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Taking fine cuts inside a bowl...

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Found myself betwixt and between today, making finishing cuts on the 10.5" Madrona bowl. Really had some bad tool marks after choosing the wrong gouge, then couldn't seem to get the right combination for a fine cut that would only remove tool marks and a bare shaving of the smoother wood. Didn't seem appropriate for a scraper, kinda between a scraper and a gouge. The worst marks were in the flattish bottom of the bowl (~2-1/2"+), so I switched from the bowl gouge to a bottom-of-the-bowl gouge. Oy! Didn't handle well on this shape, way too aggressive (I've loved it on other, smaller, deeper bowls). Went to a smaller BOTB gouge, that worked a bit better. Ended up using the scraper waaaayyyy more than seems sensible.

I'm sanding now, but any advice would help for the next one. This bowl has been a real challenge. Here I thought than a shallower, wide bowl would be so much easier. Not. Might be the wood, which is pretty hard, but I sense that there's something else making it a new experience.
 

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The inside of dried bowl is a bit of a challenge. Because of the up interupted cut caused by the warp.
I try to take several small controlled cuts ( instead of one big one) to get the first 1-2 inches of the inside wall round.

I find a 1/4" bowl gouge with a Michelson grind does a great job in smoothing the first inch or two of the wall.
The bevel riding cuts the rest if the way to the

The hemispherical bowls are likely the easiest overall to hollow.
The cuts are arcs and the curve runs from the rim to the bottom center.
With That continuous curve I am always cutting across fibers and get a clean cut.

issue with wide bowls it is difficult to make the continuous curve and we end with a flat bottom.
The gouge is cutting straight into endgrain twice a revolution

Also it is harder to keep the bevel on flat than it is to keep,it on a curve.
Often it I easier to use a scraper on a wide level bottom.

If you have the opportunity to have some one tech you the flute up shear cut it makes inside surfaces smooth
 
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I don't like the bevel rubbed finish cut, as Jimmy Clewes commented, 'it burnishes the wood, and first thing you have to do when sanding is to cut through the burnishing.' Some days, the cuts through the inside go smooth and easy. On days when they don't, the NRS (negative rake scraper) is becoming my favorite tool. Anything to save on sanding time... For your BOB tools, the fluteless gouge takes off the least or finest shavings, and the others, because they have flutes, can dig in a bit deeper. You are the one that controls the cut. If you are getting a bit tired, that does make things go less smooth...

robo hippy
 

hockenbery

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The bevel can burnish the wood if you push it against the surface.
If you are burnishing the wood you have too much pressure on the bevel
Let the bevel float over the wood just close enough to support the cut.

Shortening the bevel by grinding off the heel reduces bevel contact more
The advanced shear cut technique with flute up has almost no bevel contact.

The Michelson grind has a very short micro bevel. Does not burnish.

When just learning it is better to rub a tiny bit more than needed, than it is to let the tool come off the bevel.
Rub too much and the gouge won't cut or it make chatter.
 
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The bevel can burnish the wood if you push it against the surface.
If you are burnishing the wood you have too much pressure on the bevel
Let the bevel float over the wood just close enough to support the cut.

Shortening the bevel by grinding iff the heel reduces bevel contact more
The advanced shear cut with has almost no bevel contact.

The Michelson grind has a very short micro bevel. Does not burnish.

When just learning it is better to rub a tiny bit more than needed, than it is to let the tool come off the bevel.
Rub too much and the gouge won't cut or it make chatter.
I was being very careful about the bevel, burnishing wasn't the problem. To get the right approach, I adopted,, some time ago, the imagery of riding the bevel as one would ride a wave. All gouge heels have been ground back for some time now, but have yet to try a micro-bevel.
 

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If you grind off the bottom of the bevel it reduces the burnishing tremendously. Also trying to glide the bevel instead of push on it as Al said.
 
