Lining Up Dado Slots @ 90 Degrees

[Steve Edgar]

A friend asked me to make him a storage unit for his cordless drivers and batteries. I cobbled together a plan from a few internet videos. This is what I came up with. I laid out the dados by clamping the two boards to the table and cut the slots all at once. Whenever I had to move the clamps, I inserted a scrap piece of plywood in the dados between both parts. After all the slots were cut, there were about half that needed a little chisel work. What did I mess up?

[Tpt life]

Did you cut that as one board and then rip the 90 portion off? 

[Steve Edgar]

Nothing that fancy. Cut the two boards to width and then cut the long dado, so there would be some relief for the router bit in the perpendicular cuts.

[Tpt life]

I’d move to running the dado and then ripping off that part. Things should line up, even if you got one dado off by an eighth. 

[Coop]

I’m thinking that it looks darn good! But yeah, as @Tpt lifementioned, next time cut the dados first, then make your rip cut and as long as your guides are square, you shouldn’t need chisel cleanup. 

[wtnhighlander]

The times that you moved your clamps, perhaps the plywood you inserted to hold the alignment was a tad undersized, and allowed the work to shift a bit.

[Steve Edgar]

Thanks for the replies. 

 

COOP: I needed help to rip the 4X8 piece of plywood. We ripped it into 4-5 pieces first and then I worked solo. Even with three bodies, it’s a chore to rip a stock sheet of plywood.

 

Thanks for the compliment!

WTNH: I used a scrap from the original cut

 

I ended up chiseling the short part of the 90 degrees and it probably won’t show; I just thought that i

I had outsmarted the gremlins 

[Coop]

The Mother of Invention comes into play often when you have less hands than you need. I learned that quickly when my right hand man/son, went off to college. Sometimes my wife calls me MacGyver. 

[Steve Edgar]

McGyver never ripped a 3/4” plywood sheet, even with a piece of string, a knitting needle and a stick of Juicy-Fruit.........at night on the side of a mountain during a blizzard......

[BillyJack]

You made all the opening one size? I couldnt on mine as there were too many size changes. He sioux pneumatic drill are really small.....

 

[Steve Edgar]

I sized my friends largest drill and am getting him to return today with most of his collection. The lowers are only pushed into place.

 

Looks like you have your work cut out for you when retrieving one of your units...

[Tobykanobe]

This actually gives me the opportunity to ask a question about my recent Dado build.  I made this cabinet for work and it holds several of two different items, one is one size and the other is smaller.  I'll post a picture later, but for now picture two columns and several rows down those two columns.  I had 3 uprights to hold these rows, one on the left and right side and one in the middle.  Each upright is 48" and each row has 4 dado cuts.  One on the left and the right and two in the middle.  In setting up for the dados, the best I could do was use a pencil to mark where each dado was going to be cut and then eye ball it on the table saw from there.  Because of the length, I didn't feel like a large jig was an option.  It turned out "ok" but the dados are not perfect especially on the middle upright where there are two dados right next to each other.

If I were to build this again how can I set up so that the dados are in the EXACT same spot for each cut?

Will post a picture in a bit.

[Tpt life]

Best practice is to gang the boards for layout and milling. Absent that option, set fences and work holding and run every piece plus extra while the fence is set for that operation. 

[wtnhighlander]

With plywood like that, cut the dados across one large sheet before ripping into the smaller sections. That makes the outside pieces the same. For the center piece, have it already cut to width, then as you cut each dado into the side pieces, cut the dado on one side of the center, then flip it over and cut the other side. Make each cut on all 3 pieces before moving your fence or stop block to the next cut position. 

If using a router in hand, make the first dado across all the pieces in on pass. Cut a scrap to fit tightly in the dado, and use it to hold the boards in alignment while cutting the remaining dados, using a spacer as needed to offset the router from the alignment piece. For side 2 of the center piece, flip it over and align the ends of all 3 pieces. Use 2 scraps to fit the dados in the outer pieces, and register the spacer against them, to cut the second thru last dados in the center, then come back and get the first, spacing from the alignment piece in the second dado.

[Steve Edgar]

Update to the cordless drill rack. Here’s how it turned out; reminds me of the Atlantic coast submarine pens on the west coast of France.......