Folding Trivet, Roubo Style

I was thumbing through a catalog the other day, and stumbled upon a folding trivet.  You know, the things you put under a hot pot on the table.  It was made of two pieces of plastic joined together with a pivot in the middle, and was X-shaped when open, but folded flat for storage or carrying.  I thought to myself, “Why not make one from wood?”

Don’t worry, I’m not talking about two pieces of wood with a nail through the middle.  Rather, I’m talking about a single piece of wood, using the knuckle joint loved by whittlers and Andre Roubo alike.  The basic construction is similar to the Roubo bookstand that I made some time back, but on a much smaller scale.  Once you get the knack, these are simple to make and, using nice offcuts, would make great small gifts for teachers, party favors, or what have you.

The process begins with cutting a piece of wood to about 3/4″ x 3/4″ and about 9″ long.  This seems to yield a finished “X” to fit most pots.  Following this, mark the center of the piece all the way around, and then make 45 degree marks to form a diamond on the two opposing sides.  Then, mark lines around the stock at the points of the diamonds.

Next, divide the clear faces into thirds between the outer boundary lines, and shade alternating sections as shown above.  It is crucial that the opposing faces be marked the opposite of each other, or the joint is doomed to failure.

After all the faces are marked correctly (you’re sure, aren’t you?), drill small holes completely through the wood at the intersection of one of the boundary lines with each of the two dividing lines.  This provides a starting point for a saw blade.  Oh, and don’t to like I did and let the nose of your chuck run into the wood – see the circles?  I’m using a deep-throat fretsaw, so the hole is 1/16″.  Saw downwards from the hole to the other boundary line along the dividing line as shown.  This defines the parts of the joint.

Now comes the tricky part.  Using a chisel, remove all the shaded areas.  While this requires some care, it’s much easier that the multiple-knuckled Roubo bookstand.  One way to make things easier is to use a block of wood cut at a 45 degree angle as a guide for the last few strokes.  This is especially helpful on the inside cuts as shown above.  Yes, I know I need to make one more cut on the bottom side – I got it after I shot the photo.

When you finish, the joint should look like the photo above.  Notice that lines have been drawn from the points of the diamonds to the ends of the piece.  These will be the cut lines for your saw.

I used a handsaw for this, but a bandsaw is a better choice if you have one.  I just used my handsaw to stick with the all-handtool theme.  I chose a 12pt crosscut saw instead of a ripsaw due to the fragility of the wood.  Go slowly and carefully, especially as you approach the boundary lines which mark the end of your cut.  This is the point where the magic happens, and the one piece of wood magically separates into two.

Or three, if you aren’t careful.  Actually, the pine for the first prototype wasn’t strong enough to take the stress.  The fact that I could have been gentler with my manipulations certainly contributed to the problem.  However, even if I had treated it like spun glass, the pine was still a bad choice.  I made the second prototype from hickory with much better results.

And now, for the moment of truth.  As you reach the boundary lines, the ends should separate and start to hinge.  If things are sticky, take a close look at all your cuts, and gently tweak things.  Finally, the (now) two pieces will pivot away from each other.  As you can see from the photo above, there are little bits here and there that need to be cleaned up but who cares?  You did it!

And here it is in all its unfolded glory.  Did I hear you say that it looks a little plain?  Bear in mind, this was a prototype to prove the concept.  Though tough, hickory is not the most decorative of woods, and would not be my choice for a production model.  However, there are limitless ways to dress the basic model up.  Exotic woods, curved or sculpted profiles, and decorative carvings are all ways to turn this basic form into something worthy to give as a gift.

Hey, even if they don’t use it for hot pots, they may, like my sister-in-law,  just spend hours playing with the cool joint.