Boring Question

[Ian S CParticipant @iansc]

Ramon don’t be too worried about the green grit wheel,the teeth are ground left and right,and you can pick them to suit(alternate teeth right then left),so a diamond lap will see you getting going. the front of the tool is perhaps 2mm square of carbide. I’m a fair way from town and some times I’v got to improvise. Ian S C

[CirclipParticipant @circlip]

Bout time these web site

 

designers put safegaurds in to stop

 

 overflow so we could read

 

 ALL the posting.

 

  Horizontal advertising

 

 MIGHT help.

 

  Regards

 

  Ian.

[mgjParticipant @mgj]

Feeds for CCMT tip for steel under average conditions.

 

quoting from the Sandvik book – 

 

NON wiper   tips.

 

Roughing – 1.6-2mm per rev. Depth of cut.   feed is .2 mm per rev (for .8mm nose radius)

 

Finishing  .4mm nose radius .8mm depth of cut.. Feed is .12-.15mm per rev.

 

Varies a bit according to tip geometry, task and grade of steel. Those are average figures.

 

For sure its nowhere near the .250thou I can take with HSS as a roughing cut on the Myford.

[mgjParticipant @mgj]

Sorry – cutting speeds – 400-450metres minute.

[AESParticipant @aes]

Re this Web site:

 

This is my 1st  post here.

 

I’d been “lurking” for a few weeks then finally took the plunge and registered. From the start the pages always struck me as being rather too “busy”, especially when compared to other similar sites, but what the heck, it’s not my site and I guess all the cr@p down both sides helps the site owner to make money (or at least he/she/they  thinks it does). But now, as of today, Tuesday Feb 9th, the posts I’d been following on boring have become unreadable – all the “garbage” on the RH column is blocking not just 1 word but several, making the whole chain of posts on the 2nd page unreadable. This is a new and VERY unwelcome development!

 

I’ve tried resetting my own PC in several display areas such as zoom, text size, and resolution but nothing helps. Also I’m not having this problem with other sites, AND it was not happening yesterday when I started reading the posts on boring. So I’m fairly sure this is a problem with the site and not at my end (and the post from Circlip seems to confirm this). Can someone fix this asap please.

 

(Post copied to the web site problems link axs well).

 

Krgds

AES  

[David Clark 13Participant @davidclark13]

Hi There

It looks fine to me.

Usually the overlapping posts are caused by long URL’s being posted but I can’t see any at the moment.

Is this the correct thread with the error or is it elswhere.

If so, please post on the correct thread and I can fix it.

regards David

 

[AESParticipant @aes]

Posted by David Clark 1 on 09/02/2010 16:24:29:

Hi There

It looks fine to me.

Usually the overlapping posts are caused by long URL’s being posted but I can’t see any at the moment.

Is this the correct thread with the error or is it elswhere.

If so, please post on the correct thread and I can fix it.

regards David

 

 Thanks David,

 

Which thread would you like it re-posted to please?

 

P.S, It’s still not OK on my screen – e.g. your own post has only 1 line which is long enough to be covered by the RH side ads (line 4), but that line stops at the word “at” plus tghe letter “t” on my screen.

 

Krgds

AES

[David Clark 13Participant @davidclark13]

Hi There

It must be your browser or screen resolution.

It is fine on my computer.

regards David

 

[AESParticipant @aes]

Posted by David Clark 1 on 09/02/2010 18:06:35:

Hi There

It must be your browser or screen resolution.

It is fine on my computer.

regards David

 

 Thanks for the comment David, but the problem is ONLY appearing on page 2 of this (Boring) thread. Page 1 is OK, and so is everything else I’m looking at (on this site and others).

 

But just to be sure, I’ll try changing something at my end – what would you suggest (as per my original post, I’ve already tried zoom, text size, and resolution, all with no joy).

 

Krgds

AES

[mgjParticipant @mgj]

One that can make a difference is hte screen resolution set?

 

boring chatter.

 

I don’t get chatter with ordinary boring bars – just between centres ones. What I have done is the usual dodges – increase feed, change the tip for one with less contact area, and played with speeds. However assuming a sharp cutter, chatter is usually a function of rigidity – so I have also locked every slide etc I can, but I think the basic problem is that its difficult to get enough support from 2 centre drilled holes except on relatively small bores.(and relative is probably relative to the size of the lathe) .

 

I have to admit, i have never used a boring bar in the 4 jaw, supported at the far end in a good running centre. That could reduce the problem.

 

However I am not a great person to comment on this – I have a second big(ish) lathe nowadays and most of my large jobs get stuffed into the  big 4 jaw, and a 1″ toolpost boring bar does the rest. And equally if I need parallel bores at a very specific distance, then the mill with its power downfeed obliges.

 

I quite like those cylinder hones for critical sizing and taking out any taper, and chatter marks. Work very well. So I have dodged the issue.

[Hugh GilhespieParticipant @hughgilhespie56163]

Hi David,

 

I am also having a problem with the RHS ads covering part of the message text. Funnily nough, it doesn’t happen on Page 1 of this thread, only on the second page. I have resorted to copying and pasting into Word so I can read the posts in full. A tad irritating!