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If you grind off the bottom of the bevel it reduces the burnishing tremendously. Also trying to glide the bevel instead of push on it as Al said.
Hmmmm, you must have missed my 8:49 AM post? "I was being very careful about the bevel, burnishing wasn't the problem. To get the right approach, I adopted,, some time ago, the imagery of riding the bevel as one would ride a wave. All gouge heels have been ground back for some time now, but have yet to try a micro-bevel." You see, I pay attention to the basics!:) Hey, John, if you have time, check your messages -- I sent a ? about the aluminum wheels.
 
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...The worst marks were in the flattish bottom of the bowl (~2-1/2"+), so I...

This is one area I rely on hand scraping with the small card scrapers, mostly with the grain, lathe off. One with a very gradual curve is good for mostly flat areas. Sometimes I unscrew the chuck from the lathe and sit to finish. Very little sanding required. I have found nothing easier or quicker to get a perfect bottom center.

JKJ
 
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This is one area I rely on hand scraping with the small card scrapers, mostly with the grain, lathe off. One with a very gradual curve is good for mostly flat areas. Sometimes I unscrew the chuck from the lathe and sit to finish. Very little sanding required. I have found nothing easier or quicker to get a perfect bottom center.

JKJ
I suspect there'll come a time when I'd like to try that, John. When I was flat-woodworking, I played with a card scraper just a little bit, but would have to invest in the smaller scrapers. Do you have a favorite source?
 
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I suspect there'll come a time when I'd like to try that, John. When I was flat-woodworking, I played with a card scraper just a little bit, but would have to invest in the smaller scrapers. Do you have a favorite source?

I have three kinds: the first one I cut from a larger scraper with a Dremel.
scraper_PB054025_s.jpg

I found a set of small curved scrapers at Highland Hardware in Atlanta (now Highland Woodworking). I can spend $1000/hour in that store. Ack.
Years later I found another set of mini scrapers at Woodcraft. I see them in the online catalog, Lynx brand I think.
The smaller scrapers are good for inside curves and outside coves (with lathe spinning) but are thinner and don't seem to hold an edge as long.

Somewhere I found a set of full-sized scrapers that included two with gentle radii on the long edges. The are perfect for many shallow bowls, wings, and the center bottoms of things.

I grind new profiles from large card scrapers as needed. The higher quality scrapers used by fine cabinetmakers are the best, probably because the steel is better. I bought another stack of old flat-work card scrapers for a few bucks just last week which I'll cut and grind into some smaller shapes. Note that these are probably carbon steel and not HSS so you have to be careful not to overheat them when grinding.

I've posted this picture before, but here are some of what I use:
scrapers_.jpg

Once I got more proficient at using scrapers to remove tool marks (and tearout) I quit using the rotary drill for power sanding. There is far less fine dust in my shop. There is also the zen factor: spending some quiet, relaxing time in a comfortable chair with soft blues playing, glass of iced tea at hand instead of standing at the lathe with a respirator and face shield making a cloud of dust!

JKJ
 

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Everyone who has given advice in this thread, are very capable woodturners......and each of them are getting great results on their own turnings by varied methods.

As of late, I'm basically using the "micro bevel" on a standard bowl gouge. The very steep angle of the Mahoney style bottom feeder does work, but I think it works better for an interior that has a long continuous curve. For bowls that intentionally have a flat, or flat-ish bottom transitioning into very pronounced curves towards the sides, I'm leaning toward a bowl gouge with the micro bevel. The bevel is lightly rubbing just enough to guide the cut. (I know you get that, Jamie.) It's generally a push cut from close to the rim, and around the curvature of the sides......which becomes a pull cut as it transitions toward the flat central area of the bottom. For more initial shaping of the interior, the push cut can go all the way to the very center, but it's a bit more difficult to control well. The pull cut at the bottom center leaves a surface that is more refined, with less sanding. There will still be a need for some aggressive sanding in the interior, but with much less need for leveling little ridges and valleys......which really decreases the time needed for the initial coarse grit.

