# Diamond tool holder



## DavidR8 (Feb 13, 2020)

Has anyone used one of these?



			The Diamond Tool Holder
		



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## Spring Hollow (Feb 13, 2020)

Yes, they work great.  Very happy to have purchased them.  Very simple to sharpen the bits too.


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## Spring Hollow (Feb 13, 2020)

I should add that I can take much deeper cuts with my South Bend lathe using these than I can with a conventional holder. The only negative is the cost.


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## mikey (Feb 13, 2020)

This tool certainly does look impressive, doesn't it? Easy to grind, bits are cheap to buy and it seems to work well. Can't see a reason not to try it. I haven't seen one user who has a negative impression on these, Dave.


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## Hawkeye (Feb 13, 2020)

Why not make a project of it and make your own? Quite a few of us have done it. The first one is for my 9" Hercus. The second is on the Storebro Bruk.


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## MontanaLon (Feb 13, 2020)

Hawkeye said:


> Why not make a project of it and make your own? Quite a few of us have done it. The first one is for my 9" Hercus. The second is on the Storebro Bruk.
> View attachment 313559
> 
> View attachment 313560


I have toyed with the idea of making my own, just figuring out the geometry seems to be the hard part.


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## OTmachine (Feb 13, 2020)

It‘s geometry is copied from a Warner & Swasey box cutter.  I still have a gage tool for hand grinding the tool bits.


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## middle.road (Feb 14, 2020)

Otherwise known as a tangential lathe tool
There's several on our site also.
ToT or Joe Pie or Tom Lipton or <someone> had a video on this, which of course I can't seem to find now.
Yet another item on my 'wanna-do' list.
IIRC from the video(s) I watched, the DOC is impressive.


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## DavidR8 (Feb 14, 2020)

It’s certainly an interesting bit of kit. 
That only bit that I can’t figure is how your grind a chip breaker in the top of the bit.






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## middle.road (Feb 14, 2020)

The compound on that poor Hercus has seen some action...   


Hawkeye said:


> Why not make a project of it and make your own? Quite a few of us have done it. The first one is for my 9" Hercus. The second is on the Storebro Bruk.
> View attachment 313559
> 
> View attachment 313560


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## mikey (Feb 14, 2020)

DavidR8 said:


> That only bit that I can’t figure is how your grind a chip breaker in the top of the bit.



If you think you need a chipbreaker, free hand grind it. You will need to grind a V-shape just back from the side cutting edge; the center of the V will parallel the side cutting edge. Why not try it and see if it is effective enough that its worth your time to grind it. As an alternative to a chip breaker for stringy materials, increase your feed rate.


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## higgite (Feb 14, 2020)

Tangential tools do a good job of hogging off aluminum on my bench lathe. I haven’t tried one on steel, though. I tried cutting a chip breaker in one of the tool bits to no avail.

Rick Sparber made and published a DIY add on chip breaker that looks sorta weird but seems to work pretty well, but I haven’t made one to try myself.



			https://www.rick.sparber.org/ttcb.pdf
		











Tom

P.S. To answer your question, David, yes, I have 2 of the Eccentric Engineering Diamond Tool holders.


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## ddickey (Feb 14, 2020)

The other plus of the Eccentric Engineering made tool is that you can make a face cut without turning the holder.


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## Hawkeye (Feb 14, 2020)

middle.road said:


> The compound on that poor Hercus has seen some action...


Yeah, Dan. The only viable explanation is that it used to be a high school shop lathe. No one machinist, no matter how bad, could possible have that many chuck strikes.

IIRC, the geometry is: 15* to the left, 15* toward the work, and the tool bit ground to 30* diagonally. The radius on the cutting edge is up to preference.


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## Aukai (Feb 14, 2020)

I just mounted mine today, and made some facing, and turning cuts on an unknown steel bar,it made curls, and it does seem to work ok. Then did my first practice knurl.


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## Downunder Bob (Feb 16, 2020)

G'day Dave, Yes the Eccentric Engineering diamond tool holder. I have one and love it, it is my go to when using HSS The positives are:

1. Very easy to grind your own tools, 

2. You can use broken centre drills and milling cutters, taps, anything round, square or even hex of about the right size will work.

3. Most users report the ability to take heavier cuts than with conventional tool holders Ability to face and turn in the same setting. 

the only negative I am aware of is they are a bit pricey, but as others have said you can always make your own, but certainly worth having.


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## savarin (Feb 16, 2020)

I have a left and right Eccentric Engineering diamond tool holder.
Love em.
I've also used then somewhat unconventionally.
https://www.hobby-machinist.com/threads/80mm-long-focal-length-refractor.26212/page-2   message 54
and a better view in message 61 with a different tool bit.


