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AES10/02/2010 17:26:37
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P.S. to my post above - I've just seen a couple of typos. How does one Edit a post after posting (I can't find any "command" to let me do that . but I'm probably looking in the wrong place!
 
AES
mgj10/02/2010 18:09:57
1017 forum posts
14 photos
Ramon - sorry if i didn't make it clear baout when I have seen chatter.
 
I agree - the figures are a bit steep, but those are the figures for production from Sandviks Corokey book . Why is why I always get a bit sleepy when people say not to use coolant with carbide. Nothing is going to run at anything like that speed without coolant!! And anything that was designed to run like that was certainly designed for coolant, if only to prevent changes in dimension!
 
Sounds like you do what I do on the Myford. One size fits all, top bottom speed - 600 rpm and cut anything? I like indexable tips - I like the Zenit &Sandvik parting off tips, and SECO for ordinary turning. The latter are better than Sandvik- freer cutting. Use them just like convenience HSS, and they do very well. Lots of coolant. However, almost all my steel is 220M07, so I'm not really giving anything the hard time. For our sort of engineering its a very reasonable choice.
 
But, like I said, the real reason I like indexable, and more recently tangential, is the positioning of the cutting edge - its always forwards of the tool so you can always set the toolpost square, and drop in any tool on the QC block, including parting off, with no mucking about. Maybe I'm too lazy.
Ian S C11/02/2010 00:37:16
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7468 forum posts
230 photos
According to some Sandvik litrature,on large cnc machines the coolant rate should be enough to keep the object being machined at ambiant temperature, ie., gallons/litres minute.The machine is fully enclosed.I use a small amount, mainly for lube rather that cooling. Ian S C

Edited By Ian S C on 11/02/2010 00:41:38

Ramon Wilson11/02/2010 09:39:20
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1655 forum posts
617 photos
Yes Merrick, very rarely venture into the top range unless it's something really tiny.
 
Coolant is a problem with tips very much a case of all or nothing. Ian's right the Haas machine pumped it out at some 14 gallons a minute if I remember right - three outlets simply throwing it on. Because of this need (and the ability to contain it) all carbide tools - lathe or conventional mills - were used dry. Blue chips and stand well back! I expect there are quite a few reading this will remember having the odd hot blue spiral smack them on the cheek and stick just under the glasses.!
I remember the uncoated Seco tips well, they were always preferred for the Clarkson Hi-Flo milling cutters and on the lathe for mild steel - they always outlasted other types.
Because of the way they were used I have never felt the desire to strain the Myford and the mill simply isn't up to it. Hence their limited use at home.
 
Just going back to the 'Throw - Away' FC3 bits a moment
I totally agree about the need to get up to a shoulder and /or face off but I don't use them for that - the whole object, and the point I was trying to make was that they require very little grinding (from solid) and are ideal for making small cutters for odd jobs -  very small parting off, tiny bores, o-ring grooves, screwcutting tools ad infinitum. Once the FC3 cutters are of no further use on the mill, if a cut off wheel isn't available then a quick nick on the edge of a grinding wheel at the start of the flutes,  the flutes held in a vice, and covered with a bit of rag before snapping off with a hammer. Ergo free 6mm or 1/4 round HSS.
Putting the need to turn to a deep shoulder aside - I tried this from fresh the other day - straight forward left-hand turning tool - 12mins for 5/16 square HSS and  just over 2 for the insert. It's not so much the time but the dust and heat build up. I accept the HSS insert won't get as deep or as close as the 5/16 blank nor will that get as deep as the carbide tooling, but they are very useful when you need something quick to advoid having to grind relatively much bigger lumps of HSS. It's offered purely as a help to those
whose budget might be slightly 'restrained' as well as being a good way to use something otherwise 'thrown away'.
 
I've yet to try the Tangential tooling though I understand the principle - sharpening being very simple to achieve. I guess we all have our old habit's though. Good we're all different .
 
It's cold and miserable outside - guess I'm off to the workshop then
Have a good day in yours
Kind regards - Ramon

Edited By Ramon Wilson on 11/02/2010 09:42:49

mgj11/02/2010 14:21:03
1017 forum posts
14 photos
For coolant I just use a 2mm vetinerary needle, and since, even with carbide I'm only cutting at HSS speeds that's fine. My tips are the SECO coated ones. - mostly.
 
However I have seen real flood cooling. Brit aerospace at Filton making Harrier frames in titanium amongst others, though Vickers at Leeds and Newcastle machining armour plate came a close second.  I'm not quite into those sorts of rates.
 
Tangential I'd recommend strongly. Chris  Stephens gave me a holder and tool, and it is just so easy - and so economical on HSS, even without  anything more than an offhand grinder. One touch on the wheel with the tool in the little jig, is enough to reface the cutting surface, and thats it. No heat build up , no unlevel faces, and very sharp. Easiest system I have ever come across.
Ramon Wilson11/02/2010 14:43:22
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1655 forum posts
617 photos
Ah, now you are talking about real machining
 
I'd like to try this type of tool - are there any drawings for a home built version?
 
regards - Ramon
 
PS Don't overdose on the coolant
John Wood111/02/2010 16:11:09
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116 forum posts
There was an article very recently in MEW (I'm sure) describing how to make a tangential cutting tool which I, for one, will have a go at as soon as time permits. I am at work so can't look up the actual issue but I think it was late last year.
 
