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Posted by Bill on May 25, 2008, 3:44 am
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See we are back were we started, not quite, We had people saying that they
could not grind HSS tools yet know they are grinding tips. I give up on this
one.
> dave sanderson wrote:
>>
>>>Austin Shackles wrote:
>>>
>>>>On or around Fri, 23 May 2008 13:01:25 GMT, Trevor Jones
>>>
>>>>>An eight year old can learn to grind a decent tool. It is an
>>>>>elementary level skill.
>>>>>All new skills come with a learning period. Best to get it over and
>>>>>done!
>>>
>>>>anyone care to point to a decent place to get tips on this, ideally
>>>>online?
>>>>Or if there isn't such an online resource, does anyone fancy having a go
>>>>at
>>>>producing one? While I mostly make tools that work, it sometimes takes
>>>>more
>>>>than one "go" and I daresay mine could be better if I knew a bit more
>>>>about
>>>>it - I expect most of us end up with a tool that does the job adequately
>>>>rather than well, quite often.
>>>
>>> Take a look at the Sherline website.www.sherline.comIIRC.
>>>
>>> Several hundred pages, mostly devoted to very small lathe and milling
>>>machine work.
>>>
>>> There are a couple pages of info on tool grinding there, that are
>>>worth a look.
>>>
>>> If you are not on a dial-up account, search around and find a copy of
>>>the South Bend Lathe book, How to Run a Lathe. Tool shapes are covered
>>>there pretty well.
>>>
>>> A copy of this book in hard copy form, can usually be found for under
>>>$20 on this side of the ocean (Lee Valley Tools sels a older version for
>>>$10) and I am pretty certain it is available from the booksellers in the
>>>UK. Same book, is the Boxford manual, titled, IIRC, Know your Lathe.
>>>
>>> I usually steer beginners towards 3 UK published books to start off.
>>>
>>> The two Tee Publications books (or whomever has taken over that line)
>>>Workholding in the Lathe, and Milling operations in the Lathe, by Tubal
>>>Cain, and The Amateur's Lathe by Sparey. Between them, they cover a LOT
>>>of ground, and show that many things are possible with limited tooling.
>>>
>>> Cheers
>>> Trevor Jones
>>
>>
>> I agree with the sherline pages, I learnt to grind tools following
>> this:
>> http://www.sherline.com/grinding.htm One thing I disagree with however
>> is the recommendation to have a cup of water to dip the blank in if it
>> gets to
>> hot (pretty sure it was this article). Dipping hot HSS into water can
>> cause micro
>> cracking of the steel. The water cooling is a throwback to Carbon
>> steel tools
>> HSS should be ground hard and quickly, faffing about taking light
>> passes wastes
>> time, and heats the blank excessively.
>> My top tip: clamp the tool blank in a pair of mole grips and have at
>> it, you wont
>> burn your hands, and its virtually impossible to draw the temper on a
>> good HSS
>> blank. grind it hard and fast to approximatly the correct shape and
>> then tune it up
>> on the other wheel, and finally (if you need a good finish) a diamond
>> 'stone'
>> Dont worry to much about the angles, they are to aim for, not gospel.
>> The correct shape is one where the first and only bit that contacts is
>> the cutting edge.
>>
>> Dave
>>
> I show the guys the mole grip/ vice-grip technique.
>
> From what I read, the microfracturing of the surface tends to come about
> from dropping the red hot tool bit into the water.
> I tell folks to consider that HSS will hold a cutting edge at red heat,
> and that for the most part, they cannot hurt the tool blank enough to
> affect the way it cuts, by anything they do with a grinding wheel.
>
> A dip tank is nice, for when you have ground away the most of the tool,
> and you have to get down to the fine bits of work, and you want to be able
> to hold the tool bit by hand.
>
> It's amazing, how heavy those little bits can be, when they have been in
> contact with the wheel for a few seconds! :-)
>
> Cheers
> Trevor Jones
>
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Posted by Austin Shackles on May 24, 2008, 7:19 am
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enlightened us thusly:
>
>> If you never understand the basics of the physyics of cutting metal, you
>> will never understand why you are not getting the results you wish to, or
>> understand what has gone wrong (or right) with your set-up.
