How can I mill a cove on a curved surface?

[Glen Blanchard]

I will be starting a project in a couple of weeks that will have me placing a cove on a curved surface. David Marks milled the cove with a die grinder along with a 5 flute high speed steel ball mill and then a finer tooth carbide ball mill. I own none of these, and although I can find a die grinder easily enough, I have been unable to find the ball mills that Dave used.

So is there an alternative way to cut such a cove?

[Jamie Buxton]

It depends on how big the cove is and what the curve is. You can buy router bits to cut coves, guided either by a pilot bearing or by some edge-guiding rig. For bigger ones, a similar but larger cutter can be used in a shaper.

[Glen Blanchard]

Thanks Jamie. I had already thought of using a piloted cove cutting router bit, but this cove will be larger than any such bit I have been able to find and I don't own a shaper. Thus, I am looking for options (if such exist).

[Rod Sheridan]

Jamie had some good answers in his post.

You can also do it with a gouge by hand, it doesn't sound like you are making a very large piece.

I often do that sort of thing by hand, followed up by a bit of sanding.

Regards, Rod.

[David DeCristoforo]

What is the size of the cove and where are you looking for bits? Nordic has cove bits up to a 3" radius (!?!?)

[Rob Woodman]

May I suggest grinding a scraper to the required shape and put it in a modified version of a Veritas Beading tool.( looks a bit like a marking gauge )
I had to run some Grecian Cavetto moulds ( these are eliptical section coves ) in green oak and this technique was surprisingly quick. Of course to speed things up you can always "rough" out the moulding with a guided rebate cutter or such.
Rob.
http://lh3.ggpht.com/_4Prh-kD7KMY/SxAhzkXM8dI/AAAAAAAAAFo/uRyaeU2iyqU/s640/Spandrel-001.jpg

One of the spandrels, I screwed two of the female parts of brass double ball catches to the fence/stock of the 'gauge' to run the curved parts, takes a bit of practice to keep them in contact with the work but this comes fairly easily.

[Glen Blanchard]

What is the size of the cove and where are you looking for bits? Nordic has cove bits up to a 3" radius (!?!?)

David - The size of the cove is not really designated and there is no plan to reference. However, the stock in this image has been milled to 1.5" thick, so I am guessing that this cove has an approx. radius of 1.25"???

[David DeCristoforo]

"... I am guessing that this cove has an approx. radius of 1.25"..."

Well, like I said, you can get them. Check at nordicsaw.com or "google" around.

[Gary Gleave]

Lee Valley bits are of descent quality. Here is a link. I have never posted one here before, so if it doesn't work, copy and paste.
If you are only doing the piece in the photo, I would agree with others, and do it by hand.

http://www.leevalley.com/wood/page.aspx?c=1&p=30187&cat=1,46168,62157&ap=2