Groovy question

[woodynoob]

I would like to cut a 1/8" dado into the bottom of a small box I'm making to accept an 1/8"(-) birch ply panel.

I was just going to do it on a table saw, but I think I need to make it a stopped dado, to avoid it showing. It's joined via a box joint.

What are my options? Hand or power is fine...

[jking]

You could use the table saw and cut a small piece to fill in the exposed dado.

You could also use a router if you have the right size bit. A plunge router would allow you to start/stop your dado easily. I have also done this type of cut with a router table.

[JoeyGee]

If it were me, I would cut it on the TS. If you are using box joints, it will only show on 2 faces where it cuts through 4 "tails" of the box joint. I would fill those spots with a small 1/8" piece to replace where the kerf cut. I've done it many times that way.

[atgcpaul]

I never liked lowering a board onto a spinning blade so I won't suggest that to make a stopped groove. I took a shop class as an adult and our teacher was demonstrating this to us. Well, he lowered it down on a dado stack and the board almost immediately kicked back on him and the board cut his thumb. Not a bad cut and I'm sure his pride hurt more, but the rest of the year, we used a router table.

For a small groove (I use "dado" when talking about a cross grain groove, but use "groove" when going with the grain) like that you could do this with a router table. Lower the bit down on the spinning bit and start/stop in the right place to make your groove. That being said, I would probably plow the groove with my TS blade and then come back and patch it with a 1/8" piece of wood. If you're not sloppy with the glue and you get a good match, you probably won't notice something that small.

If you want to do it by hand, you could get a router plane.

[BadeMillsap]

I've done these many times for exactly the reason you cite. As others have mentioned using properly placed stops and a fence on the router table is how I've always done it with no problems whatsoever. Always a good idea to triple check the placement of the stops and fence.

Sent from my SCH-I545 using Tapatalk

[woodynoob]

Great comments, as usual!

It's amazing that out of all the tools I own, I just can't do it at home.

I own:
2 router planes (LV & LN), but 1/4" is the narrowest blade I have.
Old stanley combo plane and a box full of cutters--none of which is 1/8"
Craftsman plunge router hanging off a BT3000 router table. I've only used it once or twice a long time ago and have no confidence that I could get it working with enough precision to do this work.
Overhead pin router (Makita plunge) with pneumatic plunge control. Bought it at auction and have yet to repair the air valves, so won't help today.

My preferred option is to use one of the two router planes I own to cut the 1/8" groove. That was my plan as soon as I realized that using a tablesaw would likely necessitate cutting through. Only now did I figure out that I don't own a 1/8" cutter. 1/4" is my smallest!

Setting up the router table at a local community workshop is probably what I'll end up doing in the short term, but I'd like to get one or more of my options at home going too.

[capncarl]

If you cut the corners of your box at 45degrees the groove will not show. Another way of hiding the groove on a box with overlapping sides is to use a spline jig holding the box at 45 degrees and cut and install a spline into the sides at the groove location and several others. All of this is easily done on a tablesaw.

[mpc]

Cut the groove with the blade below the table surface, set the work piece down, and raise the blade into it just like cutting a ZCTP (zero clearance throat plate). Obviously one has to know how many turns on the raise handle will be needed. Once the cut is started, slide the work piece along the saw fence into a stop block then shut the saw off, letting the blade coast to a stop while you hold the work piece still. The work piece will have to held firmly down with a push block or something else for safety for the entire cut. I'd have stop blocks on both ends of the cut so the blade, as it rises into the work piece, can't fling the board off the front of the saw. Your hand force on the push block should be down and into the saw fence only - the stop block should control the "fling" force - not you... then you'll push along the fence into the other stop block. A smaller diameter blade will cut the slot to full depth closer to the end of the board too - got a 6inch dado blade perhaps? Or use a slot cutting bit in a table mounted router where it's easier to rotate the work into the bit by having stop blocks on both sides of the fence.

Neither method will get far enough into the corners of the box sides... but you can round the corners of the bottom panel a little as well to match. Might be easier than getting the slots long enough and square in all 4 box sides. As long as you can get some slot into the finger area you'll be able to hide the rounded corners inside the slots.

Usually folks plan for the slot to be within a finger (not straddling part of a finger and part of a gap) for 2 of the 4 box pieces... and thus the slot ends up between the fingers on the other 2 pieces. On those latter two pieces the slot can go "all the way across" the board - easily cut on the table saw - since the fingers of the first 2 pieces will cover it. So only 2 of the 4 boards need a plunge router cut or "raise the blade" style cut. That also reduces the corner-rounding of the bottom panel that'll be required.

The easiest, and probably safest power-tool way, to make this cut is on a router table with a small diameter straight cutting bit that you plunge the work piece into... using a stop block to control the start of the cut and a second stop block on the other side of the fence to control the length of the slot.

mpc

[woodynoob]

I'm looking at slot cutting bits. Router table seems the way to go for my purposes.