Oh Blimey I bought a CNC Lathe !!!!

[awemawson]

So now I could fit the actuating tube, and screw the female thread on the end, onto which I'd screwed the threaded rod and locked it in place with a locknut on each side

[awemawson]

Next I needed a way of turning the actuator nut in the chuck, so that I could screw it, complete with my male threaded adapter, onto the studding to make length adjustments.

A tubular spanner came with the chuck, but due to it's diameter it will only engage the nut from the mounting side of the chuck - not a lot of use in my application ! Spanner wall not thick enough to reduce so need to start afresh.

Hunting for heavy walled tube or suitable bar it then occurred to me - there is a swarf guard at the front of the nut - would it remove and let the spanner in . . . oh YES 

[awemawson]

So now I'm ready to mount the chuck and try it out . . .

. . . . EXCEPT . . . I need to be sure of the hydraulics - a lot of power in that actuating cylinder. Operating force is tweakable by setting the hydraulic pressure, and I need to familiarise myself with the hydraulic manifold before I start random twiddling 

The chuck says maximum operating force is 22 kNewtons ie 22,000 Newtons

Powering up the machine (no chuck fitted) lets me see that the current operating pressure is 30 bar, and the chart on the cabinet says this gives 4000 deca Newtons or 40,000 so presumably that pressure needs about halving.

Also I'm not sure how much tension that I can put on that 12 mm studding. It's only there to prove movement length and position, so I will turn the hydraulic pressure as low as I can for testing, then re-set it when I make the final adapter.

Have a hydraulic circuit diagram:

[vtsteam]

Always amazed by your abilities and knowledge, Andrew 

[awemawson]

A bit of fiddling about and I've reduced the hydraulic pressure to 2.5 bar (from 30 bar) which I'm sure is a safe level for testing the movement of the chuck mechanism. I've also been able to reverse the direction the hydraulic cylinder operates when told to close (The original collet chuck pushes closed, this chuck pulls closed)

Now I need to sort out the other end of the spindle where the proximity feedback sensor is housed, as it needs to operate in the reverse fashion. There is an adapter disk that is the element that is sensed, and I suspect I'll end up machining another one 'top hat' shaped so the bit that is sensed is to the rear, rather than forward as it is at the moment.

[awemawson]

Always amazed by your abilities and knowledge, Andrew 

Stop it, you'll make me big headed 

[vtsteam]

But that's why we have lathes . . . . 

[awemawson]

So I put my attention on the outer end of the spindle where the proximity sensor is.

The sensor is fixed in a housing that has two functions a/ hold the sensor and b/ act as a funnel for any coolant that pases down the bore of the spindle, directing it back to the sump.

Removing the housing shows the disk that theoretically is held in by three cap head screws - no screws in the holes ! The disk seems to be a VERY tight fit over a hub, and so far it is resisting my attempts to remove it

This is what it looks like

[awemawson]

Now  I do have a plan of a similar spindle (shown below) and it confirms that only the screws retain it, but on mine the hub on the spindle is somewhat longer, and the disk surrounds it for a depth of maybe 3/4".

So far gentle heating, tapping with a plastic mallet, and application of wooden wedges has failed to shift it. I may have to devise some form of customised slide hammer to pull it off, but duty calls. I need to have a wash and scrub up before greeting and meeting some new guests in the cottages 

[Kjelle]

Andrew, You are one h-l of a engineer! Most people would have given up looooong ago! And taking on something as complicated as this...

Now, regarding those cottages...I wounder if I can persuade the missus to take a week on an English farm next summer....

Kjelle

[awemawson]

You'd be very welcome:

http://tinyurl.com/Apple-Cottage

[awemawson]

I've been kept largely out of the workshop today - it's my birthday and apparently I have to be entertained. This morning I was taken by my eldest boy to look round 'Eastbourne Redoubt' built around 1807 as one of a series of forts to stop the French being too adventurous with their cross channel trips. Very interesting, but sadly most of the original cannons were melted down in WW2 when we were desperate for the metal to keep another foreign adventurer off our shores !

However I did manage to escape for half an hour and cobbled together a slide hammer from the jaws of a bearing puller, with a length of 12 mm studding projecting back as the slide, with a length of very heavy section cored rod as the hammer.

[awemawson]

So did it work - - - - - oh yes 

[awemawson]

So now I need to hunt out a large bit of steel to make a replacement with a different profile so that the sensing happens in reverse to this one. I need a billet to produce a 108 mm diameter by 32 mm if you have one in your pocket 

 I could turn down the original, but I will retain it with the collet closer in case I need to refit that chucking arrangement at any time in the future

[DMIOM]

...... it's my birthday ......

Hope its a good one - making your own presents?   

cheers             

Dave

[dsquire]

Andrew

I'm still following along and quite impressed by the way you are getting that equipment into shape. 

By the time you get this you will probably have finished the birthday cake. Let me just add another Happy Birthday as you start out on another journey around the sun. 

Cheers 

Don

[Kjelle]

Congrats, Andrew!!

<Kjelle

[tom osselton]

Happy birthday!

[awemawson]

Thanks chaps for the birthday wishes. I had  my first oap concessionary ticket today at the Fort - gosh it makes me feel old

[DMIOM]

... - gosh it makes me feel old

On the basis "use it or lose it" I don't think there's any risk of your grey matter stagnating just yet! 

[vtsteam]

Happy Birtyhday Andrew!! 

[PekkaNF]

HAPPY BIRTHDAY!

My aunt told me when I had my 50'th that "The life is not over, just a best part". Some people have the skill for pep talk.

Pekka

[awemawson]

Thanks chaps 


So in the absence of a suitable bar end (and it would have had to be 4 1/4" diameter) I remembered that I had had some blanks flame cut some years ago to make gear wheels. Digging through them found two that if glued together might work

[awemawson]

I needed 31 mm of thickness and these together make 30 mm which is close enough, as I'm adjusting the position that sensing occurs with the length of my chuck adaptor.

So I started by boring them out to 10 mm undersize to reduce their bulk for the silver soldering I was planning to use to fix them together

Don't often have to fit the reversed jaws but they went in today. Then I initially drilled a 2" hole in them to save time actually boring

[awemawson]

The idea was to set them up like a sandwich, with a ring of silver solder and a sprinkling of flux, then heat them dull red with the oxy-acetylene torch, but first I grit blasted the mating surfaces.