The Diamond Tool Holder

[egaParticipant @ega]

Posted by Howard Lewis on 20/01/2019 17:03:35:

My difficulty was making a neat fracture of a 3 inch length of the HSS toolbit. Then, as said found that it fouled the Top slide when trying to rotate the 4 way toolpost.. My solution was to slacken off the clamp, a long way so that the toolpost would lift clear of the pawl so that it could be rotated backwards before reclamping.

The American toolpost is an invention of the Devil, as far as i am concerned. Four way every time for me (which when I made a rear toolpost, it was a fourway, also!)

Howard

For cutting off HSS I use an angle grinder with a thin cutting disc mounted in a pivoting stand.

My DTH would foul the topslide even without the toolbit, unfortunately.

I have never used an American toolpost and have no plans to do so!

[duncan webster 1Participant @duncanwebster1]

Thanks Howard, both references consulted, another job on the to do list

[VicParticipant @vic]

Posted by duncan webster on 20/01/2019 19:12:20:

Thanks Howard, both references consulted, another job on the to do list

Pictures please when you’ve done it!

Question, I sharpen the bit for mine on a belt sander so the grind is flat. I noticed on the video that sharpening on a bench grinder gives a noticeable hollow grind. Is there any advantage or disadvantage to this? I hasten to add that mine cuts fine, just wondering.

[Clive FosterParticipant @clivefoster55965]

Vic

Hollow grind gives two line contact for the honing stone so its much easier to hone for a really sharp cutting edge. Just the job when you want to touch up a tool in the machine.

With a flat grind its really easy to tilt the hone a fraction at the ends and beginning of a stroke. Basically making the tool blunter rather than sharper which, probably, isn't quite what was intended.

Not sure which is harder. Honing dead flat or filing dead flat. After over 4 1/2 decades of home shop metal bashing I still need a following wind, a touch of luck and the shop gremlins temporarily distracted to consistently achieve either.

Close no problem.

Dead on. First time. Every time. Now thats different!

Clive.

[the artfull-codgerParticipant @theartfull-codger]

Thanks for that info xd351,never thought of that, I,m

not actually sure of the size I want,my lathe is a smart and brown model A with the standard four tool tool post if anyone knows which size tool.

Graham.

[Alan CharlestonParticipant @alancharleston78882]

I've had a diamond tool holder for years and I love it. The surface finish I get on steel for general turning has improved no end.

I'm not great at grinding tools so in the past I've cut threads on the lathe using cutters with no top rake. The surface finishes were usually poor and needed finishing off with thread nuts to be useful. I was aware from their videos that the diamond tools could be used to cut threads but couldn't see how to grind them. I e-mailed Gary at Eccentric Engineering and he was kind enough to grind both 55 degree and 60 degree threading tools for me. They work brilliantly with the metal peeling smoothly off the work and giving a beautiful surface finish even on steel which is of dubious quality.

After seeing what the tools look like, and practising grinding them with key steel on the jig that came with the holders, I found it to be quite easy to do.

Regards,

Alan

[Niels AbildgaardParticipant @nielsabildgaard33719]

I made my own that use 2mm square and 3mm round best german carbide.

 

https://www.homemodelenginemachinist.com/threads/carbide-tangentials-for-small-lathes.25950/

I use a homemade M8x0.5 Unbrako screw for clamping to day

Edited By Niels Abildgaard on 21/01/2019 05:50:54

[Anthony KnightsParticipant @anthonyknights16741]

I made both left and right handed tools from the article in MEW. The same info is on "mikesworkshop" site.

[Paul LousickParticipant @paullousick59116]

Graham,

The Eccentric Engineering web site explains how to choose the correct size tool to suit your lathe. The cutter height is adjustable but I would get the largest holder that will fit into your toolpost rest for best rigidity.

Paul.

[the artfull-codgerParticipant @theartfull-codger]

Thanks for your info Paul, unfortunately I am 10,000miles away from the workshop and don't know the measurement from the base of the tool post to the centre height and won't be home for two weeks but thank you for taking the trouble to post.

Graham.

[Clive FosterParticipant @clivefoster55965]

Graham

According to the manual and sales brochure the standard tool size for the Smart & Brown Model A Mk1 is 3/8 x 5/8 deep. I assume that is for the American style lantern toolpost as that is the one listed in the standard equipment section. A four way being an option.

For what its worth the 1024 is also listed as using 5/8" deep tools and that did come with a four way as standard.