>
>
>What had grinding got to do with how a tool cuts on a lathe?
If you grind the tool wrong, it will do one of 2 things, either not cut at
all, or snag in the work and break something.
Or it may cut poorly, leaving a poor finish and generating much heat,
resulting in going blunt quickly.
>>
>> An eight year old can learn to grind a decent tool. It is an elementary
>> level skill.
>> All new skills come with a learning period. Best to get it over and done!
>
>Ooo, I just love being patronised. And people wonder why the young cant be
>assed to get in to metal working.
>Sorry I got a lathe before a grinder.
>Sorry I wanted to turn before grind.
>Sorry I had a reason to turn and not grind.
>Sorry for even trying out the hobby.
>
>And think there was a post a while ago asking whay this is a dying hobby.
>
>It because of partonising folk like you.
Oh fer fexache, get off your high horse.
Even if it did come over a bit patronising, he's right.
No-one said you can't buy tools, most of us do. But you also do need to
learn how to make them, if you're going to do anything more adventurous than
straight turning or facing or boring.
as for patronising: it's like offending people. You can only take offence,
you can't give it. I could be as offensive as I like, but if you decline to
be offended, then I'm wasting my time.
--
Austin Shackles. www.ddol-las.net my opinions are just that
Travel The Galaxy! Meet Fascinating Life Forms...
------------------------------------------------
>> http://www.schlockmercenary.com/ << ...and Kill them.
a webcartoon by Howard Tayler; I like it, maybe you will too!
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Posted by Trevor Jones on May 24, 2008, 12:49 pm
Please log in for more thread options Austin Shackles wrote:
> as for patronising: it's like offending people. You can only take offence,
> you can't give it. I could be as offensive as I like, but if you decline to
> be offended, then I'm wasting my time.
>
That pretty much covers it, really!
Cheers
Trevor Jones
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Posted by moray on May 26, 2008, 7:05 am
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> AC wrote:
>
>>
>>>AC wrote:
>>>
>>>>
>>>>
>>>>>I have a ml7 lathe and am about to buy a set of lathe tools and was
>>>>>wondering what view others have regarding the best type, HSS or
>>>>>Indexables
>>>>
>>>>
>>>>A beginners thoughts:
>>>>
>>>>Most here seem to say buy blanks and grind your own.
>>>>
>>>>But, if you are a beginner isn't that just adding something else to
>>>>learn and worry about? Is it not better for a beginner who already has a
>>>>lathe to buy some ready to use tools so that they can get the hand of
>>>>using the lathe first? Then later on learn to grind their own tools?
>>>
>>> If you are a beginner, begin by learning how to grind tools. It is part
>>> of learning how the lathe cuts, and why it won't, at times.
>>>
>>> If you never understand the basics of the physyics of cutting metal, you
>>> will never understand why you are not getting the results you wish to,
>>> or understand what has gone wrong (or right) with your set-up.
>>
>>
>>
>> What had grinding got to do with how a tool cuts on a lathe?
>
> Everything. You learn how the cut is made, and you understand how the
> tool must be ground, to acheive the results required. They are
> complimentary skill sets.
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.
>>
>>
>>>>I mean, if you screw up the grinding you're never going to begin
>>>>turning, right? Or the turning could be terrible with a rubbish home
>>>>brew tool. You get down and potentially give up.
>>>
>>> An eight year old can learn to grind a decent tool. It is an elementary
>>> level skill.
>>> All new skills come with a learning period. Best to get it over and
>>> done!
>>
>>
>> Ooo, I just love being patronised. And people wonder why the young cant
>> be assed to get in to metal working.
>
> I don't actually give a darn if you enjoy being patronised or not. You
> were whingeing like a schoolgirl over how difficult grinding tools is for
> a beginner. Everything is difficult for a beginner. Get over it. Learn
> something.
>
> Your way is like telling someone that wants to learn to cook (fill in the
> blank) cuisine, that the best way to get started is to find a take-a way
> that makes what you would like to cook! Ugh!
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.
