Roughing Gouge doing two Cuts

[Nick Valenza]

My wife and I were invited to a famous turners (they live semi-locally) shop recently after I demonstrated at a Woodturners club. Apparently this meeting has been going on for 35+ years and we were honored to be invited. He demoed a simple centerwork piece, and then asked if anyone wanted to try and make the same piece on his lathe. No one else volunteers so I did. It was a piece of curly white oak, and the demonstrator used the Roughing Gouge mostly to make theirs, but I wanted to use a 5/8" wide by maybe 1/4" think skew with what could have been a 30 degree combined bevel angle. As I was using it, i was getting alot of chatter. I was turning at the max #2 belt at 1800 and it was a piece 2.5" diameter. By the time I was done shaping it, there were major tearout. The demostrator said that the skew is the wrong tool for the application, since the skew doesn't do well with interlocking or funky grain. When I asked if it was because the roughing gouge had so much more steel, he replied by saying the roughing gouge is doing 2 cuts at once, a roughing cut and a slicing cut. There was further discussion but they said if you put it under a microscope, you will see. So, i made the last finished cuts with the roughing gouge, not understand how the steel was able to produce that finish. Bare in mind, it was a demo under time, and we had to leave earlier due to babysitting restraints, so we couldn't ask him about it. Some people also get silently annoyed () with my engineering-like brain that wants to understand exactly why things happen, primarily when their time is being used to explain it. I don't know him that well or the crowd yet to put them through a detailed explanation on a microscopic level. lol. So I want to figure it out on my own, and come back to him next month with an intelligent question. Does anyone have a literature or a video that explains this? Or is someone able to ELI5?

Thanks for reading and Anyone to contributes to the "Make My Brain Rest" foundation!

Nick

 

[hockenbery]

My technical expertise was applied mathematics - getting the wrong answer fast- and quantifying the error.
So I’m focused on results. And getting close.

I know that when a skew lifts the grain creating tearout, a gouge will often make a clean or cleaner cut.
I always thought it was because the curve of the gouge did some cutting more perpendicular to the work while the skew was mostly horizontal.
Be interest in what you learn

 

[Nick Valenza]

My technical expertise was applied mathematics - getting the wrong answer fast- and quantifying the error.
So I’m focused on results. And getting close.

I know that when a skew lifts the grain creating tearout, a gouge will often make a clean or cleaner cut.
I always thought it was because the curve of the gouge did some cutting more perpendicular to the work while the skew was mostly horizontal.
Be interest in what you learn

Thanks @hockenbery. I feel the same way, meaning something to do with the curve. But right now, and am thinking Why not a Spindle gouge vs a roughing gouge, both are curved. The demostrator/host did say to treat the roughing gouge like a curved skew.

 

[Richard Coers]

Once you get chatter with a skew it's hard to remove it. Hone the skew, take lighter cuts, and relax your grip. The grip relaxing may sound counter intuitive, but it makes a great difference. Presentation of the spindle roughing gouge dictates how it cuts. Present it perpendicular to the work and use the bottom of the flute and it cuts like a gouge. Present it to the work at an angle and have the flute opened to 45 degrees or so, and it shears more like a skew. Saying a skew is the wrong tool is like saying a hand plane is the wrong tool to surface wood. It's the user's job to orient the tool and use it in the correct direction. The great Rick Reeves made over 11,000 spinning wheels with a wide, very shallow gouge that he used like a gouge and a skew.

 

[Asher Langton]

skew with what could have been a 30 degree combined bevel angle

I can't speak to the "2 cuts" aspect here, but 30° included is quite sharp. I use 40° included on my skews and think 30° would likely be difficult to control and would dull quickly, particularly on curly oak.

 

[john lucas]

30 degree included is a goid angle for a skew. Your rpm was a little low and you may have been forcing the cut.
I have found however on curly maple a skew will.often tear out where a tool with a curved edge will cut it Clean. I use a spindle gouge.
I have also found that I can get a cleaner cut from a 6mm Hunter carbide than I can from a 12mm Hunter carbide. Something about the smaller diameter circle just cuts cleaner.

