Sorby Spiralling Tool

[Richard Findley]

Hi All,

Just wondered if anyone owns a Sorby Spiralling Tool? I've got one and have had some pretty good results on both face plate/bowl work and on spindles.

My question is whether anyone has ever managed to make a spiral go around a ball/sphere like on a finial for example:? ?? I've been playing around for a while trying to do this in every way I can think of but every time the spiral goes wrong on the "corner" between the side grain and the end grain:doh: ! The spiral seems to change shape...:no: So is this actually possible or am I trying to do something that CAN'T be done:~ ??

I'd be grateful for any thoughts/tips,

Cheers,

Richard

[rsser]

Hi Richard,

I've got one on order after seeing what DJ produced at the turnfest downunder. So I can't answer your question except with a question .... does it depend on an even distance between the tool rest and the workpiece? If so, aren't you up for a curved rest to do a ball?

Just wonderin' as Al might say. Never having used one I admit to being a complete ignoramus.

[Skew ChiDAMN!!]

I really don't think it can be done, because the spirals you're trying to make are sorta like the segments of an orange: wide across the "equator" and tapering to a point at the "poles," but the cutting wheel on the Sorby only cuts a constant width.

Well... that's not quite true. You can adjust the width of the pattern by holding the wheel at a different angle, but I doubt it'd be anywhere near enough to make up the difference needed to cover a sphere.

I'd be delighted to see someone prove me wrong, though. :wink:

[rsser]

Good point Skew.

Tho the full kit comes with several cutters and you could try to blend in with paper ...

sounds like the proverbial pox!

[reeves]

sounds cool, i think a larger router lathe or milling machine attachment might do it (balls with spirals) an ornamental turning device or a custom bizzo that holds a dremel iwth cutting head and measures yr indexing to perform the needed spiral.

I have been watching the William Hunter DVD and he does large spiral grooves in turned work by hand, using a sanding disc on the lathe and holding the work against it by hand, then using a file to finish off the pointier bits...

http://www.hunter-studios.com/B/zimages/front6.jpg

[Jim Carroll]

It is easily done on a concave shape but have not tried on a convex shape, as you say when you go along the side ther will be no problem but when you get to the end curve you are crossing two planes.

Easiest way would be to go as far as you can on the side then go to the top and do your best there and the blend the 2 by hand carving.:2tsup:

Must give it a try though.