Before you start the project there is one thing you should think about. The design I made has a big crib area, this made it hard to find a fitting mattress, you might want to find a mattress first and adjust the sizes in the blueprint accordingly.
Step 1: Tool and supplies
hand saw (you can use a table saw for most of the parts)
sander (with soft and rough sanding paper)
screws (about 30 not longer than the thickness of the wood and 4 slightly longer)
4 metal corner brackets
fabric (50x50cm for the upholstery 100x100 for the crib)
foam mattress (42x44cm for upholstery and 96x44cm for the crib)
For this project you need to get whole wood (not MDF, plywood or sandwich boards), I got some pine plates. The 3 big pieces (the sides and the base) are 2.8cm thick, the rest are1.8cm. I recommend you consult with a professional if you decide to use anything different.
The sizes of the plates you will need are specified in the blueprint. In addition you will need a 42X44cm piece of any wood for the upholstery (thick enough so the staples wont go through).
Step 2: Blueprint and model
As Imsaid before, you might want to adjust some of sizes to better suit your needs.
I also recommend building a scaled model if you have the skill. I used some spare 4mm plywood to build a 1:16 model based on the blueprint. as you can see the scaled model is slightly different from the life size, that's because I made some changes after seeing the model, that's why I recommend you build one.
Step 3: Cutting the wood
Armrest: For the armrest just measure 5cm from each of the bottom corners and draw a line from there to the top corners, then cut.
Sides:The sides are the tricky part. Use a 125cm stick or string, measure 125cm directly above the center of the bottom and anchor the stick/string (I used a long strip of wood and anchored it with a screw to some more wood). Now trace a circle along the edge of your string while it pivots around the anchor point (see picture). The curve on the bottom is part of a circle 2.5m in diameter. use the crossing lines in the blueprint to draw the rest of your mark and cut. Use the extra wood to make armrests and support for the backboard (step 5). Sand down the curves until they rock smoothly on the floor.
Step 4: Assembly
Once the glue is set do the same thing for side A using something 40cm tall to put the base on top.
After you are certain these 3 main pieces are secure by sitting on them, flip the entire thing on its side (side A flat on the floor) and glue the wings in (I used some tape to hold the wings in place for 24 hours while the glue sets, not very professional but it did the trick, use clamps if you have any).
Now glue the armrest piece on top of the wings (I used weights to make sure its glued evenly on all 3 sides)
Step 5: Backboard and armrests
cut the backboard piece so that it fits perfectly in the space between the two armrests (you should need to trim off the thickness of the armrest piece). Using leftovers from side A, cut two pieces 7x52.5 cm and round off two corners (see pictures). Glue the backboard to these two piece and leave to dry.
Once dry, flip the entire crib sideways (the place where the backboard goes should be facing up (this is the time to decide if you want the crib on your left or your right as you sit in the chair), glue the backboard into place and hold it down with weights or clamps. When the glue is set, flip the crib back and test the strength of the backboard by leaning against it (you don't want this to fall apart when you have a baby in your arms).
use leftovers from side B to fashion a couple of armrests, I made mine 5x55.5cm with a round edge. I also cut the back corners off making the back only 4cm wide (see pictures). Don't forget to give the back of the armrests a 14 degree angle so they fit with the backboard. Glue the armrests into place (I placed them in the center of the two pieces holding the backboard up).
I also use some leftovers from the armrest piece and some scrap wood to make something that will stop the crib from rocking (if you want it to). Just glue two small triangles to a strip of wood at a distance that will allow you to just be able to slide the triangles underneath the curve.
Step 6: Sanding and paint
If you have an air-compressor and the right fittings for it you can spray paint or varnish using that. Either way, use a brush to even out the paint/varnish and get rid of dripping parts. Always brush with the fiber of the wood not against it.
I used 2 layers of varnish with brown coloring so I could keep the natural wood look and make it darker. If your not sure if the color you picked will come out nicely, paint a leftover piece of wood and wait for it to dry. Use smoothing sand paper (00, the least rough one) between each layer of paint/varnish.
If you plan on keeping this crib outdoors I recommend a layer or two of clear varnish on top of whatever you already used.
Step 7: Mattress and upholstery
I don't have any pictures of making the cribs mattress because I bought a ready made mattress that was twice the width and just cut out half the foam from inside.
Seat: Cut a piece of wood 42x44cm (at least 0.6 cm thick), round out the edges, glue the foam mattress to the wood with super glue (or any strong glue), cut the edge of the foam at about a 45 degree angle to give it a slope at the ends. Using a staple gun, tightly staple the fabric of your choosing (I chose black fake leather) from all sides to the bottom of the wood then cut off any extra fabric. Center the entire thing on the seat and secure it into place using slightly long screw from the bottom (make sure your screws are long enough to get through the base but not through the wood you used for the upholstery)