traditional vs irish grind

more details please

Matt

John,

Interested in the details of the angles, and cuts/presentation to the wood of each (both inside and outside of bowls?) When I took a class with Stuart he was pretty specific on 40/40 degrees and the presentation to the wood. For me it cuts cleaner than the Ellsworth grind, when I get it right.

Matt

But can you get the bevel rubbing?

steven antonucci

I've switched to the middle grind for deep bowls with steeper walls because the bevel in the front is much steeper, and you can sweep across the bottom of the bowl because the handle is basically parallel to the lathe bed. The nose angle on the swept back wings grind requires a much lower handle, and it usually hits the ways as you try to move through the cut.

The Hunter with the "blunt nose angle" is a great alternative if you are cutting highly figured woods because it has the sharpness of a plane blade but you can keep it on bevel with a push cut.

Re: more details please

john lucas

Matt I was shooting for a 40 degree bevel angle but got 38. I figured that was close enough for this experiment. I tried my very best to have the wood crossing the cutting edge at the same angle. I had the flute at about 45 degrees to the right when doing a push cut down the inside of the bowl. That's probably the one advantage of the traditional grind is I could roll to tool over more and present a steeper cutting angle which did produce a cleaner cut but just barely. It still didn't match the cut I got off the Hunter tool with a fresh cutter.

Just for interest I went back this morning and honed both tool with a diamond hone and turned most of the rest of the inside of that spalted maple bowl. I really couldn't tell the difference in the cuts. I would make about 4 passes with one and then 4 passes with the other comparing the cuts each time. The bowl had 2 places that wanted to tearout no matter what I did. If I pushed too fast the tearout there was worse. Just right and the tearout was the same with either tool.

Then I did a cut with the left upright wing of the traditional gouge. This is with the flute almost straight up and your just doing a very steep angle cut with the left wing. This was cleaner than I could get with the irish grind but wasn't any better than I got off the Hunter Osprey.

This was a steep sided bowl and neither tool would rub the bevel on the bottom. My 55 degree grind on my bowl gouge wouldn't either so I used a #4 Hunter to clean up the bottom. I'll try to get a photo of the bowl later but its in the finishing stages right now.

Re: traditional vs irish grind

robo hippy

To me, it seems to be more about the shear angle than anything else. Both your Irish and traditional grinds at the same shear angle should cut pretty much the same. The traditional would have a larger sweet spot. Your flute on the swept back looks to be considerably more 'open' than on most of the swept back type gouges. The one cut I don't use is the flutes straight up and cutting with the wing. Too scary for me...

On the honing, that never seemed to really do anything for me. However, the 600 and 1000 grit CBN wheels I have do make a difference. Got to try it out when brand new on some soft punky maple. Big difference.

robo hippy

Re: traditional vs irish grind

Brad Vietje

Hmmm.... I'd say it depends on the depth of the bowl, and it looks like the flute geometry between the 2 gouges is not quite the same in your example(?).

My swept-back grinds are using either the original rectangular solid-block-of-aluminum jig from D.E. himself, or a shop-made wooden clone of it for my 3/8" gouges. I have not used his newer, cylindrical jig, but I talked with him about 4 months ago and we discussed the differences. His grind on his gouge doesn't come straight up to the cutting edge, but angles inward, with the bevel wider at the base, and narrower up at the cutting edge. Maybe a quibble, or maybe significant?

I use the Ellsworth grind at 65 degrees, as well as a swept-back grind at 45 degrees, plus I have a few straight-across English grinds -- one at ~50 degrees, and the other at a much shorter bevel -- probably ~70 -- used more as a "bottom feeder". I have gotten good results with all of these, but inside a deeper bowl, I prefer the shorter bevel, because it allows me to keep the handle from hitting the rim of the bowl or the bed ways. Usually I can find a good approach that keeps good bevel contact, but that's easier with the steeper, shorter bevel.

As for the back cut (cutting on the left side of the flute) mentioned by Robo, I use it sometimes with the Ellsworth grinds, but never on an interrupted edge like a natural-edge bowl -- just too scary!

