Lathe Chuck

Shipbuilder
12th September 2009, 17:28
Hello everyone,
Hope someone may be able to help in this. Although I am not an engineer, I am not new to lathe work, having had my present one since the early 70s.

Two days ago, I needed to drill a 1/16th inch hole down the centre of a quarter inch brass rod (A thing I have done countless times before).

I placed the rod in the chuck and the drill in the tail chuck. No matter how much I tightened the main chuck up, when I advanced the tailchuck drill, it simply pushed the rod into the main chuck. I am using the same type of brass as usual. I tried a new drill and it was just the same. I washed the chuck thoroughly in white spirit in case it was a bit oily and it was still the same. I then washed it in meths and there was a bit of an improvement, but not much!

Can a three jaw chuck wear out over the years, causing this to happen?
The lathe is a Unimat SL. The chuck that keeps slipping is a MOUNT M12 x 1, 0-6mm capacity.

Bob

MARINEJOCKY
12th September 2009, 18:45
Bob, I bought a very old lathe from a ship yard and never had that problem.

I am not writing the following to be a smart ass but I had an apprentice once who had the same problem and he had the lathe in reverse !!!.

Have you tried taking out and cleaning all of the jaws

chadburn
12th September 2009, 18:56
shipbuilder, Like everything in life things do wear out, the jaws will possibly be touching each other before gripping the rod, set the rod up again and see if you can get a feeler guage between both sides of the three the jaws, without wanting to teach you to suck eggs or offend you put a collar on the brass rod, secured with a screw.

Shipbuilder
12th September 2009, 19:02
Thanks for reply. I am certainly not using it in reverse, I have been using it since 1973. (It was 2nd hand then). As you can see from above, dirty chuck was my first thought. I first cleaned it with white sprit and then with meths and only gained a slight improvement with meths. (I did manage to drill the hole - only 0,50 inch depth was required!)
I have drilled literally hundreds of 1/6th inch holes down brass rod without many problems. Last time it did this (several years ago), I cleaned it with Gunk, leaving it to soak overnight and that cured it. Can't find my tin of Gunk at the moment. When I do find it, I will try again with an overnight soak.
Bob

Shipbuilder
12th September 2009, 19:08
Chadburn,
Many thanks for reply. I will have another look at it with feeler gauge. I wouldn't mind it wearing out if I knew where to get another (SL is obsolete) and local engineering shop has gone (after 50 years or more!). Looked on Ebay, but wrong size.

Thanks for brass collar suggestion. Rather than thread it, I can solder it on and then melt it off after hole is drilled. I don't regard your comments as teaching me to suck eggs, I am an ex-radio officer who has merely picked up light engineering over many years.

When I changed the chucks round, it was still the same one that slipped.

Bob

Shipbuilder
12th September 2009, 19:24
This is what I was doing (in case anyone's interested). The 1/16 inch hole was in the bottom of the mast and the rod inserted in it was the method of fixing it to the hull.

You may note that the mast is tapered. I drilled the hole in it before I tapered it!

I also had problems when putting the taper on. The tool either pushed it into the chuck or drew it out, depending on which way I wanted to go.

I have put many tapers on without any problems. In this instance, I had to resuort to using a flat file.

Bob

chadburn
12th September 2009, 19:28
Ex Radio Officer you may be shipbuilder, but you have gained skills I admire(Thumb)

Billieboy
12th September 2009, 19:40
shipbuilder, Like everything in life things do wear out, the jaws will possibly be touching each other before gripping the rod, set the rod up again and see if you can get a feeler guage between both sides of the three the jaws, without wanting to teach you to suck eggs or offend you put a collar on the brass rod, secured with a screw.

The advice is good, but for the collar I would first skim a bit of brass and drill a hole through it, then take a skim out to true it up. Part off the small bush and then saw along the length to make a collet, fit it over the brass rod and clamp it in the chuck with the saw cut between two of the three jaws. Next, put a centre drill in the Tailstock chuck and drill a starter for your main drill.(Thumb)

Good luck.

p.s.just saw the picture of the job, you could make a thin 1/4" long bush with ataper on the inside that takes the tapered mast, near to the foot, the OD of the bush would not have to be too large, but work on the OD of the finished collet being roughly 2x mast diameter at that point. Don't throw it away after you've made and used it, you can use it on other jobs.

