First cuts with the lathe

[duncan webster 1Participant @duncanwebster1]

Diamond file is good for rounding the vertical edge

[duncan webster 1Participant @duncanwebster1]

Diamond file is good for rounding thd vertical edge. 1/4″ sq tools are a lot easier to grind and plenty stiff enough for small cuts whilst learning

[Howard Lewis]

On Howard Lewis Said:

Cutter? Surely lathes have tools and toolbits and milling machines have cutters? The difference being cutters rotate while tools and toolbits remain stationary? (Not sure where that leaves shapers though?)

While most of us are trying help a newbie, can the above please be moved to pedants corner.

Pedagogy not pedantry! Teaching a “newbie” incorrect terminology is not helpful in the long run.

[PeteParticipant @pete41194]

While there different lathe brands than yours is Chris, a couple of PDF links for good basic turning information including tool sharpening.

https://gadgetbuilder.com/How-to-run-a-lathe.pdf

http://www.opensourcemachinetools.org/archive-manuals/Hercus_TextBook_of_Turning.pdf

If you have lots of books and don’t yet have this one, put it on your mandatory to buy list. https://www.teepublishing.co.uk/books/in-your-workshop/model-engineers-workshop-manual/ Yes I’d term it as a medium level to sometimes lower advanced level book. But it’s one you’ll refer to often. And even at your current level, a great deal in it that can be used immediately. The authors thoughts about proper slide adjustments, HSS tools, and even the pros and cons of QCTP’s just for starters. I was going back through my own copy this morning in fact.

As someone has already said in this thread, problem solving is a big part of the hobby. Sometimes highly satisfying, and sometimes extremely frustrating until you finally get a reason and solution figured out. Learn to view any problem using pure logic and think everything through. And not what you think might or should be true. In the beginning it usually isn’t. 😀

[Dave SParticipant @daves59043]

Sherline has a good how to grind tools guide:

https://www.sherline.com/wp-content/uploads/2015/01/grinding.pdf

 

Dave

[Nigel Graham 2Participant @nigelgraham2]

Diamond file –

Not thought of that – Thanks for the hint, Duncan!

[jamesp1]

On jamesp1 Said:

Cutter? Surely lathes have tools and toolbits and milling machines have cutters? The difference being cutters rotate while tools and toolbits remain stationary? (Not sure where that leaves shapers though?)

My old-British books call lathe tools “knives”…

History left metal-working terminology in a mess, especially in pioneering Britain, where trades, regions and companies all had their own variations.  Whatever jargon individuals were taught in the past can’t be universally correct because there is no common standard.

I think beginners just need to be aware it’s necessary to read between the lines sometimes.  We shouldn’t make it difficult on the forum:  I suggest ‘cutter’ is easier to understand than ‘tool’ because ‘tool’ is ambiguous, whilst “knife” is positively misleading.

Dave

 

[noel shelleyParticipant @noelshelley55608]

DID THE PERSON UNDERSTAND WHAT WAS MEANT BY THE TERM ? Does a lathe tool not cut ? It should ! Noel.

[PeteParticipant @pete41194]

A lot of the books covering lathe tool sharpening are a bit lacking in details Chris. Too many of them seem to cover the powered grinder sharpening well enough, but neglect or may not even mention the needed honing after. Yes a ground tool right off the grinder will cut, but not nearly as well or with the same surface finish quality as one that’s been properly honed. Paraphrasing George Thomas, “a rough ground tool can not produce a fine finish” or words to that effect. And a well honed tool with a slight tip radius will also last much longer. Many times you don’t even need to regrind the tool, just re-hone it and it’s as good as new.

However the term honing is a bit subjective as far as how sharp the tools cutting edges should be. Pulling the tools honed edge with very light pressure down your thumbnail, it should be sharp enough to start to raise a chip is one way. A proper and very good quality stone with a recognizable brand name such as a Norton isn’t cheap. And cheap stones aren’t worth buying. And after enough use, they need to be re-flattened. Instead I chose to buy from a woodworking tool dealer a diamond coated plate. They stay flat, last almost forever, hone quicker and in some cases, are cheaper than a good stone. I also use that plate with a few drops of light weight oil. Something easy to get like 3 n 1 if it’s available in the UK, or sewing machine oil works fine.

