Best way to make this cut?

[DaveO]

I need to cut a 1/2" x 1/4" rabbet on all four edges of a piece of 3/4" curly maple. The result will be a 1/4" x 1/4" tongue. My biggest concern is chip out, curly maple is bad about that. My choices are: rabbeting set for the RT with changeable bearings (smallest cut 3/16"), new 1/2" straight cut bit in RT partially buried in the fence or TS with ATB combo blade making 2 cuts per side.
I am most concerned with the chip out because the rabbet will be visible. I am cutting the tongue to float a lid into a box and it will sit slightly proud thus displaying it's, hopefully not, damaged edge. My second concern is safety and accuracy of the cut. And third is to reduce any potential burning of the cut edges. Make any sense?
Thanks for your thoughts!
Dave

 

[Travis Porter]

My thoughts are either router table or table saw with a dado blade. Cut the grooves on the end grain first and you can do the long grain which would eliminate the tear out. You could also use backer boards to minimize prevent tear out as well.

 

[Steve D]

Dave,

The TS is a better choice to avoid tearout but has the tendancy to leave saw marks. I would probably go for the best of both worlds and cut just shy of the actual rabbet on the TS and then clean it up with an extremely light pass on the router table. And yes, end grain first. The other option is the TS and cleanup with sandpaper wrapped around a block. Or use this as an excuse to buy some fancy plane from Lie Nielsen. :mrgreen:

 

[DaveO]

Steve D that was what I was thinking. I appreciate the end-grain first tip.
Travis, the reason I didn't mention a dado blade is that the one I have sucks really bad and doesn't leave anything close to a flat bottom. But for $15 from HF, I don't expect much.

Dave

 

[Travis Porter]

Then I am with Steve. Multiple light passes with the router. The rabbetting bits probably would do the best IMO. You might want to lightly "back cut" on the initial pass to keep your edge crisp.

 

[Ozzie-x]

Yeah, I'm with Steve & Travis. In the absence of a hot rod dado blade set, the light passes on the router is probably the safest bet. Might want to sharpen your router bit razor sharp too.
Best Regards
Randy O.

 

[rbdoby]

Steve D's idea sounds the best to me. I would consider using a spiral bit in the RT to cleanup the rabbet because of it's shearing cut.

 

[erasmussen]

what ever way you go, i hope you got some scrap to try frist.
I would try 2 passes on the TS with a good sharp 80 tooth atb with a - hook
if you got one.

 

[DaveO]

Well, I was successful in not screwing anything up:eusa_danc :eusa_danc

I made the cut by first removing most of the waste with a stack dado set and then two passes 1/32" at a time to square it up and take it to it's final dimension. No chip-out and just the slightest burn spots that cleaned up with a scraper. Thanks for all the advice, it was a big help:icon_thum :icon_thum

Dave

 

[Dutchman]

As posted above, I think the router table with a good bit would work best. I would also suggest using a piece of oak or hard maple as a push block. Cut a tenon on the push block to match the rabb you are cutting and make sure it fits tight. I usually cut the end grain of one side and work my way around.

 

[D L Ames]

Dang Dave, once again you received solid advice, made your cuts long before I had a chance to chime in. Sounds like you have prevailed once again.:icon_thum I can't wait to see some more WIP pix.

D L

 

[Handturnedbowls]

Youve already been there and done that, but for what its worth...

On slots that need to be pretty, I use a single Pirahna blade or similar with an extreme hook tooth to saw both sides of my wall first but not to the finished widths or depth.

This I either advance the wood a blade thkness at a time to dado out the slot again to rough out. For the long grain, I advance the rip fence a sawblade thickness each pass.

Then I use the router. Instead of cutting the full width with a matching bit, I go with a bit approx 60% of the finished width. This will be two cuts, one for each finished wall. I set up my fence so that I will be pushing against the rotation, not climb cutting. Since this is a very light cut, a clean up cut, it leaves a super smooth wall and never chips out.

cad