Thoughts on foldable extension table

[radhak]

I want to make an extension table for my TS, somewhat like this one on woodnet (post by mbg in the middle) that looks like this :



except that I am thinking two legs (2x4 ripped into halves).
I shall be using the same folding hinges as him :



Question is - is there any functional need for the h/w frame on the underside of the melamine-top? I see he has screwed the leg/hinge directly to the melamine, so if I do the same but I could do away with the frame.
I could just use a single strip of wood to hold the piano-hinge.

You could also opine on whether it'd be better to screw the hinge to the frame rather than the melamine.

[cabinetman]

The hardwood frame would add to the rigidity (and keep it flat) of the melamine, but you could just use the melamine. It appears that the leg used was half of this HF roller stand. I bought 4 of those when they went on sale I think for $7.99.
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[LarryG]

The function of the hardware frame is to help hold the melamine flat, and to stiffen it. Then again, most of the time, an outfeed support just needs to be somewhere in the general vicinity of flat and level, so the frame could be omitted if you really wanted to do that. (I wouldn't, as outfeed tables can double as auxiliary work surfaces, and for that you'd want the thing to be fairly flat and rigid.)

I would attach the hinges using flat-head machine screws, with the heads countersunk into the top face of the melamine and the nuts on the bottom. IME, wood screws for an attachment like a folding leg don't stay secure very long in sheet goods, espcially the particleboard that is typically used as the substrate for melamine-surfaced materials.

[cabinetman]

Question is - is there any functional need for the h/w frame on the underside of the melamine-top? I see he has screwed the leg/hinge directly to the melamine, so if I do the same but I could do away with the frame.
I could just use a single strip of wood to hold the piano-hinge.

You could also opine on whether it'd be better to screw the hinge to the frame rather than the melamine.

If you decide to put a frame on the melamine there are a few fabrication alternatives. You could add the hardwood with glue and clamps to the edges. Or, rabbet the underside of the melamine and glue and clamp the hardwood to the rabbet. That way you have just the melamine on top. On the hinge side, I wouldn't use a fastener through the melamine, which, IMO would be unsightly, and a dust collector. It could also be a source for snagging items being moved around the top. You could edge glue a hardwood edge to carry the hinge.
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