Steve's right about hitting the bed with some gouges -- especially if they have long handles -- but maybe that's a good argument for a bigger lathe... Maybe 36" over the bed?

I've never had the pleasure of using a Hunter tool, so I'm just way behind the curve (and my income is a bit low for that!).

Safe spinning,

Brad Vietje

Newbury, VT

Re: traditional vs irish grind

john lucas

I ground these on my 180 cbn. Honing improves the edge because the hones I'm using are about 600 grit.

Re: traditional vs irish grind

john lucas

Brad the flutes are identical because I made them with the same ball end mill cutter.

The reason I use the Hunter for bottom feeding is the #4 or #5 have the cutter mounted flat on the bar. If you use it as a bevel rubbing tool you have effectively an 82 degree bevel so the handle is almost straight out when finishing box and bowl bottoms. However you are cutting with a 30 degree cutting edge so it leaves a much better finish than any of the other bottom feeding tools.

Re: traditional vs irish grind

robo hippy

John, this is where I need electron microscope pictures.... My 'honing' took a huge quality leap with the extra fine CBN wheels when compared to my hand honing. Maybe I needed to use the Trend lapping fluid...

robo hippy

Re: traditional vs irish grind

john lucas

Reed I've never been a fan of constant honing by hand. It's just to easy to gradually round over the edge and then you end up taking off the same amount of metal you though you were saving by honing just to get back to the original edge. Yes on some tools like my Skew I can keep the diamond hone flat and keep that original bevel. I will also hone some tools to 1200 grit when I need a really keen edge.

The CBN 600 and 1000 I think would give the same edge as honing but maintain the bevel angle if you use a jig. I may go that route some day. I talked to Ken Rizza about it but for now I'm going to play with what I have and gradually switch over.

honing

John K Jordan

I've tried a number of different diamond hones over the years and I think this is the best for turning tools:

There are some others that look close but no comparison, in my opinion to the EZE-LAP. I can hold them with my forefinger on the back of the honing surface and control it all the way around a gouge without rounding over the edge. They are expensive but some years ago I discovered I could order them directly from the mfgr in quantity for a fraction of the price. (A couple/three bucks each maybe?, it's been a long time) I now have a 3-lifetime supply of the blue superfine, the ones I use the most.

I also use an extremely fine long tapered round hone to touch up the inside of the flute right at the edge. This doesn't change the bevel geometry like repeated honings with a flat hone on the outside of a gouge or on a skew.

JKJ

Trend diamond hones *LINK*

john lucas

I prefer the Trend double sided diamond hone. I had used the EZ lap for many years but wore them out about once every year or two. Not totally worn out but they seem so lose their bite after a fairly short time. I purchased one of the trend hones at one of the AAW shows about 3 or 4 years ago and it still cuts like brand new. If you use their honing oil it really improves the cut and makes them last longer. I don't use the oil all the time. I guess I'm too lazy but when you do you can feel the difference. I don't hone my gouges all that much but I sharpen my skews constantly with the hone. It has 200 grit on one side and 600 on the other. they also sell lots of other shapes and sizes and I've been saving to get one of the big ones to work on my hand planes.

Like John I prefer to hone the inside flute of my gouges. The one I use is double sided and fits in a handle. It is tapered on one side and half round on the other so you can do a lot with it. I don't know who makes that. You can buy the tapered ones at any store that sells fishing supplies. They are called fish hook sharpeners.

I want to try one of the CBN hones sold by Ken Rizza. Maybe on my next trip to Atlanta I'll get one from him. If they last anywhere near as well as the stone on my grinder they should be fantastic.


https://www.amazon.com/Trend-DWS-MF-FC-Double-Sided/dp/B004TB69DS/ref=sr_1_21?ie=UTF8&qid=1471348567&sr=8-21&keywords=trend+sharpening

Re: Trend diamond hones

John K Jordan

Yikes, that Trend hone is expensive!!

The little blue EZE-lap hone I'm using now I've been using for at least a year or two. I'll try to remember to bring you a new one. Maybe they improved. I do use it with very light pressure on turning tools.