MARINEJOCKY
12th September 2009, 19:47
of course there is one easy way to fix it

start again with a bigger scale and that 1/16th drill could be say one inch or you could just weld it on.

Billieboy's advise is good except except how do you hold the brass in the lathe to skim it and drill the hole if the lathe chuck is the one that is the problem.

Sounds like a problem for the wife to solve (*))

Billieboy
12th September 2009, 19:54
of course there is one easy way to fix it

start again with a bigger scale and that 1/16th drill could be say one inch or you could just weld it on.

Billieboy's advise is good except except how do you hold the brass in the lathe to skim it and drill the hole if the lathe chuck is the one that is the problem.

Sounds like a problem for the wife to solve (*))

If the Chuck is the problem, then it's probably due to the chuck being used a lot for the same diameter work, a larger diameter collet should solve the problem. If not then just buy a new one, if it weighs less than a kilo or two then the cost isn't all that high. If you need a forklift to change chucks then it's BIG money.(EEK)

Shipbuilder
12th September 2009, 20:30
Thanks for all the advice. I am beginning to think I have just worn it out over the past 30-odd years. However, I have a "repair" idea that I will try tomorrow on my "day off."

Buying another is not a big deal as far as I am concerned, but it is completely obsolete and I haven't been able to find another on the internet so far. My next meeting with an "engineer" is on Tuesday next he may know where to get one.

This evening, I have been sitting there with the chuck, a brass rod, a feeler and a glass of vino. I find I can poke the feeler down quite a long way next to one of the jaws. Wear and tear - "time like an ever-rolling stream bears all it's chucks away!"

Will let you know how I get on.

Bobn

chadburn
12th September 2009, 21:04
Looks like you may need a little grinder with a disc fitted, if the jaws are not "kissing" each other then there is no need to grind the angles back a smidging, just take the jaws out and using the edge of the grinding disc to re-cut knew gripping "teeth" on each jaw, it may be that the jaws have just "bottomed out" due to wear, I have in the past wrapped emery paper around a piece to get a grip, but as you have moved over into Engineering(Thumb) you will appreciate that Engineers throw nothing away on the basis it might come in handy--------------one day. before they themselves go into the firey "boiler" furnace. Our ashes to be made into little Diamonds for lathe tools of course.(Jester)

MARINEJOCKY
12th September 2009, 21:27
Bob,

I found the following on the internet over here and have posted the link as well. Is that what you are looking for.

3-Jaw Lathe Chuck for Unimat DB200 or SL1000
3-Jaw Lathe Chuck for Unimat DB200 or SL1000 Item #: 100.100
Qty
Price $120.00 Adjusted Price $120.00

http://www.blueridgemachinery.com/

I also found this on the internet and it maybe a source of spares

Re: Where can I get a chuck for an Emco Unimat-SL lathe

--------------------------------------------------------------------------------

jon.p.weaver@alcatel.co.uk (Jon Weaver) wrote in
news:573665cf.0305220407.129772d4@posting.google.c om:

> I have just been given an Emco Unimat-SL lathe and was really chuffed.
> However, I soon found that the chuck is broken.
>
> As its an old machine, I didn't hold up much hope of finding a
> replacement chuck, but I soon learned that there are quite a big
> spares market. However my excitment was short lived.. I found that I
> could get a chuck from the US for $105 plus shipping.
>
> To be honest, if someone had offered me the whole lathe (including
> working chuck) for 70, I wouldn't have bought it, so I am not going
> to pay 70, just for a chuck.
>
> Is there anywhere that I might get a replacement chuck cheaper than
> this?
>
> If not, does anyone have any suggestions what I should do with the
> lathe.. I guess that I could sell it without the chuck, but I don't
> know how much its worth.
>

pennyfarthingtools.co.uk

Gerry usually has chucks in second hand for this type of lathe...

cheers D



Hopefully all of that helps, let me know if you need any assistence from here in America.

