketan, I'd PM these but the answers may be useful to others

1. Is there any machining to be done to the collet chuck for the C1 lathe or is it a straight fit?
2. are fixing bolts/screws supplied? – it looks from the images that there are 3 tapped holes, whereas the stock 3 jaw chick comes with studs that fit through the spindle plate.

Thanks

Hi Ian,

It is a straight fit (possibly tight) onto the chuck flange/back plate (Part 45) on this diagram

You will need a rubber mallet, to remove/fit the chucks.

Fixing studs are not supplied. 3 x Fixing holes are tapped M6 as shown in the details table on this page

Basically, the general 'Chinese Standard' for the back female register on an 80mm 3-Jaw Self-Centring (S.C.) Chuck is 55mm – to enable it to fit onto a flange/backplate with the matching 55mm male register. Also, most such chucks are tapped M6.

So, the ER lathe collet chuck registers and PCDs are made to conform to the Chinese standards of 80mm, 100mm, 125mm lathe chucks.

You may be able to unscrew the studs from your standard 3-Jaw S.C. Chuck and use them with your ER 25 lathe collet chuck. As far as I can recall, the studs would be introduced from the back of the flange, and screwed into the body of the ER25 lathe collet chuck, in the same way as your existing arrangement with the 3-Jaw S.C. chuck. Note: the stud does not need to go all the way through the tapped hole, as long as the studs go in a reasonable amount to hold the collet chuck secure in place, and you feel comfortable. Alternatively, you make up your own arrangement with studs and nuts to meet your needs.

Ketan at ARC

Edited By Ketan Swali on 25/02/2021 11:44:38

[Nick WheelerParticipant @nickwheeler]

Swapping the studs between chucks is daft. I loctited short lengths of studding in all of mine that didn't come with the lathe. I did the same with the mini-lathe when I had it.

[Howard LewisParticipant @howardlewis46836]

For my 3J, 4J, and Collet chucks, I cut M6 studding to a suitable length and loctited into each chuck..

To save having to look for dropped nuts all the time, (Not enough room for my fingers between Flange and Headstock ) I made up a "Widget" as per the article by Danny M2Z, in MEW. Have only dropped one nut since, so what little time it took to make (Minutes ) was well spent. Recommended!

Howard

[Iain DownsParticipant @iaindowns78295]

I would be most keen to know more about Danny's widget (even the Howard version). Dropping nuts as I attach a chuck is a kind of hobby of mine. One I'd like to drop!

Iain

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