Joining into the edge of 12mm ply

[Matty Jay]

Im making my son a busy board for xmas and have a small sheet of 12mm ply to use. His play area in my living room is all window/glass so i cant fix it to the wall so it needs to free standing.

See the attach pic of the design i plan to base it on, i was wondering if 12mm ply is thick enough to have the legs as shown in the pic, i feel like a light kick to the leg will rip the screw out of the main board.

If so, any other solid ideas to keep it upright.

I have very limited tools.

 

[MikeG.]

Rebate the legs and glue the vertical board into those rebates.

 

[Phil Pascoe]

If you haven't the tools to cut the housings, just glue some small quadrant in the corners between the board and the legs.

 

[MikeG.]

Oooops.......I called them rebates. Scrub that: house out the legs.........

 

[Phil Pascoe]

 

[sunnybob]

stick another piece of ply across the ends of the rear legs. That will make a very strong box section. No fancy joints required. 8)

 

[Matty Jay]

Thanks for your replies, if i was to to go with the rebate/house idea would it be stronger if I half notched out the legs and half notched out the main board or does it not make much difference.

Was thinking maybe to do that and not use glue so i can take it apart if need be

 

[Phil Pascoe]

If you cut a housing on the legs you don't need to cut the board at all. If you wish to take it apart at any stage you could epoxy some 4mm threaded rod into the board and put wing nuts on it. The rod set in epoxy would be stronger than woodscrews into ply. You'd need to drill it accurately, though.

 

[MikeG.]

No, that's would be no stronger, and with an extra process increases the chance of inaccuracy. You'll need to glue it.

 

[Phil Pascoe]

I would think threaded rod epoxied in would be harder to pull out in ply than a woodscrew. Yes, it should be glued, but I was replying to his comment that he might want to dismantle it.

 

[Stanleymonkey]

Matching slots in board and in the feet?

Someone earlier mentioned a little box for the base - that sounds very sturdy.

Or two boards joined together like an A-frame? Means two pieces of ply, but should be simple enough to make really well - as long as you have something that locks it open and keeps little fingers safe.

 

[Stanleymonkey]

Where are you based mate?

I'm sure one of us would give you access to a bandsaw, router etc. whatever you need to make something for your kiddie.

 

[Phil Pascoe]

Matching slots in board and in the feet?

of course, probably the simplest.

 

[Stanleymonkey]

I've often been called simple!!

 

[Matty Jay]

Thanks for the offer guys, i really appreciate it, I have a jigsaw which i imagine should be ok if im understanding correctly whats has been said.

Sorry for my crude drawing but is that what was meant?

 

[Phil Pascoe]

Yes, with a co responding slot in the main board.

 

[Matty Jay]

Cheers guys, ill try remember to post a pic when its done.

 

[MikeG.]

That's one way, although it would be better with slots in the main board too. I don't think a jigsaw is the right tool for that job, though.

Another way would be wedged through tenons: simple mortises in the side pieces, through which elongated tenons from the central board protrude. These have a hole through them to take suitable wedges. Two either side and you'd have something rock solid, but readily demountable.

 

[Steve Maskery]

Another approach wold be to drill a couple of holes though the plywood, close to the edge and glue in a dowel. Pilot for your holes into the edge of the ply and screw in. You will actually be screwing into the dowel rather than the ply. I use that technique any time I need to screw into the edge of ply or MDF.
I agree that a housing would be best, but it depends on what tools and skills you have.

 

[Tasky]

Just use a second piece as a hinged stand on the back?
It'd increase the collapsed depth a bit, but would fold up whenever you wanted. Locking box lid stay to stop it from accidentally collapsing...