ROBERT HENDERSON
12th September 2009, 21:48
BOB
Out of curiosity I googled your type of lathe, it started production again in Taiwan. The company I looked at is www. lathes.co.uk they also give an email address if that is any help.

Regards Robert

Shipbuilder
12th September 2009, 22:15
Thanks for further helpful replies, especially all the links from Marine Jocky that I will look into tomorrow.

As far as taking the chuck apart, I can't see any way to do that. I honestly can't even see how they put it together in the first place as there are no key slots, grub screws or anything else that might allow me to gain access.

But I do have an idea that I will try out in the morning. Don't want to say what it is at the moment as someone might say "Shouldn't do that" or "bad engineering practice" etc.

But whether it works or not, I will tell you all about it tomorrow.

--

Just for interest, this is my greatest miniature engineering feat. The giant steel-hulled five-mast barque FRANCE. Maybe you think a sailing ship has no place here, but she had twin screw diesels as well. After a number of years service, the owners decided to remove the engines and make her a pure sailing ship. She drifted ashore in a flat calm shortly after and was a total loss.

During the Great War, she was attacked by a U-Boat and managed to escape by use of full-power on the diesels as well as full sail, so maybe you will excuse the picture here!

Anyway, the engineering went into the masts and rigging. The five masts are made from a combination of brass tube, and brass rod. All the fittings on the masts are either brass or copper. The yards (supporting the square sails) are all made from either brass or copper rod. The rigging is 100% fine copper wire. The ratlines (ladders) are soldered across the shrouds. All the deck machinery and the donkey boiler is made from turned brass and the deck rails are 38 swg copper wire completely soldered with a flat copper capping rail on top painted to represent wood. The wheels are made from etched brass and the propellers are made from brass, cut to shape with a Dremel cutting wheel in a hand-held 12 Volt electric drill.

A further plea for acceptance is that I mostly build steam or motor ships, but like to keep my hand in with sail from time to time (iron and steel ones mainly).

It took about a month to build and every piece was made by myself. Tried to retire from building them a few years ago, but couldn't - habit forming! Wife helps with fancy bits of painting where necessary.

That is why I want get get my lathe back in order again.

Best wishes
Bob

Pampas
12th September 2009, 23:54
Remove the jaws and take them to a machine shop who has grinding tools, tapered faces to grind then the cylindrical shape on the gripping face ditto. will need the body to do this.

Shipbuilder
13th September 2009, 08:26
Thanks again for all the replies. I have now fixed it as my method worked.
Based on what some of you had said, I deceided that it was wear on the jaws. I placed my good chuck in the lathe and in it, I placed a thin round file from which I had snapped the tapered pointed end. The faulty chuck was placed on the tailstock with the jaws open. I advanced it over the file and turned the lathe on. With the round file spinning inside the faulty chuck, I very carefully closed the faulty one with the key until it closed on the file. This quickly produced a grinding and screeching noise. I kept an intermittant (so it didn't heat up too much) slight pressure on the key for about half a minute, by which time fine powdered steel was coming out of the faulty chuck. I then stopped it and returned the faulty one to the business end and successfully drilled a 1/16th inch hole down the centre of a 1/4 in rod. There was no sign of slipping. I then turned a winch drum from 3/32nd brass and finally a smaller one from 1/16th brass without any problem. It appears to be as good as new. Not sure how the professionals will view my "kill or cure" method. I half expected the file to shatter, so kept well out of "line of fire" and wore the necessary protective goggles, but all went well.

Neverthelss, I will still be searching for a replacement using the links supplied. This lathe is a Unimat SL made in Austria for Elliott Machine Equipment Ltd, London. I purchased it in Fareham (2nd hand) in 1973 for 69, whilst I was attending an electronics course at Southampton Tech. Awful course, but at lunch times I would sometimes creep off to the engineering section where I hovered round the door until a benevolent lecturer invited me in and showed me various aspects of lathe work.

