Progress as of 4/3/2011
I got a Woodhaven 4555 Box Joint Jig a 2 days ago. I got it set up yesterday to where it makes good 3/8” fingers on a box joint. Today I got to work on the prototype of the tote box – the separate box on the lower left of the original drawing.
First I created a copy of the SketchUp for just the tote box and printed it out. Note that my drawing does NOT incude the finger joints. In the original drawing the length is 20-1/2”. I decided to keep that same length and added a bit to the width for the finger joints. The original drawing has the 13” end pieces drawn inside the side pieces. I needed to add the 1-1/2” but the scrap piece I had was too short so I ended up only increasing the end pieces to 13-1/2”.
I’m making the prototype mainly out of pine 3/4” wood from Home Depot. The box measures 20-1/2” L x 13-1/2” W x 5-1/2” H. It uses box joint construction with a 3/8” D dado up 1/4” from the bottom to hold a 1/4” plywood bottom. I think this bottom will be okay – my wife said it will just be used to hold horse brushes or similar light-weight items. I may go to a 3/8” thick bottom on the “real” version.
On this prototype I only jointed one edge of the material to use for the reference for routing the dado. The stock piece did have some minor twisting / cupping in it and the width isn’t perfect but I thought all I needed was the bottom square in order to get the dado for the bottom to line up.
The other reason I didn’t rip the pieces to a uniform width was because I already had the table saw set up with the dado for making the box joint and I didn’t want to have to set it up again.
Unfortunately I found out I should have had the pieces fully milled because I wanted to reference the box joint from the top of the pieces and that ended up not making the end of the joint perfect at the bottom which was actuall the reference. I should have just referenced the beginning of the box joint from the bottom edge.
The other problem the cupping causes, of course, is that there are slight gaps in the joint. None of them are much more than 1/32” though (by eyesight) and I’m all right with that for this prototype.
I learned another lesson too – the dado for the ply bottom needed to be a blind / stop cut instead of just running it the full length of the pieces. I ended up with notches exposed in the joint itself.
I’m glad I’m going through this prototype phase – on the first step I’ve learned a few lessons!
I haven’t cut the ply for the bottom yet because of the table saw being set up for the box joints.
-- Randy Morter, Phoenix, AZ