Crib/Bed Design - Tusk Through Tenons

[Clayton Jones]

I'm building a crib in cherry for our first child who's due in a few months. I want her to have the bed for a long time, so I'm designing it to be convertible to a double bed later on (keeping the front and back of the crib as headboard and footboard). I don't want to use bed bolts to join the bottom rails to the posts, and the only joint I can come up with that can be broken down and reassembled without bolts is a tusked through tenon, similar to this joint. What size stock would you recommend using for the rails from a strength perspective? For a crib, I don't think it would matter, I was going to use 1 x 4" (finished size) for the posts, and 3/4 x 4" for the rails... but I'm concerned that 1x4" cherry is not sturdy enough for a bed, and that the tenon will not be wide enough to have room for a substantial enough tusk. I suppose I could have the tusk go horizontally through the joint rather than vertically, but then I would be concerned about it working loose without gravity to hold it in. I can always cut bigger mortises later to put in sturdy bed rails but I want to make sure the posts are strong enough. Do people have thoughts on this? Would 8/4 stock be better, to make the posts more like 1.75x4" (and ultimately the bed rails a similar size), or is 1x4 adequate? Or is this a bad idea altogether, should I just break down and use bed bolts?
192052

[Roderick Gentry]

I'm not sure I am getting all your questions, I am also not sure about the concept, sorta like the idea, and also sorta wonder who wants to live in a compromise design their whole life.

Post 1.75", the rail 6.5x1.125. You can strengthen the rail with blocking say 1.25 along the bottom inside for support. I have one bed where it is closer to 1, but it's a single.

If it was me, I would do the following on the joinery. Assume you want the wedges, and they are great, I would not do them on the crib where I assume people will be goring themselves because they stick out the front. I would take the motise in enough for a stub and smooth acorn hardware. I prefer an epoxy bonded threaded rod. One bonds a rod .375-.5 into a .75 hole in the rail, with boat epoxy. These are fixed, and there isn't any messing around with hardware when you want to put the bed together. The rails have the studs installed. Pass them through the hole, washer, nut. The accuracy of the stud is also assured. Awesome system. Then when you go to the big bed you can excavate the full mortise, and do the wedged tenons. Or if you want all the cutting done right away, you can do the same basic thing, but have a plate over the end of the through mortise to hold the acorn nut in place.