Well, not as beautiful as Johnny's but tidy enough not to cause offence I think.  We now have a traverse handle on the lathe.  I'm going to have to address the big problem now, the bent mandrel.....  Plan'A' is a big rubber hammer to clout the chuck in the opposite direction to the blow that bent it.  Daft as it sounds, that could bring it near enough to truth to allow a light skim of the thread on the nose and a re-facing of the back stop to put it back in truth again.  Plan 'B' is to take the mandrel out and make a new one but I want to avoid that if possible, it's a serious turning job......  The first thing to do is some serious measuring........

I've had a bit of a clean up all round.  You can't get accurate measurements off dirty surfaces.  In case anyone is wondering what the plate behind the bed with the holes in it is for, it's a fixture for carrying a profile plate which is used for doing things like turning shaped handles.  Tomorrow we attack the mandrel!

Well, what an interesting morning.......  I have done most of my checks, just a couple more this aft. to make certain, but I;ve had a bit of a shock!  The good news is that the mandrel is dead accurate.  The bad news is that it's the chuck that is out of truth.  Either Newton mounted it badly (and I don't want to believe that) or it has had a clout and what has bent is the soft brass backplate of the chuck.  What I shall do is skim the backplate up and remount it.  I shall also make a new backplate for another small three jaw I have which I know is accurate.  It's a new one and I have the outside jaws as well so I can have the luxury of two chucks and no jaw changing.

I've sorted another chuck out this morning, an old Burnerd.  Here it is in the lathe and the piece of silver steel with a point on it is a very simple and accurate way of telling how accurate the chuck and mounting is.  Take it from me, this is close enough for anything I'll ever want to do and only a high quality precision tool room lathe and chuck could do better perhaps. 

This might be a good place to say something about accuracy.  I always go back to Johnny Pickles.  He never used a micrometer in his life, or if he did he kept it very quiet!  There is a story that he was once walking through the shop in his later years when he saw one of his men using a micrometer.  The lad noticed him watching him and said " It's all right Mr Pickles, I'm just roughing out, I'll finish it with the calipers!"  Johnny smiled and walked on. 

The point is that so many people get so wound up about accuracy it stops them from getting anything done.  The best is the enemy of the possible.  You have to decide what standard you want and stick to it and it has to be attainable.  That's why the pic above shows acceptable accuracy.

Apart from the operator's skill there are three things that decide the final accuracy of work in the lathe.  The standard of accuracy in the lathe, the accuracy of manufacture of the chuck and the precision with which it is fitted to the lathe.  The lathe is OK, it's accurately made by a craftsman, despite its age it is in good condition and it all checks out.  In this case, the old Burnerd chuck is a good one and so there's a good chance it will be accurate.  It's no good going to a lot of trouble with a cheap or worn out chuck.  Once you have the lathe and the chuck all you have to do is mount the chuck on the lathe in such a way as to preserve all the original virtues of accuracy and not introduce any errors. 

The chuck is fitted to the lathe on a screwed nose with a plain section at the back and a collar or register against which the chuck butts up when screwed fully home.  It is this register and not the thread which ensures accurate fitting.  Almost all chucks are in two parts, the body of the chuck as manufactured and the back plate which has to be made on the nose of the lathe which it is going to be used on.  So, you start off in an accurate lathe and make a blank back plate, all you are doing is boring it the correct size, threading it, and turning an accurate boss and register face on the back.  If all these operations are done without disturbing the blank in the chuck the bore, thread and register will be concentric.

Take the prepared blank and mount it on the nose of the lathe which the chuck has to fit.  Turn the face to the correct dimensions and make the register on it which will fit into the register recess on the back of the chuck.  This register boss has to be dead accurate and the only way I have ever found to do this is to get it somewhere near and then reduce it carefully, trying the chuck on it after every cut, until you have a perfect fit.  Providing you have sharp tools and take your time this is straightforward, needs no measuring tackle and is dead accurate.  Once the back is finished, take it off the nose and drill the holes for the fixing screws which attach the backplate to the chuck body.  Then put it in the lathe and do the silver steel pointed bar test.  Don't expect it to be perfect but accept reasonable accuracy.  Remember that starting from the baseline accuracy of the lathe, everything you do introduces more error unless you are very lucky.  That's it, a perfectly fitted chuck.  Just one thing to remember, most chuck backs are made from castings, either iron or non-ferocious.  Castings always have stresses inside them and as you machine them these come out and distort your work.  You have to accept this.  Over time more stresses come out and it's always a good thing to occasionally strip the backplate out and  give the registering surfaces a light skim.  I suspect it is this which made the chucks inaccurate in the first place but they were doing the job so Newton never bothered to correct them.  He was too good a turner to make them wrong in the first place.

One last thing, turning brass in the front room is great but it gets everywhere and I have to be very clean and vacuum up afterwards!  Good job I haven't a house-proud woman to contend with.....

Another chuck fitted.  This is a Polish chuck and I knew the importer.  He told me that when they made the chucks they graded them according to accuracy and if they were short on an El Cheapo order they slipped some of the better ones in.  This one is tool room quality.  Note the register on me pointer test, It doesn't get much better than this.  Very pleased with it.  Tomorrow I shall make a faceplate for it........  Deep Joy!

the other end of the kitchen/dining areas

There is enough room on that sideboard for a Lorch watchmaker's lathe..........