Thread: Cutting tool question

I feel like a thickhead, but I just have to ask this question.
As a new inductee into the mysteries of lathe operation, having acquired a Sheraton without any tooling, I do have a 4 way tool post.

Do I buy a HSS pre-shaped cutting tool kit and then shim the various bits as needed to get the right height, or do some people use tool holders that go in the post which are mounted at the right height, avoiding the need for shims?

OR, do I invest in a quick change tool post and a handful of adjustable holders?

If I were to choose the QCTP, how do I work out what will fit my specific lathe? (Sheraton Conquest 10 A)

(I don't think I'm ready to buy blanks and grind them myself.)
Thanks.

Hi Vic, Guys,

Being able to grind your own tools isn't a black art ! Get hold of some HSS tool steel blanks and grind your own. Not only is it cheaper but you will learn what works best for you. There are several basic shapes.

Lathe Tool Shapes.jpg Lathe_Tool.png
These pictures will help. Unfortunately a lot of people will tell you to use carbide insert tools, which in my opinion is another minefield.

As far as shimming to get you tool bit on height is concerned, yes a quick change toolpost will get you around that problem. But here I would suggest that you learn how to shim and get the tool bit at the right height, simply because every time you regrind a tool you will change its cutting edge position.

I no longer have my QCTP ! I got rid of my Dickson simply because it was far too expensive to keep buying tool holders for each tool that I wanted to use. I made and use a "Norman" patent tool post which is more than adequate. You may have seen it in some of my pictures.

The old adage applies, if you don't try you won't learn ! If you are not sure, there are many members of these forums that are more than ready to help !

Hello Vic.
A good start that I would suggest is to buy a copy of the Fitting and Machining Tafe apprentice manual. By Ron Culley. Or borrow it from a library. You can find it on Ebay or from LPR Toolmakers web shop. The book also covers basic measuring and layout as well as machining.
It would be the best start you can get.
Regards
BC

At the end of the day do you want to turn what you need or learn how to make the tooling that you need and how to go about achieving this?

Those 4-way tool posts are generally designed around a standard tool holder size (12, 16, 20mm); fine for tool holders that take inserts, because the height never changes, but if you're grinding your own tools you'd need to fiddle with shims every time.

I'm guessing one of these two would be the right size for your lathe if you were to go the QCTP route https://www.machineryhouse.com.au/L280 https://www.machineryhouse.com.au/L292

Another option is the diamond tool holder, made locally and very versatile. Solves the height adjustment issue with the 4-way tool post as well.
https://www.eccentricengineering.com...nd-tool-holder

Baron J; Thanks for the advice, I'll consider it carefully.

BC; Thanks for the recommendation.

Pipeclay; Good question. As a novice, and with no machining experience, I am inclined to start with making 'stuff' that may have a novelty factor to start introducing lathe skills, where precision initially isn't a priority. Then to graduate toward making items that require more precision. The idea of making tools is appealing, and Baron J has made a good argument.

elanjacobs; That DOES look appealing! Thanks for the advice and links.

Gavin; Well that does look impressive.


I guess I have options to consider.
Thanks everyone, I appreciate your thoughtful comments.

The magic of carbide inserts enables you start making chips right now using your 4-way tool post.
Work out what size insert holders your tool post will accommodate and go shopping on line.
Be aware there are sellers who prey on the newcomer by offering sets of cheap but dreadful holders that are shunned by those with a little experience.
Down the track you will need to learn how to grind HSS for the special jobs, by then you will have enough experience to know what works and why it works in a DIY grind.
When you sort of know what you are doing a QCTP will make you much more productive.

Thanks Bob, it's nice to have choices. Now I just have to decide which path to take. I get there is no 'right' way. Now I just need to decide and take the next step.

I can recommend Ian Bradley's article on HSS tools http://www.neme-s.org/Model_Engineer...LatheTools.pdf

Many of the text books like the TAFE ones are aimed at the larger powerful industrial type machines. Ian's books and articles are aimed at hobby people.

Buy a A60 J or K white grinding wheel to suit your bench grinder , grinding your own tools ,its not as difficult as you think. I've found it's best not to hone the cutting or leading edge but to hone only the top face . Good Luck

Great article Morrisman, it certainly helps to simplify choices.
And thanks for the grinding wheel recommendation, that was next on my list to consider.

This is a hint if you're planning on using HSS, to help learn the angles etc, instead of using your good HSS, practice on some square bar.
Another tip if going the HSS route, beware of buying it on Ebay from China and those sort of places, they might call it HSS, but is similar to mild steel with a ground finish. DAMHIKT
Kryn

I'd also recommend you download the FSWizard app for you phone, it's an extremely useful calculator for speeds and feeds (and a whole lot of other stuff too, like drill conversions and tap charts). It will give you a good idea of what speed you should be running for any given job and, hopefully, reduce the number of burnt-up cutting tools from spinning too fast; particularly with HSS as it's much less forgiving of cutting too fast. After a while you will get the feel for what speed to use.

Your lathe is only a small one, grab a set of ccmt060204 inserts and some boring bars and tool holders to suit. This will set you back under $50 from china, use it to start making parts and learning the basics of turning, grab some HSS for when you want to play but when you fail to make your part do you want to be asking yourself if it's the grind on the HSS, your inexperience on the lathe or something else causing it ?

You should be able to work out your tool height by simply measuring it, bottom of the 4 way tool post where the tool sits to the middle of the lathe spinning axis, just put a centre or something in the head or tailstock and measure. Heck you could probably use a pencil if it's sharp and running true in the chuck...

Originally Posted by MasterSpoon

Your lathe is only a small one, grab a set of ccmt060204 inserts and some boring bars and tool holders to suit.

Just further to the inserts...

ccmt = style (each letter indicates something different, but that's not so important for now)
06 = size (the largest circle that will fit in the shape of the insert)
02 = thickness
04 = corner radius in 0.1mm (02 = 0.2mm, 04 = 0.4mm)

Full decoder here: Turning Inserts Identification | MITSUBISHI MATERIALS CORPORATION

For small lathes, CCMT and CCGT (M is a pressed insert, suitable for most general steels, G is a ground insert, suitable for stainless, aluminium, brass and plastics) in 0.4mm radius will do for just about everything, 0.2mm is also handy for very light cuts. 55 degree "D" inserts are useful for getting in close to a centre in the tailstock where "C" tool holders may not fit.