Square Bowl Tutorial Ver. 2.0

Stuart Ablett

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Tokyo Japan
Back in November of 2007 I did a tutorial on how to do this little NOT round bowls, or plates, you can see that >> HERE <<

I've decided to update that tutorial, a Ver. 2.0 if you will. I've modified my methods and I think I can show the process in a slightly better light. I'll also be using this as a basis for my handout at the JWA demo I'll be doing in June.



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OK I start with my chuck sporting the pin jaws that I have, I drill a 1" diameter hole about 1/2" deep in the center of a piece of wood.
The wood in this case is about 3-1/2" square and 1" thick. It is VERY important that the piece of wood is square and that the hole is in the exact center, basically you need a drill press to do this accurately.

Look at your piece of wood and plan out the location of the bowl in the wood, the hole is drilled on the concave side of the bowl, what will be the top, or the place you would set something into the bowl.

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The wood is placed on the pin jaws loosely, only moderate pressure should be used to hold it, as we are going to make sure it is nice and square in a moment.


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I put the large cone on my Oneway live center, I use this to make the block straight on the pin jaws....

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Push the block onto the pin jaws with the cone, and it is nice and square.
Tighten the pin jaws outward into the hole drilled in the block.
This is why I make sure the wooden block is not only square, but of a consistent thickness.

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I then remove the cone from the live center and run lathe at slow speed and bring up the live center to support the block.

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On the corners you turn a lot of air, so it is important to keep the toolrest close to your work.

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First I turn a tenon, I size the tenon to fit a plastic insert for my chuck, you will see this in the next few pictures.


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The plastic insert is made from some cheap cutting board and I have them sized for different tenons.
I try to turn them so they fit snug on the tenon and have lots of contact area.

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It just sort of pops onto the tenon.

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I finish turn the bottoms of the bowls, I like to make a slight recess on the very bottom of the foot.

Cont
 
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Now that I have established the tenon I work on the curve of the bowl, it is a very shallow curve and you can play with it if you want, you can make it almost flat or a fair bit steeper, in this picture it is not really looking curved at all, but it is, that is just the camera playing tricks.
you also want to think about where the edge of the bowl will end up, this particular piece of wood has a bunch of inclusions in it, so getting four perfect corners is maybe going to be a stretch, but with experience you can find a good spot for the edge to be. Even if you have to take the tenon down a bit to make the curve how you want it.


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I'm fairly happy with that, and I sand the bottom of the bowl with the power sander but not the corners, if you do you can catch an edge and or make the edge of the corner rounded over too much, so I only power sand if I need to, I find that I can usually hand sand just fine.
Remember to go in the direction of the grain.

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Not always but sometimes just for fun I put a little surprise on the bottom of the bowl.
At this point I finish the bottom of the bowl, in this case I put a coat of sanding sealer on the bowl, I'll finish it up with lacquer off the lathe.

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Now I've changed chucks, I have my regular jaws on this chuck, of course if you don't have two chucks then you have to swap the jaws from the pin jaws to these regular jaws. I put the plastic insert into the jaws and place the tenon into the insert, bot only tighten lightly.

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Again I use the cone on my live center to make sure the bowl is seated correctly in the insert in the chuck.
Now I tighten down on the bowl, but don't over do it!

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Sometimes for whatever reason the center of your hole may not line up with the live center tip, this can cause the bowl to vibrate when turnings, which is no fun, one way to remove this problem is to remove the tip of your live center....

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With the tip removed the live center then uses the ring to press on the bowl to support the turning, remember that plastic insert is not nearly a strong an attachment as the metal chuck jaws, you you have to go carefully.

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With the live center supporting the bowl again move your tool rest up nice and close as you will be turning air again.

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I first cut down to the edge of the bowl so I have a complete circle this allows me to visualize the shape of the bowl.

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Basically you want the top edge to be parallel with the bottom edge along the curve, as you can see in this picture it is NOT parallel, the middle part is much fatter than the corners are, I'll fix that in the next pictures.