Was first introduced to the wonders of lathes in the engineroom of SAGAMORE by 2nd engineer Bob Pryde in 1963, but I did find those big ones a bit frightening and feel more at home with my little Unimat. A friend recently gave me a spare motor, so I should be OK for some years to come.

Bob

johnb42
13th September 2009, 09:06
Just visited your web site - beautiful work.
John

Shipbuilder
13th September 2009, 09:59
Hi John,
Thanks. Took a lot of practice - over 40 years - mainly self-taught.
We may have met when you were on Ascension. I spent 1979 -1992 aboard both ST. HELENA's!
Bob

Billieboy
13th September 2009, 10:57
Thanks again for all the replies. I have now fixed it as my method worked.
Based on what some of you had said, I deceided that it was wear on the jaws. I placed my good chuck in the lathe and in it, I placed a thin round file from which I had snapped the tapered pointed end. The faulty chuck was placed on the tailstock with the jaws open. I advanced it over the file and turned the lathe on. With the round file spinning inside the faulty chuck, I very carefully closed the faulty one with the key until it closed on the file. This quickly produced a grinding and screeching noise. I kept an intermittant (so it didn't heat up too much) slight pressure on the key for about half a minute, by which time fine powdered steel was coming out of the faulty chuck. I then stopped it and returned the faulty one to the business end and successfully drilled a 1/16th inch hole down the centre of a 1/4 in rod. There was no sign of slipping. I then turned a winch drum from 3/32nd brass and finally a smaller one from 1/16th brass without any problem. It appears to be as good as new. Not sure how the professionals will view my "kill or cure" method. I half expected the file to shatter, so kept well out of "line of fire" and wore the necessary protective goggles, but all went well.

Bob

Quite a good jury rig Bob, it establishes your versatility as a marine engineer! It's not what I would have done as a turner. The way to fix it is to fit a high-speed needle grinding tool in the tool-post, clamp the chuck jaws inside a bronze ring so that the stone can pass in the jaws then true the jaws up. There will be a problem, as the work you have done will have removed the case hardened layer leaving a, "soft-jaw", chuck. I could go into the re-hardening, but it's too complicated, time consuming and uneconomical.

For the use you put the chuck to, you have probably added about ten to fifteen years of life to it. Well done.(Thumb)

johnb42
13th September 2009, 11:15
Shipbuilder,
I thought you must have been an RMS man when I saw Curnow Shipping in your profile. I was the GFA (Hogg Robinson in those days) on Ascension, so wasn't involved in the RMS operation, just our own shipping service. Nevertheless, I did get aboard your ship a couple of times. Knew one or two of the Saints that worked on her too. One was an ex-police woman from Ascension. Also knew a lady Purser who was friendly with the Master of Maersk Ascension. Names have faded into the mists of time, but four years on the Island filled quite a bit of space in the memory bank.
Still have infrequent contact with Donald and Wendy Arms (Donald was Manager of Two Boats Club), I read the Islander on line now and again otherwise ASI is another slice of my history.
Once again, congrats on your work.
John

Shipbuilder
13th September 2009, 11:53
Billieboy
Thanks. I thought I would probably remove the hardening, but it is possible that had gone anyway over the years, especially as it was 2nd hand when I got it in 1973. Over the past 17 years, it has done an amazing amount of work, possibly in excess of 700 masts and certainly over 4,000 miniature winches and other deck machinery.
Anyway, as I said, the search is about to resume for a new one. My other chuck, still as sound as a bell is one of those types where the jaw ends protrude beyond the sides when it has anything relatively big in it. Always a bit wary when using that, but I have never managed to catch myself on it yet, touch wood. Mainly use it in the tailstock where it doesn't have to rotate!

John,
Yes, I know all those people as well. Dave was master of MAERSK ASCENSION for a long time and Angie was purserette from 1978 to about 1991, previous to that, Union-Castle.

