Nick Jensen (Nick Brick) is showing he is no slouch in CAD. I've always felt that the TLG cyborg arm was a little too 'heavily armored'. This pared down variant by Nick is quite refreshing and inventive. I'm also interested to see what you could do with that hole in the shoulder.
Nick states he has plans to have this made through C Ideas, a 3D printing and manufacturing company in his area. I can't wait to see the finished product!
I recommend browsing through Nick's Flickr stream. Not only does he have other CAD designs, he has several amazing Halo firearms built entirely from LEGO!
