Light Cuts - Peeling, not Poking
It's snowing, so I'm not going to go out onto the wet woodpile after those
two chunks of birch. I'm certainly not going to buck up any more until it's dry. Are you a peeler or a poker? I was making a few of those cornered bowls/dishes yesterday afternoon when I remembered how I looked initially at some posts and sites about keeping the edges from tearing out. As I normally just run the bottom to top without significant problem http://groups.msn.com/NovaOwners/geo...nw?albumlist=2 , I asked what I was doing that others were not. Then the answer hit me. They're poking, not peeling. I peel almost all the time, and if I correctly interpret a couple of recent threads here and elsewhere, as well as some not so recent, a lot of people don't. Consider the circumstantial evidence: Threads on flying chips and tight-necked smocks. Threads on full face shields to deflect shavings. Threads on high horsepower and torque requirements. Threads on dented toolrests. Threads on turner's elbow. Threads on the need to grip wood, rather than just hold it in a chuck. If you peel, the chips pile up on your hand when the toolrest is tight, fall when there's a big enough gap. That's Newton, isn't it? In motion stays in motion, even if separated from the piece,continuing in the direction of rotation. Convex is easy to clean up, as you can see from the form and fall of shavings in the album. Concave can be a bit difficult. Those that don't pile up on the close tool and rest fall, and are flung from the bottom of the bowl against, in my setup, the wall. Sometimes in deep pieces, or pieces with a bit of undercut, they pile up until there's sufficient force to eject them beyond the rim, leaving around 2 o'clock to noon, and landing in my hair, if I don't clear them periodically. Never do they rise to my t-shirted throat or nonexistent face shield. If you peel, the best cut is the one that takes the least effort. Leave the tool on the rest, and let the work come to it. Angular velocity alone removes the shaving, not torque or horsepower. Who was it said, correctly, that the tool removes the shaving? Further, as the tool never leaves the rest, your knuckles remain pink, your elbow experiences no impacts, nor does the rest. Last, you don't need to grip and deform your wood with the chuck. Maybe that's what they mean by "light" cuts? Then you can keep the force per unit area well below the level which would leave dents. All right, now make those shavings twist and fall. Save your lathe, yourself, and your work a lot of grief by peeling, not poking. Less sanding, too. Why do the shavings twist? I used to wager Pepsi money at school that I could make them twist clockwise or counter. The old man teaching Physics at the lathe again.... |
On Mon, 2 May 2005 12:37:29 -0400, "George" george@least wrote:
George... could you please describe "peeling"? Being an old fart with several parts of my body mistreated in a less than intelligent youth, I try to make both work and play as low impact and comfortable as possible... and it sounds like I'm working too hard at this.. It's snowing, so I'm not going to go out onto the wet woodpile after those two chunks of birch. I'm certainly not going to buck up any more until it's dry. Are you a peeler or a poker? I was making a few of those cornered bowls/dishes yesterday afternoon when I remembered how I looked initially at some posts and sites about keeping the edges from tearing out. As I normally just run the bottom to top without significant problem http://groups.msn.com/NovaOwners/geo...nw?albumlist=2 , I asked what I was doing that others were not. Then the answer hit me. They're poking, not peeling. I peel almost all the time, and if I correctly interpret a couple of recent threads here and elsewhere, as well as some not so recent, a lot of people don't. Consider the circumstantial evidence: Threads on flying chips and tight-necked smocks. Threads on full face shields to deflect shavings. Threads on high horsepower and torque requirements. Threads on dented toolrests. Threads on turner's elbow. Threads on the need to grip wood, rather than just hold it in a chuck. If you peel, the chips pile up on your hand when the toolrest is tight, fall when there's a big enough gap. That's Newton, isn't it? In motion stays in motion, even if separated from the piece,continuing in the direction of rotation. Convex is easy to clean up, as you can see from the form and fall of shavings in the album. Concave can be a bit difficult. Those that don't pile up on the close tool and rest fall, and are flung from the bottom of the bowl against, in my setup, the wall. Sometimes in deep pieces, or pieces with a bit of undercut, they pile up until there's sufficient force to eject them beyond the rim, leaving around 2 o'clock to noon, and landing in my hair, if I don't clear them periodically. Never do they rise to my t-shirted throat or nonexistent face shield. If you peel, the best cut is the one that takes the least effort. Leave the tool on the rest, and let the work come to it. Angular velocity alone removes the shaving, not torque or horsepower. Who was it said, correctly, that the tool removes the shaving? Further, as the tool never leaves the rest, your knuckles remain pink, your elbow experiences no impacts, nor does the rest. Last, you don't need to grip and deform your wood with the chuck. Maybe that's what they mean by "light" cuts? Then you can keep the force per unit area well below the level which would leave dents. All right, now make those shavings twist and fall. Save your lathe, yourself, and your work a lot of grief by peeling, not poking. Less sanding, too. Why do the shavings twist? I used to wager Pepsi money at school that I could make them twist clockwise or counter. The old man teaching Physics at the lathe again.... mac Please remove splinters before emailing |