Donald Arms was a steward for a fair while, but left for better things. Our captain, Martin Smith usually called in at Two Boats each trip for a yarn with Donald in later years.

Bob

K urgess
13th September 2009, 12:35
An acceptable solution to a vexing problem, Bob.
I can sympathise with your opinion of Southampton electronics course. I was also there in early 1973 but had the "good fortune" to wreck my car on the way back from Hull one weekend.
After a couple of weeks on sick GTZM sent me back to sea because I'd missed so much (I was late joining the course anyway) and then they sent me to South Shields the following year in plenty of time (about the only Chrimple I ever got at home).
The other point about that rambling explanation is that we didn't have to hang about outside the workshop door at South Shileds. Lathe work, tempering and all the other joys of metalwork were part of the course. Somewhere I'm sure I still have the adjustable wire cutters and clamp we had to make.
It was also my introduction to one legged Doxfords, Scotch boilers (Vaux breweries), water curtain boilers and other mysteries of the engineer's world. [=P]

Kris

Shipbuilder
13th September 2009, 14:27
Hi Kris,
I did the engineering part at Southampton OK, but there was nothing practical about it apart from setting up a Foster-Wheeler boiler control system.
Engineering lecturer was a Mr. Dove. Several years later, during his holidays, he took to doing the odd relief voyage aboard ST. HELENA (I) as 2nd eng, by way of a bit of relaxation, so we renewed out acquaintnceship from time to time. He did one voyage on ST. HELENA (II), but didn't find that relaxing in the slightest as the engines were nothing but trouble. Broke a crankshaft on maiden voyage and it punched a hole in the side of engine casing. I joined in Falmouth for voyage two, but spent my first three months in port while they cut hole in side of ship and fitted a new engine!

What a work up (ST. HELENA II). Spent hours and hours of off-duty time working in all parts of ship to try and sort out all sorts of electronic things that never worked from the start. Late 1992, all ship's company from captain down was made redundant, paid redundancy money and then offered jobs back for 30% pay cut! I took the money and ran - wouldn't go back!

Never regretted leaving, but the happiest years of my sea life were spent aboard ST. HELENA (I) where I at least knew what I was doing!

Bob

GWB
15th September 2009, 10:01
Shipbuilder, if it is a three jaw chuck most likely the scroll plate is damaged or blocked with cuttings simply pull the back of the chuck and clean it out. Elliott's chucks were sourced from various places, like Poland,Czechoslovakia, even UK and other places Unimat used to brand them, as part of machine.
The back plate and mounting are a standard and fit most chucks.
If collet chuck you have to check the draw on the holder.
Best to wash chuck out with kero as it helps to lubricate then oil it up, also good Idea to remove jaws every few months and put reverse jaws in with good bit of oil watch when you spin as you could get eye full of oil spray.

Cheers
GWB

Shipbuilder
15th September 2009, 13:16
Hi GWB,
Thanks for reply. It seems OK since I ground the inside. I would have opened it long ago if I knew how, but I just can't see any way of getting into it. The only way I can think that it was made in the first places was that it was squeezed together with brute force.

At the moment, I find that I am totally incapable of loading a picture of it here (although I have never had problems before today!)

It is a tailstock chuck with no screws or any visible way of getting into it!

Bob

Shipbuilder
15th September 2009, 14:58
Here is a picture of it.
Bob

cubpilot
16th September 2009, 11:48
Looks to me like a standard jacobs chuck. new chucks can be bought quite cheaply from good tool shops. just check though you get the right thread to refit to the tailstock if the attachment is just a screw, but in all probabilty the tailstock has a taper sleeve method of fitting drills and chuck. if so you can get chucks with the taper and so avoid the worry of finding the right thread.

