# Another Reason to buy or make a diamond tool holder



## cfellows

For those of you who have been riding the fence on how useful a diamond (tangential) tool holder is, maybe this will win you over. I saw on another website, can't remember which one, where a fellow had ground a round 1/4" HSS toolbit at a 30 degree angle and mounted it in his tangential tool holder. The result was the ability to make cuts similar to the small, round carbide inserts.

I thought it was a great idea, but my homemade tangential tool holder won't hold a round tool bit, so, I chucked up a 1/4" square high speed steel bit and turned the end of it round with a carbide cutter. A toolpost grinder would have worked as well. The result is about as slick as can be. Here are pictures of the cutter mounted in the tangential tool holder and several of the cuts I made in brass.












Chuck


----------



## Blogwitch

Very nice Chuck, and very rarely do I fault your work.

Because the cutting face is on an angle, and not flat, your cutting profile is in fact an elipse, not a true circle. It might be OK for getting nice surface finishes, but could give some weird results if you tried to use it for profiling, where a true arc usually looks and blends in perfectly.


John


----------



## Nickle

Looks Great Chuck. I was thinking of trying this style of tangential cutter myself. I was intending to drill holes on the appropriate angle in a block for a toolholder and start using up my stash of old drill bits. Like John says, it wont cut a perfect circle but it should give you a great finish.

Cheers,

Nickle


----------



## New_Guy

its an oldy but a goody i got a Herburt or a Ward tooling catalog from the 40s awhile ago, they had tangent holder and they were far more technical than what you can get these days incorporating a screw to adjust center height and came in square, round or triangular carbide blanks 

by the way i love the simplicity of using carbide to turn HSS "i cant do this because i have no long series tap" no problem turn the clearance yourself on a gun tap Thm: so simple i love it!


----------



## Lew Hartswick

I did some playing around with those a few years ago. If you'd like to see them check:
home.earthlink.net/~lhartswick look at the two Diamond --- There are a couple files
that got put in the wrong folder but ignore them.  Someday I'll fix that. 
  ...lew...


----------



## cfellows

Bogstandard  said:
			
		

> Very nice Chuck, and very rarely do I fault your work.
> 
> Because the cutting face is on an angle, and not flat, your cutting profile is in fact an elipse, not a true circle. It might be OK for getting nice surface finishes, but could give some weird results if you tried to use it for profiling, where a true arc usually looks and blends in perfectly.
> 
> 
> John



Hey John, didn't really think of this as criticism so much as an observation. I did realize that the cutting edge reflects an elipse rather than a circle. Although there are occasions where a circular profile is required, in many cases, for me at least, an eliptical profile will work as well. And, as you stated, it still gives a very smooth finish. 

Chuck


----------



## Omnimill

I made my first tangential tool holder and it works great but I also ended up buying one and this takes round HSS as well as the square stuff. It does, as you say make very nice finishing cuts Chuck.

Vic.


----------



## FIXIT

Looking with interest at this type of tool holder i think i will also make one as i think that it would be a little more rigid than the standard one on the Taig,

I don't have a QCTP as it's just as easy to change the whole thing , as its basically only a one inch square bar and i have made about eight of them allready with various tools setup in them with one having a 'boat' so it;s easily adjusted.

Anyway back to the thread , it looks to me that the cutting force would be directed at a down angle rather than the conventional 90 deg angle through the tool and post reducing the 'spring in the little machine.

So! thanks for the pictures Chuck and please comment on anything you think i also should look out for and advise me of the angle the the tool is in the post.


Vic where did you perchase your one.


Any comments from anybody else would be more than welcome.


Steve


----------



## cfellows

Here's a link to a build article for the tangential holder. Or you can just do a search for "tangential tool holder"...

http://www.gadgetbuilder.com/ToolHolders.html#Tangent

I used the angles suggested by the build article - 12 degees to the side and 12 degrees front to back. You can do it one of two ways and I've done it both ways. You could first mill the whole side of the blank to a 12 degree slope, then cut a slot 12 degrees back from the front into the sloped side. Or you could first mill the entire front to a 12 degree slope, then cut the slot 12 degrees to the side. The clamping screw will need to be on whichever side you mill the slope on.

