Clarkson autolock help

Martin -

It is possible, sort of, to assemble the chuck with the collet up on the dogs rather than between them, but I think it would tell you almost straight away because you would be unable to screw the nut on more than a turn or two.

Thank you for this thread - it's helped me, and I've saved the picture of instructions!

'

It's intriguing. all this "I was taught...", against the manufacturers' instructions; and of course an apprentice never questions his superiors' natural great wealth of both skill and experience. *

I was never apprentice-trained but picked it up as I went along, so do stand to be corrected and from time to time do learn such from threads on this site . As here, since I too always thought there was meant to be a tiny gap 'twixt nut and body - it somehow seemed logical. Evidently not, and also evidently being taught didn't always mean being taught the right way; i.e. as the tool was designed to be used!

'

One of my Autolock collets has a broken 1/4-inch cutter shank jammed solidly in it; but snapped across the thread, not split. I didn't break it. It came free with the second-hand collet. I now wonder if it broke thanks to poor mounting technique - perhaps not so much "backed off" as "are we there yet".

Still trying to work out how to remove the broken cutter.

===

* That comment about superiors was tongue-in-cheek but it has had a deadly serious side, such as emerged in the 19C Tay Bridge Disaster inquiry when it considered the shoddy workmanship.

Still trying to work out how to remove the broken cutter.

Two hopes - no hope and one is dead, as we old ‘uns’ remember.

Drill it out with a carbide drill? Need to get close to the minor thread size to do any good, I would think. Normal right hand drill might loosen it, but likely needs plenty of soaking in release fluid before attempting?

The other (cheaper?) alternative is to dump it, I would think. Your choice.

In my working life, I have come across umpteen discrepancies between operating to ‘the manual’ and operating to get by. Most cost a lot of money for the company involved.

One example was a simple ‘check weigh’ system where what was “reported’ fed to a process (over a weigh-belt) was compared to what was actually fed from a hopper on load cells (material in the hopper was weighed between upper and lower level and calibrated to 0.01 tonnes in nearly 15 tonnes).

The feed-belt result was accepted as correct, even though it usually reported just over 17 tonnes, while only 15 tonnes were actually fed. Unsurprisingly, annual production (by what went over the weighbridge and physical stocks on site) never ever tallied at audit times!

Process operators were contented because it was easier to operate below design capacity and the deficit was annually adjusted in the production figures, without anyone checking how the discrepancy arose. We were talking, here, of around 20,000 tonnes every year which was not produced!

Exactly, and that's how better techniques can get ignored, or looked down on. Although at one point I was looking at apprenticeships, due to an impending academic car crash, in the end I'm glad I didn't do one Instead it means I have to work it out for myself, mistakes and all. And I'm happy to try new ideas like CNC.

Andrew

Numerical Control first appeared in the late 1940s. And here we are 80 years later in a technical hobby that considers CNC to be 'new'. We still have chaps pushing Whitworth, Imperial Measure, apprenticeships, and manual skills rather than theory.

The hobby abounds in rose-tinted nostalgia in a way not found in other engineering disciplines - you won't catch electronic engineers extolling the superiority of a Lee de Forest Audion! I hope no-one believes a Spitfire could take on a Fast Jet.

Surely the most important feature of engineering is keeping up with modern developments, not squatting in a comfortable rut? Or armchair in my case...

Dave

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But you do [or at least, I did] get advised that an ebay seller is listing these:

**LINK**

https://www.ebay.co.uk/itm/ORIGINAL-TEXAS-INSTRUMENTS-SN75451BL-TO5-METAL-CAN-CHIP-UK-STOCK-x1-fd7d47/402243634073

https://www.ebay.co.uk/itm/ORIGINAL-PMI-MAT01-AH-CHIP-UK-STOCK-x1-fd7d45/124163959326

**LINK**

MichaelG.

