Single point threadform tools?

[bodgeParticipant @bodge]

Posted by duncan webster on 31/12/2016 01:09:55:

If all JCB manufacturing is done in China, what do the 6000 people in 11 factories in this country spend their time doing?

see **LINK**

and if all threads in industry are cut with taps dies and Coventry die heads, why do tip manufacturers waste their time making inserts?

Well it just goes to prove manufacturing is global these days ( and at no point did i state production was now solely in china)

My time in the engineering industry was late 1960 s to late 1970 s and i tend to think of engineering mainly in that era also i have other interest and dont have the time to spend on the internet to see just who does what, and where

So tips and inserts are a relatively new thing to me, and seem to be the main stay of cnc , which cant really do without them

Tell you what though, i just wont post any more post , then it wont cause any more confusion ,………….b

See ya all good luck with screw cutting on the the lathe …………………….b

[Neil LickfoldParticipant @neillickfold44316]

Andrew, for me, I brought the holder that takes the 16mm full form threading inserts. There are only a few needed and they last a really long time if ya don't do stupid stuff with them. I get the full form and keep threading untill the OD of the thread form is at the diameter of the thread required to Ø0.05mm smaller. So I have 0.5,0.7,0.75,0.8, 1.0,1.25,1.5,1.75, they cover every thing that I want. Anything in between like the whitworth form, 55deg, I just use HSS as I do very little of those threads. I screwcut with the compound set at 1/2 the thread angle, so UNF or Metric I use 60 deg from horizontal. I in feed on the compound slide and leave the cross slide at a fixed position. This way, I don't need a nicely full formed tool, I only need the leading edge of the tool to be ground at 30deg from inline with the tool, and the trailing side only needs to be the form for the 1st 0.3mm or so, how ever much of a cut you take per pass. The trailing edge becomes generated, not fully formed. I leave the leadscrew fully engaged for the entire time of threading. Now days I have VFD and 220V 3 phase motor and a microswitch that stops the spindle at the end of the thread pass. I undercut the thread form end on both inner and outer threads and generally use a radius tool when doing this on OD work and just a simple groove/ oring type groove tool for the inner threads. Where possible for inner threads I use a tap, unless it has to be a precision thread then I will screw cut it, or if it is on the larger side , ie M16 and above.

For 32 tpi UNF I use the 0.8mm full form, 24 TPI, use the 1.0 mm full form,and for the 20TPI I use the 1.25mm full form.These have been the most common threads apart from the metric ones that I cut.

Full form inserts can be brought for about,$NZ 10 to $15 including tax. Cheaper from Asia if you want to wait however long to get them.

Smaller internal threads I use either a carbide internal threading bar used in cnc single point threading, or make my own from HSS. Internal threads, I use the compound slide generally at Zero and just infeed on the cross slide dial, and effectively full form thread. I do this because I preset the micro switch to a stop and then feed on the compound slide to the thread end point safe zone. This way I do not crash the threader into the end wall if it has one.

Neil

[D HannaParticipant @dhanna35823]

Posted by Neil Lickfold on 31/12/2016 03:40:30:

Neil

That brings back memories Neil! I worked with a fellow at HMAS Nirimba (NSW) Apprentice Establishment here in the late 70s and that was the way he cut threads. Quite effective but generally I rarely use that angular approach method. We all have our favourite way so I never harp on which is best. I just taught both angular and direct methods and left it to the individual to use what they felt comfortable with.

Andrew ol' mate, did you get the email I sent you? You aren't on CLAPA now so I couldn't check your address.

[HacksawParticipant @hacksaw]

Posted by duncan webster on 31/12/2016 01:09:55:

if all threads in industry are cut with taps dies and Coventry die heads, why do tip manufacturers waste their time making inserts?

 

Because when industry does a monthly stock take , they need to replace their lost / stolen ones that are on Ebay

Bodge … I did 2ft thread cutting,    meaning it looked like a thread from 2ft away !

Edited By Hacksaw on 31/12/2016 08:24:20

[John Stevenson 1Participant @johnstevenson1]

Industry doesn't use Coventry die heads any more.

20,000 video's on You Tube of all types of machining operations, show me a CNC with a die head in the turret. ?

