A better than usual guide to using a lathe ??

[AjohnwParticipant @ajohnw51620]

This pdf might be of interest to people. It was produced by Boxford years and years ago originally but lathes are lathes so it could help some.

**LINK**

The section on tools might be of interest. Pretty ancient wisdom. It even includes some info on the mysterious dark art of fine turning – tool above centre. Ideally this needs a lathe in pretty good order but the results can come as a shock on many materials. It's more of a finishing technique really and can be used more extremely than shown. This area also explains why there are these strange tool bit holders about that hold the tool bit at an angle, also lantern type tool posts with a boat that rocks at the bottom.

The only thing really missing is what the various tool bit angles do. The main one in that area is the side rake into the cut. This tends to hold the tool away from the work and prevent it from pulling in all by itself. If lots of material needs removing on low powered machines it can be increased dramatically to reduce the cutting forces. Best done in steps as it may pull in at some point. Top rake away from the cut can also be increased.

They generally show a toolmakers universal tool bit – V shaped end. Used because it can face, turn, machine shoulders and also cut in the wrong direction even though the rake will be negative.

Periodically I look at my qctp and shake my head. I could use this older method and keep a large array of cutting shapes in a tobacco tin and just use the qctp when it's needed. When – parting off but I might not have enough height available for the tool bit holders I can find.

John

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[AjohnwParticipant @ajohnw51620]

[HopperParticipant @hopper]

Thanks for the link John. Downloaded and added to my library of ancient knowledge. There is always something one can learn from those old boys.

[Brian JohnParticipant @brianjohn93961]

Thank you, I think this will be very useful. I intend to print it out at Officeworks…all 108 pages of it !

[BazyleParticipant @bazyle]

I see you read HSM John.

Just to clarify this is the well known (in UK) Boxford book "Know your Lathe" which is an anglicised version of the original South Bend book and is in effect the user manual for these lathes, not the Myford which has its own book. It was edited when the primary audience was in schools and apprentice shops which were flooded with these machines.

Mounting the tool above centre is not explained but it is to provide an outward component of force to take up the cross slide slack on worn lathes (in schools) and increases top rake as a side effect. Obviously applies to cuts not going close to the middle of the face.

[RobboParticipant @robbo]

Originally published in 1953 by Denfords Engineering. (Boxford)

A pocket-size edition (paperback size) is still published by Tee Publishing for a few pounds.

[mark costello 1Participant @markcostello1]

I have Adobe reader, how can I save a copy to disk?

[David Clark 13Participant @davidclark13]

Open in browser and click on the floppy disk icon at top right.

[Keith LongParticipant @keithlong89920]

If you've opened it in Adobe, look in the top left corner of the screen for a heading "File". Left click that you should get a drop down menu including "Save as". Select that and go from there.

[AjohnwParticipant @ajohnw51620]

I've no idea what HSM is Bazyle

Over centre turning was explained to me during training. The actual effect is that the tool can take more of a shaving cut and in the extreme probably dates back to hand metal turning. In my experience it needs things to be pretty rigid and well located. As was suggested I have tried it with a parting off tool angled around 15 – 20 degrees so into the cut. That can only be used for rather shallow cuts. The actual tools that were used for this sort of thing are more like scrapers.

Boxford outline a less extreme form of the same thing. To be honest I have never tried it on my Boxford for lack of a suitable tool holder but it worked remarkably well on a Taig – very easy to get a tool bit over height. Not used during training either as we were expected to produce work which was smack on, tool ever so slightly below centre. It was just explained. One of the instructors saw a sign stating "Fine Turning" while on holiday and managed to persuade the person concerned to show him the tools and the machine he used. He also showed us what happens when a ball end spinning tool is ran along mild steel – that one is often explained in old books, LOL the surface of the ball broke down part way through the demo. It needs to have a mirror finish and be rathe very hard.

The negative aspect is that more front clearance is required and that cuts wont be what is set on the dial. The excess front clearance and the usual tool holder which will slope a tool at circa 10-15 degrees produces a very fine edge which will wear more quickly than a blunter one but if tools are stoned from time to time that doesn't really matter. The interesting aspect is that it's aimed at a better finish rather than tool life as per cutter angle tables.

Can't agree on Boxford's all over the place. A lot were used in schools and also in workshop type environments rather than tool rooms. Harrison's and Colchester are a lot more common in more advanced training establishments. Even some schools. The Boxford's I used at school were great machines in really good order. I've still got a wax crayon firing cannon I made on one of them some where. Very easy to get an excellent finish. I was talking to a college metal work lecturer yesterday. He reckoned I would be disgusted by what is taught today. The machines he uses are Colchesters that it turns out were made in Taiwan and assembled in the UK,

John

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[Mark CParticipant @markc]

Talk of UK lathes no longer being made here, they just closed the tool room at DSG in Keighley – it will be subcontracted from now on……….

Mark

[Boiler BriParticipant @boilerbri]

Begger  I bought the original and some one put a freebie up😏

Edited By Boiler Bri on 14/09/2015 22:16:01

[mark costello 1Participant @markcostello1]

Thanks all, Mark.

[Peter G. ShawParticipant @peterg-shaw75338]

Just a couple of comments about the version John links to.

I have an older version and decided to do a quick comparison to see if it was worth my while downloading this later version,

Firstly, there is at least one mistake which appears in both versions, in that there is reference to Fig 111 in a number of places. Fig 111 does not exist, it's actually Fig 100.

Secondly, there is a complete section missing (page 79), presumably deleted concerning the use of filing and polishing in the lathe. H&S I suppose.

Otherwise, it's the same as earlier versions.

Peter G. Shaw

[AjohnwParticipant @ajohnw51620]

Any chance of a scan of the missing section Peter or the whole thing ? I use filebin.net if I want to put something on the net for others to download. No registration or any other messing about with them.

John

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[Peter G. ShawParticipant @peterg-shaw75338]

In principle, I've no objection to putting it on the forum, probably as a jpg as it's only about the size of A6, ie half of page 79. But, I am not sure about copyright etc. Perhaps the moderators could advise?

I should add, my copy is a photocopy already. There are two photos plus text, and I'm not too sure how the photos will come out.

Peter.

Edited By Peter G. Shaw on 16/09/2015 12:15:41

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