Thread: Advice / tips for turning tiny spherical shape?

It's cheating but I've turned a few small wooden spheres for SWMBO using a small ball turning attachment on my MW lathe.
I made the tool holder and height adjustment mechanizm.

Hi, it takes a lot of experience to be able to turn a sphere, I made a tool for my wood lathe to do it as I became frustrated with failed attempts.
A relatively simple way is to roughly turn it to shape then finish it with a 60 grit*skew then 80 grit up until you get the desired size, shape and finish.
*60 Grit Skew is 60 grit sandpaper.
Kryn

if you want to make several, grind a form tool from an old file use it more like the cutter on a curtain or back knife lathe.

Some nice "cheater" techniques suggested above - thanks for those. I hadn't seen the form tool approach before and google turned up some good stuff there. If I ever set out to make a chess set then I will probably go with a jig or form tool approach, but for now it is just practice, practice, practice to try to develop the hand skills.
One other very interesting approach I came across on youtube is to use a piece of pipe like a scraper. It takes off all the high points and seems to produce a really good sphere - see this video at about the 12 minute mark:
Woodturning a chess set - the pawns

(I wonder what sort of "catch" danger this technique has?)

Originally Posted by Oddy

Hi, beginner turner here. I have only had my lathe for a few months and am still at the "playing" stage. I've played with some hollow forms but have been focusing mostly on spindle work first to try and develop some skills and am starting to get confident with the skew. Last weekend I set myself a challenge to try and copy some chess pawns. I was able to duplicate the coves and beads very well but the ball on top of the piece was a disaster. I can't seem to get it close enough to a spherical shape and my error fixes mean I can never get a consistent size either.
Maybe I am being too ambitious to try something like this yet, but would appreciate any tips.

borrow or buy a copy of this



the problem with youTube is that what you get is mostly -- this works for me and so should work for you. Learning how to cut as opposed to scrape is an invaluable skill

from the book ...

Fig 7.19 Rolling the front of a knob. The left-hand photographs, like most in the book are taken from the turner's viewpoint.

https://www.youtube.com/watch?v=KfeLAHQSbqk

This is the best video I've seen on using the skew chisel and the entire thing is free to watch.

Originally Posted by Woodturnerjosh

https://www.youtube.com/watch?v=KfeLAHQSbqk

This is the best video I've seen on using the skew chisel and the entire thing is free to watch.

I have to agree, Alan Batty was a master with spindle turning tools.

Oddy, there is no substitute for practice, practice, practice and a keen edge on your spindle turning tools. Very sharp spindle turning tools make a huge difference. Certainly there are tools, like form scrapers, that will make it easier to make consistent profiles but they also require skill and the right grain properties in the stock timber. Some timbers scrape really well in spindle turning mode, most don't.

You could try these Woodturning Bead Forming Tool from Hamlet Craft Tools of Sheffield and remember to follow the sharpening instructions explicitly - hone the top face only.

One tip to gain practice quickly - instead of making a story stick with a few attempts or lots of failed complete pieces, place similar sized stock in a chuck or between centers and concentrate on making only one cut - repetitively - say one half of a cove or bead. In 20 or 30 mm of timber you can make 15 to 20 or more attempts at that one cut. Then practice the other cuts that combine to make your chess piece. Start with a scaled up version of the pieces and cuts to be made on the chess pieces then when you get them down pat, scale down to the required size. The scaled up version allows you to concentrate on the basic body movements required to make a cut and accentuates that movement to make it easier to visualize what is happening with the cutting edge on the tool. When you scale down you already have the basics, just have to adjust to the smaller size. Look up some of Jon Siegel's suggestion on turning - A Better Way to Practice http://www.bigtreetools.com/articles...o-practice.pdf.

A "quick'n'nasty" way to turn a sphere (on a stem) is to use a length of pipe with a smaller inside diameter. For a one inch sphere I'll use a 3/4" ID pipe. The pipe end must be cut squarely, with a crisp arris on the inside rim; that's the cutting edge.

It helps a LOT if you preform the blank into at least a roundish cylinder, if not a 'nearly there' sphere, as the pipe end is pressed against the blank & swung left 'n right to scrape the sphere into shape. It's a bit like rubbing an orange with the end of an exhaust pipe.

It tends to be a bouncy, noisy and scary process... at least in the initial stages... but it works quite well. A little sanding - well, OK... a lot! - is usually needed but in the interest of turning out several in a short time I'll quite happily forego getting a finish straight off the tool.

I have several different dia's of pipe mounted on handles included in my turning chisel rack, but for smaller spheres, I use a dowelling plate instead. The same principles still apply thouigh.

PS: the sphere must never be turned small enough that it nearly fits inside the pipe! That way leads to serious disaster. (Think: tool jamming onto a rapidly spinning piece of wood... :cringe: )

Originally Posted by Skew ChiDAMN!!

A "quick'n'nasty" way to turn a sphere (on a stem) is to use a length of pipe ...

I came across a video of that technique (see post 5) that was quite interesting to watch. I didn't think of a dowel plate though - that sounds like it would be better, especially for tiny diameters (dowel plates look to be pretty expensive though).