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govarney
15th May 2010, 01:32 PM
I have learnt, through the help of many people from this forum, that the shape of a bowl should be one continous curve. Since then, I think, my bowls have improved. But what about platters ?

I'm look at doing a 500mm platter, is it one continous curve too or would/should it be flat on the bottom ?

rsser
15th May 2010, 01:52 PM
As for bowls, I'd recommend a catenary curve, not an unvarying radius. Articles (http://woodturningdesign.info/articles.html)

For platters, I see these as functional objects and use diff rules. Most of the top flat, and a much wider foot for stability. Play with whatever curves to the rim you like, but obviously if they're going to be handled there are some particular design imperatives.

brendan stemp
15th May 2010, 02:07 PM
A 500mm platter??? Have you got a decent lathe to do that!!!:wink: Hope your not going to attempt it on that thing you brought to You Turn:D

I would go a long continuous curve. Subtle and hard to get right. And the curve must continue through the foot and out the other side, so it shouldn't flatten off as it hits the foot. Three carved feet always looks good on platters, if you know how to do them.

hughie
15th May 2010, 02:19 PM
I agree with Ern, catenary is the way to go.I find It is more pleasing to the eye.

Platters you have function, as a primary design consideration and you can dress up the rim with all sorts of ideas.

What I have done for some time now, is to search the net for various shapes and save them as a reference library for future turnings. Bowls, hollow vessels, platters and the like including segmented ware as well.

or buy this book as a starter I have it and recommend it.

500 Wooden Bowls
http://books.google.com.au


(http://http//books.google.com.au/books?id=Xl0xkSb7714C&printsec=frontcover&dq=500+wooden+bowls&source=bl&ots=dkVH3ZgmxK&sig=0-UA8NFweGak-IZEy4FqLkK-aFI&hl=en&ei=TBLuS4y0F8-IkAW1rsHoBg&sa=X&oi=book_result&ct=result&resnum=2&ved=0CCcQ6AEwAQ#v=onepage&q=500%20wooden%20bowls&f=false)

Texian
15th May 2010, 02:57 PM
I agree with Ern, catenary is the way to go. What I have done for some time now, is to search the net for various shapes and save them as a reference library for future turnings. Bowls, hollow vessels, platters and the like including segmented ware as well.

Good advice. A smooth, continuous curvature with no flat spots on a 500 mm platter is going to be a bit of a challenge. OTOH it will be difficult to "spot" any flat spots in such a subtle curve.

govarney
16th May 2010, 06:29 PM
Thanks for your replies Guys.

Ern, I had never heard of a catenary curve, or should I say I didn't know it had a name.:B And thanks for the links extremely interesting.

Brendan, Subtle and me generally don't make a good match But I am trying.

Hughie, I saw that wood in February for the first time and currently have 2 copies. The one I bought and the one I borrowed while waiting for my copy to arrive.

rsser
16th May 2010, 06:50 PM
Actually getting a long flat on a wide platter is perhaps more challenging than getting a good curve.

My two bob's worth: get a straight edge of around 150mm for checking; use a square edge scraper (but actually slightly radiused) and scrape and chk, scrape and chk etc etc. Light straight down on the straight edge.

Use even grained timber, and be v. careful with sanding cos you can screw it up then big time. Start with a cork block.

Good luck GOV.

Texian
17th May 2010, 03:48 PM
Straight is easy Ern. Turn it close as possible and follow with sandpaper on a straight, flat board. Granted that perfect off the gouge or scraper is best, but many folks consider sandpaper a legitimate turning tool.

robo hippy
19th May 2010, 02:54 AM
I remember writing that name down once, but of course promptly forgot about it. I think that by a process of years of learning, my designs follow that concept, but I do it by eye rather than by measuring. That being said, I don't think there is any 'right' design for a bowl. I have had some that I thought were horrible, and they sold the first time they were out. I have had some that I loved, that sat forever. I like a personal eating bowl with more straight sides as they are more functional for eating with chop sticks, which I use a lot. More rounded are for soups, cereal, and rice. Platters I prefer to have a flat bottom, and a flat rim. But again, you never know what will sell.

robo hippy