Pondering the Ogee Curve - and, a bowl

[John Keeton]

After a trio of turnings for submission to the Artisan Center in Berea, I needed a diversion. This bowl is from the other half of the silver maple log from which I turned a fruit bowl for Ms. Keeton a few months ago. This maple has it all - curl, color, spalting, a bit of Ambrosia - most of which was turned off - and, live worms!! It is 6.5" tall x 13" wide. Finish is walnut oil only at this point - after a few more coats, I will probably wax the bowl. Sorry for the irregular cropping of the pics - I had some issues with my draping around my photo tent and didn't realize that until I processed the pics.
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However, the real purpose in doing this piece was to illustrate some thoughts on the ogee curve and its use in turning bowls. I have compiled many of my rambling thoughts into a .pdf document, along with some sketches and several pics of pieces I have done over the last two years of my turning "career." :rolleyes: I hope you will take the time to look at it and give me your thoughts on the concept of the ogee curve - if you care. If it doesn't interest you, perhaps it will at least give you some idea of how my twisted mind works - or doesn't! Give it a quick read. Thanks! Oh - and all comments on the bowl are welcome, though it might be helpful if you first read my observations in the attached article.

[Roger Chandler]

Well John, that is a bit to digest..........your rationale based on the sketches you have drawn and references from masters like Raffan do validate your observations and your seeming need to analyze why you do what you do is a study in the "artist mind" I would suppose........ I am a bit analytical myself.............but my approach is much different.............I don't seem to reduce my thoughts to paper like you do, but I do think a "developed eye" or an "educated eye" as it relates to form is something one acquires as one goes deeper into the vortex of turning.

I will say, it is obvious to me that you do have writing skills as well as turning talent [among the many you display] and I suppose now that you have published this .pdf about the ogee form, that it is likely to become a "must read" study document for all upcoming turners............your contribution to the craft, so to speak! Geez..........you might just become the guru of ogee bowls! :D

I could envision this becoming a "sticky" and who knows..............I think a DVD is in order...........your status as an "arteeeest" is gaining for sure, and it might just be a great help to up and comers, and maybe pad your wallet a little also.........I don't think Mrs. K will mind that!? ;) Now.............what was your original question? :rolleyes::D:D Oh btw............nice bowl! :D

[charlie knighton]

John, do you choose your shape after or before your blank? in other words do you look at the blank and then decide the shape or do you have the shape in mind and go find a blank that you can achieve that shape?

[Jamie Donaldson]

An excellent dissertation John, but when I started turning I was told there would be no math! Since I'm both philosophical and a bit dyslexic, I like the discussions about the wood telling some turners what it wants to be.

[Ron Bontz]

John, I read your piece and liked it. I was wondering if you calculated the angles on these right triangles to get an idea of range or a ratio. If I like the ogee horizontally, will I like it vertically? Also I was wondering if you had considered "function" as a determining factor in the shape of the ogee? "Form follows function" process. IMHO, what is pleasing to the eye is not always functional/practical. But what is functional/practical can often be made to be pleasing to the eye. Removing excess wood, for example. Ok, Ok. Enough of my rambling. Beautiful piece as always. And definitely pleasing to the eye. Best wishes.

[Peter Fabricius]

Hi John;
Your "pondering" PDF is facinating indeed. I really like the bowls and hollow forms you make and now you have explained some of your thoughts that go into your work. I have saved the PDF for repeat reading and perhaps it will influence my attempts at bowls, you never know...
Thanks for putting your thoughts on paper for all to explore.
Peter

[Roger Chandler]

An excellent dissertation John, but when I started turning I was told there would be no math! Since I'm both philosophical and a bit dyslexic, I like the discussions about the wood telling some turners what it wants to be.

Yep, Jamie........that old discussion! ..... Oh the shear brutality of a turner who would force a piece of wood to become what he wants it to be, instead of letting the wood decide what it wants to become! Oh, the shear brutality! :eek::eek::D:D:rolleyes:

[Dick Wilson]

Hey John, How are you doing?? Sticking to the regemine??? Just saved it to my desktop and will print it out save it as a reference. Thanks for taking the time to do it. Be well. Dick

[Nate Davey]

John,

Very good read. A few thoughts from a novice, not-artist.

