lathe tools

Good idea - someone showed me, took about ten minutes, and it then took me a couple of hours of solo practice before I was grinding good working tools, every time, by eye.

Might take me a couple of tries now to get new type of tool cutting right, especially if I've never seen it in the flesh.

But that's all it takes.

-- Peter Fairbrother

Reply to
Peter Fairbrother
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Braggart! :-)

Some of the newer grades of Carbides will withstand an awful lot more abuse than the toughest that used to be available. Pressure upwards on the cutting edge is a bit of a bugaboo, though!

In our shop, we have the reference manuals from four or five companies, (Sandvik, Iscar, Seco, and a couple more I think) and one can get lost quickly, when all one is looking for, is a tool that will do most things reasonably well.

Add to that the plethora of shapes and geometries to choose between, and a guy the just wants to buy a tool he can use, is gonna take up basket weaving pretty damn quick.

It's even more confusing than grinding HSS! :-)

Cheers Trevor Jones

Reply to
Trevor Jones

On or around Sun, 25 May 2008 04:01:42 +0100, "Dave Baker" enlightened us thusly:

It depends what I'm doing. If I'm trying for a precise fit on something, I use coolant to stop the job heating up and therefore expanding. In the past, I've cut things that got fairly hot to an exact size (this is for something that's a tightish push fit) and then, when it's got cold, it's not the fit I wanted.

generally, though, I only use coolant if it seems like it needs it. Tend to use it for parting things.

Reply to
Austin Shackles

Reply to
Bill

I am no turner but I couldn't agree more about diamond wheels. I got my first one four years ago and find it invaluable for sharpening carbide drills, carbide tipped lathe tools, and carbide gravers.

Cliff Coggin.

Reply to
Cliff Coggin

On another thread ('I'm sure this has been asked before') is a link to a site (shopswarf). This has the lathe cutting angles for HSS.

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Best regards, Dave Colliver.
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- Local franchises available

Reply to
David

I've routinely reground (perhaps "touched up" is a better word) inserts with a cheap diamond wheel for use in home made tool holders.

I've always ground the front face only leaving the top geometry and coating pretty well unaltered. This gets the sharp edge but retains the low friction and chip control of any coated top surface geometry.

All the inserts have been of unknown origin and mostly part worn. While this seems to work pretty well my favorite tool is still a many times reground lump of stellite which takes a razor edge and is easily retouched.

Jim

Reply to
pentagrid

In article , Dave Baker writes

Much cheaper here:

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(may need to cut and paste if the wrap puts it on two lines)

I have used one of the 100mm ones, and it cuts TC very well.

David

Reply to
David Littlewood

Tell me about it. A couple of months ago I (the IT droid) was in a programming office in part of the factory at work moaning about how their bosses wouldn't cough up to replace the ancient industrial PCs that linked the large lathe controllers to the rest of the world. £2,500 apiece.

I pointed out that I knew full well how idiotic the situation was, since I had totted up that the table I was leaning on had approx £30,000 worth of inserts neatly laid out on it :-0

Mark Rand RTFM

Reply to
Mark Rand

That's all very well, but I personally agree with AC. If you're a newbie who has just bought their first lathe, then the last thing you probably want to worry about is learning to grind tools from scratch. You want to stick some metal in the lathe, and make chips. A set of preground tools will let you do that. Once those pre-ground tools aren't cutting how they should, then they can start to learn how to sharpen them, and how cutting angles work.

And your way is like telling somebody that if they want (fill in the blank) cuisine, to cook it before they've even tasted it. Most people will of tried what they want to cook before they try cooking it, or at least have a rough idea of how it will taste.

True, but there's more than one route to acheive most things.

My first set of cutting tools were pre-ground. They let me try out the lathe, and then once they started to get blunt, I started to re-sharpen them. After that I started to learn about cutting angles, before moving onto grinding from blanks. However, I now mostly use indexable tooling for easiness, but still use the odd HSS tool mainly for profiles and flycutters.

I would personally recommend that any person new to the hobby, who hasn't got anybody to guide/help them nearby, that they buy some pre-ground tools. It might not be the ideal way, but it allows them to make some chips, and provides them with a rough idea of how tools should be ground. From there, they can go on to learning to grind them.

moray

Reply to
moray

Except if you were to follow his plan, you would have bought pre-ground tools, but not a grinder, because grinding tools is hard.

Point taken. Bad example, but the best I could come up with in short order.

Yup. True.

Can you still buy a set of pre-ground tool that is not total s**te out your way?

Not here.

Chinese, round edges, burrs, and no points, made of mystery metal, are the best I have seen. For the most part, I would not spend the few dollars asked for such garbage. I would never recommend them to anyone, let alone a new user, that may or may not be able to recognise why they would not work out of the box.

And the occasional Myford set that sells for insane prices, for no reason that I can come up with. Them on Ebay, too. Not that they are exactly a bargain from Myford...

Better off making your own out of old files, if you can find one that is actually all high carbon steel, rather than just case hardened. Even if it does mean learning to heat treat them along the way too.

My recomendation is still to learn to grind a tool right, right off. Grinding a tool poorly, right off, is at the least, a step towards the knowledge that will be with you for a long time!

I figure if a new owner is so lacking in skills or experience that grinding a tool is going to be a scary thing, then that same person is going to be pretty hard done by, when the chips start coming off hot and everywhere!

Unlike AC, who was preaching that it was hard to do, and to be avoided, I am saying that it is merely another skill to learn, that looks daunting, until you get your hands onto it. It's really not such a fearsome thing, to grind a decent working lathe tool, and it should not be approached with the amount of fear that is evident from some of the posts I have seen along the way.

Cheers Trevor Jones

Reply to
Trevor Jones

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