Spiral segments chas jones Woodturning Mag Nov

[Shay Vings]

On page 75 there is a pic of a pen holder with spiral segments arranged caterine wheel fashion. I am intrigued as to how this is done so if Chas is on this forum, I would appreciate some pointers.

 

[CHJ]

This link from my web site shows the basic principle if not the full "how"

And then of course like anything else to do with woodwork, lots of practise.

 

[Shay Vings]

Thanks Chas - hadn't spotted the link. Like you say in the Mag, accuracy of cutting being tested but unlike straight line segments, no planer or belt sander to finess each piece to a standard size. Did you cut freehand on a bandsaw with a thin blade or with some guide bush thingy and a scroll saw?

 

[CHJ]

The pieces are roughly cut on a bandsaw, you will never cut the profile accurately enough with any saw.
The inner profile is finished to an exact radius on a sanding drum.
The matching outer radius and segment width is finished on a 305mm disc sander.

I consider Sanding in this context as cutting as it's profile forming not finishing.

 

[nev]

If , like me, you cant cut a smooth line (cough! tools! cough :wink: ) I guess for the inner (concave) curve you could turn a round to size and stick abrasive on the outer edge (like a grinding wheel) :? and maybe a bigger hamster wheel with abrasive on the running track for the convex curve

Edit: Chas beat me to it but I was close

 

[CHJ]

...maybe a bigger hamster wheel with abrasive on the running track for the convex curve

Good first thought =D> ,
It don't work though other than the rapid removal of the finger tips and you can't control the segment width with any consistency.