It seemed to me that your taller green form is both a catenary curve with a reversed curve at the top and an ogee....if that makes any sense??? Do the two shapes compete in someway with each other?????

In your discussion on bowl height/curve radius/line from top to bottom, I was reminded of Cindy Drozdas video where she discusses the negative space in finial design where it's not the larger diameters touching the line with regards to the rule of thirds, but where the negative space interacts with it. So I'm wondering if it's more the negative space proportions the are pleasing to the eye then the technical aspects of the curve??

Finally, Tim Rinehart and I were discussing during our visit the "planning" thing. I was wondering if, those of us who don't buy expensive blanks and get lots of free wood don't plan much because we aren't worried about ruining an expensive blank. Whereas, someone who shells out some $$$$ want's make sure they get all the value from their purchase. Tim felt it's more an individual personality thing, more than investment protection.

Anyways, I really enjoyed the literary work and have saved it to my JK folder for future reference.

[David E Keller]

Interesting! This will be something that I'll read again a couple of times, but my initial thoughts are that I find bowls with ogee curves that are steeper than about 45 degrees less appealing than forms with more flattened profiles. That relates to your height/width discussion I think. In other words, I think I might find the appearance of your piece more pleasing if the base were smaller... Not because of my small base fetish, but because it would allow the sides to project out more laterally rather than vertically. Obviously, there are functional concerns that may make a smaller base a bad idea, so the width to height ration would have to be adjusted to change the angle.Great dissertation! Thanks for making me think!

[Dale Miner]

Math/No Math Golden Rule/Wood talks to me Ogee/ Oh Gee!

John,

I also like the Ogee, but it a tough one to pull off. To me, there are no real mathematical formulas for an Ogee that is perfect to the eye. I have found that on shallow bowls, within a narrow margin, the midpoint of the Ogee needs to be midway between foot and rim, and that the radius needs to be the same on both sections. I too have the Raffan Book, and there are many (succesful) examples that fit the golden mean, and many (succesful) examples that are outside the golden mean.

In the bowl pictured in this post the foot diameter appears to be very close to the 1/3 bowl diameter, but the foot appears to large. To me, the reason is that as the height/diameter ratio becomes greater, the foot needs to decrease in size to maintain a pleasing form. If the foot of the bowl were smaller, and the same radii and length were used on each portion of the Ogee, then the approach angle at the foot would be abrupt and unpleasant looking. The solution to the dilema would be to use a tighter radius at the bottom to provide some fullness, and move the neutral point lower and use a larger radius at the top to help flare the rim.

If there is a mathematical formula for a perfect ogee, then there must be more parameters that influence the curve than radius and length. Perhaps sine waves modulated by the height/diameter ratio? Perhaps volume under the curve?

I am going to side with Jamie that No Math is my motto, never did like them differential quadratic eqautions enough to put pencil to paper before putting gouge to wood.

Also, I think that a bowl with a larger height/diameter ratio is tough to succesfully pull off. Add in an Ogee, and it gets really tough. Your bowl above is close. If you have any meat left in the bottom, see if you can pull the bottom curve into a smaller foot. The walnut oil should allow for repair without notice.

[Prashun Patel]

Thanks for the article. Very insightful & generous.

IMHO, the math is a good starting point, but turning is not a measure and cut operation. It's iterative; that's what I like about it. You aim for a form (based on golden ratios/right triangles/rules of 3rds or 5ths), and then keep tweaking until it just looks and feels right.

[Wally Dickerman]

Very well done John. The ogee form is a difficult one to get right. I'll have to say that I don't care for the ogee form without a foot or with a short, wide foot. I think that the lower curve should be allowed to continue to a fairly small foot to give the form lift. I think that Phil Brennion would say that the form you show doesn't "float". I've found that a slightly dovetailed foot works well on this form, but it has to be done right. Height in relation to the height of the bowl, small, but not too small. Raffan's book shows a few of these.

The ogee form is all about curves. The curves should be continuing. with no flat spot where the curve changes direction. Raffan's book shows some beautiful examples of that.

My opinion for what it's worth.