Shipbuilder
16th September 2009, 14:54
I use it on the driving end of the lathe as I do very fine turning, regularly 1/16th inch rod and even less! In Preston, we had a high class toolshop for the last 50 plus years, but recently they just quit without warning and departed to another town miles away. An engineering supplier comes to the market once a week and he is going to look for one, but the old one continues to be OK.
Bob

GWB
18th September 2009, 02:38
Hi Shipbuilder,
I agree with Cubpilot it is a standard Jacobs chuck the information I last sent you was for the Lathe Chuck I did not realise you were referring to the drill chuck. You can buy drill chucks with the morse taper shank to fit the tailstock. Cubpiolt has you on the right track. There was a move to go away from the thread in the chuck and just had short taper so you could tap of when changing chucks.
An old trick for tuning small diameters in larger chucks get a bit of 6mm drill hole from tailstock as near the size of part to be held take it out and cut thro to the drilled bore replace in chuck when you tighten chuck closes around the small shaft you want to turn.

Billieboy
18th September 2009, 04:48
Nothing much I can add Bob, just cleanliness, but you've already learnt that!

surfaceblow
18th September 2009, 05:48
The web site below sells parts and accessories for Unimat's. A new drill chunk is listed at 28 dollars.

http://www.tomstoolstore.com/servlet/the-37/Unimat-Drill-Chuck-%23/Detail

chadburn
24th September 2009, 20:17
Shipbuilder, like GWB I was thinking it was the smaller standard lathe chuck, chuck, the one you have shown is as previously stated most probably somewhere around its just a matter of matching the thread.

Shipbuilder
24th September 2009, 20:30
Thanks for further replies. It is still OK following my "kill or cure" with the round file. I am sure another for use as spare will turn up soon.
Bob

pensioner
27th September 2009, 20:05
Hi Shipbuilder.

If you want buy a new chuck in UK try Radio Spares website, they used to have a small tools section in there catalogue. They also used to take phone Credit Card payment, its a longtime since I used them, but give it a go.

rgds

Shipbuilder
28th September 2009, 18:41
Hi Pensioner,
I looked on the RS website, but although they had lots of chucks, I couldn't find any prices or sizes - totally confusing. They also say they will not sell to private individuals so I didn't persevere. As I said, the old chuck is back to normal again after filing the inside of the jaws, so there is really no hurry. My local ship model club is always getting things like that in for sale as we have about 60 members and even complete Unimats come in fairly regularly. Recently got a replacement motor even though the original (over 36 years old to my knowledge as I got it 2nd hand in '73) has not failed yet. Next meeting is on Saturday, so will see if any turn up.
Bob

Billieboy
28th September 2009, 20:16
Bob, I've been thinking about your chuck jaws, if it's possible to strip down the chuck, then you could re-harden the jaws quite easily, with a good blowlamp a bag of sugar and a bucket of water. you'll have to be careful to properly mark the jaws and the chuck, if they're not already marked. The strip down will also clean and oil the chuck. Bicycle axle/ball bearing grease, is the best for the springs and jaws on re-assembly.

Shipbuilder
28th September 2009, 20:40
Billieboy
Thanks for reply. That is what I would have done in the first place if I was able. But if you look at the picture, as far as I can see there is no way to take it apart. I cannot even see how it was put together in the first place! At the moment, it doesn't even matter because grinding the inside with a round file has restored it to full working order - it seems to be as good as it ever was!
Bob

Thats another Story
28th September 2009, 20:46
Now You Have Got It Working Insert A Keyless Chuck .they Are Far Better And Grip Just As Good.regards John.

Billieboy
28th September 2009, 21:02
Now You Have Got It Working Insert A Keyless Chuck .they Are Far Better And Grip Just As Good.regards John.

Also known as a sliding cone chuck, ideal for diameters from 12mm down.

OK Bob, it was just a thought.(Thumb)

Duncan112
28th September 2009, 21:44
Took one apart a few times at sea to clean the swarf etc out, seem to remember using a hammer and socket to press the outer sleeve off, however a quick google gave me a more elegant (less Dewhurst) way of doing it.

See page 17 of the link

http://www.lfausa.com/LFA_catalog.pdf

or

http://www.jacobschuck.com/drill-chuck-repair.asp

Best of luck - and I'd try with one from a car boot sale first - only did it at sea when I had no alternative.

