Saturday, March 5, 2011

Gettin' Jiggy with it!

What Will Smith meant to sing was, “getting 90 degree corner spline slot cutting jig with it…”  Jiggy is just the industry standard nickname.
After last week’s adventure we had a whole herd of boxes, rounded up, glued, cleaned and ready to be branded…well, splined at least.

In the process of pulling the tape off each box, a priceless sculptural form appeared as if from nowhere!  Somebody call the Smithsonian.  I really think this new style is going to stick.  Ba dum dum!  I’m in town all week folks!

The next phase of construction calls for corner slots to be cut for the splines.  To do that we need a jig.  No, no, no…put your Irish clogging shoes away!  No dancing allowed in the workshop.  For woodworking purposes, a jig is a device that holds the work-piece and is used to control the location and/or motion of another tool.   The idea for this particular jig is that it’s supposed to be simple and easy to build from a scrap piece of 2X4 lumber in your shop.  This is the last piece of left-over 2X4 that I had in the shop, and I had to dig to find it.  Whew!
I know what you’re thinking…”That fancy-schmancy definition of a jig, and it all boils down to a scrap piece of 2X4!”  Stay with me though.
After cutting the 2X4 down to size, it was time to hit the jointer to flatten one of the faces and square up one of the edges.

We only need one square corner and two flat surfaces for the jig to be accurate.  The machinist’s square tells me that we nailed it.

Next, I cut the piece into two parts with 45 degree angled slopes.  I also ripped a piece of Baltic Birch plywood for the side support piece of the jig.

I applied glue to the faces that were flattened on the jointer.  For the record, I’m not a fan of these flexible plastic glue spreaders.  It’s back to acid brushes for me after this.  It was handy for removing the glue squeeze-out though, so they’ll still have a home in the shop.

The two pieces are glued to the plywood so that the two 45 degree slopes meet each other to form a 90 degree angle.  The two edges that were squared on the jointer create a nice flat bottom on the jig, and should align flush with the bottom edge of the plywood.

Once I had the parts lined up and clamped together, I drove a couple screws in from behind to add some holding strength while the glue dried.  It was important to not place the screws too close to the bottom of the jig.  The table saw blade will be cutting through the body of the jig so it’s critical to not place a screw in a position to be struck by the blade.

One final check for square and the jig is ready to roll.

I’m going to be cutting corner slots into about two thirds of the boxes.  I used the small, Cherry tester box to align where I wanted the splines to land and to make the initial cuts into the bottom of the jig.

After aligning the position of the slots and making test cuts, I marked the jig so that I can repeat this set-up in the future.

Once the jig was set up, cutting the slots was a breeze…and safe.  I felt very comfortable making all these cuts quickly and efficiently…and that makes it...well, jiggy!

I also used the jig to cut slots in the two larger Birdseye Maple boxes with the thinner walls.  I wanted a short slot at a half inch from the top and another a half inch from the bottom.  These will receive splines of a darker wood like Walnut or Wenge.
With all the slots cut, the boxes have more of a Van Halen feel, rather than The Fresh Prince.  “Might as well JIG!  Yeah, go ahead and JIG!”

The Freud rip blade allowed for slots that are exactly 1/8 of an inch wide with flat surfaces.  Any of my other blades would have left a small ridge that would have to be sanded or pared away, introducing a really tight process that would just be begging for errors.  I’ll be making splines for these slots with 1/8 inch thick Cherry, Walnut and Maple.
I may pick through the woodpile for some other species, but finding something large enough to safely run through the planer that I’m interested in taking all the way down to 1/8 of an inch might be a challenge.
The thin material fits perfectly into the slots.  It’s a nice slip fit that should allow just enough room for glue to lock them in.
These splines, combined with the, glued in, bottoms of Baltic Birch plywood will make for some incredibly strong boxes that should hold up well for years and years.
Now I just need to make…you guessed it…a jig to cut the spline pieces.  Nah nah nah nah nah nah, gettin’ jiggy with it…nah nah nah nah nah nah…I’m not dancing!

1 comment:

Dyami said...

Nicely done jig, Pete.

Those boxes are coming out beautifully.