[Jim Burr]

Not bad for a self admitted "bowl rookie"! I think it looks just fine. As an experiment, try one with just the opposite dimentions...wide and short with the ogee and see what you think. It may help you grasp them differently.

[John Keeton]

Keller gets the prize!! My hope was to get others to think about this. As David noted, and as Dale described, there is a diminishing point where the ogee curve will force a modification of the "rules" - including the size of the base. That was the experiment with this bowl. The base is 1/3 the diameter of the rim, but it would benefit aesthetically by a smaller base. The problem with an ogee form used functionally (aside from lack of volume) is that the center of gravity is much higher, and the bowl gets "tippy" pretty quickly as the base diminishes in size. Given that dilemma, there would seem to be a point between the fruit bowl done previously and the poplar vase where both appearance and functionality work against doing an ogee form. That goes along with Keller's 45* theory, too.

Wally, thanks for the input - very valuable! I am not familiar with Brennion, but I will find out who he is.


....and your seeming need to analyze why you do what you do...

I will say, it is obvious to me that you do have writing skills as well as turning talent...Roger, my "need to analyze" kind of goes along with the rest of my personality. I would dare ask Ms. Keeton, but I suspect I am an absolute pain to live with.:o On the issue of writing skills, let's just say I sell a WHOLE LOT more words than turnings!!:D


John, do you choose your shape after or before your blank? in other words do you look at the blank and then decide the shape or do you have the shape in mind and go find a blank that you can achieve that shape?Charlie, I cannot recall a turning that I did not either have a mental picture of, or more likely a scaled sketch, prior to ever considering which piece of wood might be used.


...I like the discussions about the wood telling some turners what it wants to be.Jamie, I have tried holding wood up to my ear, and while I hear voices..:eek:...I don't think it is the wood!!!:confused::D


Yep, Jamie........that old discussion! ..... Oh the shear brutality of a turner who would force a piece of wood to become what he wants it to be, instead of letting the wood decide what it wants to become! Oh, the shear brutality! :eek::eek::D:D:rolleyes:Between the wood me, I am the only one with sharp tools - I shan't let a mute piece of wood determine its fate!!!!!:cool:


It seemed to me that your taller green form is both a catenary curve with a reversed curve at the top and an ogee....if that makes any sense??? Do the two shapes compete in someway with each other?????

....I'm wondering if it's more the negative space proportions the are pleasing to the eye then the technical aspects of the curve??...

Finally, Tim Rinehart and I were discussing during our visit the "planning" thing. I was wondering if, those of us who don't buy expensive blanks and get lots of free wood don't plan much because we aren't worried about ruining an expensive blank. Nate, the green poplar vase was done from a scaled drawing of a true ogee with equal arcs. A catenary curve accelerates toward the bottom. The positioning of the ogee on the vase probably is causing some of what you see.

I think negative space is as important as anything in a turning, and while I firmly feel most "good" forms are based on mathematical curves (just like in classic architecture), obviously there are deviations from those curves and combinations of curves that are very pleasing.

On the planning thing, it is just the way I function. I understand and can appreciate that there are many who feel that destroys the freedom of turning. But, for me, it is quite the opposite. The creativity comes first - mentally first, then usually on paper, and then I look for the wood that I think will achieve the goal. That isn't to say that I don't consider wood species, texture and color in a piece - that is nearly always an integral part of the planning process.

Anyway, thanks to all that looked, and particularly all that read the .pdf and "thought about" this topic - that was the goal!!

[Jerry Wright]

John: I enjoyed your write-up. While I often do a "rough idea" sketch, I don't go to the level of detail that you do. Since you enjoy this level of turning preparation, I think that you would have a lot of fun with a set o "french curves". Forgive me if you already use them, I just didn't see that you had mentioned them.

[Curt Fuller]

John, an excellent discussion on the ogee form. To add a little of my own 'pondering', I wonder if the math behind the curve might have come much later than the original human appreciation for a nice curve. In some of the oldest three dimensional art forms we always see the human form with various combinations of the rounded 'ogee' curves. Later as people had more time to sit around their art became more precise but still had a lot of focus on the human form with all its curves. If you were to superimpose the many variations of the ogee curve on the various parts of the human anatomy, I think you would see what attracts us to these curves and also see see that each of us has a little different eye for what is the best curve. To be a little more specific, I've always thought that the curve of a shallow but wide ogee shaped bowl follows pretty closely to the calf to ankle curve of a woman's leg. The rounder bowls with a more continuous curve tend to follow the form of a woman's breast. I'm not sure if anyone else ever sees the similarities in these curves, but to me they are striking.

