# DIY tangential tool | Diamond Tool Holder and plans in video description



## celsoari (Jul 17, 2020)

How i made my tangential tool / Diamond Tool Holder:


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## ShopShoe (Jul 18, 2020)

I like your version of this tool holder.

I enjoyed some of the things you showed in the video and I will use some of those techniques in the future.

Thank You for posting,

--ShopShoe


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## BaronJ (Jul 18, 2020)

Hi Celsoari, Guys,

This is my interpretation of the "Tangential Lathe" tool.






The carbide tool bit was ground using a diamond plate.





This picture shows a 10 thou cut in EN1 done using the tool.





The drawing shows a dipped section on the top.  This was done in order to allow back rake to be put on the tool bit should it be necessary.  I didn't add it to my original tool holder.


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## awake (Jul 19, 2020)

Nicely done, both of you. Question - Baron, it looks like yours is set up such that it can only do a left/right turning cut, not a facing cut (without re-adjusting the tool holder).

FWIW, I made a tangential tool holder that angles both left and forward, allowing it to both turn left/right and face without moving the tool. The attached pictures are not great, and for some reason I didn't snap one of facing (and I'm too lazy to go make one right now), but hopefully you can see how it presents the corner such that it can face and turn at the same time. As a result, this is the tool that lives in my toolholder 90% of the time.

Celsoari, I can't tell for sure if yours does the same thing as I describe above - it looks like it might?

Note that my version is kinda a hack job, nowhere near as nice as either of the ones above!!


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## celsoari (Jul 19, 2020)

awake said:


> Nicely done, both of you. Question - Baron, it looks like yours is set up such that it can only do a left/right turning cut, not a facing cut (without re-adjusting the tool holder).
> 
> FWIW, I made a tangential tool holder that angles both left and forward, allowing it to both turn left/right and face without moving the tool. The attached pictures are not great, and for some reason I didn't snap one of facing (and I'm too lazy to go make one right now), but hopefully you can see how it presents the corner such that it can face and turn at the same time. As a result, this is the tool that lives in my toolholder 90% of the time.
> 
> ...



My tangential tool is angled 12 degrees forward and to the left. Allows roughing to the left and facing.
I really liked the roughing and finishing that is on the machined part


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## BaronJ (Jul 19, 2020)

Hi Guys,

Thank you both for your nice comments 

You are right it cannot do a facing cut without rotating the tool about 75 degrees.  Though it can get into left or right corners and leave a small radius to prevent stress risers.

I made mine in response to posts on this forum by Niels Abildgaard.  Who I think was giving away pieces of square carbide in order for it to be used in his design.  Mine is tiny by comparison, I used a length of key steel for mine.


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## awake (Jul 19, 2020)

All of which proves that there is more than one way to skin this particular cat, and there are some pluses and minuses that may come with a certain design. I don't have to move anything to face and turn, but I do have to change tools to get a nice radius for stress-riser-free inside corners.

Which makes me think - maybe the best of both worlds would be to set up a holder that holds a round tool angled both left and forward. Hmm ... I've been thinking for a long time that I need to make a tangential holder for my small lathe ... maybe a new project to add to the list!


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## BaronJ (Jul 20, 2020)

Hi Guys,

Just as a point of interest.  I've found that 10 thou is about the maximum DOC you can take without forcing the toolbit down in the holder.  Though it produces a glass like finish and can take a really fine cut very suitable for a bearing fit.


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## awake (Jul 20, 2020)

Duplicate post ...


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## awake (Jul 20, 2020)

Baron, interesting results, and makes me want even more to try working up a design like yours using 3mm tooling.

For comparison, my hack job version uses 1/4" square tooling. With it I can take .025" easily - which seems to be the "sweet spot" for my lathe, using any tooling, when I am reducing a piece to size. I can take a heavier cut - say, .050" - but the lathe begins to complain. I can also take a lighter cut, but depending on material an extremely small DOC can be unpredictable. For example, in mild steel, I can take off .002" DOC with predictable results, but if I try to shave off .001", I may get more or less than that - just too little tool pressure, maybe, or maybe too much slop in this old lathe.

It would be interesting to see if your design let me take that fine a cut with more predictability!


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## BaronJ (Jul 20, 2020)

Hi Andy,

Taking really fine DOC requires a very sharp tool and well adjusted gibs.  I find that vibration from the motor causes very slight patterning on the work when taking next to nothing off.


