Lathe tool confusion

[paul]

As the other thread in which I posted a picture of my lathe tools had a rather misleading 'subject' (thread title) I though I'd re-post my question here...

First, the picture in this thread refers...

modeleng.proboards20.com/index.cgi?board=general&action=display&thread=1164490738

I can't identify what the different tools are for, can anyone help? Most of the tools i've found on the net seem to be 'chisel-shaped' rather than triangular-headed as these are.

Either way, I've managed to re-make the safety valve for my current boiler this evening and it's worlds apart in terms of accuracy compared to my 'handtools only' versions (3 off!). Hurrah!!

[starspider]

Hi Paul as nobody else has answered your question I'll have a go for you. D= a chamfering tool. C= maybe a tool for thread cutting check if the included angle is 57 or 60 degrees.M,A and A are for cutting right to left and you guessed it L is for cutting left to right. Now the "Nasty" bit In my opinion these "starter tools" are of no real use to a tyro turner they all need regrinding to a more usable condition so at least the cutting edges have a bit more meat behind them and the cutting and relief angles are of more use. sorry Paul but I think the "Hobby" suppliers should provide tools that are fit for purpose. Anyway try to get access to a green grit wheel and someone who can show you how to regrind the tools but in the mean time they will cut non ferrous metals and some ferrous metals but your finish will suffer.
colin

[John Lee]

Got to agree with Starspider here Paul; those tools really should not be sold for off the shelf use without explanation.

You can go two ways.. the old way.. get a grinder with the proper wheels and alter them until they are fit for purpose, in which case they will cut perfectly and last for years. It's a skilled job though, but that skill will allow you to make your own tools for all sorts of jobs.

Or... get indexable tools as previously suggested. Bear in mind though these are meant for (relatively) modern production methods and on an interrupted cut you are likely to knock the cutting edge off. All you can do really is go to the next edge..then finally throw it away, so can be expensive to run.

Try and get hold of "The Amateurs Lathe" by LH Sparey, or similar (A brief check.. it seems to be still available from Tee Publishing i.e. EIM). Its out of date now but will explain all about the tools you have, including what they are for, and how to change them for your needs. Ohh and quite a lot more!

John

[Steve M. W]

"The Amateurs Lathe" by LH Sparey, Very good advice, a first class book well worth the money

Steve

[Peter W.]

As above, "The Amateurs Lathe" is very good.

Can also recommend
"Using the small lathe" by L.C.Mason
TEE reprint 2001 ISBN 1 85761 118 7

[paul]

Thanks chaps, I'll order a copy of that book as soon as funds allow! Back to my tools; I only need to do turning from right to left for now (and maybe facing) so I can disregard D, C and L. Because the three remaing tools are all curved to the left I assume they need to be mounted such that the curve lies in the horizontal plane (otherwise they would be above or below the centre). If so, do I mount them with the shank of the tool parallel with the left edge of the tool-holder when viewed from above or doesn't it matter?

[baggo]

Hi Paul,

the tools are designed to be used as you suggest i.e. with the shank parallel to the lefthand edge of the toolpost. Although you can swivel them around a bit, perhaps to turn an awkward shape, the cutting angles will be altered and they may not cut so well.

John

[paul]

Thanks John

BTW, I can see what indexable tools look like but what does 'indexable' mean?

[havoc]

Take a look on this page: www.engineerstoolroom.co.uk/turning.htm

You will find a list of the tools you have, and what they are used for. (about 1/3 down)

A bit lower there are drawings/pics of indexable tools. They consist of a steel holder on which is screwed a tungsten carbide (TC) cutting plate. The small piece is the part that does the work, the rest is only for support and holding to the toolpost. When one edge becomes dull, you can turn the plate, getting a fresh edge (this is the indexing refered to). When all edges are dull, you replace onbly the plate and keep the holder.

Advantage is that these TC plates are very hard but that is also a disadvantage as they will break if exposed to blows. So when trying to face a piece sawn of a bar, the chance that the edge breaks is not neglectable.