Other things need to work in harmony to get the best cut possible. The gouge needs to slide smoothly across the top of the tool rest. This can be enhanced by doing your own polishing of both the gouge and tool rest. Your grip on the tool needs to be light and with dexterity.....your muscles need to be loose, fluid, and relaxed......so that everything is working in harmony, and the tool "flows" through the cut. This can be a problem if there is the slightest catch. A catch can dangerously fling your tool out of your hands......so knowledge of how to avoid catches is stressed. Also.....needless to say......the sharper your cutting edge, the better the results.

I don't worry about the little bump at the very center of the bottom/interior.....as long as it is above the surrounding surface, and not a "divot". Sanding this bump is how I take care of it, and it's easy to do with a disc. As always, it does take a little practice to keep the bump from becoming a divot......but, I'm confident just about everyone can learn this technique with a minimum of effort. The concept is simple......practice is the key to success.

ko
 
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Everyone who has given advice in this thread, are very capable woodturners......and each of them are getting great results on their own turnings by varied methods.

As of late, I'm basically using the "micro bevel" on a standard bowl gouge. The very steep angle of the Mahoney style bottom feeder does work, but I think it works better for an interior that has a long continuous curve. For bowls that intentionally have a flat, or flat-ish bottom transitioning into very pronounced curves towards the sides, I'm leaning toward a bowl gouge with the micro bevel. The bevel is lightly rubbing just enough to guide the cut. (I know you get that, Jamie.) It's generally a push cut from close to the rim, and around the curvature of the sides......which becomes a pull cut as it transitions toward the flat central area of the bottom. For more initial shaping of the interior, the push cut can go all the way to the very center, but it's a bit more difficult to control well. The pull cut at the bottom center leaves a surface that is more refined, with less sanding. There will still be a need for some aggressive sanding in the interior, but with much less need for leveling little ridges and valleys......which really decreases the time needed for the initial coarse grit.

Other things need to work in harmony to get the best cut possible. The gouge needs to slide smoothly across the top of the tool rest. This can be enhanced by doing your own polishing of both the gouge and tool rest. Your grip on the tool needs to be light and with dexterity.....your muscles need to be loose, fluid, and relaxed......so that everything is working in harmony, and the tool "flows" through the cut. This can be a problem if there is the slightest catch. A catch can dangerously fling your tool out of your hands......so knowledge of how to avoid catches is stressed. Also.....needless to say......the sharper your cutting edge, the better the results.

I don't worry about the little bump at the very center of the bottom/interior.....as long as it is above the surrounding surface, and not a "divot". Sanding this bump is how I take care of it, and it's easy to do with a disc. As always, it does take a little practice to keep the bump from becoming a divot......but, I'm confident just about everyone can learn this technique with a minimum of effort. The concept is simple......practice is the key to success.

ko

Thanks for your detailed description, Odie. Two questions:
  • How far around the nose/sides of the sharpened part of the gouge does the micro-bevel go?
  • My mental walk-through stumbles on the pull-cut part. More detail there - how does that work? Wonder if we could incorporate Skype into the new forum.:D
 
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Check out this interesting article on edge versus wood. http://homepages.sover.net/~nichael/nlc-wood/chapters/caop.html Notice I said edge, so that people won't get hung up on the word "plane." Your "micro bevel" or shortened bevel or other suggestions adjust your clearance angle, which means the heel won't bounce and burnish. They can also modify your pitch angle which results in a greater percentage of scrape than slice, which can be used, if you have the steady hand, to produce see-through shavings.

OR you could take advantage of another phenomenon, that of a longer bevel (decreased sharpness angle) combined with a very small pitch angle. You could combine this with an even lower effective pitch angle by skewing the edge to the work. The smoother the slice, the smoother the surface. Edge is a bit more fragile, which means if you turn it broad in like a scraper it won't last long, but keeping the rest tight and the off hand heavy on the tool will prevent that. Works best with gouges like the old bowl makers used, if you have one around. Broader the sweep, the greater the possible skew and the lower the pitch angle.

