After publishing the project for different types of foldable stool-steps, I was able to make a set of 4. This time I had to adapt dimensions for the wood bars I already had.
Step 1: Material
I sanded and cut wood bars and boards, optimizing the process making a group of four\eight pieces for each type.
This way you can mark the dimension on one piece and cut all of them at the same time.
After cutting and drilling all the pieces group them in four groups, one for each stool.
Step 2: Gluing Boards
Boards were too narrow to cover a full step, and I had to glue together two boards for each step.
To make a better junction I drilled 8mm holes and I plugged and glued two wood dowels for each couple.
I kept all the boards strongly pressed with a belt and I kept them flat on the table with a board and a pair of clamps. This is necessary since the strap tension tries to lift them.
Then wait the glue to dry.
Step 3: Drilling and Dowels
As you can see every connection is not simply glued, but there are wood dowels plugged between pieces.
This is the simplest way to obtain a strong connection, although it's not effective like a good dovetail.
There are very useful metal markers, little cylinders with a spike at one extremity. Drill an hole on one side, insert the cylinder, place the opposite piece in the right position and press it against the spike, or use an hammer. You will have the exact center for the next hole.
Add glue in the holes, on the dowels and on both surfaces, just the right quantity, you will learn it after a few tries. Then place parts in contact.
Step 4: Gluing
Glue added, you have to keep pieces strongly pressed together, at least for one or two hours, better more. Use clamps or belts.
Pay attention that every connection is making 90° angle. Otherwise you have to stretch a cord to force pieces during gluing process.
This method is very simple, check diagonals and hook the cord on the longer one, then place a little wood bar in the cord and twist it until the diagonals are of equal dimensions.
Step 5: Still Gluing
Go on gluing the pieces and groups of pieces in the right order. Always wait a few hours before taking clamps off. That is one good reason for having a lot of clamps in the workshop.
Step 6: Assembling
When you have all three parts ready to be assembled you can use metal bolts and nuts, and some big washer to connect them. Use two adjacent washers between moving parts, this will reduce the friction.
Use self-locking bolts or add glue to avoid loosing.
Step 7: Straightening Out
To straighten out crooked legs you can wrap them in wet clothes, force them with clamps in the opposite direction and wait some hours or one day.
Step 8: Finishing and Completing
Finishing is essential to obtain a nice piece of furniture. Put care into sanding and polishing after treating with shellac and wax.
Enjoy and be proud of your new creation!
Step 9: [UPDATE]
To have a better stability I added a wood bar on the small moving piece, as shown in the drawing.
Other notes in the drawing are referred to the original project.