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## GunsOfNavarone (Feb 26, 2020)

Man...no doubt that's a big machine they demo those 1/2" DOC runs...but I want it. The only downfall for me is I just don't want to use HSS...I know..go ahead and flame. That does seem uber versatile, I might take that plunge..
Just shot an email to them, unsure of what is best for my lathe. Since this is coming from Australia, I don't want to screw the pooch. Thanks for the lead David!


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## Illinoyance (Mar 1, 2020)

I decided to make my own.  They work great.  I started the project without even having a sketch.  It turned out to be a LH tool.  I then made the RH tool.
If used only for turning one could grind a groove type chipbreaker across the end of the bit.  Grind the groove in the other direction for facing.
I got the idea from looking at the grind on the bit for a box tool.


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## Ulma Doctor (Mar 1, 2020)

the tangential holders look interesting, i have not tried them.

a little off topic here, but
i f you got a bit of time to spare, have a look at a tool that our beloved @mikey expertly ground on his belt sander.
(this tool is being used on a small metal shaper to take ridiculously heavy cuts in aluminum)





i have seen that you are aware of @mikey 's thread on HSS tool modeling, great stuff!!!


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## mikey (Mar 2, 2020)

That tool will take that cut on a lathe, too, Mike. That was a fun collaboration we had and I'm glad it worked out.


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## Illinoyance (Mar 2, 2020)

The high rake angle and generous relief should make it a really free cutting tool.  It also makes the cutting edge somewhat fragile.  What kind of tool life are you experiencing?


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## Aukai (Mar 2, 2020)

I did a shaft with a welded slot, and cut down the weld to shaft diameter with no drama.


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## Nogoingback (Mar 2, 2020)

I also have a Diamond Tool Holder and like it.


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## savarin (Mar 2, 2020)

whoooo, niiiiiiice


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## mikey (Mar 2, 2020)

Illinoyance said:


> The high rake angle and generous relief should make it a really free cutting tool.  It also makes the cutting edge somewhat fragile.  What kind of tool life are you experiencing?



I know you were querying @Ulma Doctor but I've been using these tools for a long time now and at least under hobby shop conditions, have not had significant issues with tool life. Most of my lathe tools are over a decade old and have held up fine, and I don't baby my tools. I can see why folks think that the edges are fragile and perhaps in a production situation they might not last quite as long as a standard geometry tool. Then again, they cut so well that production would probably increase so having to hone a tool a bit more often might not be a bad trade off. In a hobby shop, edge life is not an issue with these tools but efficacy is and that is where these tools more than hold their own.


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## Ulma Doctor (Mar 2, 2020)

I have not sharpened the tool since i got it, even after hundreds of cuts


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## GunsOfNavarone (Mar 2, 2020)

They never replied to my inquiry. Anybody have any recommendation what I would need to order for my 10x22 AXA tool post? It is a bit ...I don't know....unorganized (their website) Like I said before, don't want to get the wrong thing and or forget pieces needed.


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## Aukai (Mar 2, 2020)

I'm using the .250, but there is a 5/16" also either one will do on an AXA


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## GunsOfNavarone (Mar 2, 2020)

Hmmmm...not seeing that @Aukai at 9.5mm tool overhang has a 12.7mm shank (.5")
It also has a technique for measuring, With QC at it lowest point, measure the top of the lower ledge of the holder to the center line of spindle. With a QCTP, I could have a pretty sizable number there if I wanted. Again, a bit confusing.


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## Rob (Mar 2, 2020)

GunsOfNavarone said:


> They never replied to my inquiry. Anybody have any recommendation what I would need to order for my 10x22 AXA tool post? It is a bit ...I don't know....unorganized (their website) Like I said before, don't want to get the wrong thing and or forget pieces needed.



I believe this is there US supplier.  https://secure.villagepress.com/store/items/list/group/415


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## higgite (Mar 3, 2020)

Aukai said:


> I'm using the .250, but there is a 5/16" also either one will do on an AXA





GunsOfNavarone said:


> Hmmmm...not seeing that @Aukai at 9.5mm tool overhang has a 12.7mm shank (.5")
> It also has a technique for measuring, With QC at it lowest point, measure the top of the lower ledge of the holder to the center line of spindle. With a QCTP, I could have a pretty sizable number there if I wanted. Again, a bit confusing.


Actually, there are 3 sizes that use 1/4” tool bits and 2 sizes that use 5/16”. The 8, 9.5 and 12mm tools use a 1/4” tool bit. The 16 and 20mm use a 5/16” tool bit.

I believe the largest tool holder shank that an AXA tool holder can hold is 1/2", which makes the 9.5mm Diamond Tool Holder the largest it can accomodate.

FWIW, I have an LMS 3540 (Sieg SC4) 8.5x20 lathe with an LMS 0XA QCTP and after trading emails with the US distributor (Bay-Com at the time) I bought a 9.5mm RH/LH set of tool holders that fit and work just fine.

Tom


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