Don't dream it, be it

23rd September, 2015

Had some questions about Tetsuo’s robot arm build. Here’s how I did it!
1 - Make a duct tape replica of the cosplayers arm, stuff it with plastic shopping bags. (Yay recycling!) This is more work up front, but will make your life a lot easier when...

Had some questions about Tetsuo’s robot arm build. Here’s how I did it!

1 - Make a duct tape replica of the cosplayers arm, stuff it with plastic shopping bags. (Yay recycling!) This is more work up front, but will make your life a lot easier when you’re painting and attaching things.

2 - Not shown, but make a glove out of metallic spandex. I cut apart an old elbow length stretch glove, copied the pattern and adjusted it to fit the cosplayer all the way up to the shoulder. It took two tries to get the fit right but it is important to get the fit right. Too loose and it won’t look smooth and metallic. Too tight and you’ll be uncomfortable all day or loose circulation!

3 - Put the glove on your duct tape arm and cut “muscle” panels out of EVA foam. Once you’re happy with shapes and layout, these get all covered with various colors of metallic spandex. Some pieces I cut small slits into and stuffed with polyfill for the 3D effect. The cuts are later stitched up and covered by “veins” or bolts or other robot bits.

4 - Pretty much everything was attached to the glove with hot glue! (Another reason you want a duct tape arm and not your real arm in that thing when you’re working on it…) The veins and other wire things are plastic tubes and ribbons found at local hardware / craft stores. Ends of plastic tubes are hand tacked with strong thread in case the hot glue gives out. (Which it will. Hot glue is very convenient and non toxic, but not always the most reliable.)

5 - Paint it! You can see there is a huge difference between the painted and unpainted versions. I mostly just rubbed black and brown acrylic paints into the grooves to make it grimy looking, and added some seams and wire looking things with puff paint.

6 - Make sure to leave an area of the glove that can actually stretch! If you wrap all the way around the arm with EVA or tubes you won’t be able to get it off your mannequin arm, or onto your own arm later! That is why the back of the arm looks naked, but it won’t be seen often so I was ok with just painting it to look a bit more detailed. 7 - Sew elastic or webbing to the top of the shoulder to make a harness. Mine adjusts with D rings and is basically modeled after what I found on Google for prosthetic arm harnesses. Try it on! Adjust! Try it on again! And then glue down some bits that came loose and you’re all done!

783 notes