 

[Dennis Weiner]

"The demonstrator/host did say to treat the roughing gouge like a curved skew."
Difficult to put in words something that one does instinctively but here goes. If you imagine positioning the roughing gouge flute up causing it to contact the spinning side grain-oriented piece so that it begins cutting into the workpiece tangentially you will be peeling the wood off the piece. This is initially how it will be cut. At the same time, As you advance the cut into the side of the wood, you begin hitting and cutting endgain with the arc of the SRG . The slightly curved arc is slicing into end-grain. This second action is a very clean cut across end-grain. Perhaps this is why he said it was producing 2 different cuts at the same time. You are peeling side grain and slicing end-grain with two different parts of the SRG.
Cutting into straight grain will work. Results will not be as good using wood with wavey grain.







Here is a Short video from Stuart Batty demonstrating the roughing gouge.

stuart batty roughing gouge - Yahoo Video Search Results

The search engine that helps you find exactly what you're looking for. Find the most relevant information, video, images, and answers from all across the Web.

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[Nick Valenza]

Once you get chatter with a skew it's hard to remove it. Hone the skew, take lighter cuts, and relax your grip. The grip relaxing may sound counter intuitive, but it makes a great difference. Presentation of the spindle roughing gouge dictates how it cuts. Present it perpendicular to the work and use the bottom of the flute and it cuts like a gouge. Present it to the work at an angle and have the flute opened to 45 degrees or so, and it shears more like a skew. Saying a skew is the wrong tool is like saying a hand plane is the wrong tool to surface wood. It's the user's job to orient the tool and use it in the correct direction. The great Rick Reeves made over 11,000 spinning wheels with a wide, very shallow gouge that he used like a gouge and a skew.

It wasnt my skew, with my sharpness, and only going 1800. I feel like i could have gotten it to not tearout had it been that way. But i did learn that the roughing gouges makes two cuts, and now i have to learn more about it!

 

[Nick Valenza]

30 degree included is a goid angle for a skew. Your rpm was a little low and you may have been forcing the cut.
I have found however on curly maple a skew will.often tear out where a tool with a curved edge will cut it Clean.

I feel like the speed was low, i would usually turn that between 2500-3000. and i was defiantly pushing to get it to rough shape, but then it was too late. The amount of tear out that was caused was very deep, then i felt alittle embarrassed cause of the tear out, But i am telling myself it was cause the skew wasn't very sharp and the RPMs were too slow relative to how fast I wanted to push/gluide the steel through the wood so I would not bore the audience. But if I am wrong, i want to know. I am not saying any of the other turners are wrong, i just want to push the boundries and do what I truely think can be done, and if I am wrong, then learn a great lesson by failing!!

 

[Nick Valenza]

You are peeling side grain and slicing end-grain with two different parts of the SRG.

I ended up using the SRG nearly upside down, using the left wing to 'Peel' at the side grain at a negative rake angle. I still cant imagine how that is 2 cuts. Did the Demonstrator/Host mean that is makes two cuts only when it is used the the traditional sense, fully upright?

 

[hockenbery]

I ended up using the SRG nearly upside down, using the left wing to 'Peel' at the side grain at a negative rake angle. I still cant imagine how that is 2 cuts. Did the Demonstrator/Host mean that is makes two cuts only when it is used the the traditional sense, fully upright?

I don’t use the SRG often in demos. Do have these two shots.
While they don’t seem close to your description of the cuts you were making, you can sort of see two cuts going from square to round..
The cross grain cut moving into a peeling cut. The peeling cut is at close to 90 in angle to the typical skew cut.

 

[Dave Landers]

Here's what I think your host may have meant about "2 cuts".

As an example: If you cut along a cylinder (left to right or vice-versa) and have the flute of a gouge up (like this: U ), then the bottom (nose) of the gouge is hogging out (roughing) a "shelf" of wood ahead of your cut. And the side wing is following that, rubbing the bevel and making a shearing or slicing cut (sorta like a skew would). So the nose is getting rid of wood at the same time the wing is making a cleaner cut.

Similar thing happens (to varying degrees) with any gouge making any sort of cut. But it's more evident with the SRG due to its shape.
I've heard Stuart Batty make a similar statement about the push cut with a 40/40 gouge.

A skew, since it does not curve like a gouge, can't always make as heavy a cut, because it doesn't have a "nose" to clear the way.