Chuck


----------



## owenh

hmmmmmmmmmmmm I wonder how small a piece of round the commercial tangential holder will grip? must find out. A bit of drill rod of the right size hardened up to cut whatever sized radius. I wonder if a negative rake would cut brass? then the arc would be a true circle. You never know where an idea is lurking, just what I like about these sites.
Owen


----------



## shred

I suppose if you really needed a circle, you could turn a ball on the end of the cutting bit, then carefully grind that halfway down. If I remember my geometry, any planar section through the center of a sphere ought to be a circle. That seems like a lot of work, there's probably an easier way to generate it.


----------



## Omnimill

Here you go Steve:

http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=2&Itemid=17

They have a UK agent now so no import duty etc to worry about.

The only problem I _had_ was that I sharpen all my tools on a belt sander and the supplied sharpening jig is for a bench grinder, luckily Chuck also sharpens his tools on a belt and published details of his tangential grinding rest/jig on this forum - Thanks Chuck! Thm:

Vic.


----------



## steamer

Hi Chuck,

What kind of carbide are you using to cut HSS?  edge geometry...ect.  enquiring minds want to know....ie I would love to do that.

Dave


----------



## Tin Falcon

Lathes and lathe work
Paul Nooncree Hasluck
http://www.archive.org/details/lathework01haslgoog
talks about those tool holder IIRC on page 437 
Tin


----------



## Niels Abildgaard

Another home-made tangential tool.
Cheap and much stiffer than anything comercial


----------



## cfellows

steamer  said:
			
		

> Hi Chuck,
> 
> What kind of carbide are you using to cut HSS? edge geometry...ect.  enquiring minds want to know....ie I would love to do that.
> 
> Dave



Dave, the carbide inserts are TPG321 or TPG322. The 1 or 2 on the end signifies the radius of the cutting tip, 1 being the smaller radius. These are triangular, with positive rake and can only be used on one side. There is no center hole so they have to be held on with a clamp. I made my own holders and buy up the inserts on ebay whenever I can find a deal. They are usually pretty inexpensive. I've also bought a bunch of reground inserts which work well and were cheap.
Chuck


----------



## cfellows

Niels Abildgaard  said:
			
		

> Another home-made tangential tool.
> Cheap and much stiffer than anything comercial



I like that. What is the angle, front to back that holds the insert?

Chuck


----------



## Niels Abildgaard

15 Degree


----------



## f350ca

Hi
New here, a great wealth of information and ideas.
Has anyone tried making a tangential tool holder to use in a shaper. Would seem to be a natural, with built in back rake.
Might need to use Niels clamping method to with stand the cutting forces.
Greg


----------



## Dan Rowe

Greg,
I just gave my commercial tangential holder a try in the shaper and it works great. It never occurred to me to try it.

Thanks and welcome to the forum.
Dan


----------



## f350ca

Dan
The shaper doesn't get used a lot, but I guess building a holder just got moved up the list.
Greg


----------



## Niels Abildgaard

Another type of holder.
Cannot choose so I use both


----------



## DICKEYBIRD

Niels, aren't you the clever one! ;D 

I really like the one on the left. Is there an allen head draw-bolt that pulls the tool holder against a channel in the body? How did you make the square hole for the bit? A broach?


----------



## Niels Abildgaard

Hello DickeyBird 

Glad You like the tools. 
Right one is made by EDM.
Left is a simple turning,sawing .milling and threading job.
I will show some pictures and please ask if unclear.

Happy chipmaking


----------



## DICKEYBIRD

Thanks Niels. Sorry, I just realized I typed left when I meant right. :

Do you have any pretty CAD renderings of the one on the right? 

Cheers,
Milton


----------



## Twmaster

Tin Falcon  said:
			
		

> Lathes and lathe work
> Paul Nooncree Hasluck
> http://www.archive.org/details/lathework01haslgoog
> talks about those tool holder IIRC on page 437
> Tin



that only goes to page 275....


----------



## Niels Abildgaard

DICKEYBIRD  said:
			
		

> Thanks Niels. Sorry, I just realized I typed left when I meant right. :
> 
> Do you have any pretty CAD renderings of the one on the right?
> 
> Cheers,
> Milton



Sure


----------



## Twmaster

Chuck, that is pretty slick. I really need to make a similar tool for my little lathe. That will be a good project for this weekend in the workshop. I think I have some steel square stock on the shelf.


----------



## Twmaster

Quick question...

How critical is that rake angle? I see some of you have your tool at 12° and some of you have it at 15°.

I don't think I have a protractor small enough to get that angle exactly at that small number like 12 or 15. I have gauges for 30, 45, 60, 90 etc...


