Bullnose on curves?

[Brian Penning]

Can't figure out how to get a bullnose type edge(or any table top edge bit) on a curved piece.
For example a round table top or large radius edged table corners?
TIA

[Steve Jenkins]

the easiest way is to use a router bit that has a bearing on it (like a roundover). The bearing will ride on the edge and for a bullnose you rout from the top first then flip the table over and rout from the bottom. For a full bullnose you can't quite make a full pass from the bottom because the bearing will be riding on a rounded over part of the edge but with a some sanding it will look fine.

[Stephen Edwards]

the easiest way is to use a router bit that has a bearing on it (like a roundover). The bearing will ride on the edge and for a bullnose you rout from the top first then flip the table over and rout from the bottom. For a full bullnose you can't quite make a full pass from the bottom because the bearing will be riding on a rounded over part of the edge but with a some sanding it will look fine.

I second Steve's suggestion. In fact, I finished a project yesterday using this same techinque. If you'll use the appropriate roundover bit for the thickness of your piece of work and set the bearing to travel in the center of the thickness, minimal sanding will give you the desired results.

[Anthony Whitesell]

I've accomplished this two ways.

1. Bearing guided round over bit and make the cut in two passes (top and bottom), followed with a little clean up sanding.

2. Make a zero clearance insert for the router table for the bullnose bit. The ZCI will keep you from cutting too deep into the workpiece (ie., the ZCI will act as a guide bushing of sorts if done properly)

[Brian Penning]

the easiest way is to use a router bit that has a bearing on it (like a roundover). The bearing will ride on the edge and for a bullnose you rout from the top first then flip the table over and rout from the bottom. For a full bullnose you can't quite make a full pass from the bottom because the bearing will be riding on a rounded over part of the edge but with a some sanding it will look fine.

I've done that before and wasn't happy. There's too much of a recess due to that roundover from the 1st pass.

Something I just thought of...Is it possible to buy a bearing to fit over the bit shaft that's the same diameter as the bullnose outside diameter?

[Anthony Whitesell]

Interesting concept. I looked at the Whiteside Catalog and it looks like you could buy a separate bearing, but what would it ride against?

[Mike Wilkins]

Ditto for the other posters. However, be careful on some sides of the board to watch the grain direction. It may be necessary to turn the board over or do a climb-cutting operation. Routing against downhill grain invites tearout.
Be safe and watch those fingers.

[Frank Drew]

For a circular table you can make an auxiliary fence for a shaper, cut to mirror the curve of the table, with a hole for your shaper cutter. This job specific fence can be made of ply or MDF and only has to be as thick as the workpiece. Depending on how finicky you got in making your fence/rounding your workpiece, there will be more or less cleanup and refining the shape. If you had a router bit with the correct profile but didn't have a bearing there's no reason this wouldn't also work on a router table.

You could also use a bearing collar with loose knives in the shaper, but, as with the router techique, you'd have to leave a flat to bear against.

[Brian Penning]

Interesting concept. I looked at the Whiteside Catalog and it looks like you could buy a separate bearing, but what would it ride against?

A template? Nah, that wouldn't work cause the template would have to be the same size as the top. Too much potential for errors there(for me anyway).

[Peter Quinn]

uh...template?

[Anthony Whitesell]

If you want to go the template route. The top bearing on the roundover bit would need to be the same size as the large diamter of the bit. If you could find a rabbet bit the same size you might be in business.

1. Attach the template material to the work piece but space shim it up to allow for the cutter-bearing gap.
2. Use a bottom bearing pattern bit to make the template material identical to the workpiece
3. Use the rabbet bit to recess the template back from the edge of the work piece
4. Use the top-bearing bullnose bit to roundover the workpiece

I don't usually go the template route. In the case the template will be one shot because you probably won't be able to align it to another work piece. Secondly, I don't like try to hold the pieces steady all at once (even with tae and/or hot glue).

[Frank Snyder]

Brian,

I've used Amana's Roundover bit with their radius bearing to route bullnoses on radius stair treads. It works as advertised.

http://www.amanatool.com/bits-fv/57190.html

Frank

[Lee Schierer]

the easiest way is to use a router bit that has a bearing on it (like a roundover). The bearing will ride on the edge and for a bullnose you rout from the top first then flip the table over and rout from the bottom. For a full bullnose you can't quite make a full pass from the bottom because the bearing will be riding on a rounded over part of the edge but with a some sanding it will look fine.
In addition to Steve's method, do the top first then flip the table over and do the bottom, but instead of the bearing guide following the edge use a large circle cutting jig on the router. The pivot hole in the center of the table will be hidden from view and will avoid the sanding Steve describes or the undercut if you use a piloted bit for a full depth second cut.

[jason lambert]

Something is confusing me what do you mean by recess on the first pass?

I usally use a router with a large base to ride the top it is very stable, or add a extended base then do a ruff cut 3/4 of the way or several small cuts then do a light finishing cut. Don't try to do the whole cut at once.

A template will work or you can just try to make the outside edge the way you want eithor way you will have to make a good curve. A templet is the safer way but more work.