3/4" wide gouge taking excelsior shavings. http://i35.photobucket.com/albums/d160/GoodOnesGone/InsideTrim.jpg
Orientation of gouge and a view of that area above it that tears out when you're too wide in the cut. Yellow birch, which is really prone to tear, and none showing. http://i35.photobucket.com/albums/d160/GoodOnesGone/Frame-From-MVI_1017.jpg

Action leveling then smoothing with the same gouge shows a couple of interesting points. First, the combination shear/skew angle being varied as the surface approaches true. Second, the swing entry performed by the control hand, where the tool does not move along the rest until the proper angle is obtained, as evidenced by the shaving. Frank Pain was right when he said the wood teaches you how to turn. http://vid35.photobucket.com/albums/d160/GoodOnesGone/TrueBottom.mp4
 
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Thanks for your detailed description, Odie. Two questions:
  • How far around the nose/sides of the sharpened part of the gouge does the micro-bevel go?
  • My mental walk-through stumbles on the pull-cut part. More detail there - how does that work? Wonder if we could incorporate Skype into the new forum.:D
Don't know about Odie, but one of the French demonstrators (Yann Marot) who is an instructor at the Escolen school in France, uses a 35 degree bevel on his spindle gouges and it is less than 1/16 inch . He uses this to clean up cuts and it was very effective
 

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...... OR you could take advantage of another phenomenon, that of a longer bevel (decreased sharpness angle) combined with a very small pitch angle.....

I did a double take before I figured out that you weren't talking about intentionally dulling the edge although if used improperly as you said, that would be the result. :D
 

odie

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Thanks for your detailed description, Odie. Two questions:
  • How far around the nose/sides of the sharpened part of the gouge does the micro-bevel go?
  • My mental walk-through stumbles on the pull-cut part. More detail there - how does that work? Wonder if we could incorporate Skype into the new forum.:D

I'm currently on vacation, and am having some difficulty using someone else's borrowed laptop.......

The entire interior surface can be done with the same deep flute bowl gouge, and I suspect it's ground similarly to the French demonstrator's spindle gouge Gerald mentioned above. Regardless, it's a very narrow strip where the angle changes slightly from the original grind of the heel.

Jamie, it's hard to know what it is you are visualizing with my description above pursuing this cut throughout the entire interior surface......but, in case you are thinking that the cut transitions from a push cut, to a pull cut with one continual sweep......it doesn't. At that point where it's decided to switch, a whole new grip and setting of the tool rest will be necessary to continue. Most of the innermost part of the interior can be done entirely with continued removal of material with the push cut over the entire surface....up until that point where you decide to continue with a more refined cut in the flat area of the interior. THEN, it can be pursued with the more refined pull cut.......

ko
 
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I'm currently on vacation, and am having some difficulty using someone else's borrowed laptop.......

The entire interior surface can be done with the same deep flute bowl gouge, and I suspect it's ground similarly to the French demonstrator's spindle gouge Gerald mentioned above. Regardless, it's a very narrow strip where the angle changes slightly from the original grind of the heel.

Jamie, it's hard to know what it is you are visualizing with my description above pursuing this cut throughout the entire interior surface......but, in case you are thinking that the cut transitions from a push cut, to a pull cut with one continual sweep......it doesn't. At that point where it's decided to switch, a whole new grip and setting of the tool rest will be necessary to continue. Most of the innermost part of the interior can be done entirely with continued removal of material with the push cut over the entire surface....up until that point where you decide to continue with a more refined cut in the flat area of the interior. THEN, it can be pursued with the more refined pull cut.......

ko
Gotcha, thanks! It was the part "which becomes a pull cut as it transitions...." that confused me.
 

odie

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Gotcha, thanks! It was the part "which becomes a pull cut as it transitions...." that confused me.
My fault.....I try to be as descriptive as I can make words be, and in doing so, I make some pretty obvious mistakes sometimes!......and, I probably won't win any awards for my proof reading either......:D
 