This thread has been fascinating and hugely informative.
 
All the best
John
Michael Cox 111/02/2010 16:19:53
555 forum posts
27 photos
Ramon, there are some photo's of a very simple tangential toolholder in my photo file (Mikes Tools) on this site. If you would like drawings I have them in dxf format.
Mike
Les Jones 111/02/2010 16:35:22
2292 forum posts
159 photos
Hi Ramon,
                  The tangential toolholder was in the Autumn 2009 (No.156) edition.
Les.
Circlip11/02/2010 16:58:17
1723 forum posts
And that's the present "Have a free look" issue at the moment on the front of the forum.
mgj11/02/2010 18:03:07
1017 forum posts
14 photos
Well I shall certainly have a look. (with my vast experience of tangential holders. Ha!), the only hassle I can see is to set an offset for a milling cut, which is hardly the most stressing of tasks. Yes, its a compound angle, so the tilt is set with a tilting table and the front clearance either by putting the tilting table on a rotary table, of just drawing up a template in card. Card seems like a lot less hassle.
 
Back to Ramon and FC3 cutters.  I have been a bit cavalier about chucking them away- in any case I do resharpen. Buy new, use on brass, resharpen use on steel.
 
The question is how good quality HSS are they. They seem very good, and given some of the monkey metal that has been passed off as HSS, I might well be a bit more open with the old tobacco tins.
 
Which will gain me points with Circlip too.

Edited By meyrick griffith-jones on 11/02/2010 18:03:27

Ramon Wilson11/02/2010 18:58:42
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1655 forum posts
617 photos
What a lovely bunch of chaps you are.
 
Thanks a lot for your posts. I've studied Mikes pictures (thanks for your offer Mike) and can see what needs doing so will check out the freebie article too. I see that the tool needs to be trapezoidal (spelling?) so I guess these are available - I think that now I really will regret not having access to all those grinders - just think of the bits that could have been made in a lunch hour! One of the chaps I worked with does have a 540 so perhaps if I offer to do the holders he will do the tool bits???
 
Careful now Merrick - you're weakening   Personally I've never found the quality lacking on FC3, but I know what you mean about the monkey metal though. We had a buyer who thought she knew better - Clarkson ordered - ended up with such a cheap alternative that 16mm end mills could be 'sharpened' with a file - honestly! Totally unhardened. They were 'nice and shiny' though and above all of course "they cost much less" - 'we' won that one though ! Happy days
 
Thanks again - Ramon
chris stephens11/02/2010 19:29:55
1049 forum posts
1 photos
Hi Ramon,
The tool holder that Meyrick has takes plain ordinary 1/4" square Cobalt HSS.
For those with half an ounce of intelligence all you need to know is that the tool leans left 12 degrees and forward 12 degrees and the tool is ground at 30 (60 included angle) degrees from opposite to opposite corner.
There are plans on the net, try Google-ing "tangential tool holder"  that's how I got the info to build my first one, some years ago. I have since redesigned the thing to hold the tool bit even more firmly, using my simple square hole technique, but that is for another time.
chriStephens
PS If Meyrick can be persuaded away ( even temporarily) from his beloved carbide tips, there must be something to these holders. 
PPS If you have been  thinking about making a Tangential holder, go ahead and spend the time to do it, you will not regret it. Ain't that right MGJ?

Edited By chris stephens on 11/02/2010 19:32:34

Michael Cox 111/02/2010 19:38:56
555 forum posts
27 photos
Ramon, the tool in the tangential holder is ordinary square tool steel. The tool is ground 30 degrees across the diagonal which makes the front face a right paralellogram.
Mike
mgj11/02/2010 20:16:54
1017 forum posts
14 photos
I have them made for me. I shall be issuing a "By appoinment to" sticker.
 
Chris, you are quite right - once you have the 12 and 12 that is all you need to know, and that was what I was looking for. The only other wrinkle is the height for the clamp screw so it doesn't foul a facing cut.
 
I use that holder exclusively on the big lathe. Apart from the occasional time I need a specific large nose radius, that's the tool I use. I can vouch for the 1/4 square toolbit, which would be easier to come by than oblong - or trapezoidal to some.
 
(And for those who are going to have a go, don't forget you are cutting the SPACE, so the blank has to be tipped such that the BOTTOM of the slot is UP by 12deg under the cutter. Then when you put it in the tool holder the TOP will be 12deg nearer the work.(thicker) No mirror images please. With apologies to the ancient and decayed Grannies)
Ramon Wilson11/02/2010 21:38:46
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1655 forum posts
617 photos
Yes "I can see clearly now" what you mean - it was that first image of Mikes plus the fact that I was visualising the tool being held vertically in both planes. The article in the sample issue gives all and as I do have some 1/4 square HSS and plenty of steel  theres no excuse. Back on this one (sooner, rather than) later!
 
My thanks again guys - Ramon
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