Rabbets and tearout

[Alex Berkovsky]

Not too long ago Tom Jones III posted a thread (http://www.sawmillcreek.org/showthread.php?t=42799) about NK style drawers. I am about to start making eight drawers for a dresser (have never made drawers before) and want to use this method. I tried to cut a rabbet with a straight bit using hard maple for rails, but was getting a lot of tearout along the rabbet. I figured that I was taking off too much at once and decided to try smaller cuts... slightly better, but not good enough. Am I doing something wrong? Should I just try making the cut with a dado blade buried in an auxiliary fence?

[Jim Becker]

Consider your cutter...is is a spiral or straight? Personally, I'd use the dado blade for this operation as it would be really easy to mill up a bunch of the necessary stock from longer material and then cut to length as needed.

[glenn bradley]

If you have a quality dado set I would use an aux fence and the dado. I don't have a good dado blade (yet) and so use the router. I don't usually get tearout except for lower quality ply and a 2-flute bit. I've switched to a spiral bit and am quite happy. Check your bit for sharpness, absence of buildup, etc. If the bit is good and sharp . . . hmmm. I had one piece of oak that literally blew out during routing no matter how gentle I was. The other material I bought at the same time machined well.

[Greg Heppeard]

Another thing to watch is your grain direction. Look at the edge that would normally tear out and orient it so that the grain goes toward the dado as you cut it.

[David Rose]

I have to give a little plug here. http://www.woodcraft.com/family.aspx?FamilyID=20060 Shows a wing cutter. I can't remember who first suggested it to me, but it has basically ended my tearout on rabbits, with some grain watching and such of course. There is a lot of advantage to a larger bit where it can be used. And I would not use this outside a router table. I should have asked that question first.

David

[Steve Jenkins]

when doing a rabbit with a router bit if you climbcut a light pass (1/16-1/8)first it will pretty much eliminate any tearout.

[David Rose]

That's true. I just hate climb cutting.

David


when doing a rabbit with a router bit if you climbcut a light pass (1/16-1/8)first it will pretty much eliminate any tearout.

[Alex Berkovsky]

Great tips all... sounds like a job for a Freud dado blade that has been hanging on the wall collecting dust.



when doing a rabbit with a router bit if you climbcut a light pass (1/16-1/8)first it will pretty much eliminate any tearout.Steve,
I was thinking of a climb cut, which I hear is dangerous, but I thought that the very last cut would be a climb cut to clean up any tearout.

[Steve Jenkins]

The way I do it, I use a bearing guided bit to set one dimension of the rab and measure the bit to baseplate distance for the other. I thought it would be less confusing to say that rather than depth and width which can be interchangeable depending on how you orient the stock.
Once set, I make the first pass in the climb direction but not letting the bearing touch the wood. I just watch the cut and keep it 1/16-1/8 or so pulling the router to me then follow up going the other direction with the bearing against the stock. It doesn't take any longer really and you don't need to reset the router.

[Dave Richards]

Climb cut? Perfect job for a WoodRat. :D

You might also consider cutting along the limits of the rabbet with a very sharp knife. You don't have to go too deep to prevent tearout.