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Jamie I will add my two cents here and hope it will help on future bowls. When finishing a dried bowl think of the process as two stages. The first stage is what I call my initial rough cuts. This is where I take the bowl to it's final shape,depth and wall thickness, not really worrying about tool marks. The second step is the most important step to prevent having to use sand paper so much.(Please remember sand paper is a cutting tool and the final product doesn't tell anyone how it got to be so beautiful)(chuckle) Before I start my second step I go back and sharpen my bowl gouge again. Then I turn up the speed faster than I used on the first process. One of the most important things to remember here is to take light cuts and slow down. With practice you will quickly find that just by resharpening before the last few passes will help greatly. The increased speed makes the gouge flow smoothly and cut easier. Taking light cuts with smaller curlies also helps. Good luck
 
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Jamie I will add my two cents here and hope it will help on future bowls. When finishing a dried bowl think of the process as two stages. The first stage is what I call my initial rough cuts. This is where I take the bowl to it's final shape,depth and wall thickness, not really worrying about tool marks. The second step is the most important step to prevent having to use sand paper so much.(Please remember sand paper is a cutting tool and the final product doesn't tell anyone how it got to be so beautiful)(chuckle) Before I start my second step I go back and sharpen my bowl gouge again. Then I turn up the speed faster than I used on the first process. One of the most important things to remember here is to take light cuts and slow down. With practice you will quickly find that just by resharpening before the last few passes will help greatly. The increased speed makes the gouge flow smoothly and cut easier. Taking light cuts with smaller curlies also helps. Good luck

What happens if you forget to take light cuts with the bowl gouge at higher speeds. :eek:
I usually take a break and sharpen the tool and start fresh when make finishing cuts, otherwise you can get in a hurry and end up with a tool catch.
Most mistakes happen when you spend too much time during a turning session and try to push the project along too fast.
Most of the time when I get in a hurry I end up having to spend more time fixing the mistakes from loosing focus or attempting a short cut.
No fun putting long hours into a piece and messing it up when you are close to the finishing process!
 

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Jamie I will add my two cents here and hope it will help on future bowls. When finishing a dried bowl think of the process as two stages. The first stage is what I call my initial rough cuts. This is where I take the bowl to it's final shape,depth and wall thickness, not really worrying about tool marks. The second step is the most important step to prevent having to use sand paper so much.(Please remember sand paper is a cutting tool and the final product doesn't tell anyone how it got to be so beautiful)(chuckle) Before I start my second step I go back and sharpen my bowl gouge again. Then I turn up the speed faster than I used on the first process. One of the most important things to remember here is to take light cuts and slow down. With practice you will quickly find that just by resharpening before the last few passes will help greatly. The increased speed makes the gouge flow smoothly and cut easier. Taking light cuts with smaller curlies also helps. Good luck

Howdy Breck.......

Thinking of the process as 2-step is a good way to understand it. I do have a question for you, though......If the increased speed makes the gouge flow smoothy during the second step, why not use the increased speed for the first step, as well?
 

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If the increased speed makes the gouge flow smoothy during the second step, why not use the increased speed for the first step, as well?
Speed is a trade off.
Faster speed generally makes for a better cut.
Faster speed makes more vibration and more vibration makes for a poorer cut.
I generally adjust the speed up to an acceptable vibration. Once it is round the vibration Decreases and the speed can be increased.

Vibration is a function speed, size of the piece, the amount of warp, How well the grain is balanced,density balance of the wood, and how well the bowl was lined up for re-turning.
With a smaller bowl up to 10" or so you can probably go full speed without vibration.
With a 15" bowl you might have to go a 1/3 of the speed you would with the 10" bowl until it gets round.
A poorly lined up bowl will require a slower speed than one that is lined up well.
 