The only people selling die head chasers are small concerns selling to the jobbing shops and repair industries, not manufacturing. Look in any of the big catalogues of cutting tools as sold to industry and you won't find die heads or inserts listed because fact is there is no demand.

How industry worked in the 60's and 70's has no relevant on how t works today

[Raymond AndersonParticipant @raymondanderson34407]

bodge, You don't need to stop posting just because you don't agree with some others. Jesus, I have had quite a few "difference's of opinion " It all part of being on a forum. If everyone that had a disagreement on the forum were to stop posting… there would be no forum. Just relax .

[HacksawParticipant @hacksaw]

I meant

the its the tips that are pilfered and are replaced..

[John Stevenson 1Participant @johnstevenson1]

Posted by duncan webster on 31/12/2016 01:09:55:

If all JCB manufacturing is done in China, what do the 6000 people in 11 factories in this country spend their time doing?

see **LINK**

and if all threads in industry are cut with taps dies and Coventry die heads, why do tip manufacturers waste their time making inserts?

Correct Duncan.

As someone who travels the A50 past JCB at least 4 times a week there is massive roads works being carried out.

As I can't see at this point exactly what is going to take place I googled the proposal and this snippet came up from Staffordshire Council.

"

The A50 Growth Corridor is a Highways England scheme aimed at easing congestion and supporting economic growth. The A50 is already supporting traffic flow to businesses such as JCB and Alton Towers and the investment is needed to support significant businesses and housing growth in East Staffordshire.

JCB, for example, has announced major expansion plans, which could create up 2,500 jobs in Staffordshire and many more in the supply chain, and developer Uttoxeter Estates has submitted a planning application for 700 new houses and a business park development to the west of Uttoxeter, creating 1900 new jobs.

In total it is expected that the two projects could support the creation of 7,500 jobs and 1,800 news homes in and around Uttoxeter."

[MWParticipant @mw27036]

Posted by bodge on 31/12/2016 00:34:31:

Still want to tell me About small scale works ?

 

If I may, I don't think what I meant was said very clearly, when I was talking about scale, I was referring to it in the primary sense of the word, in relation to the size of the object being worked on.

So when I said small scale, I meant that taps are mainly used under around 8.0mm clearance (give or take a few mm I suppose), under that size, a threading head or boring bar will not fit inside the hole or wouldn't be practical to do so. (I have actually ground a threading tool that can just about tap a 3-4mm hole)

Other than that, every single hole size above that has the potential to be screw cut, to whatever thread depth or pitch. And I would say at the massive end of the scale it becomes almost a necessity, i think.

Michael W

Edited By Michael-w on 31/12/2016 09:16:55

[bodgeParticipant @bodge]

Posted by Hacksaw on 31/12/2016 08:21:45:

Because when industry does a monthly stock take , they need to replace their lost / stolen ones that are on Ebay

Bodge … I did 2ft thread cutting, meaning it looked like a thread from 2ft away !

Edited By Hacksaw on 31/12/2016 08:24:20

Good point, I dont suppose engineering companies " lost " many 2 inch plus unc taps , or die heads one needs a whacking great big Colchester lathe with 35 hp 3 phase hanging off the back just to turn a tap like that day in day out..

Now that you you mention it i have seen a fair bit of tipped tooling sold unused in s/h tool shops , and then there is always ebay !!

Are you joshing me with your thread cutting attempt ? …..If genuine continue.

Trouble with tipped lnserts, they are ok if you have a spare , but not much use if you just happened to trash your last one late saturday afternoon on a bank holiday week end………………..b

[bodgeParticipant @bodge]

To Micheal W

Point taken !……..Things were done a bit differently pre – cnc

Like most folk if i can, i use a tap to cut a thread, i do, but over a certain size its not really possible / practical to use a tap,( any thing over about 1/2 inch in my case, as accuracy and fit is usually upper most requirement )

Happy new year to all,……………regards …..b

[EmgeeParticipant @emgee]

Posted by bodge on 31/12/2016 09:31:05:

Trouble with tipped lnserts, they are ok if you have a spare , but not much use if you just happened to trash your last one late saturday afternoon on a bank holiday week end………………..b..

