Large scotia

I need a 70-80mm (around 3") white oak scotia for a grandfather clock and I just can't seem to source one anywhere, let alone in the UK. As for how to cut one myself, I'm a bit stumped -- not having a CNC milling machine lying around. I was wondering whether I could rig something up with a router. Does anyone have any ideas or suggestions?
Jon
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"Jon Connell" wrote ...

[...]
Just to make sure we're using the same moulding names here in the Colonies as in the UK; by scotia you mean an asymetrical cove mould, where the profile is a concave section of an elipse, and where one edge juts out beyond the other?
Are you trying to make a radiused piece to go along the top edge of a clock bonnet, or just straight pieces, as along the base?
Straight pieces are fairly straightforward, lay out the profile on the end of your stock. For an asymetrical moulding, you may need to keep the stock oversize to allow for sufficient stock to ride on your router or saw table. The excess stock would be removed after the radius is cut.
A compound radius may be cut by running the piece over the saw blade at varying angles, using your layout on your workpiece as a guide. Running stock through the sawblade at an angle is a common way to cut large cove mouldings, and is perfectly safe when done correctly. Don't attempt to do this without first learning exactly how this is done safely!!! By running the front edge and back edge of the radius at different angles, a compound radius is achieved.
Grind a heavy cabinet scraper to match the desired profile, and use this to clean up the cove.
If a radiused piece is required, rough out what you can with a router, then finish using carving gouges, and finally clean up using the profiled scraper.
-- Timothy Juvenal www.tjwoodworking.com
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VibraJet is exactly right in describing a scotia molding. Here is an illustration as he describes it. http://www.realtor.org/rmomag.NSF/pages/arch37?OpenDocument I would also use the table saw to make the eliptical cove scotia. Here is a nifty way do do so. (I like to trap the molding board between two guides). http://www.binkyswoodworking.com/CoveMouldingTip.htm Cheers
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Here is a more detailed description of making a cove on the saw. Experiment visually (saw unplugged) until you see the ellipse you are after. Mark DeCou describes this method: http://lumberjocks.com/jocks/decoustudio/blog/312
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wrote:

your stock. For an asymetrical moulding, you may need to keep the stock oversize to allow for sufficient stock to ride on your router or saw table. The excess stock would be removed after the radius is cut.

varying angles, using your layout on your workpiece as a guide. Running stock through the sawblade at an angle is a common way to cut large cove mouldings, and is perfectly safe when done correctly. Don't attempt to do this without first learning exactly how this is done safely!!! By running the front edge and back edge of the radius at different angles, a compound radius is achieved.

Excellent - thanks.
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