Duncan

pensioner
28th September 2009, 22:23
Hi Shipbuilder.
Sorry to confuse you, as I said its a longtime since I used them, they must have change their system.

Shipbuilder
29th September 2009, 20:20
Thanks for further replies. List of chucks was totally confusing I am afraid. I am OK practically, but not up to much with engineering theory etc. As it is now working normally, my R/O's brain has "backed off" until the next crisis. I am no scholar, but can usually fudge through. Grinding the jaws with a round file may not have produced a precision repair, but I seldom make anything that actually has to run and one or two thou' here or there is nothing to me!
Bob

chadburn
1st October 2009, 17:36
Shipbuilder, it was just a matter of getting to "grips" with the situation(Jester) , as it was the chuck was useless to you so trying anything was better than doing nothing(Thumb)

michael charters
9th May 2010, 18:48
Thanks again for all the replies. I have now fixed it as my method worked.
Based on what some of you had said, I deceided that it was wear on the jaws. I placed my good chuck in the lathe and in it, I placed a thin round file from which I had snapped the tapered pointed end. The faulty chuck was placed on the tailstock with the jaws open. I advanced it over the file and turned the lathe on. With the round file spinning inside the faulty chuck, I very carefully closed the faulty one with the key until it closed on the file. This quickly produced a grinding and screeching noise. I kept an intermittant (so it didn't heat up too much) slight pressure on the key for about half a minute, by which time fine powdered steel was coming out of the faulty chuck. I then stopped it and returned the faulty one to the business end and successfully drilled a 1/16th inch hole down the centre of a 1/4 in rod. There was no sign of slipping. I then turned a winch drum from 3/32nd brass and finally a smaller one from 1/16th brass without any problem. It appears to be as good as new. Not sure how the professionals will view my "kill or cure" method. I half expected the file to shatter, so kept well out of "line of fire" and wore the necessary protective goggles, but all went well.

Neverthelss, I will still be searching for a replacement using the links supplied. This lathe is a Unimat SL made in Austria for Elliott Machine Equipment Ltd, London. I purchased it in Fareham (2nd hand) in 1973 for 69, whilst I was attending an electronics course at Southampton Tech. Awful course, but at lunch times I would sometimes creep off to the engineering section where I hovered round the door until a benevolent lecturer invited me in and showed me various aspects of lathe work.

Was first introduced to the wonders of lathes in the engineroom of SAGAMORE by 2nd engineer Bob Pryde in 1963, but I did find those big ones a bit frightening and feel more at home with my little Unimat. A friend recently gave me a spare motor, so I should be OK for some years to come.

Bob
Used the same lathe to repair speed govenor on sagamore engine, hit heavy seae and the govener flew apart. The miracles the engineer can perform, this was when two sphere on the mast "not under command". Many moons ago, great ship, thanks for the memories.

Shipbuilder
9th May 2010, 22:22
The lathe chuck saga dragged on for quite a while. It was OK for a time after my repair with the round file, but eventually it jammed completely. Seemed to be completely obsolete and I couldn't find one in UK with correct thread. Found replacement at Blue Ridge USA, but couldn't purchase it because I couldn't register on their site for some reason and they weren't particularly helpful when I phoned. Eventually got a 2nd hand one on Ebay for about 12 from USA and it was in mint condition. Then shortly after, someone saw my request and gave me another one (from Scotland). So I now have one on the business and and another on the tailstock and everything is functioning 100% again and I am grateful for all the advice received here.
Bob

PS.
45 years since I left the SAGAMORE, but agree - a great ship!

Shipbuilder
9th May 2010, 22:37
Here are some tiny Clarke-Champan totally enclosed steam winches I made with the new chuck. They look a bit rough, but consider their size against the millimetre ruler below.
Bob

Billieboy
10th May 2010, 08:58
Glad to hear that you've re-tooled Bob, the lathe should be good for another 30years now!