I learned a huge amount from the men who taught me as an apprentice, to this day I have great respect for them. I saw huge changes in the car manufacturing industry. When I started my apprenticeship as a maintenance electrician I was drawn to the technology in the tool room, which had a bay where R&D had trialed numerical control and a giant size edm machine. I moved off the shop floor to welcome the large scale introduction of PLCs and robots, the chaps who had taught me so much were now struggling to adapt to the new world while us relative youngsters, me still in my mid twenties soaked it all up. One day I was called down to help one of my original mentors and the thought came to me that I was helping one of the chaps that answered all my questions just a few years before. 30 years later the young guns were helping me out, the combination of a quick young brain and 40 years experience can work well together. Hopefully I managed to pass something useful on to the young guns.

Mike

One thing you can be sure about with any type of Autolock or Posilock, is the repeatability of the depth of the cutter. The centre hole in the end of the cutter fits in the centre inside the body of the holder. It cannot go any deeper, and the thread on the cutter then pushes the collet downwards as the cutter tightens. This tightens the collet due to the tapered end fitting into the tapered bore of the screw on nosepiece. This is why the makers say fully screw home the nosepiece first, before screwing tight the cutter. The system is not foolproof as the small 1/4" and 6mm shank cutters can break at the threaded end. The core diameter of the small cutters is not very big.

Anybody who has one of these Clarkson Autolocks with a damaged centre inside the body may be in luck, as some new centres are listed on ebay UK at present.

Well there as been a lot of personal comments to read here. All good I may add. From my new experience of using the Clarkson I can only say , it worked very well . I did with the ER25 collet chuck manage to wind out a cutter & push it into the face of the work & ruin the cut. Jason put me right on that occasion as I was climb milling, did not have a clue. I will keep the limited remaining grey matter entertained as long as possible. Again thanks to all the info received.

One member did say that the collar can also be used to eject the taper. Which of course is correct. I do not tighten the taper too much & have not had a problem removing the devices in the MT2. But have read previously where some have trouble with the MT tapers sticking.

Steve.

I was thinking a bit more about my early days with Clarkson autolocks,now the type with collets having two pegs was the early type of clarkson ,the later type ,ie the S type was I believe introduced in the 1960s and had a different system for driving the collets ,and it always seems that the S type literature is the one that most people refer to ,so there must have been instructions for the early type but I never saw any. I did remember today that I was told that the backing off a fraction of a turn of the nut was done to avoid the nut jamming and and apparently being very difficult to loosen. Now there is some comment about the workers who back off the nut,but judging the from the replies there are are number of us who back off the nut and it was common practice at the time.

Used one of my large Clarkson autolocks today, 24mm slot drill. Procedure: fit collet, screw in nose piece hand tight, screw cutter up tight by hand, job done. cut 4 recesses to fit some thrust bearings, fairly low speed job, only cutting 4mm deep each time. Needed the spanner to loosen the nose piece but, the cutter height had not changed, which I think goes to prove that once seated correctly the cutter will not move but the collet does move and tighten as the cutter meets the work.

During my apprenticeship, I was also informed by my mentor to back off the nose before fitting the cutter then tighten up with the spanner. Being a headstrong northerner (and coming from a long line of marine engineers who taught me well as a youngster and owning a Centec mill fitted with an autolock chuck), I duly informed said mentor that his method was incorrect and that I would fit the cutters in the correct manner, not his way, as may be expected this did not go down too well and was given a b*ll***** for being a smart arse.

So first job required a 1/4" cutter, mentor set up 'his way' half way through and bang, removed cutter to find it split in the back and snapped just below the threads. So smart arse fits a new cutter 'the correct way', finishes job and two more and returns undamaged cutter to the box. "I told you so' saw me running out of the workshop to avoid a clout with a big tap wrench

Moral, just 'cos thats the way you've always done it don't make it rite!

I apologise if anyone took umbrage at my earlier throw away remarks about apprenticeships.

I've played with one of the old C-type chucks, as I ground a new centre for the owner, but never used one in anger. All my Clarkson chucks are the later S-type. I've never had a problem with the nut sticking, even on the larger ones I use on the horizontal mill.

