Thread: shapes and profiles on grinding wheels ?

Hi Bill,

Common practice to profile a wheel for specific grinding jobs, you most commonly use a radius dresser.



If you search youtube you can find some demonstration...



Don Baileys video's are always good to watch
Ray

Any sort of grinding of profiles....

Classic example being gear grinding and thread grinding..

Thanks Ray and RC

I had no idea that grinding could be used for cutting gears I just assumed sharpening chisels and tool steel and cylinder grinding was all that was done.

Off to read the Workshop Practice Book.

Bill

If you wanted to grind an accurate radius on a corner!

Gene

A surface grinder with a Diaform attachment. The wheel is formed by the diamond following a path that is generated by a stylus which follows a template.

Gene

Originally Posted by steamingbill

Is it common practice for some people to dress their stones differently for different tasks ? I've only ever used the wheel as I got it and although interested in the idea I thing Id be cautious about mangling a decent wheel to do a one off job.


Bill

Bill it depends on what you mean by "common practice", but yes it's not unusual and a lot more things are ground in a hardened state than you may possibly have realised.

I'm just getting in to profile grinding myself right now, and have a job later today I may profile grind .... but may not too. It seems some people do a Google search, declare themselves experts and pontificate how this is all done. From my experience in trying it over the past few weeks, it's not that easy in practice. The major issue I've been finding is that you may well dress a profile in a wheel, but maintaining that precise profile isn't simple. Sharp corners look great courtesy of Google, but try standing in front of a grinder getting pinged in the face with pieces of decomposing wheel for any length of time and see what you think of that theory then! The wheels commonly used for flat grinding have quite a soft bond and decompose as they're being used to expose fresh "rock" that is sharp and will grind cooler. However that very trait makes them very poor at maintaining an accurate profile. For grinding large radii such as the picture in the pdf you'll be fine, and in my (limited) experience the wheel will hold the profile ok. However don't even think about using the same wheel to, say, grind a thread. It looks good on paper, but ain't gunna happen in real life!

I recently ground 52 90deg V in MS, 350mm long and with 13mm flats.

I used a new 12x1" 32A60L wheels, it did every one of them without needing to be re-dressed, and still had a sharp point. Of course the V's were milled and the most i took off was about .010" in small steps.

I could have set up the sine table and used the face of the wheel but it would have taken twice as long.

Cheers,
Ew

Yes a 60L is a medium grain, medium grade wheel, and I'd guess would be the minimum required for this type of work. My 60s are K IIRC, and don't hold up well. But as you quite rightly pointed out Ewan, it depends on how the wheel is addressing the work. If you dress and angle (or profile) in, and the surface used to create the profile (or preferably touch up an existing profile) then you're pretty sweet, but get the sharp edge to do the work and it's a whole new ball game from what I've seen. It's recently been suggested on the forum to create a profile by plunging the wheel in to a solid steel block and in my experience you'll have Buckley's chance of that popping out the other end with anything like the original profile on it! I tend to use the corners of my wheels a lot on the T&C grinder and when freehand grinding, and exactly the same issues arise there.

I'm keen to do some reading in the area of thread grinding, as I suspect many of the answers will be found there.

Out of curiosity Ewan, how did you accurately grind that V profile in to your wheel? I presume with a sine plate but I'm keen to see how the diamond was guided.

Originally Posted by Pete F

Sharp corners look great courtesy of Google, but try standing in front of a grinder getting pinged in the face with pieces of decomposing wheel for any length of time and see what you think of that theory then!

You're standing on the wrong side...

Originally Posted by PeteF

Out of curiosity Ewan, how did you accurately grind that V profile in to your wheel? I presume with a sine plate but I'm keen to see how the diamond was guided.

Radius dresser is the way I do it.

Ray

Originally Posted by RayG

You're standing on the wrong side...

Radius dresser is the way I do it.

Ray

Yeah that time I was using the T&C grinder and the wheel was facing me. Even with a guard on I was copping it. ... and yes the thought about what might happen to my face if the wheel let go DID cross my mind

I've seen both radius/angle and sine dressers but have neither. The radius dressers typically don't come cheap and I wouldn't think many here would have one. I figured the radius part would be easy to make, but the angle part not so much. At least not the type where the diamond is actually wound up and down in a controlled manner. I was real close to buying a cheap Chinese angle dressed, but on closer look it seems to be nothing more than a dovetail and you just slide the diamond up and down by hand. I don't like that idea, as value my fingers!

GQ had a nice radius dresser, I remember borrowing it, but it ended up being too short to reach the wheel on our setup... he might still have it?

Ray

Hi Pete,
I have a Yuasa radius/angle dresser i bought from Michael G a while back. It is the larger size so it can dress the 12" wheels, although the coolant spout gets in the way and you really want coolant when dressing to control the dust. On that dressing the corners right of a 12"x1" wheel makes a huge mess.....

Ew

I don't think Greg owns anything much more technical than a screwdriver these days We'll win the big fella back ... I'll use all my charm

I forgot to mention in my previous post that tools4cheap have radius dressers, and the price was good. I'll see if I can find the link ... yep here it is http://www.tools4cheap.net/products.php?cat=12
As always, getting it back from the US isn't free, but the price of that was certainly quite good. Just how far I want to go down this path I don't know. Buoyed by my recent hard turning triumphs* using The Noodle, I'm possibly not as keen as I was a week ago!! However it's also very clear that hard turning can't always substitute grinding, at least not on the gear I have, and they'll just have to compliment each other.

*anyone who reads PM would know what I'm talking about in reference to this.

Here is a simple face to length and chamfer tool bit. Only ground 1 side, clearance front to back is .006-.007, front side clearance is 6°. Poor camera pics is the best I can do. It's nice to make a good looking tool.1107141152-00.jpg1107141153-00.jpg