dado or router?

[lynn]

I am building a coffee table and need to cut a 3/8" groove. I do not own a dado set but do own a router. My question is can I cut it with a router, instead? I think I can but am not sure whether to use a 1/4" bit and move it incrementally or use a 3/8" bit. What do you think?
lynn
PS-Raven, my middle name.

[handi]

Lynn,

Use the router. Preferably with a 1/4" downshear spiral bit. (the downshear will keep the dado edge crisp)

Set two straight edges, one on each side of the dado. They should be separated by the width of your router base plus 1/8" That way, you make one pass, slide the router over to the other edge, and make a second pass. If the dado needs to be a hair over or under 3/8", this method allows you to set the dado to a precise width.

An upcoming issue of Woodworker's Journal Magazine will have an article I wrote on making a dado base for the router which will allow you to make this sort of cut using only one straight edge

Hope this helps,

Ralph

[JohnP]

Lynn / Raven; For most of my dados I prefer to use a stacked dado set,but they will cost between $100 to $300. You will get what you pay for. If you only have the one dado to cut use a router bit, I would suggest the full 3/8" bit, increasing the depth with multi passes.
Hope this helps
JohnP

[handi]

Lynn,

Not to argue with John, but there are reasons to use a smaller bit when creating dados. First, the odds that any give piece of wood will exactly match the bit diameter are very small. By making two passes with a smaller bit, a very precise dado can be milled.

Second, most bits will flex a little during milling operations. Plowing a 3/8" dado with a 3/8" bit that flex might mean it's a touch off center. Also, you might notice that at the end of the cut, the bit unflexes as it sits there, leaving a slightly elongated end to the dado.

Just my opinion,

Ralph