Unfortunately we don't have any more detailed information in the files on the Smart & Brown Yahoo group. If you aren't signed up I could ask.

Clive.

[John MCParticipant @johnmc39344]

I bought one of these in 1980 something. Work took to me to Australia so I arranged to buy 8 plus grinding fixtures, not all for me! I think that there were only two sizes then, I had one of each.

Initially I was impressed, they worked well enough on my relatively light weight lathe. I upgraded to more rigid machinery, and found that the the tool would move downwards under a heavy cut/feed. Could also be the source of vibration. Easily sorted with the large butt-welded HSS tooling I had. Not as easy to sharpen though! For a while longer I used the diamond tool holder as a finishing tool until I got to grips with disposable tips. The tool holders went when I upgraded the smaller of my two lathes, something I have occasionally regretted.

A couple of criticism I have of them is how often is an internal square corner needed? Best avoided if at all possible. A good friend who worked in a toolroom ground radii along the edge of several pieces of HSS for me. Was this something offered by the supplier at on time?

Also, tougher steels would soon bring on the need for frequent sharpening that (near) square corner could be a bit delicate.

John

[the artfull-codgerParticipant @theartfull-codger]

Thanks for the reply Clive,didn know about the s and b Yahoo group, I'll see about joining

Regards Graham.

[VicParticipant @vic]

Quick picture of mine, more in my album.

[JC54Participant @jc54]

I made the tool holder as per Mikesworkshop for my ancient Drummond lathe and as a beginer found it to be one of the best tooling parts that I have ever made. So easy to sharpen for the beginer. I have just made two more to suit my Myford/Drummond M. Have mounted them on a Norman Patent style tool post mounted on the crosslide.

John

[OuBallieParticipant @ouballie]

Can attest to what John said about tool being pushed downwards on a heavy cut, but in my caseI hadn't tightened the holder enough.

That moving down, however, saved my bacon when I had a dig-in, due to not paying attention, the toolbit being pushed clear of work.

Here's my Edge gizmo for setting the toolbit heights, and what a pleasure using it:

Upside down tools a little tricky to set in my rear QC though, but I can put up with that.

Geoff – Ham & cheese followed by Rooibos tea

[VicParticipant @vic]

This is my height gauge. Easy to make from a small length of scrap bar.

[Tim StevensParticipant @timstevens64731]

I wonder – we have here a tool which is held in another tool and clamped to a third. Would it make sense to combine the first two – The square-bit holder and the cutter holder? A slab of steel with the angled clamp-slot at one end and a dovetail slot in the middle to match your QC? And if you did that, what is to stop you making it double ended? In this case the two ends would have to be opposite hands – one downwards and the other upwards – to avoid the second end from fouling the top slide as you change its position.

There would be one clear advantage for some of us – once set up, it would avoid that awkward delay when we needed to change tools but couldn't remember where we had put the next one.

If I have a go at making one of these, would EN1A be OK or should I go for something a bit up-market, and if so what?

Regards, Tim

[duncan webster 1Participant @duncanwebster1]

My idea for the Cowells is to take off the topslide (it's always in the way) and make up a plate to fit in the hole with a spike for one of those split block tool holders, and have the tangential tool part of it, not too distant from Tim's suggestion. If I could remember the official name for the tool holder this might make more sense.

[VicParticipant @vic]

One of the advantages of the Tangential tool is that it has built in height adjustment. No need for shims or a QCTP, in fact it’s likely more rigid without the latter.

[duncan webster 1Participant @duncanwebster1]

Remembered it, Norman Toolholder see **LINK**

As Vic says I won't need the adjusting screw on the tangential one, but will for other tools

[Michael GilliganParticipant @michaelgilligan61133]

Duncan

Have a look at what John Haine built recently: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=132573&p=1

MichaelG.

[VicParticipant @vic]

That looks nice and solid Duncan.

[JC54Participant @jc54]

Duncan, Norman toolholder is standard on Drummond M topslide, so I made one to bolt onto the crosslide, made several holders for different tools with height adjusting screw, easy QCP. Also holders fit both slides. John

[Howard LewisParticipant @howardlewis46836]

The standard Eccentric Engineering toolbit has a small radius ground on the cutting edge to improve the surface finish.

It is only small, but combined with a fine feed rate, gives a good finish, especially with a little neat cutting oil added..

I tried doing the same thing to an ordinary toolbit, did it badly so that it did not extend the radius far enough down. The tool rubbed and the finish was terrible!

Howard

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