Clarkson auto lock

[RobonthemoorParticipant @robonthemoor]

Got one with a mill I bought but no idea how or what type of bits fit, I have an S type clarkson on mt2 but this is not the same, please see photo, and if you can post photos of how it work.

rob

[RobonthemoorParticipant @robonthemoor]

How does it work?

[ken king, King DesignParticipant @kenkingkingdesign]

Hello Rob, it seems that the two smaller items, if combined into one, would perform the function of the Clarkson nosepiece, apart from there being no obvious driving dogs. At any rate there would be a need for a collet to hold the tool, which would be tightened by the short taper in the central piece illustrated. I take it you have no collets ?

Regarding potential tool slippage, are there any driving lugs or similar buried up in the main body ?

Sorry I can't really help, I've not seen one like this, but I'll bet there are members who have. Hopefully they will come forward and shine the necessary light. Good Luck !

Ken.

[RobonthemoorParticipant @robonthemoor]

Thank Ken, yes two driving dogs at the bottom, & no I have no collets. I think it is a C type! But would like it confirmed before I start buying collets that don't fit. 20mm or 3/4 OD collets would fit.

rob

[Tony Pratt 1Participant @tonypratt1]

Hi Rob, 20mm & 3/4" aren't the same size so they can't both fit?

Tony

[Anonymous]

A picture of the internals of the chuck body would help identify the type of collets required. It looks like a Clarkson C-type; does it have 'Clarkson' engraved anywhere?

Regards,

Andrew

[BazyleParticipant @bazyle]

It looks too new to be a c-type!. Posilock perhaps. There are several ‘own brand’ versions of that eg axminster. The sleeve looks unusual as there is no taper either in it or on it and the groove is for what?
Could it be for something else – like part of a sliding tapping fixture, or tailstock die holder-holder.

[RobonthemoorParticipant @robonthemoor]

I will take a photo of that sleeve you can see, and yes it has a taper, also it says clarkson Autolock On It and a part number, when I get home I will post photo & number.

rob

[Keith LongParticipant @keithlong89920]

Hi Rob

I've just checked my Clarkson "C" type chuck and it looks the same as your's, apart from mine being a bit more battered on the outside. Mine is stamped quite clearly Clarkson Autolock on the face of the closing nut.

The collets that I have for it are all in the region of 20.64 – 20.65 mm od so well over either 3/4 in or 20 mm. They need to be a good sliding fit in the sleeve as this helps with the concentricity, and the sleeve is a VERY nice sliding fit in the body. I also have 3 collets that I've picked up separately that won't actually go into the sleeve, being slightly oversize on diameter. One of them is just 0.01mm too big so should be possible to get it to size fairly easily, the other 2 are more like 0.1mm oversize so more of a problem as they are HARD. It may be that those are for another make of chuck that uses the same principle, so be careful when you buy collets. If you can take the sleeve with you to try the collets for fit. Also good luck with finding metric ones, they seem to be VERY thin on the ground.

None of my collets are marked in any way with a trade mark but a number came with the chuck so I don't have any real reason to assume that they are NOT of Clarkson origin.

The sleeve for my chuck also has that groove, it's there as an undercut for where the nose taper meets the parallel outer diameter of the collet, so it avoids any "hang-ups" in that corner and also helps to minimise the effects of swarf or debris that gets in there so it doesn't affect the closing and centrering action.

"S" type metric collest have a groove in the od of the tail end flange to identify them, on the 2 metric "C" type collets that I have there is no such identification, I've sized them by trying the shanks of the milling cutters in when it was fairly easily able to tell the difference between 1/4in and 6mm and also the 1/2 in and 12mm collets. Without some definite marking though it would be pretty easy to pick up the wrong one and wonder why the cutter was running off centre.

Keith

[RICHARD GREEN 2Participant @richardgreen2]

Hello Rob,

Here are some pictures of a Clarkson "C" type ? chuck that I've got, the collets are all 811 thou in diameter, the metric ones have an identifying groove around them, all collets have two locating "dogs" on the top end,

There are 1/4 , 3/8 , 1/2 , and 5/8" , also 6mm , 2 x 10mm,1 x 12mm and 1 x 16mm,

The lot can be yours for £ 40 if they are any use to you, I'm in Bucks. ( collection only )

All collets are in very good condition. ( nice original box as well )

Richard.

[RobonthemoorParticipant @robonthemoor]

Thanks Keith all very good points' mine measure 20.64mm inside that sleeve too, & yes it looks like yours.

Richard, you have a nice set"and yes" I would buy them as at the moment I have none to fit. I do have a set of clarkson s type, and a reducer from mt4 to mt2 , so I can use it in my deckel fp1. Can I convince you to take them down to the post office! if I give you my address? I'm up in Lincolnshire, fair way down to you in Buckinghamshire, give it some thought with the post.

Rob.

 

Edited By Robonthemoor on 07/09/2013 21:25:06

Edited By Robonthemoor on 07/09/2013 21:26:32

[RICHARD GREEN 2Participant @richardgreen2]

Rob,

Posting is no problem, I've sent you a PM.

Richard.

[RobonthemoorParticipant @robonthemoor]

Sent you a pm Richard, thanks to you all for your expert advice, again" you all have anther of my problem solve.

regards

Rob

[babielsParticipant @babiels]

Hi I have two questions for you experienced chaps:

1. I have a small C-type Clarkson Chuck that came with my ancient mill (in fact the Chuck is integral/ non-removable from the spindle shaft). I received it with a single 12mm collet and threaded endmill and have since bought a 1/4” collet and cutters. Both work great and very sturdy while making heavy cuts, however I realise now that I have been using them without the sleeve pictured in this thread. My Chuck came with the closing nut and collet only, so I didn’t know any better. It seems sturdy as hell AND concentric so is this a problem? The collet sticks out of the bottom of the closing nut by about 1/8” when done up and cutting.

2. I have been looking for a small 5/8” C-type collet for a long time, and I’m wondering whether it would be possible to modify a small 5/8” S-Type collet, by grinding the racetrack shaped dog down into the two dogs necessary for a C-Type collet? Does anyone know if they share outer dimensions including length?

thanks!

Edited By babiels on 27/02/2022 08:30:38

[not done it yetParticipant @notdoneityet]

I very much doubt a Clarkson is a non-removable part of a spindle.

You should be able to remove it from the spindle with a pair of suitable wedges.

[babielsParticipant @babiels]

Oh maybe your right. But it doesn’t have a drawbar…? I’ll give it a try and report back. Thanks!

[Michael GilliganParticipant @michaelgilligan61133]

Posted by babiels on 27/02/2022 09:46:46:

Oh maybe your right. But it doesn’t have a drawbar…? I’ll give it a try and report back. Thanks!

.

Don’t be over-enthusiastic in your efforts … your original understanding may be correct !

What is the ‘ancient mill’ that you have ?

[ someone, somewhere on the forum, might know about it ]

MichaelG.

[babielsParticipant @babiels]

It is called a Swisten (a rebranded Carsten’s mill **LINK**&nbsp

photos of mine in a disassembled state:

**LINK**

[peak4Participant @peak4]

Babiels, the link on Tony's site suggests that the mill originally came with an MT3 or an as yet unidentified taper.
It's quite possible that the latter is actually a Clarkson fitting, or a variation on it.
If you have a look in my album, of which this is one photo, there is a variety of different chucks on show there.

When I got my Centec, it came with a Clarkson C type and a set of imperial collets; I successfully made a full set of metric ones myself to suit, so it's quite possible to make your own from scratch.
I've since picked up a full set of genuine ones over the years.

I don't think it will be practical to convert S type to C type, though I will happily supply any measurements you need.

On the C type, there should certainly be a closing sleeve.

Whereabouts in the world are you roughly?

Bill

Edited By peak4 on 27/02/2022 11:46:22

[babielsParticipant @babiels]

Thanks Bill. I guess I should start by making a sleeve then. If you have dimensions for the sleeve that would been much appreciated. Unfortunately I think making a collet from scratch is beyond me: I only have a micro lathe with no screw cutting or cross slide capability.

Looking at your photos, none of them look quite like mine. My experience of morse taper tooling is nil, so I am well have missed something.I would LOVE it if it turned out to be a removable Chuck, without a drawbar, if that’s a thing.

I’m in Hammersmith, London.

[babielsParticipant @babiels]

Oh I should say I would LOVE it if it turned out to be a removable Chuck without a drawbar or a tang. And the spindle has no tang-access slot either.

[Martin ConnellyParticipant @martinconnelly55370]

Babiels, I have a 1/2 inch collet and sleeve that are of no use to me. If you want them you can have them for the price of the post and packing. Message me.

Sleeve is 0.811" bore, 1" outside diameter 30mm long

Martin C

[peak4Participant @peak4]

here you go, I hope this reproduces/prints OK
I don't have a CAD package, so this was a quick sketch in Visio and reproduced as a jpg
N.B. it is not to scale.
The 30° angle is as close as I could measure it, but obviously to suit the collet. I came up with 15° per side.

If you need any more measurements, just shout up.
Bill

[babielsParticipant @babiels]

Thanks Bill

[babielsParticipant @babiels]

In case it is of any interest, I’ve taken out my spindle shaft /Chuck and taken some photos, added them to my folder:

**LINK**

[Author]

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