On Thu, 05 Jan 2006 14:40:59 -0800, David wrote:

Using a 1/4" diameter round nose bit to make flutes, should the depth be
set to 1/8" and the spacing between the flutes be equal to their width
(1/4") for best appearance?

If you want the flutes to be adjacent, then you _must_ have a sharp and
straight arris (the ridge) between them, or else it looks terrible.

You can't do this by routing to one radius depth. This would leave the
top edge impossibly thin. You're better off routing to 1/2 or maybe
2/3rd of radius at most. You can't tell visually how deep a flute is -
you certainly can tell what its edge looks like.

Depending the stability of your router fence, you might even find this
best achieved with a tiny gap in routing, then using a rebate plane to
slightly cant the edges so that they meet exactly.

Classically, flutes generally met at this sharp arris. In
furnituremaking though, it was more common for them to be slightly
separated, by around 1/3rd diameter.

It's also fairly unusual for flutes to "fade". Reeding and chamfers
fade, but not usually flutes. If a flute does fade it's more like an
oval flute that's maybe twice the length compared to the diameter, not
at all a gradual tapering. This is a job for a gouge, which you
certainly ought to get hold of - a couple of gouges are always handy.

You'll be wanting to prototype these cuts in similarly coloured timber,
just so you can see what they look like, as well as how they cut.