I am using my router table with a diy pin attachment for routing some patterns out of 1/2" baltic birch plywood. I am using a 1/4" whiteside downcut spiral bit. There is quite a bit of fuzz, if you will, on the top of the ply when routing against the grain.

I am trying to do this by multiple passes with only the router, without trimming the wood to within 1/16" of the pattern because it is an attempt at production and it would be faster for me that way. It would be pretty slick if I didn't have to sand or roundover the edges since some of it is inside slots that are hard to sand and too narrow for any roundover i have seen. Do they even make a roundover bit that could fit into a 5/16" slot? That would probably make everything much easier and this fuzz a non issue.

If I was to use a compression or up/down bit, would I still get fuzzys with the multiple pass method, since the top of the bit is doing an upcut and not going all the way through for the first pass? Also I can't seem to find a 1/4" up/down bit with less than a 1" cut length, if that even matters for the 1/2" ply, I've never used the compression bits before so I dont really know.

I tested a regular flush trim on the plywood for ****s and giggles and even only taking 1/16" off it gave a bit of fuzz on both sides and even some slight burning.

Is the only option for a fuzz free rout with multiple passes to use a down cut for the first pass and an upcut for the breakthrough? If that was the case I would use two tables set up with pin routers, but that would not be my preferred method. But like I said this is an attempt at production so if that's what I have to do, that's what I have to do.

I use these small router bits for getting in tight spaces,and they go down to 1/16" r. Carbide Router Bits | Router Bit Sets | Shaper Cutters | Saw Blades | Planer Knives | Jointer Knives | Infinity Cutting Tools

Also have a set for the dremel in 1/8" shank and a router base works good too.

Herb

Sorry not sure if you were referring to where I asked if they make a roundover bit that would fit into a 5/16 slot, I didn't see any on that site you posted to.

dcdc; wouldn't this one work?
Roundover & Beading Router Bits-Carbide Router Bits | Router Bit Sets | Shaper Cutters | Saw Blades | Planer Knives | Jointer Knives | Infinity Cutting Tools
if it was centred wouldn't it do both sides of the slot at the same time? And the ends of the slot as well?

I always get fuzzies on the end grain of teak and maple when routing a repetitive project with a carbide spiral upcut bit...I accept it as normal, a quick swipe with 400 grit sandpaper, or even the rubber end of a vac hose and they're gone...fwiw.

Pix of cutter or cut? I'm thinking this is an up cut spiral.