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I prefer to turn at higher speeds. It doesn't make for a better cut, but it does make cutting easier/smoother. I think for me, the slower speeds are slow enough that my thought train stalls where faster speeds keeps the concentration in line, if that makes any sense. You get more cuts per inch than at slower speeds....

I have always wondered at how much wood elasticity plays into vibration.... Dry wood, not as much, but wet wood a lot, especially as your speed goes up. With grain orientation, especially with high speeds and thin walls, the bowl will elongate along the grain, and shorten up cross grain, pretty much in the same way it warps as it dries. Probably a big part of why green pieces go oval as you turn.

robo hippy
 
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When I said to think of the final turning as two stages that is a method I use with students or those who are not real experienced turners. The main reason is to get them used to resharpening their gouges before their final finish cuts. The extra speed is more of a mental thing for newbies because a little extra speed seems to put them out of their comfort zone just a hair. I have found they will then concentrate a little more on rubbing the bevel before tilting the gouge into the wood for smaller shavings. Also it seems to help them to remember not have a death grip on the gouge. For me the speed doesn't really need to increase because I am comfortable with the higher speeds. Being a little more cautious before allowing the gouge to bite into the wood seems to help my students. Being an old teacher I use whatever works until I find something better. I have found that there are many different ways to do things and get good results, so try stuff until you find what works for you.
 

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Thanks for the clarification, Breck.......I get it! :)

Great food for thought here in this thread.......! :cool:

As I see it, there are two reasons one might slow down the rpm......out of balance, and harmonic vibrations caused by general shape compounded by thin walls. There isn't much you can do for out of balance, but slow down until it's gone. For the harmonic vibrations, I've found the Oneway bowl steady to be a great help to me.

As for size of the workpiece, Al......Yes, I can agree that size is a factor, particularly for very large bowls...... but bowls that are smaller can also have both out of balance, and harmonic vibrations......either, of which can be contributing factors.

Robo.......I think your word "elasticity", and my words "harmonic vibrations" are referring to the same thing. I think you are absolutely right that, if you can, a higher speed is more desirable than lower speeds, particularly during the final few cuts prior to sanding. This is where I've found the Oneway bowl steady to be applicable to the results possible. It's not a "silver bullet", but it is a help......the rest is up to you!
 

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As for size of the workpiece, Al......Yes, I can agree that size is a factor, particularly for very large bowls...... but bowls that are smaller can also have both out of balance, and harmonic vibrations......either, of which can be contributing factors.
!

Small things can vibrate for sure.
Lathe size is also a factor. An out of round bowl will vibrate more on a lighter lathe than it will on a heavy lathe.
A small bowl might vibrate a lot on a100 pound midi lathe and not at all on an 800 pound Oneay.
 

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Small things can vibrate for sure.
Lathe size is also a factor. An out of round bowl will vibrate more on a lighter lathe than it will on a heavy lathe.
A small bowl might vibrate a lot on a100 pound midi lathe and not at all on an 800 pound Oneay.

True for an out of balance condition, but not necessarily true for harmonic vibrations. In the case of the latter, it's strictly a matter of tool application, geometry, integrity of a specific piece of wood, and wall thickness. The weight of the lathe is less of a factor for this kind of vibration than it is for an out of balance condition. There are ways to successfully deal with it.
 

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True for an out of balance condition, but not necessarily true for harmonic vibrations. In the case of the latter, it's strictly a matter of tool application, geometry, integrity of a specific piece of wood, and wall thickness. The weight of the lathe is less of a factor for this kind of vibration than it is for an out of balance condition. There are ways to successfully deal with it.
I would think vibration from tools is likely to be more with a lighter lathe.
When you get those vibrations from the tool use you just have to back off what you are doing.
Sharpen the tools, take lighter cuts, use less bevel pressure, keep thicker supporting wood toward the Chuck or faceplate.
Taking the 1/128" cut with a gouge takes a lot of practice.
Beginners get the 1/4" cut and the 1/8" cut pretty quickly.
Mastering the thouch to make the light cuts take a while.