However, we all use our tools a bit differently, and we all tend to develop our own way of thinking about how/why they cut like they do.

 

[Tom Gall]

“My wife and I were invited to a famous turners (they live semi-locally) shop recently after I demonstrated at a Woodturners club. Apparently this meeting has been going on for 35+ years and we were honored to be invited…..”

I’m assuming you went to Mike’s shop. Mike reinstated the meetings after Dave Hardy passed away in 2015. Look him up!

Mike, a long time woodcarver - turned woodturner, is one of the best out there and one of the most creative people I know. Look him up! He won’t steer you wrong.

The SRG can give an almost skew-like surface when used at an angle on a trued up surface. I think the mass of the SRG and small cutting edge makes it easier to use than a skew, especially for long cove-like shapes. Then again, I rarely use the skew!!!

 

[Richard Findley]

I feel like the speed was low, i would usually turn that between 2500-3000. and i was defiantly pushing to get it to rough shape, but then it was too late. The amount of tear out that was caused was very deep, then i felt alittle embarrassed cause of the tear out, But i am telling myself it was cause the skew wasn't very sharp and the RPMs were too slow relative to how fast I wanted to push/gluide the steel through the wood so I would not bore the audience. But if I am wrong, i want to know. I am not saying any of the other turners are wrong, i just want to push the boundries and do what I truely think can be done, and if I am wrong, then learn a great lesson by failing!!

I never turn anything that fast, there really is no advantage as far as I’m concerned. One of the finest spindle turners I know turns incredibly slowly compared to this, often around 1200rpm. 1850rpm is the fastest I ever turn.

 

[Richard Findley]

When a skew struggles with difficult grain a roughing gouge will usually cope better. I’m still trying to work out exactly why. I’ll be interested to read your findings. My skew is usually around 40° included, my roughing gouge is 35° so it’s not the angle of the grind, I don’t think.

 

[Don Stephan]

My spindle roughing gouge (SRG) is an arc of a circle, and is shaped straight across, with a consistent sharpening bevel from corner to corner. Thus the active portion of the cutting edge has the same relation to th3e oncoming wood regardless of the direction the flute is facing. Don't understand why the direction of the flute was mentioned or important. This would seem to be true when the axis of the SRG is perpendicular to the lathe axis, taking a peeling cut, and when the axis of the SRG is angled relative to the lathe axis, taking a shear cut. Can someone explain?

 

[Dean Center]

Your engineering brain that has to know Why may be in for a rough time in the company of turners. Rarely, someone will get out a microscope, even a scanning electron microscope, and get down into the weeds. Occasionally, someone like John Lucas or Reed Gray will test out a variety of different methods or tools or grinds, and reach a useful conclusion. And sometimes, extraordinarily observant and capable woodturners like Glenn Lucas or Stuart Batty will share their observations of what works best with the rest of us. Most often, there's no real data to support an answer on the Why. It just is. Skews and screwy grain may have an explanation, (and the potential for disagreement about that explanation) but most of us just accept that it's true, and get on with making stuff. Like your host.

 

[Adrian Wilson]

I can't speak to the "2 cuts" aspect here, but 30° included is quite sharp. I use 40° included on my skews and think 30° would likely be difficult to control and would dull quickly, particularly on curly oak.

I have been watching a lot of Steve Jones (woodturner21) videos; he is the best I have seen on a skew, and I am trying to learn how to do what he does.He uses 30 degrees. My skews are at 40, so I was introducing a new one, and ground that at 30 degrees. Immediately a big improvement in my results. The new one is actually an antique chisel, not HSS, and there are some other differences, but I am going to pursue it and add another new skew, at 30 degrees. I'm not sure if it is harder to control; different, yes.

 

[Asher Langton]

I have been watching a lot of Steve Jones (woodturner21) videos; he is the best I have seen on a skew, and I am trying to learn how to do what he does.He uses 30 degrees. My skews are at 40, so I was introducing a new one, and ground that at 30 degrees. Immediately a big improvement in my results. The new one is actually an antique chisel, not HSS, and there are some other differences, but I am going to pursue it and add another new skew, at 30 degrees. I'm not sure if it is harder to control; different, yes.