----------



## tel

I don't think the angle is real critical within reason - I think I measured mine by the tried and true 'about there' method. It works fine.


----------



## Omnimill

I think the commercial ones are inlined 12° forward and 12° left. Thats what I also used for my home made version and they both work well.

Vic.


----------



## 8ntsane

Interesting tool holders
I have been looking at the pics, and reading of course.
Maybe its the angle of the shots of the pics. I can see the 12 to 15 degree angle front to back, but at appears that in some pics, of the tool holder Niels has posted, it apears that it dosnt have the side angle to the left? I was wondering if the side angle is absolutly nesessary?

If some of you omit that angle, does the tool work equally


well? It appears to to me the cutter would be introduced to the work at totally different angles when tuning and facing with the extra side angle.

Can someone verify this for me?

Thanks Paul


----------



## Niels Abildgaard

Hello Paul

If You make a tool holder with 15 degree tilt as shown there will be very close to 12 degree clearance on the two cutting edges. 

Regards

Niels


----------



## Niels Abildgaard

Please tell me what version You will prefer ?
In my view the best tool-bit size is 5 mm or 3/16 inch.
Smaller is difficult to hold and bigger takes longer to regrind.
My favourite HSS is SeCo WKE 45 and price is more or less identical for 4,5 and 6 mm sizes.
The distance from top of compound slide to lathe centerline is very close to 25 mm on my Boxford and I guess it is 25.4 on a South Bend.
Can I have some information from other types of lathes used by members of this forum?
First five answer will get one free if I go commercial.
My wirespark friend is going to make a 5 mm bit from carbide and if this works I have primary cutting tools for rest of my life.


----------



## Omnimill

Hi Paul,

On the one I made (and bought) the shank is at 90 degrees to the lathe bed so you need both 12 degree side and back relief. On the version Niels has made the shank is at an angle to the work - I'm guessing 45 degrees.

Vic.

There is some more info here, "A Tangential Tool Holder for the QCTP"

http://www.gadgetbuilder.com/ToolHolders.html

And here:

http://www.model-engineer.co.uk/forums/postings.asp?th=29818


----------



## Ned Ludd

Hi Guys,
I thought you might like to see another version of the Tangential tool that was made by a friend of mine.
Ned


----------



## Omnimill

Looks good Ned!

I wonder if anyone has made something Flycutter style for a Vertical Mill? I'd certainly like to try using some of my round HSS if anyone has any ideas for a design.

Vic.


----------



## phlegmatic

In this Swiss clip you see a tangential tool holder, that I never seen before? Is it commercial?

[ame]http://www.youtube.com/watch?v=4w8EB2rBU0I&feature=mfu_in_order&list=UL[/ame]


----------



## Niels Abildgaard

Hello Phlegmatic

Thank You for the video that brings back memories from the four years I lived in Basel,Switzerland.
The quick change holder is a TRIPAN and absolutely the best and most expensive if You can find some.
The tools are made by IFANGER that have a catalogue on the web.

Kind regards

Niels


----------



## phlegmatic

thanks


----------



## lazylathe

I love the swing over tailstock on that Schaublin!!!!!

VERY COOL!!!!


----------



## Niels Abildgaard

Final (?) design for tangential holders for my Boxford (Southbend clone).
Pure Lathe work
The one shown takes 4 mm toolbitts (Because I had two 4 mm bitts ) .
Body is milled in the lathe.
Two round holes and wedges are lathe work.
The tool cuts 3.5 mm deep in mild steel,makes blue chips and everything OK.
Prototype was made in 3.5 hours .
Next takes less than two.


----------



## Niels Abildgaard

Have made and used three types of holders.The easiest to make is the uppermost.Toolbit slips when going gets tough.
The middle one was inspired by an Australian device and can be made with a milling maschine.Mine is showing weakness in the grip area and this indicates need for a better material and heat treatment.
The lower is by far the best but I need the good will of my wirespark-er friend to make it.
Not everybody has access to such things.
The lower one gets some 5 mm square tool bits from Fagersta WKE 45 and easily eats silversteel with a depth of 4.5 mm and a feed of 0.003 inch per rev on a Boxford lathe
Next test is to try to repeat that with a carbide stick but much faster.