[John Keeton]

Curt, without drifting into a religious discussion (contraband!), I would suspect none of the observations you note, nor the mathematical involvement behind the curves, is happenstance! It would seem to all be part of the "plan."

[David E Keller]

Curt, without drifting into a religious discussion (contraband!), I would suspect none of the observations you note, nor the mathematical involvement behind the curves, is happenstance! It would seem to all be part of the "plan."

It's funny how different people get different things from reading a post! I read Curt's post, and my thought was, "I guess I'm more of a breast man than a leg man."

BTW, did I read something about a prize in one of JK's posts?!?

[Hayes Rutherford]

Keller, it would be interesting for you and Curt to take the Rorschach ink blot test. Then someone would hopefully explain the results to me.

Seriously, I have been pondering over JK's pdf and it is good stuff. However, towards the end I started to think I was like the Jazz musician that was asked if he knew anything about music theory and his response was "not enough to hurt my playing". But that is just me and John has demonstrated time after time the rewards of good planning and that is something I could benefit from.

[Lee Koepke]

thanks for taking the time to put your thoughts in writing. You certainly have shared your mathematical analysis with me before and for some reason, I have yet to 'commit' to the teachings. I find that either my mind wanders or the wood's mind wanders whenever I have tried.

I shall make a New Years Resolution now ... I will turn an ogee bowl .... it may not be good, but i will try!

[Rich Aldrich]

Most of my bowls have an ogee at the rim. It is a shape I like, but difficult to keep tool marks out and a bugger to sand because of the tool mark issue. Burls are much easier to minimize the tool marks and sand.

I like your dissertation on the subject.

[Thomas Heck]

Nice bowl. I saw your from central Ky. I live in Harlan Co., Ky. I haven't been in the artisan center , but have been told it is worth the stop. I just started turning around a months or so ago.

[Mark Hubl]

Wow, I feel like I been lawyered up! But seriously, nice essay John. Have you read Mike Darlow's Woodturning Design? If not I think you would find it a good read.

[Bob Bergstrom]

Wow, this is a great discussion. I will throw a couple suggestions out. First is to really study the look of the bowl, use some very plain wood and paint the finished bowl black. This will give the true picture with all the pretty wood aside. You could put the picture posted into photoshop and color it black, but the real thing will give an even better perspective. Another aspect is how does the curve look when viewing into the bowl. Some may look good from the front only to show too much curve on the inside. Also if you follow the bottom curve of the posted bowl it does not seem to come through the foot and up the other side. A small point but my eye seems to go down into the table. A talented turner friend of mine actually shapes the bottom to the foot to follow the contour of the bottom of the bowl, not always easy to do, but really adds to the whole. John I want to thank you for this great post and all you creative thoughts. I appreciate all that you do here and always enjoy you pieces.

[Jamie Donaldson]

John, Phil Brennion is a past president of the AAW and was the victim of a freak accident, and is now partially paralyzed. He was an early advocate of the SW Indian pottery forms as a turner, as well as a deep thinker and interesting conversationalist. I can't imagine anyone sitting down to read Darlow's design treatise for fun, as I have conceptual philosophy books that are easier reading!

[terry mccammon]

Your paper is an excellent basis for an interesting discussion of what is beauty. I have not had time to set it up yet, but I have a feeling that the variation in "pleasing" that you notice as you vary the various relationships within the boundry of ogee, will turn out to be maximized when you are in the locus of the "golden" ratio.

I also wonder if this is a "Western" taste, is it inherent in homo sapens, part of our development, does the appreciation of what is pleasing in the ogee change as we examine "eastern" presentation.

I am not a musician but the difference between the well tempered clavier and penatonic is rather apparent. Does the appreciation of pleasing within the ogee vary across genetic phenotypes vary as well? As you point out the more spherical product is much more practical. Does that mean that the ogee form is more "refined" just as the pentatonic is found throughout the world, but refined in more modern times to the various forms called hepatonic?