[ron]

Hi Paul
I've only had problems with indexing inserts breaking with rough cast iron, but the brazed tipped tools can come to grief on that as well.
As I posted before, if you decide to buy an indexing tool, look on Ebay for the tips, you can usually get 10 or 12 of a named variety for the same money as the dealers want for 3 or 4.
Ron

[SteveW]

Paul

johnleepbs said:

Re. get a grinder with the proper wheels and alter them until they are fit for purpose,...
John

Forget grinding them unless you have a 'green' wheel for doing TCT. A normal bench grinder won't do much to them.

It is said that our little lathes aren't man enough to use TCT tools effectively. However, they will survive the hard surface of cast iron like nothing else.

I've always wondered about these sets as they don't seem to have cutting angles suited to anything else but brass or CI. I've modified some of my set (yep! I also bought a set) using diamond laps to both improve the top rake and sharpen them. If you want a good surface HSS tooling is better especially if you finish the edges with the afore mentioned diamond laps.

The set I bought includes tools for parallel turning for left and right directions, facing forwards (tail stock side) and back face (chuck side), 55 (Whittworth) 60 (Metric) degree internal and external threading, a boring tool and a parting off tool. Don't throw any away they will come in handy one day. I have had a lot of success using the right facing tool in a fly cutter for cutting flat surfaces in the lathe (think about it). However, get a set of HSS tooling as well. At least you can modify them to correct angle for alloy and steel and take thinner more delicate cuts.

[waggy]

Hello peeps,

I've used tipped tools for some time now. At first I went for a "cheap" set, sadly dissalusioned! I was persuaded by club members to buy better quality holders, these are so much better than "cheap" items. Perhaps there is a lot of truth in the fact that only budgies go "cheap"? (Cheep)

Suppose "you gets what you pays for!"

The only material they don't like is aluminium, the cutting angles aren't acute? enough.

Waggy.

[paul]

Havoc: Many thanks - and here I was thinking 'indexable' was something technical when it just means you can work through the surfaces sequentially! Thanks for the link also - helps to clear things up

ron: Cheers for that - I don't plan to make anything out of cast iron, at present I'm timidly playing with brass only!

[paul]

Er, things are getting very mixed up here. Here's an image showing the tools and description from the link provided by Havoc (above) and below it an image from the current Chronos catalogue.




I think something is amiss - surely A should be described as right-hand facing and B as left-hand facing??

Furthermore they can't agree on types L and M!

I think L in the top image and M in the bottom one are for use when cutting from right to left, and M in the top image and L in the bottom image are for use when cutting left to right.

Is this correct?

[baggo]

Hi Paul,

A is probably called a LH facing tool because it cuts on the LH edge towards the left and B a RH because it cuts on the RH edge towards the right?

As you suggest, L in the top is for cutting right to left and M for cutting left to right. Mind you, I'd use L and M for facing as well! Saves changing tools ;D

John

[chris vine]

Hi Paul,

Traditionally a right hand turning tool faces the chuck, IE to the left...

Chris.

[paul]

Thanks Chris - that's what I thought... all I can do now is put them in upside down! What? I am putting them in upside down? LOL

[Tony K]

Paul, if you want something to put on your Christmas list this year, I can recommend the following ....

Model Engineering: A Foundation Course (Paperback)
by Peter Wright (Author)

It is what it says, a foundation course, but I can recommend it as a modern book written in a practical way and will answer certainly most, if not all of the questions you have. The Amazon price is about £16 and I have found it excellent value for money.

Kind Regards, Tony.

[paul]

Thanks for that Tony - I'll add it to the ever growing list of things I need/want!

[John Lee]

paul said:

Thanks for that Tony - I'll add it to the ever growing list of things I need/want!

Ahh but it's like that. You get stuff, make stuff on the cheap, things go around, make a noise, fascinate others (and you), from babies to pensioners, and you can take 100 different directions as you please, and never get to the end or know everything

Sort of like Golf, but you don't need funny clothes.

More seriously; it can be as expensive or cheap as you like..but still can be enjoyed. Don't worry about the shopping list

John