----------



## Ned Ludd

Hi Niels,
I was given a stick of solid carbide by a friend at SMEE to use in my Tangential tool. It works fine but does need a noticeable radius at the working corner to prevent chipping it. 
He, the friend, uses his to turn the case hardening off gearbox shafts so that new inner tracks can be fitted with new bearings. It seems that modern gearboxes have bearings running on bare shafts, which soon wear out! Progress, yer right! 
Ned


----------



## Niels Abildgaard

Hello Ned Ludd

My first carbide test went wrong exactly because the corner radius was to small.
Another reason was that when tool bit is canted 15 degree as shown the side clearances are 12 degree which is way to much.
I am making a new holder where tool tilt angle is 12 degree giving 9 degree clearance angles.
Carbide inserts normally are working at 5 to 7 degrees clearance but going steeper still than 12 degree for the tool is next to impossible if I want to keep a Small toolbit-section stable and that is the whole point of the exercise.
Another strategy can be to facet the cutting edges ever so sligthly as shown.


----------



## Ned Ludd

Hi Niels,
Slightly less top rake helps too.
I shall try your faceted grind, although we are starting to get away from a tangential tool's main advantage, ease of sharpening.
Ned


----------



## Lockstocknbarrel

Niels, :bow:
Fantastic CAD drawing.
May I ask for entry to competition EMCO Super 11 lathe........................ :big: :bow: :bow: :bow:
Kindest Regards
Beagles


----------



## Niels Abildgaard

Hello Beagles

Your Emco is no match for my Boxford on the Rock,but if You care to measure the distance from top of compound slide to centerline You can borrow the second best of my holder family and try for Yourself.


----------



## hopeless

I've been watching this thread because I bought a tang. tool here in Oz when I first started machining 10 years or so ago (found brazed carbide wasn't the best option) and used it almost always. Then I started to learn how to sharpen and shape HSS tools and now it spends time in the cutter tray. It still gets used but not as often and I still have some carbide tipped tools but usually to rough down a large lump close to size then out with the HSS tool. The main reason I bought the tang. tool was the ease of shapening and I could use round stock as well  though I haven't as yet but may try some after reading this.
Pete


----------



## Niels Abildgaard

Hello Pete

I see the main advantage in the stiffness.Compare the loadpath from tip of carbide stick to top of compound slide.
The homeground carbide did 4.5mm deep and 0.003 feed at 1000 rpm on some 100 mm scrap iron yesterday.It still looks and cut as a new insert.


----------



## Lockstocknbarrel

Hi Niels,
Height is 23mm.
How can you not like this sight attached...........
Go on say you wish you had one too.......go on........go on.
Kindest Regards.
Beagles


----------



## Niels Abildgaard

Hello Beagles

I do like the lathe,but I am to old to divorce my Boxford.
Are the bedways hardened?
The crossslide with lot of T tracks would be handy on a Boxford also.
You can borrow a tangential holder from me but You will have to remove cirka 2 mm from underside.Putting the toolbit 2 mm lower is not enough for clearance reasons.

Kind regards

Niels


----------



## Niels Abildgaard

Latest design for a tangentialholder using 4 or 5 mm square toolbits of carbide or HSS.
It was tested yesterday and works very well .The idea is that the block can be any kind of banana iron and the pull in thing is made from a 12.9 quality Allen bolt.
This is as strong as any unhardened steel normal mortals can get.
The tool fore and aft angle is 12 degree giving clearance angles around 8,5 degree for the cutting edges.


----------



## lazylathe

Hi Niels,

Are you going to be making these available for members here to purchase?
I would be interested in trying it out on the Myford!

Andrew


----------



## Niels Abildgaard

Hello Andrew

My wife is ill so I go to the workshop and improve the design to ease my mind.
Going commercial is not an option for the time being and the uppermost model is very easy to make Yourself.
It is not a heavy duty thing compared to my favourite version but still very good.
It eats 3.5 mm wide swarf at lowest axial feed of my BoxRock.If I try to up feed it chatters and lower tool and my favourite pull inn thing do not.
Your Myford has not power enough to go into that country.
Let us make a design exercises for a suitable 12 degree holder for a Myford using 4 mm square bits.
First step 
Measure height of centerline over compound surface.It is 25.14 mm on my Boxford.
Put a piece in the lathe and turn it round and measure diameter and divide by 2.
Remove toolholders and and put top of compound slide under Your round thing and use feeler gauges to measure the missing distance.Calculate the wanted dimension.
Non Myford or Boxford owners are welcome to join the game.


----------



## Peter.

I made a couple of tangential tools by brazing a stub of stellite onto a steel shank which was milled at an angle on the end to receive it. They work fantastically well. I've just about worn one out and the other I gave away but I'm making a few more shortly.


----------



## Niels Abildgaard

Hello Peter

Have become Stellite/Tantung addicted and like to show my sharpening procedure.
It cuts very well and fast for a long time without the cooling water mess.
Carbide can do the same but is not quite so easy to regrind.
First picture is my present bid for the ideal amateur cutting tool.
Name is TanTool, very original.
The Tantung 4.76 mm bit is tilted 12 degree giving 8.5 degree clearance on cutting edges.
Top of block is exactly on lathe centerline making adjustment easy.
One of the bit edges is rounded as shown.

The rake is  ground using the TanTool as holding tool.
I find that the fore and aft rake angle is not that important .20 degree looks fine to me and cuts well.
More follows


----------



## Niels Abildgaard

Hello Peter again

A little top honing is not harmfull and easy to do.
The 8.5 degree clearance angles is really to much.Something like 5 to 7 degree makes tool edge everlasting and as I do not cut/feed very aggressively it is OK
Facetting is done as shown and last picture is ready to cut.
Regrind ca 2 minutes and a new one ca 5 minutes.


----------



## hmember

Regarding the holder shown in the pic in the reply immediately preceding this one, I gather that it offers the most rigidity/stability of the different designs discussed in this thread. Obviously it requires an EDM to make the square hole in which the HSS sits.

Just wondering, on behalf of those of us who have mill and lathe but no EDM . . . what if one made a circular hole instead of a square one? Granted, it wouldn't be as nice as one which secured the cutter using all four sides. But one would have two sides (as milled into the main/biggest piece) plus the opposing edge of the cutter by which to grip it.

In other words, the HSS cutting piece would contact the main body of the holder on the usual two sides as always (darkened sides in crude drawing) and the pull-thru piece of the holder would contact the cutter at one point/line (darkened dot).

Might this be enough to secure it?

See crude drawing . . .


----------



## Niels Abildgaard

Hello Hmember

Very interesting and sent me thinking.
Start make parts as shown,put in a good quality bit,give it a real fore and aft pressure and make all the nice clearance milling-gs afterwards.And please tell us how You improved the procedure?


----------



## hmember

No claim to have improved the procedure. Just wondering if with only lathe & mill, one could make an acceptable (not improved) holder along the same idea of the one that requires the square hole. Point being, I suspect many machinists don't have a way to make the square hole themselves.

The attached picture shows more closely what I'm thinking, as the largest component of the holder would be pretty much unchanged i.e., it would have a right-angle notch to fit the HSS.

No claims, just musing . . .


----------



## Niels Abildgaard

Hello hmember

Your scheme will work and I put in a sketch seen along the toolbit .
Another possibility is to go the press way as shown on second picture.


----------



## hmember

Exactly. And your pictures illustrate the concept nicely :bow:


----------



## Niels Abildgaard

My latest and most easy to make tangential tool holder.Sawing 30 *26*90,drilling a 14 mm hole for holding down,a 20 for flex ,a 6.7 mm hole tilted 15 degree and slitting with an angle grinder. 
Insert intended toolbitt .Pressing 14 tons
Restore slit with angle grinder.
Drilling and threading for m8 clamping screw.
Make beatifull and finalize heigth .25.14 mm
Very fast and high clamping power

Kind regards


----------



## Niels Abildgaard

Pictures from manufacture of a press formed tangential holder.
 First is pressing with intended tool bit in place
Last is the tricky step.Eliminating spring back from pressing around tool bit without overdoing.
Not easy and a 50% scrap rate is OK until a smart guy describes how to do it.
If  not done accurately tool will be a pest  to use.
Clamping screw is there to clamp and not to deform holder


Kind regards

Niels


----------



## Niels Abildgaard

Toolamania is incurable but harmless


----------



## ConductorX

Niels Abildgaard said:


> Toolamania is incurable but harmless


Beautiful helper you have there.

I am addicted to brake fluid but I can stop anytime.  woohoo1
"G"


----------



## Niels Abildgaard

The latest pressed  TTH  was tried with a homemade stick of carbide from a broken endmill,my beloved Crobalt and a piece of Swedish WKE45 HSS that by common consent is worlds best.
All three made nice surface  on steel shown ,but carbide was nicest (Outher band )and WKE45 HSS (innermost band) was  worst,but still useable.
The subject material was from a scrap container at a firm that makes fishing trawl vanes.Steel price matters


----------



## vtsteam

What about making the toolholder in two halves, forming the groove in each, and joining them together by fasteners or braze?


----------



## Niels Abildgaard

Here are more pictures from my search for best cutting material.
First is from outher to inner 

Selfmade carbide stick,Crobalt and WKE45 HSS.

Second and third picture

Cabide, Crobalt , WKE45 HSS and ASP 60 Powder HSS.

Visually there are not much differense and using my finger nail as roughness tester Crobalt is winner,but close.


----------



## Niels Abildgaard

First picture shows my first CCMT 0903 holder plus start of a better looking  brother.

The bottom of the new one was machined by the CCMT 09T3 holder in picture 2.
Depth of cut 1.2 mm;facing feed lowest possible on my Boxford and speed as fast as I dared ca 500 rpm.

The top was machined by a squeze manufactured tangential holders with a homesharpened carbide stick.Depth of cut as before and removed 7 and 4 mm and still cuts well.

Next picture is a close up.

Homebrewing tangential  carbide is legal,works well and is cheap.

Last picture show finished CCMT holder .


----------



## Niels Abildgaard

It is nice that the pressed tangential holder and carbide stick work as well as anything  one can buy. 
I  needed to find an excuse for making a new CCMT holder for some ten Swiss Lamina CCMT 09T3 ,because I already have more than one of  these amateur cutting tools.
I feel having more than one of any kind of tool is greed .
Luckyli economy gave a valid reason.
The ten swiss CCMT`s were 15 dollars on Ebay and gives me 40 perfect rounded tool corners.
There are many nice things in this world and then there are nice Swiss things.
The homemade carbide stick was made by a wiresparking friend from a broken endmill and needs a lot of grinding and honing to get under the spark eroded skin.
Max carbide stick length on my  lathe  is 65 mm and 40 of these are usable.The two times I have had to regrind was more than1 mm each.So unless Iscar ,Sandviken etc see the shining ligth and offer suitable preground and cornerrounded stick for less than say 10 dollars,homebrewed tangential  carbide is not worth the effort.
HSS and cast Cobalt(Crobalt,Tantung ,Stellite etc) is quite another matter.
I will desribe my newest CCMT holderin a fresh thread.


----------



## RonGinger

Nice holders- how did you cut the square slot for the tangential one?


----------



## OrangeAlpine

Niels is proceeding in a direction I have decided take - making massive tool holders that sit rigidly over the saddle.  Yes, they are not quick change, but oh how nice they are!

My boring bar holder in action:



Made from 1" thick aluminum, drilled on the lathe to accept four boring bar diameters.

Here is very temporary lash-up.




Sometimes the best toolholder is no toolholder.

Bill


----------



## Niels Abildgaard

Hello Ron Ginger and Bill

The channel or slot is not cut but formed by pressing .
There are some pictures a little earlier in thread.
Do please make oneYourself,send us a picture and let us make a club to the abollishment of quick change holders.
If the server here is big enough a picture of Dog,bike, grandaugther and myself cannot harm.


----------



## Jdunbar

What angle is the bit tilted foward and is the bit ground at 30 degrees.

Thanks

John


----------



## Niels Abildgaard

Hello John

My first tangential was  15 degree tilt and that is what I recommend for first tryers.
Today I make them 12 degrees.The tool top plane angle relative to horizontal is 0 degree when I do cast iron or brass and approximately 25 degree for aluminium.
Steel somewhere in between.It is NOT very important.
There is a picture 27 of may where a homeground carbide stick is tilted 12 degrees and flat top eating mild steel.Still sharp and hungry.

kind regards
Niels


----------



## SE18

awesome, thank you


----------



## Jdunbar

Here are pictures of mine, thanks for the help.  I used a 3/16" broach which worked great to house the tool bit.  This tool works better than the quick change tool post version  that I made several years ago.

John Dunbar


----------



## Niels Abildgaard

Hello John Dunbar

Very nice shape
Where did You get the broach and is it expensive?

Can You make a couple of Photos showing Broaching.

I have neither seen or tried it.