Most thread cutting inserts have 3 cutting points which reduces the occasions above, best to grind off the first used/blunted tip to be aware.

Emgee

[bodgeParticipant @bodge]

Posted by Raymond Anderson on 31/12/2016 08:44:51:

bodge, You don't need to stop posting just because you don't agree with some others. Jesus, I have had quite a few "difference's of opinion " It all part of being on a forum. If everyone that had a disagreement on the forum were to stop posting… there would be no forum. Just relax .

HI Raymond

Well as you can see i am still posting , as i would consider it impolite on my part to not reply to the last three post , yours being the third,

I do take on board what you say and l feel about the same as yourself about it , as you can probably see from my last two post,………………b

[bodgeParticipant @bodge]

Posted by Emgee on 31/12/2016 10:30:29:

Posted by bodge on 31/12/2016 09:31:05:

Trouble with tipped lnserts, they are ok if you have a spare , but not much use if you just happened to trash your last one late saturday afternoon on a bank holiday week end………………..b..

Most thread cutting inserts have 3 cutting points which reduces the occasions above, best to grind off the first used/blunted tip to be aware.

Emgee

Info no use to me ,dont use them or plan to…………b

though of course this maybe help to others 

Edited By bodge on 31/12/2016 10:53:27

[Neil LickfoldParticipant @neillickfold44316]

There is also live tooling for making threads. It consists of a router mounted on the lathe tool post and a single row thread milling cutter with the thread angle on it, ie 60 deg included. These typically are short threads so about 20mm long is normal depending on the size of the cutter. These are effectively cut on a lathe in a similar way to thread milling on a mill, ie in 1 or 2 passes at a fairly slow rate, about 50 to 70 rpm, for both inside and outside threads. As the cutter is not inclined at the correct helix angle, it does not create an exact true form, but is good enough for a nut and bolt. There are for mills, multi thread cutters, that cut an entire thread length ,inside or outside in 1.5 turns of the work piece, or around the work piece which ever the case may be. A lot of people who do very nice wood work and work with Ali, like to use the live tooling method for thread generation. There are also full form live threading these days as well. In industry, a lot of threads are rolled with rolling heads, even into Stainless steels, etc. They also have special heads that effectively knurl splines and gear forms as well. But the rolling boxes as I call them really aren't in the area of a hobbyist. The live threading is though absolutely. Screw cutting is very popular in job shops or when there is only a small run of parts and the other threading methods are just not viable for the number being made. I recently saw a Titanium part that was solid 3d Printed with an M14 fine thread and it worked fine. I was just blown away with what I saw. 2 years ago, the thread would still have needed to be chased, or a die nut of some sort run over it. I have hopefully attached a needle and body that was all made on a small cnc mill. The back of the needle was set up and parted off the bar. Even the M4 thread was live thread milled. In theory, if I could model good enough, I should be able to make these parts on my CNC router, but don't bother as I am good on a lathe.

Edited By Neil Lickfold on 31/12/2016 11:13:01

[Nick HulmeParticipant @nickhulme30114]

The reason a range of Thread Mills are made for different major diameters, even when the pitch is the same, is that the cutter profile differs and is designed to cut the correct form for a limited range of major diameters.

The form will only be wrong if you use the wrong cutter for the size of your work,

– Nick

Edited By Nick Hulme on 31/12/2016 11:37:29

[bodgeParticipant @bodge]

Posted by John Stevenson on 31/12/2016 08:42:16:

Industry doesn't use Coventry die heads any more.

20,000 video's on You Tube of all types of machining operations, show me a CNC with a die head in the turret. ?

 

The only people selling die head chasers are small concerns selling to the jobbing shops and repair industries, not manufacturing. Look in any of the big catalogues of cutting tools as sold to industry and you won't find die heads or inserts listed because fact is there is no demand.

 

How industry worked in the 60's and 70's has no relevant on how t works today

I missed this one , who said any thing about using a cnc with a die head ? how about you show me where i made a statement saying that ………….b

or to that effect ?  

this really isnt going any where 

Edited By bodge on 31/12/2016 16:25:38

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