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## Steamchick (Jul 21, 2020)

Thanks for the tips - and cents on tips! My (crude) diamond tool holder - made a few years ago - lives in the 4-way tool post as with a very sharp tool it will take 2 thou. In brass, but the the lathe groans and I have to slow the feed rate. But I like the idea of using a round bit, although I have an 'old faithful' bull nosed carbide tipped tool that does all my heavy maichining very successfully. So the diamond bit does sharp-cornered shaped parts and single thou finishing. I also made a sharpening holder, but it's so good I hardly ever need to sharpen the tool bit. Maybe because I don't  do much heavy cutting on tough steels, or cast materials? I like the geometry of the diamond tool holder, but is the same advantage necessary on a round tool? The corner will be a nice large (Low-stress) corner of slight eliptical form...? (Spell check called this "elitist" ... ! ).
Well done for these tips!


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## Steamchick (Jul 21, 2020)

For "cents" read "comments".


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## BaronJ (Jul 25, 2020)

Steamchick said:


> Thanks for the tips - and comments on tips! My (crude) diamond tool holder - made a few years ago - lives in the 4-way tool post as with a very sharp tool it will take 2 thou. In brass, but the the lathe groans and I have to slow the feed rate. But I like the idea of using a round bit, although I have an 'old faithful' bull nosed carbide tipped tool that does all my heavy machining very successfully. So the diamond bit does sharp-cornered shaped parts and single thou finishing. I also made a sharpening holder, but it's so good I hardly ever need to sharpen the tool bit. Maybe because I don't  do much heavy cutting on tough steels, or cast materials? I like the geometry of the diamond tool holder, but is the same advantage necessary on a round tool? The corner will be a nice large (Low-stress) corner of slight eliptical form...? (Spell check called this "elitist" ... ! ).
> Well done for these tips!



Gmorning K,

Its nice to be able to get those smooth rounded corners, and this tool does that with ease.  Certainly its nicer in respect of delicate or fine work.


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## goldstar31 (Jul 25, 2020)

I'm sort of aiming for - as Martin Cleeve described years ago- barely perceptical swarf. The stuf which will crumble between the fingers without having to pulled out with a watchmaker's loup and a fine needle.

Personally, I'm too shaky to hone by hand and rely on 'something mechanical'  Grumbling slightly, I got a taper cup Aloxite wheel with 60 grit. That's not fine enough.

As for 'rounding off' lathe tools,  I have in mind the Jim Whetren  gadget to fit on my 'Worden' grinder- which is in construction. 

My thoughts for the day

Cheers

Norman


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## BaronJ (Jul 25, 2020)

goldstar31 said:


> I'm sort of aiming for - as Martin Cleeve described years ago- barely perceptible swarf. The stuff which will crumble between the fingers without having to pulled out with a watchmaker's loup and a fine needle.
> 
> Personally, I'm too shaky to hone by hand and rely on 'something mechanical'  Grumbling slightly, I got a taper cup Aloxite wheel with 60 grit. That's not fine enough.
> 
> ...



I thought you used a shear tool like me for ultra fine cuts !  Nearly as good as grinding.


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## jack620 (Jul 25, 2020)

goldstar31 said:


> I'm sort of aiming for - as Martin Cleeve described years ago- barely perceptical swarf. The stuf which will crumble between the fingers without having to pulled out with a watchmaker's loup and a fine needle.



Then this is what you need Norman. These are designed for aluminium, but work very well on mild steel too. The swarf that comes off these is like fluff.

carbide inserts


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## goldstar31 (Jul 25, 2020)

jack620 said:


> Then this is what you need Norman. These are designed for aluminium, but work very well on mild steel too. The swarf that comes off these is like fluff.
> 
> carbide inserts


I'm a bit old fashioned. Yes I've been 'into carbides' since- well the beginning of WW2.  Again, I helped in the research into cuttings and breakages in very abrasive acoustic tiles and Ive eve n been to Reutte in Austria or is Bavaria where the stuff is mined.  Not impressed- sorry.
I went back to Holzapffel where he describes really fine finishing. He used walrus hide
Trying to emulate the classicists, in engineering, peope like Sparey talked of a 'a pinch of diamond dust', whilst  G H Thomas talked of  producing gleaming facets and Tom Walshaw.
Well, read it up but today,  grades of synthetic diamonds pastes are quite cheap and so are things like diamond wheels.

Well that is my thoughts


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## jack620 (Jul 25, 2020)

goldstar31 said:


> Not impressed- sorry.



I think they've improved a bit since WW2.


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## goldstar31 (Jul 25, 2020)

jack620 said:


> I think they've improved a bit since WW2.



I'm 90, I was a teenager in WW2 and in battle dress a couple of years after the end.

That was when I was playing with 12" to the foot engines that people are making replica of now.


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## terryd (Jul 26, 2020)

Hi all,

It's interesting to note that tool holders similar to the 'Diamond' holders now available and examples being shown here were being used in the 19th Century.  I have a facsimile of a Victorian treatise on engineering tools and machines which illustrate two different examples of such tool holders.  My facsimile is of the eighth edition of the book published in around 1880 so it is probable that such devices had been around long before then.