[Martin KyteParticipant @martinkyte99762]

I use window cleaning fluid with my diamond hone plates. It’s convenient in the spray bottle and less messy than oil. Wipe clean afterwards with kitchen roll.

[PeteParticipant @pete41194]

Thanks Martin, I’ll have to give that a try.

[jamesp1]

On jamesp1 Said:

On Howard Lewis Said:

Cutter? Surely lathes have tools and toolbits and milling machines have cutters? The difference being cutters rotate while tools and toolbits remain stationary? (Not sure where that leaves shapers though?)

While most of us are trying help a newbie, can the above please be moved to pedants corner.

Pedagogy not pedantry! Teaching a “newbie” incorrect terminology is not helpful in the long run.

Perhaps you may have overlooked the start of that particular ‘conversation’ at 06:56 ?

[SillyOldDufferModerator @sillyoldduffer]

The difficulty of sharpening HSS can be avoided by using carbide inserts.  Grinding HSS is an acquired skill, not everyone is good at it, and for many purposes carbide is better, or at least more convenient.  Carbide inserts are precision made and shaped with edges and relief needed to cut optimally.   Inserts fit accurately into the holder so there is no need to reset tool-height when one breaks; just swap in a new insert, or rotate a fresh corner into position.

 

A beginner advantage is that inserts eliminate grinding mistakes!  Starting out, self-teaching oneself to cut metal for the first time with a new lathe, it may pay to avoid having to buy a grinder and learn how to use it.  Save grinding HSS for later.

Inserts aren’t entirely plane sailing because shapes optimised for industry may not perform well on slow, underpowered and not very rigid hobby machines.   Inserts also come in bewildering variety*.  Nonetheless, at least 80% of my hobby turning is done with inserts because they save a great deal of time compared with HSS.  HSS isn’t redundant: once in a blue moon, carbide struggles to produce a good finish, so I switch to HSS.  Another reason  for HSS is it can be ground into non-standard form shapes for special cutting.  Form cutting is rarely needed in my workshop, but might be common in yours.

*Hints: the range of inserts sold by ArcEuro are a good match to hobby requirements. Also, the sharp inserts normally used by industry on non-ferrous metals perform well in a hobby machine cutting steel.

Dave

 

 

 

[Howard LewisParticipant @howardlewis46836]

Chris 12

You have  taken the first steps to climb the learning curve (It goes on for ever!)

You are doing the right thing by practicing on relatively cheap material, rather than something expensive, like a part from a kit.

As you gain confidence and experience, you could continue to learn by making simple tools that will not only give experience, and confidence, but can be used in the future.

I would suggest, as a start, making a Centre Height Gauge. Once made, it will help setting up tools in the lathe. An off centre tool does not cut properly, and leaves a pip on the middle when facing the end of a bar, so it is useful for that reason.

When you find a need to cut threads, start by using Taps and Dies.  Zeus charts, and charts provided by folk such as Tracy Tools, will show the sizes for various threads (Use your books to learn the difference between different thread types, their forms and uses. If you have not got it, Tubal Cain’s “Model Engineer’s Handbook” is a good reference book to have)

Then you can start to make a Sliding Die Holder for the Tailstock You can buy the sets of Die holders, and Arbor to make your own body. Have a look at supplier websites, such as Arc Euro Trade, Warco or RDG

No one seems to sell anything for a Sliding Tap Holder.A pity, since the load need to drag the tailstock  along the lathe bed, can strip the newly cut thread. (ME 40 threads are particularly fine, and therefore shallow, so can easily strip).

A small drill chuck attached to a body which slides on the arbor, will accommodate a variety of Tap sizes.  There are other ways of holding Taps, but making the holders involve techniques that are not suitable for a newbie.

Don’t forget to reverse the Tap regularly, to break and clear the swarf.  They are less likely to break and scrap the job, that way!

For thread cutting, you will need a lubricant, such as Trefolex or Rocol RTD.

Until you are more experienced, do not worry about screwcutting, or you will become embroiled in working out gear trains, some of which can be complicated,, and the techniques for taking multiple cuts without losing your place, and ruining what you have already done.

When you have mastered the ability to provide a steady, consistent feed, by hand than you can think about power feeds.

Again, this will mean you learning how to set up a gear train to give the right ratio between chuck and Leadscrew.  All part of the learning to walk before trying to run.

P M me if you want more details about Centre Height Gauges, or Sliding Die or Tap holders.

HTH

Howard

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