Are there flush trim router bits smaller than 1/2" diameter?

[JonW]

gjat- I'm not totally following your description. Sorry.

just4funsies- Yeah, I had thought about that. Hmmm... At the moment, I'm favoring trying out scorrpio's jig.

LCHIEN- Interesting idea about the piece of metal or plastic. That could solve the problem and all it would take is a piece of plastic or whatever...

[softop41]

dado cutting

I have the Accurate Woodworking dado jig and LOVE it! I have the Holbren undersize plywood bits and they are good. But, invariably, what you need a nice, tight-fitting dado isn't exactly what ANY routher bit can cut by itself. If the stock matches one of Brian's (Holbren) bits, great; but if not, the other one allows ou to use the wood you have and still get a good dado
We just never have enough tools; they all have some little knitch the they fit better than any other tool. Is technology and ingenuity great or what?
HTH,
Jerry

[Black wallnut]

OOps!

First of all, nitpicking ... most people consider a "flush trim" bit to have the bearing on the bottom. One with the bearing on top is usually called a "pattern maker's" or "template" bit or (imagine this) "top bearing" bit. You will see both types lumped together in catalogs but these terms will likely result in less chance of confusion with a vendor.

"Pattern maker's" implies something used to make a pattern. There are "pattern maker's" vises, files, and rasps, but a search of several router bit lists show no "pattern maker's" bits.

A top mounted straight cutting bit is also called a "pattern" bit or a "template" bit; I have also seen them listed as plunge cutting flush trim bits.

Unless "pattern maker's" is a regional term that is popular in your region. Like the difference between pop, soda, coke, and soft drink.

Without a dado blade set I'd use first a straight bit the same size as the shelf if I had one or second two guide boards equally spaced and a straight cutter and template bushing.
If you dont have a template guide bushing you can space your boards wide enough to leave a gap and just use your routers base to locate the dado.

[LarryG]

No oops; I've just heard something you haven't.

"Pattern maker's" implies something used to make a pattern.

I've heard them called pattern bits, pattern cutting bits, pattern maker's bits, template bits, template cutting bits, top-bearing bits, and probably more. Whatever. The essential point was, and remains, that when most people hear "flush trim," they assume a bottom bearing.