# Difficulty with setup



## Southernsandman (Feb 15, 2020)

I have a difficult thread that I need to set up on my myford and I hope that your combined knowledge will
Crack it my thread form is a 10 WF .


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## stevehuckss396 (Feb 15, 2020)

I think it's a whitworth form thread. British used whitworth threads. They are alot like imperial but might be 55 degree unlike imperial 60 degree but I would need to do some checking. You might need 55 degree cutter.


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## fcheslop (Feb 15, 2020)

I have a few early tools over 130 years old that are stamped W F ,Whitworth Form from the days when whitworth was the only standardised thread .
I think its to show the tool is to the standard
55 degrees for Whitworth and British Standard Fine  and just to confuse during ww2 they shaved a 1/16 of the bolt head


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## goldstar31 (Feb 15, 2020)

It's 55 degree  Coarse Whitworth Form  obtainable from  40 and 50 gears of preferably  20DP pitch.

After saying all this, you have all this information on the 'casing' of both the ML7 and Super7.
These- and a block of gears divisible by 5 should be standard on your lathe. If you  eventually need to go 'Metric'
a correct transposing gear of 127  of 20DP will not fit but an approximate 63 or 21's can be used.

Two things which I would commend are a thread gauge which are cheap and would have answered your question and will in future be used to check the setting up of your 'banjo' and  Martin Cleeve's book Screwcutting in the Lathe.

Again, my best wishes to Frazer and a comment to say that have a form tool which could be too much of a strain on a Myford leadscrew.


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## BaronJ (Feb 15, 2020)

Hi Guys,

That thread chaser could easily be used to cut the thread once the lathe is set up for ten threads per inch.

Use it just as you would for single pointing but ensure that the body is at exactly 90 degrees to the work.  The reason for doing this is that the cutting teeth on the end of the chaser are sloped down to the right.  So the initial cut will be done by the first tooth and the other teeth will come into effect as each cut removes material.

The second tooth will barely scratch and the third tooth won't until a few thou of feed is applied, and so on until full depth is reached.

Thread chasers are very good for cutting full form threads.


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## goldstar31 (Feb 15, 2020)

John
Your eyesight is obviously better than mine

Cheers and thanks

Norman


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## Southernsandman (Feb 15, 2020)

BaronJ said:


> Hi Guys,
> 
> That thread chaser could easily be used to cut the thread once the lathe is set up for ten threads per inch.
> 
> ...


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## Southernsandman (Feb 15, 2020)

I new It was worth getting some help.ill sort it tomorrow with some luck. I was using the thread chaser to figure out the T P I  and what sort of tool to grind but I dont really do much free cutting with threads on my machine.


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## BaronJ (Feb 16, 2020)

Hi Southernsandman

If you have ever seen a Coventry die box, you will note that they have four threading dies in them.  The dies can be obtained in a multitude of threads.  Properly mounted they make superb single pointing tool bits for cutting threads.  One of the features of chasers is that the threads produced will be of exactly the correct form.

There were many millions of them made, and scrapped because no one wanted them any more.  Without the Coventry die boxes the war effort wouldn't have been as effective.


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## goldstar31 (Feb 16, 2020)

I totally agree with Baron's observations about Coventry boxes. Historically, we Brits had Whitworth Coarse and Whitworth Fine with an 'electrical' dash of British Association threads

However all this very inconclusive dialogue had my  back to  crests on threads or in some cases, their absence.
I seem to recall when I made my Quorn tool and cutter grinder in the days of Yore that Professor Dennis Chaddock  'truncated' the threads on the measuring ( I think that's right) spindle. Again,  in Screwcutting in the Lathe that Martin Cleeve truncated his tailor made special screws for industry on his much modified Myford ML7- and then he  made his own micrometers on it. Then Norman Tinker on his original Tinker used his Myford leadscrew to calibrate his tool and cutter grinder. I note that on the Canadian Guy Lautard  version that those notes are absent. 

And then- oh dear- no one has got on to Jo Blocks.  I have a set but nothing fancy or NPL quality.

Somewhat quizzically

Norman

an


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## BaronJ (Feb 16, 2020)

Hi Guys,

FWIW "Tracy Tools" in the UK, stock both the dies and a handle so they can be used as a hand chaser.  there are pictures on their web site of them.  Whilst I would not advocate using the handle in the tool post of a lathe and would use a specially made holder for them that would stop them from twisting out of line.

Disclaimer !  I have no relationship with "Tracy Tools" other than a satisfied customer.


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## goldstar31 (Feb 16, 2020)

I suppose confession is good for the 'sole'( Dover or Lemon) but I have  a two ended die holder which I made with a Number 1 Morse Taper and fitted a jumper sleeve to work in a Number 2   tailstock. As I have 'new-ish' Myford Super 7B with the power cross feed( and probably a decent coat of paint) to arrive shortly  it is probably time to tart things up a bit and go into the 20th Century from the Dark Ages.