Interesting! I watch a lot of Steve's videos too. I assume some of the differences are just immaculate tool presentation. Some of the cuts he makes would be instant catches in most turners' hands. But I've got a spare Benjamin's Best skew or two, so I'll grind one to 30° included and see how it works for me.

 

[Neil S]

Here's what I think your host may have meant about "2 cuts".

As an example: If you cut along a cylinder (left to right or vice-versa) and have the flute of a gouge up (like this: U ), then the bottom (nose) of the gouge is hogging out (roughing) a "shelf" of wood ahead of your cut. And the side wing is following that, rubbing the bevel and making a shearing or slicing cut (sorta like a skew would). So the nose is getting rid of wood at the same time the wing is making a cleaner cut.

Similar thing happens (to varying degrees) with any gouge making any sort of cut. But it's more evident with the SRG due to its shape.
I've heard Stuart Batty make a similar statement about the push cut with a 40/40 gouge.

Yes, @Dave Landers, that is a good explanation.

Stuart Batty goes into this in some details in some of his demos that can be seen online.

 

[Adrian Wilson]

Interesting! I watch a lot of Steve's videos too. I assume some of the differences are just immaculate tool presentation. Some of the cuts he makes would be instant catches in most turners' hands. But I've got a spare Benjamin's Best skew or two, so I'll grind one to 30° included and see how it works for me.

He discusses it in this video on 'skew chisel basics'. Yeah, report back, interested what you think.

View: https://www.youtube.com/watch?v=IpGRrF7SyHE&t=16s

 

[Dean Center]

I have been watching a lot of Steve Jones (woodturner21) videos; he is the best I have seen on a skew, and I am trying to learn how to do what he does.He uses 30 degrees. My skews are at 40, so I was introducing a new one, and ground that at 30 degrees. Immediately a big improvement in my results. The new one is actually an antique chisel, not HSS, and there are some other differences, but I am going to pursue it and add another new skew, at 30 degrees. I'm not sure if it is harder to control; different, yes.

In general, the narrower the included angle (the pointier the skew), the better the cut you will get, but also the grabbier it will be and the more it will lift funky grain. The wider the angle, the 'safer' it is, but the less effective it will be at what skews do best.

 

[Dennis Weiner]

Not to be confused with the included angle, The actual cutting angle of the skew is not as important as the angle it makes when slicing the wood. You can position a 30-degree tool to cut at 40-45. I wouldn't buy a second skew.

 

[Ron Solfest]

Rightly or wrongly, I think of a skew cutting “into” the grain on a spindle, hence prone to tear out; while an SRG or gouge cuts “into” the grain as well as “across” the grain because of the curve, hence cutting off the sliver before it gets long enough to tear out.

Stop short of the end with a skew and see all of the fuzz you get, stop short with a gouge and it leaves a clean shoulder.

 

[john lucas]

Not totally true Ron. I make flowers out of green limbs. You start the cut lifting the fibers and then stop before the end of the limb. You get the same lifting cut with a spindle gouge. I thought you needed a skew to do these flowers but found out I could do them with a spindle gouge as well.

 

[Dean Center]

I make flowers out of green limbs. You start the cut lifting the fibers and then stop before the end of the limb. You get the same lifting cut with a spindle gouge. I thought you needed a skew to do these flowers but found out I could do them with a spindle gouge as well.

OK, John. You're ready for the Bedan.

 

[john lucas]

I've got one. I still use my skew and rarely find an advantage of the Bedan. I have seen jean Escoulen do miracles with it.

 

[Asher Langton]

When a skew struggles with difficult grain a roughing gouge will usually cope better. I’m still trying to work out exactly why. I’ll be interested to read your findings. My skew is usually around 40° included, my roughing gouge is 35° so it’s not the angle of the grind, I don’t think.

What angle do you grind your beading and parting tool to? I ground my homemade beading and parting tool to 50° included, same as my parting tools, but maybe that’s too blunt?

 

[Richard Findley]

What angle do you grind your beading and parting tool to? I ground my homemade beading and parting tool to 50° included, same as my parting tools, but maybe that’s too blunt?

I use 22° on each face, I find it’s a good balance between being sharp enough to get a good clean cut but still be controllable. Long grinds give lovely king shavings in a planing cut but are much more difficult to use for cuts like rolling beads.