Andrew

Not Done It Yet -

Carbide drill. Thank you - worth a try. I wonder if a new masonry-drill would touch it? I know the tips on such a drill have no , or negative, rake, but nothing ventured and all that. At least unlike a sheared stud, a cutter has a centre-hole.

I can assure you I have tried to buy replacement collets but they seem rarer than poultry-dentures!

Silly Old Duffer -

I agree our hobby still clings to old ways of doing things but sometimes that's more necessity than choice, often to match whatever we are building, or our own machine-tools and skills.

Our projects are obviously choice, whether a miniature traction-engine whose prototype was commercially obsolete in 1920, or a gas-turbine to the very latest 2020 design.

Even if you are criticising instead our usual methods, most of us have to use what tools and equipment we can afford and use; and very many model-engineers are anyway perfectly happy to follow plans that could have been first published decades ago, to replicate in inch-scales an even older, British-built machine. Though I admit oodles-of sixty-fourths from random data points is a pain when using a milling-machine with "thou" dials and decimal DRO!

Few of could afford NC machining-centres and SolidWorks software even if we wish we could (and had the space). As for using BSW threads and other old standards, so what? It's our choice whether we use modern specifications and all-mm designs on CAD prints; or follow without deviation (hesitation or repetition...) 1960s drawings by LBSC or Evans. If you are making that traction-engine to exhibition standards you might use O-rings in its internals, but would you plaster its visible bits with modern details like embossed metric screw-heads, 'Nyloc' nuts and circlips? Or it wrong to make a miniature of an Edwardian machine anyway?

And yes I do know BA threads are metric....

If "rose-tinted nostalgia" in a hobby is wrong, then presumably anyone who learnt the piano should never attempt a Classical sonata; anyone who learnt to paint should abjure portraits....

The way I read your comment is like a classic motorcycles, that I have had a few of. To display as concourse it had to have everything as original even if it was not the best. To be immaculate as most of mine were then it had lots of stainless parts & sometimes metric bolts etc. Even down to old paint vs Acrylic or powder coat. Can see your points from both sides.

Steve.

For various reasons I have both C & S types , as well as a Titanic, and something else quite obscure of which I can't remember the name.
Of the three, I always seem to go for the C type unless it's in use on the other mill.
Possibly because it's the first one I acquired.
It does have the advantage, that used with care, it will hold plain shank cutters, as the closing sleeve is separate to the collet.
I've never found any instructions for the "C" type; can anyone assist please?

Bill

Have you looked at spark erosion , there must be someone in the UK that does it. Guy in US on youtube explains the method while doing it.

Steve.

Yeah, who would think a hobby focussing on making working miniature replicas of 19th century steam engines, early 20th century IC engines, obsolete Stirling engines and the like would be so backward looking.

Edited By Hopper on 01/05/2020 06:55:40

I wonder if a new masonry-drill would touch it? I know the tips on such a drill have no , or negative, rake, but nothing ventured and all that. At least unlike a sheared stud, a cutter has a centre-hole.

Nothing wrong with even an old one as long as it is true. A green grit wheel can be used to sharpen a masonry drill to a suitable profile - it is only chunks of carbide fixed to a steel shaft, after all.

Edited to add that once a hole has been drilled, larger ones could have a suitably modified nut welded to the cutter shank to free it off.  More than one way to skin a cat, as they say.

Edited By not done it yet on 01/05/2020 07:11:30

The old style straight shank TCT masonry drills are easily sharpened using a green wheel, or diamond wheel. For anyone not sure of being able to sharpen them properly, there are Bosch multiconstruction drills which have the sharp edge already, and are superior to sharpened standard TCT even after sharpening. I have a quantity of solid carbide drills which are expensive and require careful handling. The Bosch are much tougher and can even be used freehand in an electric drill. They are not expensive, a small set is less than £10.

**LINK**