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## fcheslop (Feb 16, 2020)

Cromwell Tools in the UK are currently selling hand chasers at a discounted price
I have hand chased fine threads in brass in a former life but always found it a butt clenching experience
We used to polish the threads to a near perfect fit although sometimes I  think it was just to keep the apprentice busy.


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## Charles Lamont (Feb 16, 2020)

I regularly finish external threads with hand chasers. I have sawn off the handle tangs and use them in a toolholder. I find they have to be skewed very slightly to ensure cutting on the first tooth.


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## Apprentice707 (Feb 17, 2020)

The Whitworth form of thread was devised by British Engineer Joeseph Whitworth in 1841 and established the first thread system in the world and continued in common usage by British manufacturers until the early '70s. My 1960 Myford Super Seven has BSF and BA threads. I am a traditionalist and have a good stock of British Nuts and Bolts and threading equipment so I still use them on my projects. Let us hope Brexit sees the reintroduction of these threads (Heh Heh).
Seriously I have some Coventry die head cutters that I use as chasers. I believe Tracy Tools in the UK sell these and a holder to make them handheld chasers.

Cheers

B


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## RonW (Feb 17, 2020)

Gents, 
This is probably a little off topic but back in 1963-4 I attended a demonstration at a trade show in Salisbury, Rhodesia (now Harare, Zimbabwe) where a local trade school demonstrated a "thread swirling system" of cutting threads on a lathe. In comparison to single point threading the results were spectacular. I have never seen or heard of it since. Has anyone, maybe Norm in his vast experience, ever built a device to do this. There was recently a short video showing cutting threads using a vertical mill but obviously computer controlled.
RonW


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## holmes_ca (Feb 17, 2020)

When I left school at fifteen my first job as a Turner Improver was at a small shop in London UK machining water pump castings and one job was on the production line chasing brass shafts and I found that slow rpm was not good it went 100% better with a higher speed, that was 70 years ago, don't ask what the speed was, but I got pretty good at it,

Edmund..........Alberta


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## goldstar31 (Feb 18, 2020)

RonW said:


> Has anyone, maybe Norm in his vast experience, ever built a device to do this.
> 
> RonW



I am quite baffled to be associated with full size, 12" inches to the foot sort of thing. Maybe there is confusion with another Norman Atkinson who wrote the biography of that great engineer Sir Joseph Whitworth.
As I have said- far too many times that I was a 'bean counter' until the age of 55 and at that point had enough of my version of the rat race and retired- for longer than I had ever worked.
As a MODEL( Apologies Cogsy  but the message must be forced home) engineer, it seems  fairly easy to assume that with sufficient horse power,  people can move away from single point machining.  I'm always ashamed to find that I agree  with a leading expert in model engineering that people 'ask the the same silly questions and get the same silly answers' I'm like him, I spend far too much time  having to work things out for myself.
As both gentlemen have  have Myford ML7's, it is fair to mention that another L7 owner  made a good living out of his highly modified lathe- screwcutting- and probably very little in royalties.  As far as I am aware he bought half a Myford and added a One horse motor and a half horse one and drove his version with old traditional line shafting.  He was too poor to finalise Patent applications or bu any tools and made and describe how he built up his workshop with fabricated mild steel sections rather than castings which he hated.

Thinking back, people do  create threads with dies and looking a m sets of BA ones, they cut threads- one following the other whilst my other assorted stuff is three fold. Harking back to the 7 Series Myfords, the tailstocks have three start threads in the tailstock poppet. No doubt that they were cut at -one operation.

Returning to myself, I have travelled fairly extensively in Europe, a bit in America and Canada and not enough in the Far East. In the UK and Europe we bought property but Far from the Madding Crowd of Industry. On my wife's death, I sold up, ensured that my grandchildren  would also benefit as well as my children with better educations that I was previously subject to. As a bean counter, I am constantly aware of the problems of inheritance and simply  and also the need to extend charity to those who haven't been  quite as lucky as myself.

So I've little time to brood especially on questions which have been discussed time without number- and which are still largely ignored.

Now at almost 90, I have real problems which only the fortunate amongst you will experience.
I hope that this goes somewhere to clear the matter and frankly, if it doesn't, it's only a hobby and should be treated as such.

Norman


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## David Shealey (Feb 19, 2020)

fcheslop said:


> Cromwell Tools in the UK are currently selling hand chasers at a discounted price
> I have hand chased fine threads in brass in a former life but always found it a butt clenching experience
> We used to polish the threads to a near perfect fit although sometimes I  think it was just to keep the apprentice busy.



Being in the USA, the use of "Thread Chasers" was not something I was familiar with.  I looked at Tracy Tools, and created a link on my desktop to them.  Some nice stuff there.  US suppliers want an arm and a leg for Metric Drills, Tracy is less expensive, not sure what shipping would be though.

I also tried looking at Cromwell Tools, but that is blocked by my security system as a dangerous website.