"mac davis" wrote in message ... On Mon, 2 May 2005 12:37:29 -0400, "George" george@least wrote: George... could you please describe "peeling"? Being an old fart with several parts of my body mistreated in a less than intelligent youth, I try to make both work and play as low impact and comfortable as possible... and it sounds like I'm working too hard at this.. Short answer, it's what drops the curlies rather than throwing the chunkies. Longer answer, it's presenting the tool to the work so that the rotation draws the wood along the edge to cut and release. It involves beginning almost perpendicular to the surface to get the cut started, then rotating the tool so it slides and peels. The motion of the tool - downgrain, of course - allows a continuous twisted shaving. Have you taken a look at my page at http://personalpages.tds.net/~upgeor...20Pictures.htm, where I show the gouge angles I use? They're just quick illustrations, but you can see how the leading edge of the gouge begins the cut, while the trailing end - the convex shape keeps you from digging in - is almost vertical as it finally severs the shaving. In roughing a bottom, you cut from center outward, bottom to top like http://personalpages.tds.net/~upgeor...ugh%20Page.htm , hugging the rest, until you've got an uninterrupted surface. It's easier to get one in close than out near the rim. Then you can guide the bevel and peel like the last picture on that page. Page five shows some inside hogging, center toward rim and vice versa - both are downgrain - check the broad gouge in http://personalpages.tds.net/~upgeor...-Thickness.jpg to see the twist and fall. You can see gouge angles for roughing (used as a skew), forged spindle and bowl gouges on http://personalpages.tds.net/~upgeorge/Smooth%20Two.htm Note that the worst mechanical support is the one for the bowl gouge, especially if you use either a square-top or round toolrest. I'm resting it on two places in the picture. This is why a lot of people use long tool handles on their bowl gouges - they're using themselves to steady the tool instead of the rest. If they were using forged pattern gouges on edge, the rest would take the knocks as they take the shavings, and the vertical travel of the handle would be much less. The Nova has square-topped rests, which favor the forged gouges with a blunt, rather than fingernail grinds. http://groups.msn.com/NovaOwners/geo...to&PhotoID=228 gives a look it the rest, and at the way I collect shavings - I let them fall into a bag! The better you support the tool on the rest, the less you have to take it in the elbow. A-B-C Anchor the tool to the rest. Bevel touched to the surface. Cut to the curl. Once you've got the curl, continue. Pull or push, as appropriate, with the opposite hand along the rest. Your good hand rotates to compensate for differing curves as you go along. I like to show off sometimes by raising one hand or the other as I'm cutting. You have to actually have a bevel guiding to do this, though, and you can't rotate the gouge for curve as easily. I've got some other pictures that might help, if you don't mind off-group. |
On Tue, 3 May 2005 13:58:39 -0400, "George" george@least wrote:
Short answer, it's what drops the curlies rather than throwing the chunkies. Longer answer, it's presenting the tool to the work so that the rotation draws the wood along the edge to cut and release. It involves beginning almost perpendicular to the surface to get the cut started, then rotating the tool so it slides and peels. The motion of the tool - downgrain, of course - allows a continuous twisted shaving. Have you taken a look at my page at http://personalpages.tds.net/~upgeor...20Pictures.htm, where I show the gouge angles I use? They're just quick illustrations, but you can see how the leading edge of the gouge begins the cut, while the trailing end - the convex shape keeps you from digging in - is almost vertical as it finally severs the shaving. In roughing a bottom, you cut from center outward, bottom to top like http://personalpages.tds.net/~upgeor...ugh%20Page.htm , hugging the rest, until you've got an uninterrupted surface. It's easier to get one in close than out near the rim. Then you can guide the bevel and peel like the last picture on that page. Page five shows some inside hogging, center toward rim and vice versa - both are downgrain - check the broad gouge in http://personalpages.tds.net/~upgeor...-Thickness.jpg to see the twist and fall. You can see gouge angles for roughing (used as a skew), forged spindle and bowl gouges on http://personalpages.tds.net/~upgeorge/Smooth%20Two.htm Note that the worst mechanical support is the one for the bowl gouge, especially if you use either a square-top or round toolrest. I'm resting it on two places in the picture. This is why a lot of people use long tool handles on their bowl gouges - they're using themselves to steady the tool instead of the rest. If they were using forged pattern gouges on edge, the rest would take the knocks as they take the shavings, and the vertical travel of the handle would be much less. The Nova has square-topped rests, which favor the forged gouges with a blunt, rather than fingernail grinds. http://groups.msn.com/NovaOwners/geo...to&PhotoID=228 gives a look it the rest, and at the way I collect shavings - I let them fall into a bag! The better you support the tool on the rest, the less you have to take it in the elbow. A-B-C Anchor the tool to the rest. Bevel touched to the surface. Cut to the curl. Once you've got the curl, continue. Pull or push, as appropriate, with the opposite hand along the rest. Your good hand rotates to compensate for differing curves as you go along. I like to show off sometimes by raising one hand or the other as I'm cutting. You have to actually have a bevel guiding to do this, though, and you can't rotate the gouge for curve as easily. I've got some other pictures that might help, if you don't mind off-group. wow! thanks, George.. I printed this out, it's a LOT to absorb at one reading... I've seen your pages and the pics that you mentioned, but as my knowledge and experience increase, they begin to be understandable.. I spent this evening just playing with branch wood on the chuck.. different grinds for the tools, lighter pressure, smoother cuts, etc.. paying attention to where the shavings (well, still mostly chips) were going... quite an experience and opened a few mental doors.. mac Please remove splinters before emailing |
"mac davis" wrote in message ... I spent this evening just playing with branch wood on the chuck.. different grinds for the tools, lighter pressure, smoother cuts, etc.. paying attention to where the shavings (well, still mostly chips) were going... quite an experience and opened a few mental doors.. As another turner friend said - the shavings are instant feedback. |
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