TerryD


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## goldstar31 (Jul 26, 2020)

TerryD
I've 'prattled on'  probably since the 1880's  about 'Turning and Mechanical Manipulation' by Charles Holzaffel.  I bought the set of books which were re-printed ? Lindsay Books but were from the internet.

A bit like Mrs Beeton's Cook books which say'First Catch your Pheasant as these set mention using walrus hide and shark's skin-- but a great read.
Of course the Holzapffels were part of 'Maudsley and his factory. 

Yo- before u see I did all this - before I was 17------1947, when I studied Economic History as part and parcel in what could laughingly be described once as 'Political Economy'.
Another great read is 'Moon Beams of a Lesser Lunacy' by Stephen Leacock who was Emeritus Professor of Political Economy at McGill University.  I probably say=t where George Stephenson's son- Robert sat in Newcastle's Litt and Phil Library before going from my office to study at night at college- like him

Norman


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## terryd (Jul 26, 2020)

The book I have, which was a standard text book, is entitled " Workshop Appliance" and subtitled       
 " - including descriptions of some of the gauging and measuring instruments, hand cutting tools, lathes, drilling, planing and other machine tools used by engineers" (the Victorians loved their subtitles) by CPB Shelley who was a professor at Kings College, London.

I have another interesting text facsimile by the same man with another author which is called "The Whitworth Measuring Machine" which is as much a treatise on the methods of taking very accurate measurements as it is a description of Whitworth's various measuring instruments, especially the 'millionth' comparator.  It is a fascinating view of the Victorian Engineers methods.

TerryD


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## justintime (Jul 26, 2020)

Steamchick said:


> Thanks for the tips - and cents on tips! My (crude) diamond tool holder - made a few years ago - lives in the 4-way tool post as with a very sharp tool it will take 2 thou. In brass, but the the lathe groans and I have to slow the feed rate. But I like the idea of using a round bit, although I have an 'old faithful' bull nosed carbide tipped tool that does all my heavy maichining very successfully. So the diamond bit does sharp-cornered shaped parts and single thou finishing. I also made a sharpening holder, but it's so good I hardly ever need to sharpen the tool bit. Maybe because I don't  do much heavy cutting on tough steels, or cast materials? I like the geometry of the diamond tool holder, but is the same advantage necessary on a round tool? The corner will be a nice large (Low-stress) corner of slight eliptical form...? (Spell check called this "elitist" ... ! ).
> Well done for these tips!


Elliptical is spelled with 2 Ls.


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## Steamchick (Jul 26, 2020)

Yesterday I was cutting 0.001" for the final finish cut on a work-piece in Mild steel. With slow hand feed the finish (on return - taking off the peaks at about half the cutting feed) was better than fine emery polish - as I needed for painting. And that with a sharp-pointed Diamond tool. (Not dressed on the tip with a stone slip). 
I also needed the sharp corner when I made a 1/4" x 40 ME adaptor for boiler testing today. (screws into a boiler bush to seal with a fibre washer). Now off to "the club"  - City of Sunderland Model Engineering Society Ltd - to test some old boilers! (wives excluded!).


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## Steamchick (Jul 26, 2020)

justintime said:


> Elliptical is spelled with 2 Ls.


Thanks, I love to learn. - Too few people today seem to be able to give feedback so we can learn and improve. (I have probably changed the spell check with my error! - Now how do I find out and fix that?).
Cheers, "just-in-time"...


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## Steamchick (Jul 26, 2020)

eliptical, elliptical. The spell-checker has got it right, so it's just me that is wrong (again?).


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## BaronJ (Jul 26, 2020)

Steamchick said:


> eliptical, elliptical. The spell-checker has got it right, so it's just me that is wrong (again?).



I wouldn't worry about it, winblows cant spell anyway !


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## L98fiero (Jul 27, 2020)

terryd said:


> The book I have, which was a standard text book, is entitled " Workshop Appliance"



It's available at Workshop appliances: including descriptions of some of the gauging and measuring instruments ... : Charles Percy B . Shelley : Free Download, Borrow, and Streaming : Internet Archive

[/QUOTE]I have another interesting text facsimile by the same man with another author which is called "The Whitworth Measuring Machine"[/QUOTE]

And it's available at The Whitworth measuring machine : including descriptions of the surface plates, gauges, and other measuring instruments, made by Sir Joseph Whitworth, bart., C.E. F.R.S. D.C.L. LL.D. &c. : Goodeve, T. M. (Thomas Minchin), b. 1821 : Free Download, Borrow, and Streaming : Internet Archive

There are a lot of these old, out of copyright books available, thanks for pointing out the titles!


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