interlocking baltic birch plywood

[chris fox]

I am designing a simple step stool for my 16 month old son. I want to use baltic birch plywood and cross 2 panels and interlock them. And have the top set onto tabs. Simple design, could even be flat packed if they were sold.
MY question, what kind of tolerances should I have for designing interlocking plywood, 1/16"?

thanks
chris

[Dave Richards]

I'm no expert but I would think even 1/16" might allow for a rather wobbly step stool. I think I'd try a joint or two in some scraps to get an idea. Start tight and sand the slots wider until it fits together.

How do you plan to lock the parts together? You've got a little guy who will want to haul the stool around the house. How will you make sure it stays together?

[John Seiffer]

Here's a company that makes interlocking furniture. Don't know what their tolerances are - but maybe you could tell by some of the pix.

http://chmoebel.com/en/index.html

[chris fox]

I would tie up with screws just for that reason of coming apart. The 2 panel legs will cris cross. The 2 will be almost identical except for the center interlocking detail. The top will locate on tabs profiled on the leg panels.
I will try and post a JPEG from the CAD program I use. This is a site I was gathering ideas from:
http://www.moderntots.com/go_play/ho...ction=0&page=1

thanks.
Chris

[chris fox]

attached are .JPEG images of my stool design. For time sake, I will use glue to secure the interlocking pieces. [ATTACH]stool_2.jpg[/ATTACH]