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Discussion Starter #1
Hi All,
I'm a little iffy on the correct dimensions for rabbets so bear with me. I have a cmt rabbet bit that will cut a 3/4" wide x 1/2" deep rabbet. The rabbet iscut with the baseplate on the board face. The rabbet I need is 3/4" deep, which would require running the baseplate on the edge of the board. I figure an extra board clamped to the face would add enough surface to prevent the router from wobbling.

Is it advisable to run the rabbeting bit on the board's edge? The material is plywood, if it makes any difference. Thanks
 

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where's my table saw?
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how long is it?

How long is the rabbet and the board and how thick is the board?

It's always preferable to have the base of the router on the face of the board, since it's more stable. If you have to rig up side supports to prevent tipping that's possible. You will need a straight edge guide also.
I would use a dado set in the table saw for this. OR I would get a longer bit for the router and the diameter won't matter since it's a rabbet not a dado.
 

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Wood Snob
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I can't say for sure because I'm to sure what and why your doing it. But I would offer advice on the cut. Even in plywood 3/4" is too much of a cut for one pass. Work it in more than one pass.

Al

Nails only hold themselves.
 

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Discussion Starter #4
The two sets of panels that need the rabbet are 47" and 30" long, and the rabbet is 13" long. A dado blade on the TS would be the easier (best) option, but I have to work within the confines of my current tool set. Post number nine on this thread shows the joint. I could use a straight bit and the router fence. The fence I have is super crappy, I think I would be better off doing the edge dance.
 

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Remove the base plate that came with the router. Make a rectangular wooden one, plywood or melamine works well. You can then either screw or clamp a straight edge fence to that, use small C-clamps. The standard base plates can be limiting so you should have some alternatives, very easy to make but you may need longer screws, most are standard 1/4" 20, available at any hardware store. You will need a drill bit large enough for the router bit to pass through and a countersink for the screw heads. You can use a straight bit to cut the rabbet.
 

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where's my table saw?
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that goes on the edge or the face?

Looks like on the face to me, since there is little support to prevent tipping on an edge. I think the straight bit really solves the issue, just make a couple passes and lower the bit for each pass to avoid hooging off too much at a time. Depending on the bit diameter, you may have to reset the fence to get a 3/4" X 3/4" rabbet.... I'm not really sure of that?

QUOTE: rabbet bit on edge
"Hi All,
I'm a little iffy on the correct dimensions for rabbets so bear with me. I have a CMT rabbet bit that will cut a 3/4" wide x 1/2" deep rabbet. The rabbet is cut with the baseplate on the board face. The rabbet I need is 3/4" deep, which would require running the baseplate on the edge of the board. I figure an extra board clamped to the face would add enough surface to prevent the router from wobbling."
 

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Old School
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I prefer to use bits as they were intended to be used. If the rabbeting bit didn't suffice, I would use a straight bit, and place the base on the face. Using a rabbeting bit from the edge can produce chipping and tearing because of the orientation of the cutting faces of the bit. It would be cutting into the material, instead of shearing off at the edge of the flute.




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John
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Hi All,
I'm a little iffy on the correct dimensions for rabbets so bear with me. I have a cmt rabbet bit that will cut a 3/4" wide x 1/2" deep rabbet. The rabbet iscut with the baseplate on the board face. The rabbet I need is 3/4" deep, which would require running the baseplate on the edge of the board. I figure an extra board clamped to the face would add enough surface to prevent the router from wobbling.

Is it advisable to run the rabbeting bit on the board's edge? The material is plywood, if it makes any difference. Thanks
If I read this correctly, the bit you have has a cutting length of 1/2" and a cutting edge to bearing dimension of 3/4"?
That just says the maximum depth of cut per pass is 1/2" (which is waaay to much anyway) but doesn't limit the total depth of cut until you get down to the maximum depth of cut of your router. As long as you have stock thickness sufficient to guide the bearing, there is no reason you cannot exceed the 1/2" cutting length by running successive cuts. :smile:
 
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