A bloke with big bowls.

[Peri]

Ok, I know its not technically a bowl, but 'A guy with a big cup' wouldn't have got your attention

I found this magazine cover on the net, and as a complete novice its really piqued my interest.

What does something like that weigh when it was first put on the lathe (ie before it was hollowed out).
Given that its going to be considerably heavier than a sack of spuds, how is it actually fixed to the lathe? It only appears to be supported at the one end, and even if it had some kind of metal rod arrangement going through the stem, the lathe its fixed to hardly looks capable of holding it without being pulled off its mountings.

 

[jpt]

What you see there is only a small bit of the lathe and a small goblet, have a look at this video.

http://www.youtube.com/watch?v=DC0Sxix7054

john

 

[Peri]

Thank you for that - the more I find out the more interested I become

 

[Frank S]

Peri,
be very very careful, you are standing on the edge of a very steep slope !!!

 

[Peri]

Haha, I know it can never be more then intellectual curiosity - if I tried to make something that big I'd have to stand outside my workshop and work on it through an open window

............. but the finished work does look so striking and beautiful ........... hmmm, I wonder where I put my hat and waterproof overalls ;P

 

[wallace]

I have always been fascinated by big turnings, thats why I got my wadkin RS. I have yet to turn something substantial yet. I wish I'd waited when I got my lathe as I've noticed there's been a few wadkin RU lathes for sale recently and one was the H variant which is the biggest made.

 

[flh801978]

If I remember correctly the lathe "pedestal" is infact a poured concrete piller that he cast into his workshop floor the shaft is 6 inch diameter and supported on 2 huge bearings.
he uses big coach screws to mount the blank onto a huge faceplate when he starts and a portable crane to lift the blank up and on the lathe

Ian

 

[Peri]

That makes sense Ian. On the extreme right of the photo you can just make out the shaft and one of the bearings, the other bearing must be out of shot.

I find it hard to believe anything could hold that mass of wood onto the plate (not that I'm disputing it), especially when it started to rotate - even more so at the beginning of the project when the centre of mass wouldn't necessarily be ideal.

 

[jurriaan]

I have a home built big lathe (center some 34" above the bed), so I can get in with some points:

1) turning big is fun

2) getting big wood is big trouble. I've now got some experience with moving parts of trees over 30" in diameter, and you basically need a crane to load them. That limits where you can get wood. As for unloading, the same. For loading it on the lathe, again a crane. Splitting a > 30" log is fun too, you need a big chainsaw or a medium one and a lot of muscle (and a big commander hammer helps)

3) turning big takes a long time. Trying to turn a 40" bowl sounds fun, until you see that you need to remove a lot more wood than you'd remove from a 15" bowl. Since it works in three dimensions, it's 40/15 * 40/15 * 40/15 or about 18 times as much wood! Your gouges don't scale up in the same way, even if you use that Ashley Iles 1" monster bowl gouge. Since lathe weight also doesn't scale that way (my lathe weighs something like 1800 lb), turning starts slowly. My nominal speed is 270 rpm @ 50 Hz, and I often start at 25% of that. Hitting of corners and irregularities at that speed takes time and muscle.

4) in the center, all bowls are small - but big bowls have to move slow. Trying to finish the bottom when the bowl is turning at 200 rpm and you can't speed it up because otherwise the rim will explode can be frustrating

5) You need to find out what to do with the bowls - your significant other most likely won't like stacks of monster bowls in the house. Don't ask me how I know this. Special pricing available on 30" ash crotch natural edge bowl!

As for mounting the wood on the lathe, it's not that big a problem. My lathe has a M45 spindle (on a 3" shaft). I use coach screws 1/4" x 3" or 3 1/2 " and I tend to use 12 to 16 on big pieces of wood. Since the wood turns really slowly at first, I've never thought the wood wasn't safely mounted. I don't have any experience with these very deep objects.

 

[Benchwayze]

If that 'cup' was actually spinning when it was photographed, I'd be surprised. Too much detail on the turning. It looks like a Photoshop job to me. :wink:
Not April though.. So maybe... :mrgreen:

 

[Noggsy]

Impressive baby bath.

Jurriaan, what do use to part it off...a samurai sword?

 

[Grahamshed]

I wonder if he has finished it yet.

 

[jurriaan]

Jurriaan, what do use to part it off...a samurai sword?

I have a 160 mm metalworking chuck with custom made jaws (pricey!), so after the bowl is finished, I have a tenon left.
I then use an electric hand planer and lots of sandpaper to get the bottom flat or curvy as the shape of the bowl dictates.

 

[disco_monkey79]

You'd need arms like Popeye to drink out of it when filled...