----------



## Jdunbar

I bought a used broach for $30 to make this tool and to make a boring bar.  You simply drill an undersized hole and push the broach through using a press or vice and you end up with a perfect square hole.  The broach is a piece of HSS that starts out round to fit the pilot hole, and then is a hexagon, then square.  It is about five inches long and is tapered the entire length.


----------



## Niels Abildgaard

Due to illness, long projects are not possible but squezed tangential holders are less than 4 hours work.
It is also nessecary to go to my automechanic that has a 25 tons press and this is combined with shopping and all in all give a more pleasant day.
Excuse for making one more is that clamping screw wasted to much power deforming holder and to little for the carbide bit.Not that I have had any slips,but for safety thigthening was violent.
This is much more civilized/nicer in the newest version illustrated here.

I really need to find an evening class with a course in BETTER ANGLEGRINDING

Chatter comes at more or less the same rate of cutting as the CCMT holder shown somewhere else.This means that toolholder rigidity is not the issue anymore,but lathe design is.
Making lathe more rigid is not  a four hour job.
Wonder what lathes there are in heaven.Is it too much to hope for swiss Schaublins?


----------



## JAndrew

Hello,

Nice tool holders! I played around with these angles in Sketchup and figured: With a 30 degree ground bit and 12 degree angles on the bit the angle that is being transferred into the work is 83 degrees. So my question is what angles are used for threading with one of these tool holders to get your 60 degrees?

I don't see a real advantage to making a whole separate holder just for threading but it's certainly appealing for turning and facing.

Thanks in advance!
-J.Andrew


----------



## Niels Abildgaard

Hello Andrew

My threading is done by preformed carbide inserts,so hopefully a satisfied Eccentric Enginering Diamond User will answer.
I bought one years ago and gave it away when my homemade ones worked OK.
As I remember it the manual has a way to grind a threading tool.
Or we make a protest movement like in the CocaCola case and demand triangular  Crobalt sticks.


----------



## charlton

Hi Niels,

Thanks for all the posts about your TTH across the various forums. Do your tool holders only have a fore/aft angle or do you actually have a compound angle? From the pictures, it seems like you only do the fore/aft thing but I'm not 100% certain.

Thanks!
Charlton


----------



## Niels Abildgaard

Hello Charlton

It has only 12 degree fore and aft angle made as on photos.
This gives around 8.5 degree entrance or clearance angle  on the two cutting edges.This is the real important angles in tool grinding and we get them free and ready from toolbit manufacturer.The top plane angle is NOT very important.
Unless it is a foot driven lathe.
Make one,test it and let an old man hear about it.


----------



## charlton

Niels Abildgaard said:


> Hello Charlton
> 
> It has only 12 degree fore and aft angle made as on photos.
> This gives around 8.5 degree entrance or clearance angle  on the two cutting edges.This is the real important angles in tool grinding and we get them free and ready from toolbit manufacturer.The top plane angle is NOT very important.
> Unless it is a foot driven lathe.
> Make one,test it and let an old man hear about it.



Thanks for the clarification Niels. I'm just getting started in metalworking so I have much to learn. It'll probably be a while before I actually get around to making a TTH but I'm trying to soak in as much information as possible.  Making square holes is a foreign concept to me (except in wood via chisels) and I don't have access to a big press so it looks like I may have to utilize one of your original two-piece designs. 

Thanks for sharing all your knowledge on this subject. It's enlightening to say that least.


----------



## Niels Abildgaard

Hello Charlton

You will enjoy making things with Your hands and head.
I used around 14 tons to press the picture from 15 of April 2013 and then reground the slit.
I should have used a little more of my old brain and less anglegrinder  .
The hole for the toolbit is 6.7 mm and the slitholes 5mm.
I do not need 3.35mm times two /14 tons squeze.
3 to 4 tons will give two times 1.5 mm deformation and this is more than enough.
3  tons can be made with a car jack and two pieces of all thread.


----------



## james_III

What about this drawing, this should be doable, not sure is there enough dimensionlines, but will this work?  

View attachment SP6X6.pdf


----------



## Niels Abildgaard

Hello James

You will need to remove some  jaw material close to the cutting point.
This can be done manually on a bench grinder.
If not You cannot turn and face into a corner.
Having been used to my own creations yours look to flimsy for my taste but try.If working I was wrong and if not everybody learnt something and that small piece of iron is not very expensive.
Give us some words and pictures


----------



## james_III

Yes I agree and I might try to redesign, so cornering is possible, now this is more like chamfer tool for really small outside corners


----------

