Do Angles Count?

[Grant Wilkinson]

Tks, Reed. I've seen how Stuart and Mike do it, using the lines drawn on the platform. I had not heard that they say it can't be done with a jig. It's too bad that Stuart has not been back to this thread, which he started. He could, no doubt, clear up my confusion.

I've played with the 40/40 and 45/45 grind by hand for a while to see how I would get on. I tried the 45/45 using the Varigrind. It was obvious that the wing angle was not the same. However the 45 degree nose angle remained, and the 45 degree sweep angle did, too. (I ground them on the platform before putting the gouge in the Varigrind.) So, if Stuart is, in fact, saying that his grind cannot be duplicated with a jig, I have to conclude that he is referring to the wing angle, which, he does not mention at all in any of the videos that I have seen, or in the post that starts this thread. It's easy to see how that angle could affect the cutting style, though.

Tks again, Reed.

[Reed Gray]

I am thinking that the reason it can't be duplicated with a jig is that the jig does not roll over far enough and the bevel on the wings is more vertical which would make the wing rather thin. When hand rolled, You get a more blunt angle, and more heavy duty wing.

It has been a while, but I seem to remember that Stuart used his gouges with the flutes more up/vertical rather than rolled onto the side. That would give a higher shear angle when cutting. Problem with that is that it didn't take much to wander over onto the high side of the wing, which makes the tool unbalanced, and I would get catches. I always have the gouge rolled onto the side.

I have tried the 40/40 angles, and just didn't care for them. It made the gouge too pointy for me. I prefer a more open flute, a rounded nose, and rolled over.

robo hippy

[Dale Miner]

I am thinking that the reason it can't be duplicated with a jig is that the jig does not roll over far enough and the bevel on the wings is more vertical which would make the wing rather thin. When hand rolled, You get a more blunt angle, and more heavy duty wing.

It has been a while, but I seem to remember that Stuart used his gouges with the flutes more up/vertical rather than rolled onto the side. That would give a higher shear angle when cutting. Problem with that is that it didn't take much to wander over onto the high side of the wing, which makes the tool unbalanced, and I would get catches. I always have the gouge rolled onto the side.

I have tried the 40/40 angles, and just didn't care for them. It made the gouge too pointy for me. I prefer a more open flute, a rounded nose, and rolled over.

robo hippy

In my mind's eye, the 'higher shear angle' from a straight up flute is not apparrent. As the flute is rolled over on it;s side, the final cutting of the fibers occurs more and more at the bottom of the flute. At a full rolled or 'closed' flute, the final cutting is done with the very bottom of the flute and that portion of the edge is in the full shear and no peel position. A bowl bottom, or bottom feeder grind with a consistent beverl angle used with the flute straight up has the highest shear to my way of thinking. Much easier to control though if rolled over about 30 degrees to prevent the top of the flute from entering the wood.

Like you, I prefer a more generous radius in the bottom of the flute and the flute rolled over to about 45 degrees. With the flute rolled at 90 degrees, or fully closed, the all shear and no peel presentation makes taking anything other than a very light cut impossible. Makes a great cut though.

I have no idea what angle my gouges are ground at, but the angle between the tip and the wing is just barely acute from 90 degrees and as such the gouge can be used to make a square corner for chucking in straight jaws.

I attended a full day demo by Stuart and his explanation of grinds and angles. He seems to be knowledgeable about the various factors affecting cutting action and grind angles, but for me, it was to precise. Most edges are able to cut if near to a 45 degree angle. In that demo, Stuart promoted a push cut only for the outside of bowls. However, in that demo Stuart did not use tailstock support when roughing the outside of bowls. He mounted between centers, cut a mortise in the bowl face on one bowl, and used that mortise to cut his tennon and OD rough sans tailstock support. I use tailstock support for roughing the outside and cutting the tennon and use a pull cut for a portion of the OD and cutting the tennon.

Also, spent a day in a hands on with Mike Mahoney. I think Mike and Stuart use similar hand grinds. As I understand it, the advantage of a hand grind aside from being quicker, is that the edge angle is consistent from tip to end of wing, and is less prone to come off the bevel when using a straight up flute. Mike had most of the students regrind to his grind, but left me to my own devices. Hmmm.......

Both Stuart and Mike are very good demonstrators and I would recommend them.

[Mike Cruz]

Okay, am I the only one not drinking the Cool-Aid here? I mean, yes this is informative. Yes, the OP has a point.

BUT, as I started reading this, a couple things hit me... The title suggests that the OP is asking a question. No, it is fact/information that he is giving. This was posted pretty much right after the OP became a member. He not only has only 4 posts, but never responded to the thread again. And as I was reading, the all important message of the thread seemed to come through... He invented a gismo to measure the angle. AHA! Looked like he was trying to sell his gismo.

THEN I noticed this was an 8 month old thread...and the OP STILL hasn't responded to the thread. Very suspect to me... Now, that said, again, very informative. And you don't have to buy his gismo to benefit form the info...just add a few degrees to you bevel angle, and you get the edge angle correct...

[Duane Meadows]

And you don't have to buy his gismo to benefit form the info...just add a few degrees to you bevel angle, and you get the edge angle correct...

In Stuart defence(not that he needs it!)... even he said that in his original post! Also his videos on turning, IMHO, are the best I have seen.

[Grant Wilkinson]

Tks again, Reed. I believe that you are right about Stuart's "jig statement". I've done the 45-45 grind using a platform and using the Varigrind. I can quite easily duplicate the nose angle and sweep using the jig. However the wings are much straighter and therefore narrower using the jig.