 

 

[Ramon WilsonParticipant @ramonwilson3]

I really wasn’t trying to teach grannie here Merrick, but re-reading your post it seemed to infer you were (having chatter problems that is).

 

Whatever, I’m surprised on the chatter bit using ‘between centres’, can’t recall having had a real problem with that type of op so far -definitely not on finishing cuts but have on occasion had to deal with it when holding in the chuck. I agree that the centres can be a source – they should be as large and as deep as they can be for the bar. I’ve not tried the chuck driving method so can’t comment but as long as it’s running fairly true would have thought that that would go some way to help stiffen the bar. Biggest bar I have used  (on the Myford) is the larger in the pic – 1″ diameter.

I did make a booboo when I said the ‘jacking’ screw could be left in. It has to be removed of course to be able to measure across the bar. That does make it a bit fiddly at times but I have found the result worth the extra little bit of inconvenience.

 

Regarding the feed/speeds you quote I feel this goes to show perhaps that they could be considered a bit overkill for our needs.

 

If the figures are right – and I certainly don’t dispute them – then as average – ‘optimum’? figures they make the eyes water a bit not to mention the Myford cringing at the thought.

 

400mtrs/min equates to just over 1300 ft/min so on that basis RPM for a 1″ bore would be 5200 (Using CS x 4 over D) At .2mm/rev that’s a feed rate of 1040mm/min or near 41″/min. Totally unrealistic for a Myford – Colchester Triumph 2000 maybe but not a Myford – well not mine that is! Even if this was dropped by 75% when the carbide will be soon be wearing it’s still a fair rate to apply by hand. (In order to preserve the leadscrew I never use it to apply anything other that the final finishing cuts and screwcutting of course). The one thing a Myford S7 lacks is a ‘feed’ screw – what a transformation that would make!!

 

Howeverrrrr.

 

Today, rummaging through a box of my homemade HSS boring bars guess what I found! A Sandvik SCLCR boring bar no less. Total surprise, have no idea if I bought it, was given it, or what. Probably came home with all my tools. Simply had no idea it was there. Theres aging for you!

 

Well nothing ventured etc so it was mounted up and tried it on a piece of tool steel at 600 RPM – good but bitty- more speed – one down from top and it was going fine, certainly cuts metal well though the depth was held back to 20 thou. Can’t remember the last time the lathe saw ‘top gear’. Can’t say it will change my views by a great amount but it certainly handled the material ok – I think it will get used again particularly on the tougher materials

 

I have no power down feed but that may change later in the year says he hopefully!

 

Regards – Ramon

 

 

 

 

 

 

[David Clark 13Participant @davidclark13]

Hi There

Checked out by web writer.

Looks OK to me in IE, Safari and Firefox…

Must be your software or computer.

regards David

 

[VersabossParticipant @versaboss]

No problems with long lines here too with Opera.

Greetings, Hansrudolf

[CirclipParticipant @circlip]

What we have to ensure AES is that we fill the postings with drivel long enough to get past the bottom limit of the strip ads as your posting of 9/02/10 at 16.45.41 has done.

 

 Unfortunately the technological lepper syndrome has hit my computer also and on numerous occasions my own unit (as in the case of THIS posting) displays, or lack of it, the full posting.

 

 One problem that was noticed on other foreyes was the use of overlarge photos and PERHAPS Ramons side by side is the cause of it?????????

 

   Hey ho, the wonders of tekknowlidgy, NEVER had this problem with the “Paper” M/E.

 

   Regards  Ian.

 

 As an aside AES, do you also have an overlap on the centre of the home page on the MEW digital age ad??

Edited By Circlip on 10/02/2010 14:15:55

[AESParticipant @aes]

Circlip,

 

Thanks for your post Ian.

 

QUOTE:   Hey ho, the wonders of tekknowlidgy, NEVER had this problem with the “Paper” M/E.

 Regards  Ian.

 As an aside AES, do you also have an overlap on the centre of the home page on the MEW digital age ad??

UNQUOTE:

 

Yup, 100% agree, all this new-fangled stuff is “grate”, but sometimes it drives one (well me anyway!) to distraction. OTOH, it would take an age (or I’s need to have a personal intro to a whole circle of experts) to pick up the sort of “gold nuggets” that you can find on this site (and others) almost every day. BTW I’m using Windoze Internet Explorer with XP Pro and still have the problem with page 2 of the “Boring” post despite having fiddled with font sizes, display res, etc. That “Boring” thread is full of very useful info & comments for a dummy like me (quite by chance I’m about to start some boring this weekend – the first time ever!). So juswt like someone else who mposted on this subject yesterday I have now resorted to cut & paste into Word, where I can then  read the complete text and see all the pix quite comfortably.

 

To answer your 2nd Q, no, the home page of the digi MEW is working fine for me.

 

Thanks for your comments anyway.

 

Krgds

AES 

[AESParticipant @aes]

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

[mgjParticipant @mgj]

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 CParticipant @iansc]

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 WilsonParticipant @ramonwilson3]

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

[mgjParticipant @mgj]

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 WilsonParticipant @ramonwilson3]

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 Wood1Participant @johnwood1]

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 1Participant @michaelcox1]

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 1Participant @lesjones1]

Hi Ramon,

                  The tangential toolholder was in the Autumn 2009 (No.156) edition.

Les.

[Author]

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