Regarding base width vs actual width

[John Kananis]

How wide (in proportion or ratio please) should the base of a bowl be in relation to the absolute width of the piece (maybe height matters also?) in order to be a stable "user"? I see some pretty wide bowls (online) with ridiculously small feet or bases and yeah, they look cool but arent they going to tip over if used? The largest set of jaws I have are #4's on a stronghold chuck and I can turn up to 18" on my lathe (so say 16 inches maybe final)... is that large enough if I don't expand the jaws? I'm trying to let the foot of my bowls roughly the size of my jaws so I don't mar when I grip the tenon (meaning the backside is finished and I don't have to jam chuck). This is why I ask for a ratio, so I can apply to different sizes... thanks in advance, fellas.

[Kevin Jenness]

How wide (in proportion or ratio please) should the base of a bowl be in relation to the absolute width of the piece (maybe height matters also?) in order to be a stable "user"? I see some pretty wide bowls (online) with ridiculously small feet or bases and yeah, they look cool but arent they going to tip over if used? The largest set of jaws I have are #4's on a stronghold chuck and I can turn up to 18" on my lathe (so say 16 inches maybe final)... is that large enough if I don't expand the jaws? I'm trying to let the foot of my bowls roughly the size of my jaws so I don't mar when I grip the tenon (meaning the backside is finished and I don't have to jam chuck). This is why I ask for a ratio, so I can apply to different sizes... thanks in advance, fellas.

It depends. If you don't have a copy of Raffan's The Art of Turned Bowls it is worth perusing. A few samples will help you decide on optimum stability for your purposes. I don't think your work holding fixtures should determine your designs.

[John Kananis]

Thanks, Kevin, I'll for sure pick up a copy... I'm not looking to allow my gear to limit my design, I'm just trying to figure out what proportion works best for stability.

It depends. If you don't have a copy of Raffan's The Art of Turned Bowls it is worth perusing. A few samples will help you decide on optimum stability for your purposes. I don't think your work holding fixtures should determine your designs.

[roger wiegand]

For ultimate stability, as wide as possible. Dog bowls are shaped that way for a reason. After that it's aesthetics. Somewhere around a third works for most bowls that are intended to be used, less than that will get tippy. There are many, very beautiful, examples of bowls with much smaller feet, and also bowls like calabashes with no foot at all. I think it's really all about making a graceful, smooth curve in the sides. Making a good looking shape with a foot bigger than about half the diameter is challenging. Height of the bowl will also play into this-- you can get away with a much wider base on a shorter bowl, until it eventually transitions into a platter.

Second the suggestion of Raffin's book. There's also a book that has silhouettes of about a thousand bowls made over the last 4000 years that is quite helpful for seeing the possibilities. I can't seem to find the name right now, perhaps someone else knows it.

My cat's favorite (see avatar) is about half the width. I think he appreciates the added stability.

[Bill Howatt]

I think it is a mistake to base your design on the size of the chuck unless absolutely necessary. One of my pet peeves is looking at the bottom of a bowl and seeing what I consider to be "the tenon". My preference is that the tenon, if still there, is turned and blended into the bottom not stick out like a sharp-sided, mini-pedestal. One of my first bits of info I picked up at the turning club was the if a bowl is being adjudicated the tenon must be finished nicely and this also included internal tenons.
The diameter can make or not make a bowl tippy so if the bowl is a utility bowl then you do have to go wider, if it is an art bowl that is just looked at then you can reduce the diameter.

[John Kananis]

Thanks, Roger and Bill. I guess it's all about perspective and purpose then. I'll experiment and see where it takes me.

I'm not trying to base my design off of chuck size, though it seems that I gave that impression. I mentioned the largest jaws I have as a reference to how large a tenon I can make relative to the maximum diameter I can turn on my lathe. I've covered most things I believe with 6 chucks, each with different jaws. I have a supernova 2 with stepped spigot jaws, a talon with #2 jaws, another talon with #3 jaws, two strongholds with #'s 3 & 4 and a stronghold with mega jumbo jaws (although I find myself using jam chucks sometimes - maybe I'm doing something wrong but I don't get a true turn when using these). I went with all the different sizes so that I wouldn't be limited to basing design off of chuck size.