>>>>When I got my ML7, also got 1 tool, clearly ground by the previous
>>>>owner. It worked ok, but I went out and got a set of cheapo tools to get
>>>>the hang of the lathe. Then I started grinding up the cheapo tools to
>>>>get the hang of grinding. Then lastly I bought some good blanks and now
>>>>make my tools.
>>>
>>> Pity! You were stuck using one tool, and had no other options. Had you
>>> learned to grind your tools early on, you would have had ALL options
>>> open to you right away.
>>
>>
>> I did, I bought tools.
>
> Should have bought a grinder, and some blanks. You'd still have the
> grinder, and likely still have some of the tools you'd have made.
>
> Like as not, you would also be farther advanced in your skills.
True, but there's more than one route to acheive most things.
<big snip>
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
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Posted by Trevor Jones on May 26, 2008, 9:19 pm
Please log in for more thread options moray wrote:
>
>>AC wrote:
>>
>>
>>>
>>>
>>>>AC wrote:
>>>>
>>>>
>>>>>
>>>>>
>>>>>
>>>>>>I have a ml7 lathe and am about to buy a set of lathe tools and was
>>>>>>wondering what view others have regarding the best type, HSS or
>>>>>>Indexables
>>>>>
>>>>>
>>>>>A beginners thoughts:
>>>>>
>>>>>Most here seem to say buy blanks and grind your own.
>>>>>
>>>>>But, if you are a beginner isn't that just adding something else to
>>>>>learn and worry about? Is it not better for a beginner who already has a
>>>>>lathe to buy some ready to use tools so that they can get the hand of
>>>>>using the lathe first? Then later on learn to grind their own tools?
>>>>
>>>>If you are a beginner, begin by learning how to grind tools. It is part
>>>>of learning how the lathe cuts, and why it won't, at times.
>>>>
>>>>If you never understand the basics of the physyics of cutting metal, you
>>>>will never understand why you are not getting the results you wish to,
>>>>or understand what has gone wrong (or right) with your set-up.
>>>
>>>
>>>
>>>What had grinding got to do with how a tool cuts on a lathe?
>>
>> Everything. You learn how the cut is made, and you understand how the
>>tool must be ground, to acheive the results required. They are
>>complimentary skill sets.
>
>
> 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.
Except if you were to follow his plan, you would have bought
pre-ground tools, but not a grinder, because grinding tools is hard.
>
>
>>>
>>>>>I mean, if you screw up the grinding you're never going to begin
>>>>>turning, right? Or the turning could be terrible with a rubbish home
>>>>>brew tool. You get down and potentially give up.
>>>>
>>>>An eight year old can learn to grind a decent tool. It is an elementary
>>>>level skill.
>>>>All new skills come with a learning period. Best to get it over and
>>>>done!
>>>
>>>
>>>Ooo, I just love being patronised. And people wonder why the young cant
>>>be assed to get in to metal working.
>>
>> I don't actually give a darn if you enjoy being patronised or not. You
>>were whingeing like a schoolgirl over how difficult grinding tools is for
>>a beginner. Everything is difficult for a beginner. Get over it. Learn
>>something.
>>
>> Your way is like telling someone that wants to learn to cook (fill in the
>>blank) cuisine, that the best way to get started is to find a take-a way
>>that makes what you would like to cook! Ugh!
>
>
> 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.
>
Point taken. Bad example, but the best I could come up with in short
order.
>
>>>>>When I got my ML7, also got 1 tool, clearly ground by the previous
>>>>>owner. It worked ok, but I went out and got a set of cheapo tools to get
>>>>>the hang of the lathe. Then I started grinding up the cheapo tools to
>>>>>get the hang of grinding. Then lastly I bought some good blanks and now
>>>>>make my tools.
>>>>
>>>>Pity! You were stuck using one tool, and had no other options. Had you
>>>>learned to grind your tools early on, you would have had ALL options
>>>>open to you right away.
>>>
>>>
>>>I did, I bought tools.
>>
>> Should have bought a grinder, and some blanks. You'd still have the
>>grinder, and likely still have some of the tools you'd have made.
>>
>> Like as not, you would also be farther advanced in your skills.
>
>
> True, but there's more than one route to acheive most things.
>
Yup. True.
> <big snip>
>
> 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
>
Can you still buy a set of pre-ground tool that is not total shite
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
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