My own was forty odd years ago Ramon on a “Wickman OPG” ( An excellent one recently fetching the magnificent sum of £275 on the “Flee”).

 

  Seems that toy builders affluence not only has carbides with everything, we now have diamonds with everything. As we are now instructed to use indexable carbides and chuck ’em when blunt polishing with a diamond wheel seems a bit frugal. They tell us that usingthem on HSS tends to bung them up (Like grinding alumininininium on conventional wheels) but I remember using diamond “Burrs” used on Jig Grinders for hardened tool steel.

 

   Regards  Ian.

I’m interested in this one.

 

I can tell you what I use on the Quorn. 60grit – (WA 60 JV as I recall) but that is not a diamond grit, that’s a white aluminium oxide.

 

That produces a mirror finish. BUT it will load up eventually, and as Ramon says, you have to dress the stone up.

 

Also its absolutely NBG for roughing – youdd be there all day hacking into a HSS blank. So, I do that on the offhand grinder – whatever stones that came with. 1 coarse and one so called fine, but fine is not tool sharpening fine!

 

So do these diamond stones load up? If so how do you clean them? 

 

Also are diamond grit sizes equivalent to ordinary oxide sizes

 

Is there any point to a diamond stone? It takes 2 secs to run a diamond across the front of a stone,  and you only take .001 inch at a time, tops. If you have roughed out, you don’t have to dress every time you use it. My 4″ 60grit Universal cup has lasted 20+ years and its not really on the way out yet.

As I’ve said it’s quite some time since I was involved with these matters but unless things have changed this was how it was –

 

Our press tools were made up of individual parts made of hardened (various) tool steels or carbide. The diamond wheels were only used on the carbide and never on the steels. I was not involved with the carbides but I recollect the wheel was brought down on a ‘block’ of some material which trued the wheel and removed any detritus.

 

The tool steels were ground with a myriad of wheels – sorry but I can’t remember all the grits and grades but most were white for form ginding ranging from soft to very hard, brown 46J for basic surfacing and/or roughing, pink for the really hard chrome steels. These wheels were all dressed regularly with a diamond held rigidly in a holder on the chuck or in the optidress wheel grinding attachment. All well to the rear of the technology queue now I guess but it may have relevance.

 

All of our diamonds were ‘single point’ of varying carats but someone at some time gave me a very small piece of diamond impregnated steel section about 12 x 6mm. This is bolted to a piece of steel for a crude handle. I have no idea what it is called or where to get it from but it is absolutely the best thing for hand dressing abrasive wheels – as the steel grinds away fresh diamonds are exposed – I used it only at the weekend to trim the wheels on the off hand. I’ll take a pic of it tomorrow so you can see what I mean.

It’s getting rather short – if you know where I can get another I’d be grateful

 

Hope this helps –  Ramon

Regards – Ramon

Can’t remember Frank, the smug B*rstewerds in Jig Grinding wouldn’t open their air conditioned “Kennels” to the likes of Apprentices, but as a finishing operation on the punches and dies for stamping my post name they were removing tenths of thous.

 

  Used both the Bakelite bodied resin bonded wheels and also the metal diamond impregnated ones, the latter being £60, as, when as a paid slave on the princly sum of £3 7s 6d a week, was told that was the cost to replace one I’d just dropped. Thus the ref. to the Wickman Optical Profile Grinder.

 

   Regards  Ian. 

I got a Chronos one and can recommend it- code GEO 1 but Arc Euro also list one except theirs seems to be a hollow square section attached to a handle with diamond on one side of the square bar. Not sure what the benefits of the bar will be ?

 

Having tried 100 grit diamond cup wheels on both steel and carbide they work and give a beauutifully smooth finish but , certainly on HSS , they’re damn slow and heat it up something wrotten. Could be I’m taking too bit a cut mind!

 

The great thing is- no grinding dust- it’s only powdered steel coming off . I tried runnign with a bit of water on the weel to keep things a bit cooler. RDG told me to run em wet and they last longer. Only 1 year inot use but no detectable wear as yet . Then again only just starting to use it as I learn by experimenting.

 

 

Ian

Hi All, Some good replies here. At the risk of repeating myself a bit perhaps I should elaborate a little.
As said diamond wheels were only used as far as I remember for surface grinding the cutting faces of punches and dies. Most of these P&D’s had very complex shapes the forms of which were wire eroded. The use of diamond wheels was purely down to the hardness of carbide. Prior to the accelerated use of carbides in these press tools  these parts were made from varying grades of tool steel and whilst the more complex were wire eroded many were formed by grinding with conventional wheels. The forms were shaped on the wheels by a single point diamond using an ‘Optidress’ wheel forming attachment.( Big panic when you hooked the diamond out of the end of the dressing ‘stick’ !) The forms took many different shapes of angles and radii all dressed in this way. To give an idea of the limits of dressing involved it was frequently required to dress a 1/4 wide 6″ wheel down to a thin blade with a .8mm (yes that is right) radius on the end. (That form had to be ‘dropped in’ some 16mm which required an awful lot of re-dressing as the wheel glazed up) Sorry for repeating myself – the wheels came in all sorts of grades, bonds and hardness to allow this to be carried out. I mention this to give you some idea of the (relative) ease of which conventional abrasive wheels can be shaped – not to suggest you do it – or even need to do it – at home but if you have a T&C then this is going to be a lot more beneficial to expose new clean grit than not being able to shape a diamond wheel.

 

Merrick is right to say these are finishing ops or to put it another way if you do intend to cut from solid – eg HSS blank for turning – then you need to take your time. Grinding is not something that can be forced. I don’t wish to raise the dreaded H&S but be aware that grinding wheels are not shatterproof and do rotate at a peripheral speed that will shower lumps of abrasive everywhere at a phenomenal rate of knots – it makes a big bang and you don’t get an advance warning! Sorry if it sounds like a lecture but it has to be said – Keep your wheel guards on. Really!  And whilst we’re on the matter its not good to beathe the dust created when grinding carbide particularly if you use a diamond. The dust, once in the lungs, does not come out and it’s accumulative. I know the amount that the home user is likely to be exposed too is very small, probably very very small – but it’s a health issue that you should really be aware of.

 

Finally can I just remind you this was ten years ago – the progress since then particularly in the use of carbides and wire eroding has made these techniques very much a thing of the past. Things have moved on – I just haven’t so don’t beat me up if I’m off the mark!!

 

Thanks for the info on the diamond dresser – I couldn’t open the pics on the link but the price was much better than anticipated. This is the type I mentioned, I guess the Chronos one will be similar, as you can see it’s on it’s last legs so it’s good to know I can replace it.

Hope this helps a bit more

Regards – Ramon