/cgl/ - Cosplay & EGL

Okay, so I wanna create Junkrats arm. I have never worked with making props like this and I know it's probably not the best starter project, but I'm gonna try.

I have pretty much all of the materials I need to start (eva foam, heat gun, contact cement etc), but I just can't wrap my head around how to make a pattern that would work.. I thought it would be easy, but everything I've tried ends up not working.

My questions are 1, if anyone knows about someone who's made his arm and published a pattern of how they did it
2, If anyone here has made it and if they would be willing to share the the pattern they made (I wouldn't mind paying a bit, I understand that a lot of work and thought goes into it)
3, if anyone who has experience with props in general could give some tips on how to make a pattern

Also, what would be the best thickness of foam? I'm using those workout mat things, but I'm thinking they might be too thick

Thanks in advance!