Routing Slots into White Oak with CNC Equipment

It's rough on bits, but what are the options? Pros suggest some possibilities. October 8, 2005

I am presently routing 1/4" x 10" slots in 1 1/2" white oak. These slots go all the way through the oak. It is very time consuming (takes 4 passes) and the chip removal is a real problem (solid carbide up spiral with chip breakers). Any suggestions? 3/4 inch passes work, but sometimes the chips snap the thin bits. Let's be creative!

Forum Responses
(CNC Forum)
Can you set up a tablesaw to cut a 1/8 in slot in the middle of your 1/4 in slot?

Do you have a tool changer on your CNC router?

Have you tried compressed air for chip removal during the cuts? A small copper tube rigged near the spindle could help clear the chips, and possibly allow some faster passes.

Have you tried a ruffer bit?

If the design allows, you might try making the slot a little wider, say .020" wider. First pass at 3/4" depth, one direction, come back at a faster feed rate, still at 3/4" depth but offset .020". This pass will clear the chips from the slot and give a little extra room for the chips on the through cut passes. Might save you some time by not having to clean out the slot when you're all done, too.

You can do this on 3 passes. Use an extra long up shear necked backed to 1 5/8, with serrations (ruffer/finisher). This is standard off the shelf. Rex hits the spot. Blow free air into the cut, which will assist in chip removal. If they are straight cuts, position the air behind the tool.

Clearance is the way to go. Try a 6mm cutter: this gives 0.35mm clearance in a quarter-inch slot. Then go round as suggested above.

This is an ideal application for an aggregate tool in your CNC machine. With a single output right angle head, you can use a saw blade for this application. This will allow you to eliminate multiple passes and increase your feed speed without the concern for breaking the tool. We offer this aggregate tool in a continuous duty series so that you can run this profile for extended periods of time without the need to cool down the aggregate.

I agree with the above. We have several Benz aggregates, and I don't know what I'd do without them. The saw aggregate, in particular, is invaluable to us.