We are starting to see a stream of really cool robot designs pass through the Shapeways space-time portal and I just wanted to take a moment to share some that I could find.
It would be really interesting if we could standardize a scaleso that components from different robots could be interchangeable, with standard sizes for apertures in torsos for arms, legs, heads. Standard hand/grip sizes so that weapons/tools/whatever could be purchased from each other. Please let us know if this is something you are interested in? what scale the robots should be? What size the hands, holes etc. etc. etc....
Until then, here are some of the robots currently on the site, in varying stages of realization...
Most of the actual toys on my desk use a standardized 5mm
Transformer guns or other weapons will have a 5mm post to fit the robot's hands.
Additionally, a small robot character(dubbed a 'Minicon') uses a 5mm hole to connect to a 5mm post to mount to a hardpoint on a larger robot companion. I plan to make some more robots using both a 5mm post(to be held as a gun) and 5mm hole (to be mounted on a hardpoint)
Sadly the transformers line does not use any universal system for joints for robots, but it seems many recent Minicons or Legends-class figures(approximately 3-inch robots) use 5mm for their balljoints as well. Larger figures have joints of a staggering array of shapes and sizes.
The 5mm(diameter) posts minicons use for mounting seem to be about 4mm tall, whereas 5mmpost on rifles seem to come in various lengths, but none shorter than 4mm(Classic Jetfire's rifles are closer to 8mm tall, for example)
Two of mine in there (Ratchet and Doubletime)! There are some fantastic designs on that list.
As Redshift says, most Transformer weapons (there are always exceptions) use a standard 5mm peg to fit into their owners' hands; these vary in length, but generally are between 4 and 6mm.
The posts used to attach Minicons are the same diameter, but about 4-5mm long, and also have a 2mm diameter hole in the centre; Minicons were originally designed to activate special features when attached to the larger figures, they have 2mm posts within the ports which can push down a button in the post. They don't usually include these features anymore now, so it's just a matter of attaching the Minicon as a "power-up".
I'm working on designing some weapons at the moment as well (like my Turbo Rifle), and they're all going to have the Minicon-style peg with the 2mm hole in them (saves a little material as well ).
With regard to ball-joints, I personally am using a standard 4mm dia. ball with a 3mm shaft, and I know at least some of the Minicons use the same sizes (I just swapped Armada Firebot's arms with Jolt's, and they also fit onto my Despoiler figure's hips ).
@Whystler: I don't know how useful it'd be to have downloadable model pieces, unless they were available in several formats; I know I personally have trouble using most formats; I can import them, but they're not editable. I also find that sockets, in particular, need to be tailored to whatever component they're built into, so having a downloadable one probably wouldn't help that much, except possibly as reference.
Now a tutorial on how to make them would probably be a lot more useful, and I'll be doing that very soon. As long as we've got an accessible guide on what sizes to use, it should be fine.
I was trying to keep it simple for the non-transformers folks, DSH. A 5mm hole on a model will still peg fine to a minicon port(5mm post with hollow center), especially since it's been a long time since toys have come with the activated features from Armada
As for file formats, Accutrans can handle tons of formats
5mm parts has a deep history in Japanese robot toys that goes back to the early 70's, more on that here:
Aside from Transformers, 5mm is compatible with a lot of other toys, from Legos to a number of other Japanese toys both recent and old (with 3mm a close contender, particularly in Zoids and smaller TF parts).
I just joined (this thread is partly what encouraged me to sign up, especially seeing that RetroroBo design!), but I hope to create some 5mm-based items once I get the hang of things here. I also used 5mm parts for accessories when I worked on the Invader Zim toyline for Palisades Toys.
Aside from 5mm, there's also the interchangeable "Glyos" system which has been licensed to a couple of indy toylines and has a growing customizing community of fans:
(scroll down for some great examples nearer the middle and bottom)
I'm not certain on the post/socket size on them, I think it's something like 3.5 or 4 mm, but will find out soon...