The good news is that people who don't have finesse with the tools can still do really nice pieces.
 
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Taking the 1/128" cut with a gouge takes a lot of practice.
Beginners get the 1/4" cut and the 1/8" cut pretty quickly.
Mastering the touch to make the light cuts take a while.

Hi Al,

That's definitely something to work toward! Can I ask a few of questions?

1. How much cleaner do you think consecutive micro cuts gets the interior of the bowl? In my experience so far, a couple 1/32 cuts on difficult grain is about as clean as it gets for me. I've tried finer and haven't noticed a difference, but I'm at best an intermediate turner on a good day.

2. You mentioned the Michaelsen grind as good for the first couple of inches. I'm a big fan, though I usually use a 3/8 or 1/2" with a Michaelsen grind. I prefer the flute-up cut with the Michaelsen grind once past the rim.
Do you have a favorite gouge or cut for the rest of the interior, both the curve further in and the bottom? On steeper curves of course the flute-up doesn't work very far in, and I find micro cuts more difficult when rolling the flute clockwise. I find an Ellsworth grind best for flat bottoms.

Thanks!
Zach
 
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I will not use the flute up cut. Mostly it is prone to catching because if you come off the bevel even the smallest bit, you have a scraper pointing up into the spinning wood. I prefer more open fluted gouges, like Doug Thompson's fluteless gouge, and roll it over almost vertical for a higher shear angle, and hold the tool almost level. If it comes off the bevel, you have a shear scrape. 70 degree bevel, relieved heel, and ) nose profile. I am different that way. I don't use the swept back gouges at all, mostly because they work better with a dropped handle and you cut more with the wing than the center of the nose.

robo hippy
 

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Hi Al,
1. How much cleaner do you think consecutive micro cuts gets the interior of the bowl? In my experience so far, a couple 1/32 cuts on difficult grain is about as clean as it gets for me.

I don't use scrapers inside bowl very often. On about a third of the crotch bowls I do I have to use a scraper on the bottom because the twisty grain will get lifted up by the shear cut. The edge of the gouge slips under the grain stead of cutting it. Just the nature of how the edge meet the fiber. A round nose scraper removes the last little bit of wood when this happens.
On a very few deep cut rim bowls I will have some difficulty keeping the bevel and get a hint of chatter and USA a scraper to clean it up. I switch to the scraper when I have enough wood left to scrape and not enough to fail again with the gouge and scrape.

What I strive for with the gouge cut is to be able to sand with 220. Most of the time I can sand 90% of the surface of hollow forms and NE bowls starting with 220'once they have dried for a few days. There are usually a few spots where I use 180 especially a transition line where I have not been able to match the two surfaces more than a 1/3 of the way around. On cut rim bowls I usually start sanding with 180 unless I have turned beads or other details which I sand at 220 or 320 depending on how they look. With a 1/32 cut you should be able to start sanding with 180 or 120.

Small bowls are easier than large. I returned a 10" hard maple bowl recently used only the Ellsworth except for turning inside the foot where I used spindle gouge some. This bowl was easily sanded with 220. Probably 320 in spots. Of course hard maple is a wood the cuts cleanly easily.


2. Do you have a favorite gouge or cut for the rest of the interior, both the curve further in and the bottom? On steeper curves of course the flute-up doesn't work very far in, and I find micro cuts more difficult when rolling the flute clockwise. I find an Ellsworth grind best for flat bottoms.
Zach
I use the Ellsworth almost exclusively on the inside of bowls. Don't do many steep walls and I like a curve to make the flute up shear cut work. I do do a few NE hollow form openings that are close to straight.

I will not use the flute up cut. Mostly it is prone to catching because if you come off the bevel even the smallest bit, you have a scraper pointing up into the spinning wood. robo hippy
. Reed,
The flute up shear cut is best learned in a hands in session.
Anyone trying to learn without help is likely to get lots of big catches especially if they hold the tool too tightly. When teaching ourselves we all have a natural tendency to tense up when we Are apprehensive.
The Ellsworth grind on a parabolic fluted gouge works really well. People that learn the shear cut don't get catches because the tool does not roll into the wood once the bevel is locked in it just follows the curve.