All very interesting and worth pondering over a glass of single malt and a cigar sometime. :)

t

Having said all that, as an absolute novice turner, I am still struggling to figure out which end of the gouge to apply to the work. If I get to where I can do things like this, I will be very pleased and frankly amazed. Thanks again for your good efforts on our behalf.

[Jamie Donaldson]

Terry is going all philosophical on us now, so I refer all to the original source of discussions regarding ideal forms, and that is Plato's Allegory of the Cave found in his Republic. BTW, Plato is much easier reading than Darlow! There are cultural preferences in idealized shapes, but many do relate to Curt's reference of the female human figure, or more utilitarian forms for function. I believe one of the purest bowl forms is found in some oriental rice bowls that have evolved down through history.

[Tim Rinehart]

I enjoyed how you laid out the different intersection points and will likely print this out to look at in the shop. I also gravitate towards the ogee for bowls and platters. I agree with need for foot on these forms and that has been common for me to integrate on similar items.
Well thought out and worth a second/third read for most of us to fully benefit from this very good design input. I do tend more and more to always draw out a form before cutting chips, especially if one that I've not done.

That being said, I tend to get the wood first (vs design), based on what I believe is a 'nice looking chunk of wood', and with appropriate dimensions to fashion the kind of form that will show off it's qualities best.

[Ken Hill]

I tend to get the wood first (vs design), based on what I believe is a 'nice looking chunk of wood', and with appropriate dimensions to fashion the kind of form that will show off it's qualities best.

I was thinking of a way to say that, thanks!

John, I enjoyed reading your thoughts. While I do try and follow the turners here that ebb towards or surpass "art", I tend to gravitate to the practical and try to show the beauty of the wood in a basic form. I do the same in my photography so it is of no surprise to me that plain and simple is my stye.

[Justin Stephen]

Nice bowl. I saw your from central Ky. I live in Harlan Co., Ky.

Small world. I have been in Harlan Co. many times to run my truck through the offroad park near Evarts. Pretty country.

[Dan Forman]

Having read the PDF, I am again reminded that the math gene was apparently out of stock when I was assembled. :) Though I struggle with the verbal description of the concepts, I do better with the illustrations. I would like to try working with the ogee form, have been postponing until I get better control of the basics. I am also missing the visualization gene, so I need to either draw things out, or turn a mockup piece in order to work out new ideas concerning form.

The golden ratio has been shown to be attractive across cultures. My first exposure to the concept was a PBS show on perception of beauty. People in a variety of cultures consistently rated human faces more beautiful when the features conformed most closely to the golden ratio. While desirability of lean vs voluptuous body types may vary, the preference for the ratio remains.

Dan

[John Keeton]

I want to thank everyone for participating in this thread - some great comments!!! The whole idea was just to convey my journey with the ogee, and that journey is far from over. There were a lot of great ideas that I may later add to the article.


...I think that the lower curve should be allowed to continue to a fairly small foot to give the form lift. I think that Phil Brennion would say that the form you show doesn't "float". I've found that a slightly dovetailed foot works well on this form, but it has to be done right. Height in relation to the height of the bowl, small, but not too small....Wally's point is well taken, and no doubt the foot on this bowl, while being 1/3 the diameter of the rim, does not work.

Raffan, on page 53 of "the bible", talks about the perceived convergence point of the lower curves as they relate to the base. If the point at which the side curves would converge is within the foot, the form seems to sit higher (lift?), whereas if the point of convergence is below the base the form seems to sit more firmly. The bowl that is posted suffers from this, as well. The convergence is well below the base, and when combined with the seemingly larger foot, the bowl appears too heavy in the base.

This has been a great learning experience - at least for me. It has furthered my understanding of "breaking" some of the rules, and has further piqued my interest in the ogee form. In more recent times, I am doing a bowl every 6-8 turnings, so there will be others!

Thanks, again, and I hope some of you gained from all this. If nothing more, it as again brought up the clear division among us - separating the anal over-planners from the free thinking, "let the wood talk to me" group!!:D I could be wrong, but I am betting the heart attack rate is higher on my side of the line!!;) Maybe it wasn't fried foods at all?!?!?:confused: