Clarkson autolock again …..

[Tim OstleyParticipant @timostley22330]

[Tim OstleyParticipant @timostley22330]

Hi,

Well I give up. I obtained a Clarkson S autolock chuck and whilst it was on its way I bought a collet to go in it ( the chuck was just that, no collets or spanner). As you might expect the collet didn't fit – I thought I was getting a small model s chuck and a large one arrived. Ho hum silly me. So I got a 1 1/4" collet instead and blow me that doesn't fit either. The chuck is definitely a Clarkson and the outside dimensions match those for a large chuck. The collet looks like a Clarkson but is too big. It is also 32mm but that is another story. There is precious little data on Clarkson chucks on the 'net.

The chuck has an outer ring screwed on the body with Tommy bar holes, has a 3MT arbour and the number 40096 engraved on the back of the ring. The body is also engraved with Clarkson S and a patent number. The outside diameter of the collets needs to be 1 3/8 as near as I can measure it.

Before I spend any more money on collets can anyone tell me what I have got and what specification of collets I need to obtain?

All the best.

Tim

 

 

Edited By Tim Ostley on 07/04/2015 19:56:58

Edited By Tim Ostley on 07/04/2015 19:58:08

Edited By Tim Ostley on 07/04/2015 19:59:14

[Tony Pratt 1Participant @tonypratt1]

Any chance of photos?

Tony

[Tim OstleyParticipant @timostley22330]

iPads are not the greatest for this but …..

[JasonBModerator @jasonb]

Tim you will need to host them elsewhere or create an album on this forum

[Tim OstleyParticipant @timostley22330]

Second attempt ….

Edited By Tim Ostley on 07/04/2015 20:29:17

[RobboParticipant @robbo]

Maybe this will help. The capacity of the large chuck depends on the size of the taper it seems.

[Graham WhartonParticipant @grahamwharton]

I'd say that's a Medium S Type chuck on an MT3 Taper. It looks identical to the one I sold a couple of years back due to not being able to find any collets other than a 1" one that I had. In the approx 1 year that I was monitoring ebay for collets, I dont think I ever saw anything other than 1" (at a price I was willing to pay)

Clarkson part numbers for the medium chuck range are

• 40094 – 1" Collet
• 40095 – Spanner Medium
• 40096 – Medium Damping Ring
• 40097 – 25mm Collet
• 40098 – 3/4" Collet
• 40099 – 20mm Collet

Hope this helps. Good luck in the hunt for collets.

Graham

[JasonBModerator @jasonb]

And this will give you where to measure the gauge line.

I would say MT3 has a smallish gauge dia so you could have a large holder that will only thake a 1" collet

[Tim OstleyParticipant @timostley22330]

Thanks for all the info guys. It looks like a medium autolock (didn't realise there was such a thing). I guess that the 3/4" and 1" collets for the medium and large chuck are different. Ho hum.

Tim

[Roy MParticipant @roym]

Do not despair, unless you are going to be seriously out of pocket,you may consider making a series of bespoke inserts to covert the chuck into a sidelock holder, fly-cutter, boring bar, etc., etc. It looks a sturdy bit of kit.

Roy M.

Edited By Roy M on 07/04/2015 21:11:05

[Graham WhartonParticipant @grahamwharton]

For more info,

Small Collet O/D = 7/8"

Medium Collet O/D = 1-3/8"

Large Collet O/D = 1.683"

Graham

[VicParticipant @vic]

Home and workshop machinery often used to have these chucks for sale, maybe they have spare collets?

[LambtonParticipant @lambton]

The ring at the top with tommy bar holes is a Damping Ring the purpose of which is explained in the instructions as follows:

"The purpose of these rings is to give stability to chucks which have small tapers and relatively large overhang below the machine spindle. The chucks listed are supplied with a left-hand thread on the back face of the body to which the rings can be fitted. When the damping ring is screwed onto the chuck and tightened back against the machine spindle nose it greatly improves the stability of these particular chucks."

Although Clarkson do not mention it the ring can also be used to eject the chuck from the machine spindle provided the draw-bar has not been over tightened.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Tim Ostley on 07/04/2015 19:56:19:

There is precious little data on Clarkson chucks on the 'net.

… The body is also engraved with Clarkson S and a patent number.

.

Tim,

In the interests of increasing the data available on the 'net …

Could you please quote that patent number.

Many thanks

MichaelG.

[Tim OstleyParticipant @timostley22330]

As requested, the engraving on the chuck says:

3 MORSE TYPE S

BR PAT 915713

ENGLAND 1/2 BSW

Tim

P.S. If anyone has any of the 4 collets made for this chuck, do get in touch!

[SteveIParticipant @stevei]

Hi,

 

If all goes well you will see an image below my text. Hopefully this will add to the thread.

 

Since you have a MT3 chuck taper you could have a miniature, small or large collet chuck. I can't be 100% sure if its a small or a large from the picture. MT3 (and R8) large are limited in that they only work with 1" and 25mm collets because the taper gauge line is smaller than 1.5". So you would be looking for a 1" or 25mm collet.  normally the large autolock chucks came with 2 collets in the Imperial version a 1" and a 1 1/4" or Metric version with 25mm and 32mm.  Originally there are 2 cutouts in the foam in the box for these two collets. The exceptions are this more limited shank types e.g. MT3 & R8 came with both  a 1" and a 25mm. I.e. you still got your 2 collets but the set is both Imperial and Metric but the set omits the largest sizes.  The information in the thread will enable you to confirm definitively if you have a small or large chuck. If you have a small then you are looking for in Imperial 1/4", 3/8" 1/2", 5/8" and Metric 6mm, 10mm ,12mm, 16mm. These small sizes collets are readily available from dealers and ebay.co.uk. Where are you? Perhaps a local dealer may be able to help?

Steve

 

 

 

 

Edited By SteveI on 08/04/2015 20:23:27

[Graham WhartonParticipant @grahamwharton]

Steve,

I think at some point Clarkson must have changed the name of the large chucks with a taper gauge of less than 1/2" to medium to remove confusion about collet sizes. The 1" collet for the large chuck with taper gauge of less than 1/2" is a completely different size collet to the 1" collet for the large chuck with taper gauge of more than 1/2".

This applies to all of the 803XX series from the table above. The body diameter is smaller than the other large chucks, and the collet O/D is smaller than the other large chucks.

The full range of collets for the three chuck sizes are

Small 6mm, 8mm, 10mm, 12mm, 16mm, 1/4", 3/8", 1/2", 5/8"

Medium 20mm, 25mm, 3/4", 1"

Large 20mm, 25mm, 32mm, 3/4", 1", 1-1/4"

Looking at the clarkson part numbers, the 8mm Small, 20mm Large, 3/4" Large and all medium collets all appear out of sequence with the other original collet part numbers, so these may have been introduced after the above clarkson images were produced. I'm guessing the extra collets were introduced at the same time as the range was changed to small, medium and large.

Cheers

Graham

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Tim Ostley on 08/04/2015 19:30:40:

BR PAT 915713

.

Thanks for that, Tim

Here it is

MichaelG.

[SteveIParticipant @stevei]

Graham,

Thanks for educating me with that extra explanation of sizes. I agree that my image must be from an older document.

I have never seen a 3/4" or a 20mm collet that fits my R8 "large" chuck. And I have sorted through quite a lot of collets at various dealers looking. Nor do I have any endmills or slot drills with that size shank. At the risk of "being an anorak" the reason I have looked is out of curiosity as I do have a 8mm, 20mm, and 3/4" collet (amongst others) for my clarkson T&C grinder air bearing flute grinding attachment. Those P/N's are also out of sequence so again that points to a later product.

To aid the thread as a future reference I will add that I also picked up a number of replacement centers as a lot all P/N 40102 and these fit the R8 small and MT3 small (as in miniature, small, large). I have yet to see what my R8 large takes as the center is in vgc.I also include a picture with some of the other types of accessories. Are there others?

Steve

[Graham WhartonParticipant @grahamwharton]

Clarkson part numbers for Collets and Chuck Spares. Hope they are of use.

