Question about rabbet router bit vs straight bit

[lwhughes149]

I am in the process of setting up to make a large number of cabinet drawers. When it comes to cutting the rabbet cut (1/4") for the drawer bottom I would like to set up my router table to make all these cuts leaving my tablesaw set up for straight cuts, kind of like a production line. I have a 3/8" rabbet router bit which I think is too much for 1/4" plywood bottoms. I looked in Lowes for a 1/4 inch rabbet bit but they only had 3/8". What would be the problem with using 1/4" straight bit? Lorraine

 

[DaveO]

Are you wanting to make a rabbet, a notch on the edge of the board, or a dado, a groove in the middle of the board away from the edge?
I usually capture my drawer bottoms in a dado about 1/4" up from the bottom of the drawer sides. If that is how you want to do it then a 1/4" straight bit would be the best way to go. If you want to create a 1/4 rabbet on the edge of the board a 1/4" straight bit can do that also. Set your RT fence in line with the back of the cutter edge, or in other words a 1/4" back from the front of the bit.
Clear as mud right :-D

Dave

 

[lwhughes149]

Clear as mud Dave. Thanks

 

[DIYGUY]

There are many ways to plow out a groove - certainly you have choices! I like to use tools for whioh they are well-suited to do a particular job. Nothing is wrong with using a router to plow out a dado and it is done all the time. I just find it oftentimes is "less filling." My experience when building drawers and plowing with a 1/4" bit has been that the bit can wander slightly, even with the workpeice well supported and braced on a router table, and as well you must feed slowly due to the size of the bit. It is also susceptible to clogging in the cut. For these reasons I rarely use one for this purpose anymore, but if so primarily when making small boxes where the length of the dado is not overly long. For me, the better path is to use the dado blade on the TS. The groove is almost always smoother and very straight. I realize this defeats your intention of trying to avoid changing blades and that may make the suggestion less attractive.

BTW - be sure your plywood is actually .25" and not 5mm! If it is the latter it will not fit in a groove cut with a router bit of the former size. Another factor in favor of a dado blade ...

 

[DavidF]

I would second Marks advice to check the ply size before deciding either way. I would also go with Dave's method of using a straight bit on the router table; not withstanding the sizing issue above. A rabbet bit generally refers to a bearing guided bit that is larger than the bearing, used to completely take away the edge of a board. A bearing guided rabbet bit would be required for a curved rabbet, a straight bit will do the job here.

 

[McRabbet]

I agree with Mark's advice too on using a dado blade and setting your drawer bottom in a dado cut starting about 1/4 - 3/8" up from the bottom edge of the drawer sides, back and fronts. You can shim a dado blade for exact fit (I use 6 mm Baltic Birch for bottoms and either 1/2" solid wood or 12 mm Baltic Birch for sides and backs) and the bottom can fit in snugly without rattling. Much stronger and squares up the drawer as a bonus.

 

[adowden]

I used my router to make the dado for drawer bottoms, but I used a 1/4" spiral router bit instead of a straight bit. It is supposed to clog less and make a cleaner cut. It is also good for cutting mortises with the router. They are around $20 at Lowes.

Amy