Metal lathe? Peterborough area?

[pe2dave]

If you are seriously concidering making your own new trammel 'point' and you haven't previously used Threading Dies, then make sure that you get a 'split' Die and don't try to go to finished size in one pass, nor think that you don't need to support the Die-stock square on to the workpiece -- ie. with something in the chuck of a pillar drill to keep it 'Square'.

Beging too fussy? 60 years ago I was shown how to use a tap and die (metalwork at school).
As (all of) those on youtube, I simply took care to keep it square?
I'm guessing you mean die holder on drillpress bed, clamped? Bar in drill chuck? To get it
started square? I can see the logic... Is it OTT?

 

[Ttrees]

Not having a metal lathe to get things perfect, nor have partially cut my cheapie solid liddle ones
to make a split die, I can say it's not easy.
Not even with a decent lead in, and tried a few times experimenting with various bevels and still ended up with pathetic results, as I needed to reduce overall thickness beyond what it should be.

Maybe this would be a different story with good dies, or even a cut in the cheapie solid ones.
I'll definitely be attempting this should I need a thread which doesn't need to be perfect, otherwise I will likely cough up and go to my local to get some nice ones.

 

[J-G]

Beging too fussy? 60 years ago I was shown how to use a tap and die (metalwork at school).
As (all of) those on youtube, I simply took care to keep it square?
I'm guessing you mean die holder on drillpress bed, clamped? Bar in drill chuck? To get it
started square? I can see the logic... Is it OTT?

Apologies, Dave. From other conversation I have mis-understood your level of competence

No, I wouldn't put the Die-Stock on the drill press bed, I'd clamp the work in a vice, (or collet chuck), put a small bar with an enlarged flat 'head' in the drill-chuck and use that to press down upon the Die-Stock.

This is not just to 'start' the thread, I'd keep the support pressure on until the workpiece came in contact with the bar. 'Drunken' threads are too easy to make so I don't think this method is OTT.

 

[J-G]

Maybe this would be a different story with good dies, or even a cut in the cheapie solid ones.

Being 'Solid' doesn't (necessarily) mean 'cheapie' - I have both solid and split dies for all the threads that I generally need (all HSS). The solid version is used for the final cut which will be 'to size'. The split versions I use for the first, second ..... however many cuts I feel necessary - (it will vary according to the thread size and material). This is primarily because it is possible to adjust a split die to cut 'under-size' - been there, done that!

Oh yes, I have converted 'solid' to 'split' with a Dremel and thin abrasive disc.

 

[pe2dave]

This is primarily because it is possible to adjust a split die to cut 'under-size' - been there, done that!

Oh yes, I have converted 'solid' to 'split' with a Dremel and thin abrasive disc.
[/QUOTE]
So why are dies not sold as per taps? First, second and bottom tap?
So open, half closed, tight to emulate first second and bottom cut?
Sort of makes sense

 

[J-G]

This is primarily because it is possible to adjust a split die to cut 'under-size' - been there, done that!

Oh yes, I have converted 'solid' to 'split' with a Dremel and thin abrasive disc.

So why are dies not sold as per taps? First, second and bottom tap?
So open, half closed, tight to emulate first second and bottom cut?
Sort of makes sense

Economics!

The boot should be on the other foot Dave . . . "Why aren't 'Adjustable' Taps made"?

Looked at like that, I suggest that the answer is obvious.

It's easy (ish) to make a Die which can be adjusted (within small limits) and therefore use one die to cut multiple diameters (1st, 2nd...) at the cost of one item. Squeezing a ring from the outside will reduce the diameter consistently along its length.

To do the same with a Tap is vastly more complex - I believe they do exist for large pipe threads (though I've never seen one) - they would need to have pressure applied from both ends via some sort of 'cone' arangement. The cost of making three 'solid' Taps will be lower than the cost of producing an adjustable version. Get below something like 25mm Ø (1") and the physical improbability of manufacture would be the guiding principle.

 

[John Hall]

This has all got unnecessarily complicated….the cost of buying a die etc to do the job would be more than value of the part, and probably never used again.
I would be happy to make you one if you send me the parts you have.
I have all the taps, dies, bolts etc to make you one…
cheers john
Manchester..

 

[pe2dave]

This has all got unnecessarily complicated….the cost of buying a die etc to do the job would be more than value of the part, and probably never used again.
I would be happy to make you one if you send me the parts you have.
I have all the taps, dies, bolts etc to make you one…
cheers john
Manchester..

Quite agree John, hence the request.
Do you have a #12 UNC die too? That seems to be the oddity?

 

[John Hall]

Yes I have all the tools required…I think it is more likely to be BSW, but I have both..
UNF and UNC were not usually used for tools unless it’s American..

 

[pe2dave]

Yes I have all the tools required…I think it is more likely to be BSW, but I have both..
UNF and UNC were not usually used for tools unless it’s American..

Which I think it is (American) Sent a pm John.

 

[pe2dave]

Yes I have all the tools required…I think it is more likely to be BSW, but I have both..
UNF and UNC were not usually used for tools unless it’s American..

Many thanks to John, I now have a working beam compass (points or super-slim pencil - thanks again John).
IMHO very elegant in polished brass!
Up to 56" diameter - more than I'll likely want!

 

[Inspector]

Compass looks great. John what did the thread end up being?

Pete

 

[John Hall]

Sorry…I’d have to kill you…
7/32” BSW….which I had….
A. 12-24 UNC may have fit, but thats one I haven’t got..
Cheers Pete..

 

[Inspector]

Thanks for the quick and merciful death. ⚰

The recently departed
Pete