Tool Shapening

[Bob Brown 1Participant @bobbrown1]

We all are probably guilty of doing things that may be we shouldn't, and if you followed all the health and safety stuff you'd never much done, I think most of it is down to common sense.

I think the main reason for not using the side of the wheel is that it is not designed for loadings in that plane

The advice given for not using the side of the wheel is probably more relevant for grinding chunks of mild steel not grinding tools.

Has anyone thought about fitting a cup wheel and making up new guards that way you have a flat face but then you cannot use the curved part, ho hum!

Bob

[JasonBModerator @jasonb]

I find the belt sander/linisher gives a flat face once the grinder has got the basic shape and tend to use that to touch up an edge rather than the grinder.

J

[Ian S CParticipant @iansc]

Bob, cup wheel one end, plain wheel the other, no problem unless like me you look for, and can't find a green grit cup wheel for touching up the carbide tools. It is possible to grind a (fairly) flat tool using the periphery of the wheel, and moving the tool vertically. Ian S C

[Roderick JenkinsParticipant @roderickjenkins93242]

Begs the question of what is wrong with having slightly curved faces? Curvature on a 3/8" square tool from a 6" diameter wheel isn't much – you could even argue that it might help swarf removal. The counter arguement is that it might reduce the support for the cutting edge but I have never had a problem with chipping on HSS tools.

Rod (who has happily rough ground on the periphery and finished on the face for years – before the Worden)

[NJHParticipant @njh]

I agree with Jason once you have made the right shape on the grinder a linisher is quick to put back an edge when it dulls. You don't even need to take the tool out of the "boat"!

Finishing touches then made with an oilstone.

Norman

[colin hawesParticipant @colinhawes85982]

Where a lot of metal is to be ground off a HSS tool I hold the toolbit in the vice and use an angle grinder fitted with a cut-off disc designed for use on stainless steel to cut off most of the waste. Much quicker. Also, I prefer the cutting edge of the tool to be concave as it clearly gives a sharper edge and better swarf clearance. Colin

[JOHN BRIDGE 1Participant @johnbridge1]

Thanks for all your replies Gentlemen, I do not have a problem with the concave shape of the hss with my hss being 1/2 inch square the concave shape is more pronounced, I bought these hss pieces from RGD on Ebay and they come with one face already ground to approx 15 degrees, is there a reason for this, should I be leaving this face as is and using it as one of the faces if so which face should this be?

John

[Clive HartlandParticipant @clivehartland94829]

John, I think its time to study lathe tool shapes and cutting angles, in basis for general shaping work you need a left and right hand roughing tool, then a R/H knife tool and also a L/H version of then same thing. So that there is no confusion, stand at the back of the lathe and name the tool in the direction it is used. Further tools are for finishing to a smooth surface and parting off. Further shapes are added as needed like chamfer tools. Parting tools and thread cutting tools as needed. Many basic engineering books will show diagrams of tool shapes and they all show, 'Flat' surfaces. Ergo, side of wheel ground, It has gone on so long it becomes a second habit that you do not think of, we are talking here of kissing the wheel with the tool and not ploughing into the side of the wheel until the tool turns red or blue. I have seen some diabolical tool grinding by experienced Engineers and it is not long before thy come borrowing tool bits from your box. Grind a tool until it does what you want from it, persist and succeed.

Clive

Edited By Clive Hartland on 24/05/2014 16:11:13

[NJHParticipant @njh]

John

As far as the preformed 15 deg. goes the most common tool you will use is the knife tool and this is an angle you will "need" on this. So I guess, with the preforming, it will save you a lot of sweat!

Click HERE to see Ian Bradley's comments. ( Ian was one of the early writers on the model engineer scene and his books are still a great read.)

Regards

Norman

[Neil WyattModerator @neilwyatt]

Mark,

As you comment yourself, I can't see any company giving advice different from that in the Norton 'safe practice' guide.

The best safety advice is summed up in two words: "be careful".

Neil

[Rik ShawParticipant @rikshaw]

Grinding on the side of a wheel is OK if done correctly. Best results are obtained by dressing the side of the wheel. It's that complicated. On a six inch grinder don't try side grinding a massive piece of steel as it shocks the wheel and can be unsafe – the smaller the safer.

The only exception to this is wheels on a universal or cylindrical grinder where it is routine procedure to flash the ends of component flanges etc. by undercutting the side of the wheel to leave a small land at the periphery. This method of grinding on the side of the wheel is quite capable (and safe) of removing material and leaving a near mirror finish

Rik

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