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## Cogsy (Feb 19, 2020)

David Shealey said:


> I also tried looking at Cromwell Tools, but that is blocked by my security system as a dangerous website.
> View attachment 113900



Seems like they have an SSL issue so they are vulnerable to being 'hacked' but there is nothing actually malicious about the site. Should be quite safe to browse normally. You can check the report here : https://www.ssltrust.com.au/ssl-tools/website-security-check?domain=www.cromwell.co.uk


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## goldstar31 (Feb 19, 2020)

I'm running Norton, obviously the UK one and Cromwell Tools is OK on my Mac.

Actually Cromwell is a very big UK outfit and principally supplies to  industry. We are 'peanuts' to them.

However, we little peanut people in the UK have to pay the earth for drills which are not metric.

My son is big  in the 'transport of parcels business' and despite being in the family so to speak, he isn't bothered about the hassle of small time no bodies - like me. 

Just to put things into perspective, I have just far more time trying to unbolt a Crompton Parkinson rotary switch on my old Myford prior to sale/exchange. Can I find a 1/4 inch 1/4 inch socket to fit my metric box of goodies- no way, Jose! 6.5mm is a sloppy fit ----

There ye go, laughin' and scratchin'.


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## Apprentice707 (Feb 19, 2020)

There is no doubt that our hobby is becoming more and more expensive, some of us will have a good stock of drills, mills and other semi consumable items acquired over the years, but will still need a top-up or in my case to buy metric items in an attempt to join the 21st century. 
I agree with the correspondent who observed that metric items were being overpriced in the USA. ( I live half the year in the US and half in the UK). Even the imperial stuff is expensive in the US, not a good situation.
In an attempt to economise I buy cutting tools directly from China, they can be delivered anywhere in the world and are usually tax-free (Small items only). The delivery times can be quite long (Forward planning is needed here), but the wait is worth it. Friends at my Model Engineering Club have been surprised at the quality of the items I order and have started to order themselves.

I use either eBay (Try the US eBay site for imperial items) or Banggood with all carrying their usual money-back guarantees, what can you lose? I recently bought a 50mm face cutter with 10 inserts for £23 from China, the cheapest I could find in the UK was £65 rising to £140 from another supplier. The quality is good and it does a good job.

This is Banggoods url    https://www.banggood.com/

Cheers

B


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## David Shealey (Feb 21, 2020)

Cogsy said:


> Seems like they have an SSL issue so they are vulnerable to being 'hacked' but there is nothing actually malicious about the site. Should be quite safe to browse normally. You can check the report here : https://www.ssltrust.com.au/ssl-tools/website-security-check?domain=www.cromwell.co.uk


Not going to chance it though.


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## goldstar31 (Feb 22, 2020)

Apprentice707 said:


> There is no doubt that our hobby is becoming more and more expensive,
> B



As I sit it is almost a month since coronavirus stopped almost all production in China and as I view the news on TV, the USA seems to have caught  a loss of production. In schoolboy arithmetic, devoid of political propaganda, this is a 1/12th.
No one knows just how long it will continue but lost production means that someone swill have to pay for it-- and sadly, this means us.


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## L98fiero (Feb 22, 2020)

RonW said:


> Gents,
> This is probably a little off topic but back in 1963-4 I attended a demonstration at a trade show in Salisbury, Rhodesia (now Harare, Zimbabwe) where a local trade school demonstrated a "thread swirling system" of cutting threads on a lathe. In comparison to single point threading the results were spectacular. I have never seen or heard of it since. Has anyone, maybe Norm in his vast experience, ever built a device to do this. There was recently a short video showing cutting threads using a vertical mill but obviously computer controlled.
> RonW


The thread seems to have diverged a bit from threading but I think you saw a demonstration of 'thread whirling', it's a system where the thread is basically milled, it's used a lot now, particularly on Swiss lathes to produce titanium bone screws and the like. Those threads are similar to a wood or sheet metal screw that has a narrow projecting thread with a large pitch, i.e., ^----^----^ Schwanog and P Horn are big on making tooling for this.
When geared to the spindle whirling can be used to produce polygonal and other shapes on turned parts. The following videos show how it's used, probably beyond the capability of most home shops though the same can be done with appropriate gearing to synchronize with the spindle as I've seen it done on screw machines.  and


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## chrsbrbnk (Feb 26, 2020)

With just about any 3 axis cnc mill    thread milling will give you anything you put in  you could mill a thread on the out side of a triangle if you were so inclined But I suspect the lathe in the video  is using a cnc powered milling cutter  with rotation encoding  along with the lathe spindle having its rotation position encoded   versus a really complicated gear train.  then it would be be up CAM software to get things in the right spot at the right time.   all requiring programming skills wildly beyond me


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## Southernsandman (Feb 29, 2020)

I thought I'd bring this all back on track the thread I had difficulty with turned out to be 10 tpi  i used a 60° thread tool. I turned the OD to 28mm to match the existing piece but I got it sorted my small lathe only just coped the thread isnt very clean but it works all that's left is the milling and parting off.


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## awake (Mar 3, 2020)

Southernsandman said:


> the thread isnt very clean but it works



From what I can see in the pictures, nothing at all wrong with those threads - they look great!


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## BaronJ (Mar 6, 2020)

I agree ! Nothing wrong with those threads at all.


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