Cont
 
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Now the edge is getting better and but it is still too thick. I cannot stress enough that you have to take very light cuts while turnings at a speed to get a nice smooth cut. I turn around 1800 RPM or even higher on a smaller piece.

Please turn at the speed you feel safe.

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Now I have the shape of the bowl I want and I'm now going to remove the rest of the bulk of the bowl.

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Again you want to go in small steps, and make sure that you keep the curve of the bowl in mind, nice and smooth.
Above you can see that the bowl gouge is coming to the center of the piece where the hole was drilled, I always stop at this point and change how I present the tool to wood. If continue to cut in this direction, you can very easily break through and push your nice bowl gouge into the live center, and no one will be happy!

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Instead flip your gouge so that you are cutting towards the headstock of the lathe, this way you will not shove your gouge into the live center.

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Now I'm down to the nub of it, the bowl is mostly turned but you have to remove that nub.

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Again, it is really important how you present the tool, that plastic insert does not have nearly the bite on the tenon that the metal jaws would have, that is why the insert does not mark the tenon. If you cut in this direction you will almost surely pop the bowl out of the chuck, and bad words will be said.

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Instead, present the gouge like this and cut with pressure towards the chuck

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OK the nub is gone, now for some sanding.
If you can make a super smooth cut with no bumps and ridges along the way, well my hat is off to you, but I find that I'm more concerned with having no tear out. A few bumps and wiggles can be easily removed with some sandpaper, but tear out cannot, so I concentrate on getting little or no tear out, and then level things off with some sand paper.

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At this point I do not power sand with the lathe running. I'm using #180 grit and I power sand with the lathe off, I support each corner and sand at a slow speed very lightly, then I hand sand going with the grain up to #400.

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At this point I'm ready to put some sanding sealer on the bowl, but wait, look at that ugly corner that busted out!

Cont....
 
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The bowl I'm working on this little trick will not work because that is an inclusion and it is too large, but sometimes no matter how hard you try, you get a small piece breaking off of a corner, so to fix it, I get out my low angle block plane.

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You can also do a similar thing with a straight piece of wood and some sandpaper, but I find the block plane makes a smoother cut.

This will not work for a large chip, but for a small one you can get away with it.

Here is the finished product.....

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you will notice that I put the corner with the inclusion away from the camera :D

I hope you enjoyed that, any questions please ask them any comments or idea on how to improve how I'm doing this let's discuss.

Cheers!
 
Thanks Stu great tutorial i can see that style of bowl being a big hit with the audience you will have.:thumb: One thing i keep being reminded of is the need to get a better center. This spinny stuff sure is a vortex. :)
 
Thanks Stu great tutorial i can see that style of bowl being a big hit with the audience you will have.:thumb: One thing i keep being reminded of is the need to get a better center. This spinny stuff sure is a vortex. :)

Jeezzzzz Rob, are you just figuring that out. Get with the flow and empty your pockets. Help the economy (the equipment person's economy, not yours). Then

Enjoy,
JimB
 
My lovely wife is reading these posts, as she will be helping me translate them into Japanese for the JWA demo, she suggested that I take a picture showing the square blank being drilled to show the whole process, who am I to argue.

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Making the soft insert.

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I buy these cheap cutting boards at the 100 yen shop (Dollar Store) they work well for this.
If you have a holesaw the right size 52-53mm or about 2" (Inside diameter) then you can just drill a round blank out of the cutting board.
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That is the easy way to do it, if you don't have a hole saw the right size, then this is what you do.

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First you cut a square blank about 2" or 53mm and drill a hole in the middle, I used a 9mm drill bit to fit my screw center for my chuck.

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Then you mount it on your chuck and use a parting tool to make the square round.

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I use the parting tool because it is easy to control and you are going to kiss that chuck jaw and the parting tool is easy to sharpen.


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Then you chuck up the piece and turn a recess, this one is about 30mm 1-3/16" I make is about 4.5mm deep or 3/16"

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Next flip it over and make a larger recess on the other side, this one is 35mm or 1-3/8" again the same depth or slightly deeper.

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I then put it in my vice and slice it open on one edge.
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That will do to make the insert compress to grip the tenon of the piece.
 
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