Thread: Diamond Tool Holder

I am looking at ordering a Diamond Tool Holder from Eccentric Engineering, together with a 1/4" Crobalt tool bit.

I am a little uncertain as to which size to get. I have a 9x20 Steelmaster lathe, which I use with an AXA Quick Change Tool Post. Eccentric tells me to measure the distance from the bottom of the tool groove, where the tool holder sits, to the centre line line of the lathe.

http://www.eccentricengineering.com....id=6&Itemid=19

On my lathe/QCTP combination this is about 10.5mm, so I assume that I need to order a 9.5mm Diamond Tool Post?

Is this assumption correct?

What do others with this combination use?

Hey Fred,

I purchased the 9.5mm holder for my 9" Hercus. Initially I thought I needed the 12mm holder but I rang Gary at Eccentric for clarification.

BT

Originally Posted by Anorak Bob

Hey Fred,

I purchased the 9.5mm holder for my 9" Hercus. Initially I thought I needed the 12mm holder but I rang Gary at Eccentric for clarification.

BT

Thanks Bob, did you get the Crobalt bit with it, and if you did, have you cut stainless with it?

Quite impressive to see a 2mm DOC on that video, have you tried that?

How many different sizes do they have.
Do you know what there centre height is.
Wouldnt you have to know how big there tool shank is,and then the centre height of there tool.
After looking at there web site its very self explainitory as to what they require you to measure,they even show a qctp in there diagram.

Originally Posted by pipeclay

How many different sizes do they have.
Do you know what there centre height is.
Wouldnt you have to know how big there tool shank is,and then the centre height of there tool.
After looking at there web site its very self explainitory as to what they require you to measure,they even show a qctp in there diagram.

Yes it is, but as a typical book machinist I wanted confirmation.

Hi Fred,
I have an AL340D and they recommend 16mm tooling but I am assuming that is with a normal 4 way tool post. My first diamond toolholder was a 12mm (present from the missus) and it fits perfectly in the quick change tool post.
Hopefully this will help.

Phil

The only time previously that I had attempted to use my Diamond tool holder was when I had the Crobalt fitted and I tried to cut the outside of a slice of 160 mm diameter 4E cast iron bar. It had trouble achieving a good finish so I used a CCGT insert instead with OK results.
Today I had some facing to do on some 4140 that I had cut by hand with a hacksaw. Maybe as a lack of skill the blade wandered enough that the cut face was skewed and would have meant an interrupted for the carbide which often results in a broken insert. So I fished out the Diamond and fitted the HHS. The results were just superb. I applied neat non diluted soluble oil with a brush and ran the Hercus at 900rpm with a pretty delicate feed. The 4140 was 17mm in diameter.

The delicate feed was necessary because I couldn't afford to have the part fly out of the chuck as a result of a greedy, overambitious cut.

BT

the 1/2inch fits the AL960. These come in both LH and RH where as the bigger size does not....you can always pack a smaller one up and why doesnt my curser show up as to where I am supposed to be typing...is this still a problem with the new layout?......cant go back and correct a small mistake without deleting lots of words...is it just me?

eskimo please don't hi-jack this thread with off topic posts, they have been moved to

http://www.woodworkforums.com/f36/so...ml#post1555567

which is the appropriate place to get help with updated forum problems.

Originally Posted by Anorak Bob

The only time previously that I had attempted to use my Diamond tool holder was when I had the Crobalt fitted and I tried to cut the outside of a slice of 160 mm diameter 4E cast iron bar. It had trouble achieving a good finish so I used a CCGT insert instead with OK results.
Today I had some facing to do on some 4140 that I had cut by hand with a hacksaw. Maybe as a lack of skill the blade wandered enough that the cut face was skewed and would have meant an interrupted for the carbide which often results in a broken insert. So I fished out the Diamond and fitted the HHS. The results were just superb. I applied neat non diluted soluble oil with a brush and ran the Hercus at 900rpm with a pretty delicate feed. The 4140 was 17mm in diameter.

The delicate feed was necessary because I couldn't afford to have the part fly out of the chuck as a result of a greedy, overambitious cut.

BT

Any particular reason for using a CCGT rather than CCMT.

Originally Posted by pipeclay

Any particular reason for using a CCGT rather than CCMT.

Good question Peter,

I started using high positive Kennametal CCGT inserts when I purchased a SCGCR tool holder. They were what K2 Engineering, the seller, recommended. Subsequently, I've purchased more inserts on Ebay and stuck with the same specification. The third letter refers to tolerance. I don't know what the difference is between G and M. I should find out. Might lead to more, and more importantly, cheaper alternatives.

Bob.

Originally Posted by Anorak Bob

Good question Peter,

I started using high positive Kennametal CCGT inserts when I purchased a SCGCR tool holder. They were what K2 Engineering, the seller, recommended. Subsequently, I've purchased more inserts on Ebay and stuck with the same specification. The third letter refers to tolerance. I don't know what the difference is between G and M. I should find out. Might lead to more, and more importantly, cheaper alternatives.

Bob.

The 3rd character is the dimensional tolerance as per the following table.

Code Letter	Cornerpoint (inches)	Thickness (inches)	Inscribed Circle (in)	Cornerpoint (mm)	Thickness (mm)	Inscribed Circle (mm)
A	.0002"	.001"	.001"	.005mm	.025mm	.025mm
C	.0005"	.001"	.001"	.013mm	.025mm	.025mm
E	.001"	.001"	.001"	.025mm	.025mm	.025mm
F	.0002"	.001"	.0005"	.005mm	.025mm	.013mm
G	.001"	.005"	.001"	.025mm	.13mm	.025mm
H	.0005"	.001"	.0005"	.013mm	.025mm	.013mm
J	.002"	.001"	.002-.005"	.005mm	.025mm	.05-.13mm
K	.0005"	.001"	.002-.005"	.013mm	.025mm	.05-.13mm
L	.001"	.001"	.002-.005"	.025mm	.025mm	.05-.13mm
M	.002-.005"	.005"	.002-.005"	.05-.13mm	.13mm	.05-.15mm
U	.005-.012"	.005"	.005-.010"	.06-.25mm	.13mm	.08-.25mm

Thank you Gavin,

It looks like it comes down to how much you are prepared to pay to minimalise variation. M should be cheaper than G.

Bob.

Originally Posted by Anorak Bob

Thank you Gavin,

It looks like it comes down to how much you are prepared to pay to minimalise variation. M should be cheaper than G.

Bob.

And you have to ask, for the type of work we do, does it really matter if the diameter of an insert varies by 1 thou or by 5 thou between inserts?

HI Big Shed,

How'd you go with your purchase? What size did you end up getting? Is it worth the money? I only ask as it's my birthday tomorrow and I'm trying hopefully get one for my Hercus 260.

cheers Ben.