One think I like about the EZE-lap is unlike most others the grit goes all the way to the edge and the end on a very flat metal base so it is easier to get into tight corners, for example when sharpening a pen mill or cutting bit.

I bought two double-sided CBN hones from Ken Rizza and they work fine. I like them since they are so big - 2.75x8" I think. Far too big for me to hold with precision against a gouge but great for many other things like chisels and knives. I can bring them to the meeting if you want to take a look - maybe bring something to hone?

However, I don't really see the value of CBN over diamond for hand use since I understand the problem with diamond is when the metal gets hot, such as when used on a bench grinder. Things are supposed to degrade with carbon transfer (I don't remember the details.)

Since diamond is harder than CBN, would not a diamond hone be better? Since turners are switching to CBN wheels is that feeding a mild CBN everything craze? Don't know.

I did find out Ken can special order diamond hones in any size made by the same people who supply his CBN wheels. I ordered two double-sided steel hones the same size as his CBN hones with grits up to 1200. I have a special application where I want to sharpen ceramic cutters for llama shearing. These cutters are amazing and outlast the steel cutters by many times. However, no one can sharpen them so they must be thrown away. I found one guy sharpening his with flat diamond hones.

JKJ

Re: traditional vs irish grind

Brad Vietje

Ah -- I see now, the top 2 tools are slightly rotated with respect to one another, giving the illusion that they are different.

I'm still pretty sure the signature Ellsworth gouge has a larger diameter shaft, so the flute is a slightly smaller percentage of the entire diameter. Sure seems that way, as my bevel is wider than the flute (if that makes sense), but that could be hard to see in the photo.

I need to go visit Mike Foster and try out his Hunter tools; they look like an exceptionally good design. I'll need to decide which one I need most, since I can't afford a set of them .

Safe spinning,

Brad Vietje

Newbury, VT

Re: traditional vs irish grind

john lucas

Yes there are a lot of different flute designs. Glen Lucas went into that in his demo I saw at the AAW. The flute shape changes the cutting angles on the wings and how the nose is shaped after grinding. I don't know if one is better than the other. Seems like the one you get used to what ever it is will probably work best for you.

If Mike Foster can't council you on the Hunter tools feel free to call anytime and I'll try. The two I use most are the Osprey and the #5. The Osprey is used whenever I need a really clean cut in problem wood. The #5 or #4 are my go to tools for cleaning up the bottom of boxes or the bottom on steep sided bowls. It's my bottom feeder. You can find my videos of the Hunter tools on youtube. Just type in john60lucas/hunter

Re: traditional vs irish grind *LINK*

Peter Hyde

Liam O'Neill was the "inventor" of the long grind that has now become the Ellsworth or irish grind. In one of his demos a few years ago he talked about how the long grind came about and he considers it as an alternative grind to a fingernail grind. He also suggested finger nail should be the grind of choice and the long grind used only when necessary.

The grind is indeed dependent on the flute shape and this leads to all sorts of claims. Roy Childs was the person who did extensive research on flute design and you can read it here.


http://http://www.peterchild.co.uk/info1/sflute.htm

could not get that link to work

I got this to work to find his site  *LINK*


http://www.peterchild.co.uk/

Re: could not get that link to work

John K Jordan

The link has a few extra characters - try this one:

http://www.peterchild.co.uk/info1/sflute.htm

Ha!

John K Jordan

We must have been looking at that at the same time. You beat me by a couple of minutes. I got bogged down by starting to read the article - excellent article! Well worth reading and saving!

JKJ

Brad, here's another vote for the #5 Hunter....

JamieDonaldson

...that is a mainstay in my tool collection. It works!

Re: Brad, here's another vote for the #5 Hunter...

John K Jordan

Me too. That and the Osprey and Hercules. Once you learn to use them you can't go back.

JKJ

Re: traditional vs irish grind

Keith Tompkins

HI Brad, that angled-in grind is the key to making this tool work, in my opinion. Ground so the grind is facing straight up makes the tool nearly useless unless cutting only straight on. I took a class years ago with David, who showed me how and why the grind should appear to angle inward.