Tool and cutter grinder wheel dressing.

Please forgive the basic question but this is my situation:

I recently acquired a Clarkson T&C grinder and am figuring out how to use it. The user is quite helpful with all the grinding, but as far as wheel dressing it simply says "dress the wheel" which rather leaves me wondering what the correct procedure is for this.

Amongst the tooling that came with the machine is a diamond dresser mounted to a stand, which is is about 1" taller then the centres. I think it may have been taken from a different machine. It can be mounted on the table, but only sits fully on the table if the foot of the stand runs along the T-slot, which doesn't look right as this means the dresser is parallel to the axis of the table and wont sweep the wheel with the table in its usual orientation. I can mount it with the dresser perpendicular to the table but that leaves it overhanging, which might be workable but I'm just not sure.

Any guidance anyone can possibly offer on how to go about any aspect of the wheel dressing would be much appreciated.

Thanks

The Quorn book may be useful for this? Can you remove the dresser from its stand and just put it in a collet?

Exactly what wheel are you trying to dress?

Tony

John: I could mount the dresser in a collet or in some other way no problem, it's just that since it came with the machine I imagined it to be usable as is somehow.

I'll look for the quorn book, thanks.

Tony, I suppose I want the ability to dress either of the standard wheel shapes, which is to say a cup wheel and a disc wheel.

Another vote for the Quorn book.

I bought one several years ago when thinking about making one.

I quickly decided that it was not financially worth buying the castings and bits.

I got a very nice Jones and Shipman 310 grinder for less money and far more useful.

However, the Quorn book does give all sorts of ideas on machine use for you to adapt to your machine.

Les

I have a single point diamond set in a block of steel. I use a cheapo mag base to hold it for dressing. Plonk the base onto the slide, hold the block up to the other face of the mag base and turn the magnet on.

Should one also dress the wheel by hand sometimes, or only ever with a mounted dresser?

It depends on the shape of the wheel but for the most part the dress should closely follow the travel of the slide. Hand dressing is OK for bench grinder wheels.

The important thing is that the dressing diamond point trails the wheel rotation and that it held lightly so that if something does go wrong the point is pushed away from the wheel rather than digging in which can fracture the wheel.

I've seen it said that mounting the dresser above centre-line can improve the point trailing geometry. Personally I think that niceties of technique don't make much difference for the ordinary parallel dressing I mostly do.

Generally Clarkson wheel guards are on the skimpy side so exploding wheels are very dangerous. Mine is the very early type with a simple bent steel strip. More likely to be hopeful than effective in a emergency. I scaled out and drew up diagrams for a reasonable replica of the latest type which made a nice ecercise in my teach yourself MIG welding course. If the welding had been cosmetically better I might well have written it up for MEW. Ugly maybe but plenty effective though.

T&C grinder wheels tend to be less robust that the grey wheels commonly found on bench griders which are designed in the expectation of being attacked with star wheel dressers. They are also specified to put up with agressive use by folk less than sympathetic to the stresses involved in heavy grinding.

Clive

Thanks Clive, if I understand you correctly you're telling me to mount the dresser such that if the wheel were to grab it somehow then it wouldn't be able to cam into the wheel, but rather would be spat out. Is that right?

For dressing cup, dish, or wheels for general sharpening end mills slot drills lathe tools, etc just dress free hand this gives a much more open wheel and dosnt burn the tool, general tool sharpening slot drills etc you only want to be cutting on a very small corner area of the wheel, slightly rotate the wheel axis so as not to grind on the back of the wheel as you pass the wheel if that makes sense. Brace yourself against the machine hold the dresser firmly and dress the wheel almost like using a wood turning tool until the desired shape is achieved. For dressing the wheel for surface grinding etc as previously mentioned mount the dresser onto a mag base or similar with the diamond at an angle about 5 degrees just past the centre line of the wheel and pointing away from the direction of rotation of the wheel lock the table then it will push away if you dig in

Thanks, when you say "away from the direction of the surface of the wheel" does that effectively just mean "down"?

Michael

Yes thats right. Angle the dresser so the point can't grab the wheel whatever happens it needs to be just spat or deflected away.

Light touch is the order of the day here.

Those are the only things that actually matter. Plenty of variations in technique to get the best results for a specific job but anything reasonably acceptable will work well enough for folk like us. Albeit more slowly than perfect expert technique. But isn't that always the way for everything.

Just don't burn the tool when grinding. Proof positive of too heavy a hand.

As colin said careful free hand dressing generally gives a more open wheel for tool sharpening. Which is why I normally dress free hand. But ultimately I'd trust my gentle hand grip over anything solid.

Clive

Thanks again, and when you dress free hand what type of dresser do you use?

Michael

Ordinary cheap diamond dresser about 6" long from one of the usual ME suppliers. Long forgotten which one tho'.

Stout rod clamped in a three way pivoting vice does for a support. Vice similar size and layout to the official Clarkson one but much cheaper. As always in that era, 20 odd years ago, a bit of rework needed to get it just so but nothing major. Only thing I recall was having to re-eningeer around some cheap, nasty and ill installed roll pins. Possibly a 2' version of the Soba Universal, now £130 odd from Chronos, but badge and memory have long faded.

Clive

When I dress a grinding wheel either for the off hand grinder my Diamond wheel grinder or cutter grinding wheel wheels I use one of these. A carborundum dressing stick, a diamond dressing stick, a chistle edged single point diamond on single point diamond holder with fine adjustment.

This is used to rough dress any wheel carefuly Norton dressing stick.

This is used to dress a diamond wheel to remove build-up and ckean up diamonds in face of wheel.

This chistle edged diamond is good to shape a wheel edge ie undercut or radius etc.

This is used to straight dress a face or side of a wheel to shape it can be held in a vice or magnetic stand or can be used on a off hand grinder to follow the edge of the toolrest to produce a straight face and put on small cuts. There are other dressing tools but these are the ones I use.

David

Norton make a very dark shiny looking dressing stick called a Norbide dressing stick. It is very good for hand dressing of wheels, especially hand forming a radius. The dressing stick above works well for a course dressed wheel. There is a lot of technique involved when hand dressing a wheel. Like been said, hold it in such a way that if anything goes wrong, it falls away from you and falls away from the wheel being dressed, and make sure that there is nothing to trap the dresser. So clear away the work piece from the wheel when dressing or touching up etc. You can use a piece of thin card or brass or steel shim, to push against the wheel , to then see the shape or measure the radius and where it may need adjusting to get right. The trick is to dress and take away any vibration which is runout from the wheel. A fixed diamond is the best for truing a wheel. Generally I have the diamond at about 30deg off the angle to be dressed. There are books on tool and cutter grinding, maybe one is in your local library.