Collets and Parts
40070	Small Sleeve
40071	1/4 Small collet
40072	3/8 small collet
40073	1/2 small collet
40074	5/8 small collet
40075	Small Spanner
40076	Large sleeve
40077	1" large collet
40078	1-1/4 large collet
40079	2MT Large Centre
40080	1MT Large Centre
40081	Large Spanner
40086	Large to Small Adapter
40088	Small Damping Ring
40090	0MT Small Centre
40091	3/4" Large Collet
40094	1" Medium Collet
40095	Medium Spanner
40096	Medium Damping Ring
40097	25mm Medium Collet
40098	3/4" Medium Collet
40099	20mm Medium Collet
40100	Medium Sleeve
40102	1MT Small Centre
40245	1/4" – 5/8" Small Collet Set
40246	1" & 1-1/4" Large Collet Set
40247	6mm – 16mm Small Collet Set
40248	25mm & 32mm Large Collet Set
40M71	6mm Small Collet
40M72	10mm Small Collet
40M73	12mm Small Collet
40M74	16mm Small Collet
40M77	25mm Large Collet
40M78	32mm Large Collet
40M91	20mm Large Collet
40M92	8mm Small Collet

[Graham WhartonParticipant @grahamwharton]

Clarkson part numbers for chucks. Hope they are of use. There's probably some gaps which you may be able to work out. e.g I reckon my 3MT Large Chuck is actually part number 80103 etc.

Chucks
80002	2MT Small Chuck
80003	3MT Small Chuck
80004	4MT Small Chuck
80005	5MT Small Chuck
80007	B&S#7 Small Chuck
80008	R8 Small Chuck
80009	B&S#9 Small Chuck
80010	B&S#10 Small Chuck
80013	3MT Small Chuck Victoria
80014	4MT Small Chuck Deckel
80016	50ISO Small Chuck Arborlock
80020	40ISO Small Chuck Deckel
80030	30ISO Small Chuck ISO297
80038	1-3/8" NS Small Chuck
80040	40ISO Small Chuck
80047	45ISO Small Chuck Caterpillar
80049	50ISO Small Chuck Caterpillar
80050	50ISO Small Chuck
80072	40ISO Small Chuck DIN2080
80073	50ISO Small Chuck DIN2080
80090	30ISO Small Chuck BE System
80091	40ISO Small Chuck BE System
80105	5MT Large Chuck
80106	6MT Large Chuck
80115	5MT Large Chuck DIN2207
80116	50ISO Large Chuck Arborloc
80120	40ISO Large Chuck Deckel
80126	6MT Large Chuck DIN2207
80140	40ISO Large Chuck
80147	40ISO Large Chuck Caterpillar
80148	45ISO Large Chuck Caterpillar
80149	50ISO Large Chuck Caterpillar
80150	50ISO Large Chuck
80172	40ISO Large Chuck DIN2080
80173	50ISO Large Chuck DIN2080
80191	40ISO Large Chuck BE System
80201	1MT Miniature Chuck
80202	2MT Miniature Chuck
80203	3MT Miniature Chuck
80303	3MT Medium Chuck
80304	4MT Medium Chuck
80308	R8 Medium Chuck
80314	4MT Medium Chuck Deckel
80330	30ISO Medium Chuck ISO297

Edited By Graham Wharton on 08/04/2015 21:43:29

[Tim OstleyParticipant @timostley22330]

Steve,

It appears that there are two forms of the large autolock chuck. The largest will take 3 different collets 3/4" 1" and 1 1/4". Plus three metric equivalents. The metric equivalents have a groove on the outer 'wings' of the collet. The one I have takes two imperial collets 3/4" and 1" only and the metric equivalents. The collets for mine are smaller in outside diameter than the large ones so are not interchangeable. The Clarkson chuck documents I have seen on the net don't mention my chuck. See Graham Wharton's post earlier for the part numbers of my chuck.

It has been very interesting to find out about the Clarkson chucks – this thread probably contains most of what is known.

Thanks to all.

Tim

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