Here is a step by step, how to assemble a jumpsuit for action man figure dolls.
This tutorial is to make a costume for a doll, but of course if you make a bigger size of it, it can be for human as well.

This pattern was made for the Action Hero Tailoring workshop at Fablab Berlin.

You will need the following parts to assemble the jumpsuit: Pants x2, shirt back x1, shirt front x2,
sleave x2, collar x2
You can download the SVG file from here >>http://www.thingiverse.com/thing:129443 to print the paper to cut fabric with laser cutter or simply print it and use it as a paper pattern to cut with scissors.

You will also need a sewing needle, threads, a pair of scissors and a sewing machine.

Step1:
Let’s start with pants.Fold the pant pieces into half with printed side facing inside. You will get something like a tube. Stitch the straight open edge of the tube with sewing machine. Make sure to stop sewing before the rise curve. The seam for the edge is 5mm.

Step2:
Reverse one of the tube so that the printed side of the fabric faces outside.

Drop this into the other tube until it matches the edge on the rise. Pin it together to fix the position and stitch it together with sewing machine. The seam is 5mm.

After you are done with stitching, you can pull out one of the tube, and it is a pair of pants now.

Step3:
Now the shirt. Place the front shirt part onto the back shirt part facing the printed side of the fabric inside. Match the shoulder edge and side edge, fix the position with pins and stitch it together. The seam is 5mm.

Step4:
Fold the sleeve part in half. Make sure that the printed side faces inside. Fix the position with pins and stitch the straight edge with sewing machine.

Step5:
Turn the sleeve tubes inside out so the printed side faces outside. Drop the sleeve into the body of the shirt until the shoulder edge matches. Fix the position with pins and stitch with sewing machine. The seam is 5mm.

Step6:
Now to assemble a collar. Place two of the collar parts together with printed side facing inside. Stitch it with 5mm seam. Chop off the extra fabric at the corner so when you flip it around, it does not bunch up. Flip the inside out. Now the printed side is facing outside. It is good to go.

Step7:
Now we attache the collar onto the neckline of the shirt. First, fold the collar into two and mark the center by making a small cut. Do the same for the neck line of the shirt. Match the center point and pin the collar and the shirt together. Please check the second picture to make sure the direction of the collar relative to the shirt.

After centering the collar, pin the collar down all the way to the end. In this example, I am bringing the collar down to the front line of the shirt, so the collar opens wide around the chest, instead of following the neckline. Notice the extra triangle shaped fabric. Cut off this extra fabric following the collar’s edge.

Now it is ready to sew. Place it on the sewing machine and stitch it straight. The seam is 5mm.

It should look like this now.

Now fold in the edge of non-stitched edge of the collar to the neckline and pin it all the way.

This is how it looks from the other side

Then stitch it together. You can use sewing machine as well, but as it is very small, it maybe easier to hand stitch it.

When you are done stitching, it will look like this.

Step8:
Now we connect the pants and the shirt together.
Turn the shirt inside out so the non printed side of the fabric faces outside. Leave the pants on printed fabric side facing outside.

Now drop the pants into the shirt like this. Check the direction of the pants. The front side has smaller curve on the rise. Make sure that the center of the pants matches the center of the shirt.

Pin it around to fix the position and stitch it with sewing machine. The seam is 5mm

Now, when you open it, it should look like this. You can fold up the hem of the pants and sleeves and stitch it to make it nicer if you like.