Ian J. Huckin
13th May 2010, 16:57
Well, nothing fresh to offer as this thread is supported by many good engineers. However, I would like to show you all something....I was surveying a workshop to judge if they were profficient enough to contract in on a big hydro project I'm on. The attachment is a picture from their machine shop.....needless to say they did not get any of my work.....

Shipbuilder
13th May 2010, 17:03
I am not an engineer, but wondering what the problem is, but would not care to leave the chuck key in the chuck myself! Is that it, or is it something else?
Bob

Ian J. Huckin
13th May 2010, 17:07
I am not an engineer, but wondering what the problem is, but would not care to leave the chuck key in the chuck myself! Is that it, or is it something else?
Bob

I'll let the crew answer......(LOL)

Satanic Mechanic
13th May 2010, 17:10
Well, nothing fresh to offer as this thread is supported by many good engineers. However, I would like to show you all something....I was surveying a workshop to judge if they were profficient enough to contract in on a big hydro project I'm on. The attachment is a picture from their machine shop.....needless to say they did not get any of my work.....

Ooooofffff

Lesson No.1 - Never ever ever leave etc etc......

Shipbuilder
13th May 2010, 17:26
I suppose that must be it then, but I would have thought that was common sense and nothing to do with being an engineer!

I feel the same about neighbours leaving their cars with engines running in winter to de-ice windscreens and then going back in house!

Or maybe the point is that whatever they say they are, they lack in common sense, so don't give them the job!

Bob

Satanic Mechanic
13th May 2010, 17:29
I suppose that must be it then, but I would have thought that was common sense and nothing to do with being an engineer!

I feel the same about neighbours leaving their cars with engines running in winter to de-ice windscreens and then going back in house!

Or maybe the point is that whatever they say they are, they lack in common sense, so don't give them the job!

Bob

To be fair , except in fairly specialised and exceptional circumstances cars don't embed themselves in your head

Shipbuilder
13th May 2010, 17:55
True, but how often do we hear this? Car owner starts engine to warm it up and goes off. Yobbo jumps in car, car owner rushes out and on impulse tries to stop car. Car runs over owner?

Less disastrous scenario. Car owner comes out again - car gone!

Bob

Billieboy
13th May 2010, 20:35
The first, second, third and last thing, an apprentice turner learns, is to remove the chuck key from the chuck before letting go of it! I've seen apprentices leaving lathes, never to come back, with cauliflower ears that they never got in a rugby scrum!

johnjames06
31st March 2011, 20:24
Hello everyone,
Hope someone may be able to help in this. Although I am not an engineer, I am not new to lathe work, having had my present one since the early 70s.

Two days ago, I needed to drill a 1/16th inch hole down the centre of a quarter inch brass rod (A thing I have done countless times before).

I placed the rod in the chuck and the drill in the tail chuck. No matter how much I tightened the main chuck up, when I advanced the tailchuck drill, it simply pushed the rod into the main chuck. I am using the same type of brass as usual. I tried a new drill and it was just the same. I washed the chuck thoroughly in white spirit in case it was a bit oily and it was still the same. I then washed it in meths and there was a bit of an improvement, but not much!

Can a three jaw chuck wear out over the years, causing this to happen?
The lathe is a Unimat SL. The chuck that keeps slipping is a MOUNT M12 x 1, 0-6mm capacity.

Bob


Start with 1 inch piece of brass, drill your hole and turn the required length down to 1/4 inch. This will give you a better grip.

Shipbuilder
31st March 2011, 21:45
Thanks, but the problem was solved months ago when I located a replacement chuck in the USA. Then, shortly after it arrived, someone was kind enough to give me another one as well, so I now have one on the business end of the lathe and another for the tail stock. Not practical for me to start with one inch brass as it wouldn't even go in the chuck and I machine to very small scales. Here are a couple of miniature 5-ton cargo winches that I made this afternoon for a small model of the Moss Hutchison cargo ship MEMPHIS of 1947. They look pretty rough when viewed like this, but bear in mind they are very small and look OK when viewed on the model.
Bob