Router roundovers

[winty03]

Hello, I am new to routing and just purchased my first router and was doing some practice runs and had a question. I am attempting to round over a 3/4 thick piece of oak. I never seem to be able to get both sides of my round over to match, completing a nice smooth round over. I am running the router by hand, not in a table. is there a easy way to deciede the correct size of round over bit for a thickness of wood and should your roundovers meet nice and smooth in the middle or do you always has to come back with a sander to match them up? Thanks

[JOE MOHNIKE]

Yes sanding will be required absed on your description.

To obtain the results you are looking for is best accomplished on a router table with an offset fence, and even then there will be some sanding required if you are useing a 1/4 round over bit. You could use a bull nose bit which cuts both edges at the same time, but again you will need a table with an offset fence.

[winty03]

OK, I was going to elaborate, I was thinking....what I am having problems with is of course now I have figured out that I would need to use a 3/8 inch bit for 3/4 inch wood to round it over...but what happens is after routing one edge...when I go to do the second edge my ball bearing guide must ride too far in, (the round over I just cut) and makes the second round over deeper than the first.

[Lee Gordon]

Raise the bit a little so you leave a little flat spot in the middle for the bearing to ride on when you cut the other side. You will, of course have to do some sanding to make it completely rounded. Of course, by doing it on a router table you can take the bearing out of the equasion.

Lee

[Joe]

The reason you will need to always sand based on your description of your technique is that on the second pass, the bearing is not riding on the square edge as happens on the first pass. Instead it rides on part of the round that you just cut, which is inside of the square edge. That is what produces the aris on the tip of the completed bullnose. This is why you should perform this in the router table with a fence. Even then, you will probably have to sand a little, just a lot less than routing by hand.

JC

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[Charley]

When I want to do this I make the first cut with the router mounted in a router table and the bit and it's bearing positioned to give me the curve that I want. Then I move the router table fence into position and align the fence surface with the bearing surface and I flip the board over to make the second cut. I don't move the router bit height at all. The bearing doesn't actually get used for the second cut as there is no material in the proper position for the bearing to ride on. The fence takes it's place. This will give an equal curve from each edge to the center. Still, some light sanding may be required, but it will be very negligable.

[pat]

[Ellestad]

You may be able to do better by using an edge guide which will ride on the very uncut nose centered between each cut.

Tim

[Andy Dingley]

This is hard to do, so don't try. If you try to get it _exactly_ right, then you might cut too much or too little. Too much of a cut raises a sharp arris that's noticeable. If instead you attempt to cut just a bit too little, it's a lot easier to get an acceptable result.

A radius of half the thickness (or a smidgeon less) and then adjust the height until it doesn't quite cut a "quirk" The diameter is usually fixed by the guide bearing, which ought to be accurate.

There's also the problem of tilting the router base by accident, which will tend to cut a false quirk. Try to hold it level, or switch to a table.

Carbide cutters are the only sort worth bothering about. 1/2" is favoured over 1/4". Good brands do make a difference, but you can usefully get a full set of cheap ones to start with. Read Pat Warner's excellent router website too.

Get a table, or make one. It's very easy, even when you make your own fence.

rarely use a router freehand, nearly everything happens in the table.

[Gerald Ross]

You could rout the second cut from the edge with the guide running down the flat side of the board. Not easy to do without a router table.

[marks542004]

if your bit has a guide post or bearing it needs a surface to follow, so you normally get a small flat in the center of the curve.

You either need a table mounted router with a fence or you can clamp a guide in place that the router base plate will follow. This works well on wide shelving but requires very careful setup , or a jig.

[seelyjv]

If I understand your question correctly, you are trying to do something that a "roundover" bit was not intended to do. The feature you are trying to create is called a "bullnose"; and, while it can be created by using a roundover bit in a router table it is almost impossible to create freehand. A roundover feature is a relief of only one corner of an edge. A bullnose is an edge feature that has both corners of the edge rounded the same amount to create a full radiused edge. Bullnose bits were created to produce this profile and they can do it freehand. While it may be possible to use edge guides or other careful freehand procedures and some creative sanding to accomplish a bullnose profile with a roundover bit, it is far easier to just use a bullnose bit. Jim Seelye

[sheldon.mandel]

If you play with the depth setting, you can get it very close... there will be a little ridge that has to be sanded away. It was real easy to do in pine. Use the sander tin a rocking motion over the rounded edge while moving up the board. Takes 2 seconds.

shelly