Edit: I went with all dovetail jaws so that I can get a good grip on a short tenon and not mar the piece. I'll post some more things soon and will be more than happy to hear critiques... as far as cross grain work, I've only posted a cherry bowl and a candy dish so far. The candy dish is what prompted my question as I was trying to make it look like it was floating on the table.

[Neil Bosdet]

The rule of thumb is 1/3 of the diameter should be the size of the base. This is only an approximation, but it’s good to use for a rough guide as it’s pleasing to the eye.

[Bill Howatt]

Floating is nice!
I've reversed bowls to finish the bottom and they have not been perfectly true. If only out a little bit (whatever that measurement is) you can still finish the bottom and when sanded (not much) the blending will be undetectable particularly since it is at the lower part of the bowl.
A real handy gizmo for reversing a bowl when vacuum chucking but it could be used for other methods is an adapter from Oneway that screws onto my Oneway chucks and the other end screws onto the thread on my Oneway live center.
https://www.highlandwoodworking.com/...%20onto%20your
The combination (the bowl never left the chuck) is placed on the tailstock and brought up to the vacuum or other chuck. This locates the bowl on center - the description in the link is for actually starting with it centered on the tailstock and then put on the spindle for hollowing.

[John Kananis]

Perfect, thanks, Neil.

The rule of thumb is 1/3 of the diameter should be the size of the base. This is only an approximation, but it’s good to use for a rough guide as it’s pleasing to the eye.

Oh that's pretty neat, I think I may "need" one of those. Thanks, Bill.

Floating is nice!
I've reversed bowls to finish the bottom and they have not been perfectly true. If only out a little bit (whatever that measurement is) you can still finish the bottom and when sanded (not much) the blending will be undetectable particularly since it is at the lower part of the bowl.
A real handy gizmo for reversing a bowl when vacuum chucking but it could be used for other methods is an adapter from Oneway that screws onto my Oneway chucks and the other end screws onto the thread on my Oneway live center.
https://www.highlandwoodworking.com/...%20onto%20your
The combination (the bowl never left the chuck) is placed on the tailstock and brought up to the vacuum or other chuck. This locates the bowl on center - the description in the link is for actually starting with it centered on the tailstock and then put on the spindle for hollowing.

[Richard Coers]

Depends on the use of the bowl. Making real salad bowls? I make the base larger. Just a bowl to set on a shelf, it can be much smaller. If you make straight sided bowls, much larger base. Making a cantenary shaped bowl, much smaller base.

[John Kananis]

Thanks, Richard. I've been studying shapes online (on the aaw forum mostly) and I think I'm starting to see the how and why of shapes. The Raffan book, mentioned above, arrives tomorrow and I'm looking forward to it.

Depends on the use of the bowl. Making real salad bowls? I make the base larger. Just a bowl to set on a shelf, it can be much smaller. If you make straight sided bowls, much larger base. Making a cantenary shaped bowl, much smaller base.

[Wally Crawford]

There's also a book that has silhouettes of about a thousand bowls made over the last 4000 years that is quite helpful for seeing the possibilities. I can't seem to find the name right now, perhaps someone else knows it.

My cat's favorite (see avatar) is about half the width. I think he appreciates the added stability.[/QUOTE]

I would be interested in this book if the you remember the title.

[roger wiegand]

I'm beginning to wonder if I hallucinated it (maybe I'm an AI!!). The fellow I took a pottery class from a number of decades ago had it on the shelf. I can't find a reference using any google terms I've come up with.

[Wyatt Holm]

It may not be the exact book you are referring to, but my copy of "Woodturning a Designers Notebook" by Ray Key has those silhouette designs, as well as historical pottery, glass design etc.