I encourage people to learn the flute up shear cut in handsome on. It is not a safe cut for people to learn on their own.

Al
 
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hockenbery

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@Zach LaPerriere
A tool I use a tiny bit is a finishing gouge Trent Bosch introduced me to.
He used a 3/8 bowl gouge for flute up finishing cuts inside and out by grinding the two sides differently.

image.jpeg
The right side is a traditional grind the left side is swept back with a very short wing.

The right side is used flute up on the outside of the bowl cutting foot to rim with the bowl jamb chucked so that it makes a near verticle slicing cut.

On the inside it makes a flute up shear cut similar to the Ellsworth.
The leading edge of the left side is bit more vertical than the Ellsworth leading edge.
I have one somewhere in the shop but since I do mostly hollow forms and natural edge bowls don't use Trent's tool for the few cut rim bowls I do each year. Also my little Michelson does as well if I need it.

You may not want an extra tool,
However anyone doing production bowls might consider it.

A weekend workshop with Trent has changed a lot of lives.
 
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Al, the above gouges look to me like SRG's (spindle roughing gouge). The flute shape is identical. To me, the safety point is the part of the gouge that is doing the cutting should be directly over the tool rest, so all of the force of the cut goes down into the tool rest. This keeps the tool 'balanced'. With the flutes pointing straight up, you are working one side of the teeter-totter/seesaw, and it wants to roll into the cut. Roll it onto its side, and cut with the bottom 1/3 of the tool, and you have a balanced cut that will not catch, even if you come off the bevel. You still get the high shear angle for a clean cut.

I am playing around with the NRS (negative rake scraper) for bowls. I never have used a scraper flat on the tool rest for that bottom sweep to take out the ripples or for clean up. The NRS works in some of the harder woods, but I still find the shear scrape to cut cleaner most of the time. When you sweep across the grain with a scraper, like across the bottom of a bowl, it will cut more cleanly than it will when you are plunging down through the grain like going down the side of a bowl. I still like a 70 degree or so shear cut or shear scrape for my bottom finish cuts.

robo hippy
 

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Al, the above gouges look to me like SRG's (spindle roughing gouge). The flute shape is identical.
Robo hippy

Big difference from an SRG.
Trent's finishing tool is a 3/8 bowl gouge made from a round bar with a flute cut in it.
A "u" fluted bowl gouge can look like an SRG at some level of abstraction but the steel is thicker
And being milled from a round bar the bowl gouge is much stronger than the typical SRG.

The smallest SRG I KNOW OF IS 3/4" and most are 1 or. 1.25"
Most are made from a flat bar that is bent into a flute after a tang is cut in the bar.
SRG is too big and too weak to use on bowls.

A catch with a 3/8 bowl gouge can be bad but it is sort of limited to gouging out a 3/8 diameter chunck of wood.
An SRG gouging out a 3/4" or 1.25" chunk of wood is many times more dangerous.
 
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Al—

Thank you very much for your detailed response. My apologies for a late response...I was out commercial fishing for a bit over a week, far from the internet, land, and my lathe.

I would feel like I'd gone strait to heaven if I could consistently begin sanding the inside of bowls at 220. I know a lot of my courser grits is the nature of the soft woods here in Alaska, but I know my skills aren't what I would like them to be.

I've been paying attention that you've mentioned a course with Trent twice now. Seems like a great thing to do this Fall.

Trent's finish gouge makes good sense to me. I'm a huge fan of sheer cutting the exterior of the bowl on finish cuts, and that is essentially what it looks like his finish gouge is up to, especially where it's most needed on the interior.

Anything to save on courser grit sanding time, short of selling my soul or importing wood!

Best,
Zach
 
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