C.R.A.B. Robot - Concept Design / 3D WIP


So, having finished my latest robotic design, I thought I’d tackle another, but on a slightly larger scale.

Below are some sketches showing the general concept. The idea is that this is a sort of grandiose armed security robot, placed to stand guard at areas of importance. It’s equipped with 2 over-sized weapons, one on either side of it’s main body. The large cylinders that the guns are fixed onto house huge coils of ammunition. The body is mounted on a 360-degree rotatable platform, which is maneuverable via crab-like legs. Perhaps not the most ‘sensible’ approach to a method of movement, but one I thought created an interesting/different concept at least.

The first 2 images below are the more recent variation of the concept, and the one that I’ll now start modelling in 3D. I will of course update my progress here.

Please feel free to share your comments and crits. Thanks for looking.


Hey man, I love the concept. Might I suggest though adding two more legs? I feel like 4 little spindly legs isn’t enough to hold this guy upright. Also, it might look more crablike with the right amount of legs. Anyway, looking forward to seeing what you come up with!

P.S.: I just saw your finished video of the sentry bot. Oh my GOD! The amount of work you put into that project is just staggering, with the whole fake website and all. Can’t wait to see what you do with this concept! :thumbsup:


Hey man,

I agree with TerranCmdr, adding more legs or just make those legs bigger… and you should add more articulations to the root of each leg because right now i cant figure how this robot is gonna walk… and why put such tiny hydraulics on the legs and have huge hydraulics for the mounted part? The robot looks cool overall but its not very functional imo.



Great feedback, thanks all.

TerranCmdr - The legs issue is something others have mentioned. The most recent version of the design (top image) has 5 legs, but perhaps more are required? Regarding this project, I’d like to actually try and implement the final 3D model into some real-life video footage, such as having it composited so it looks like it is guarding a real building, with people walking past. But time will dictate if that’s do-able. I’m glad you enjoyed the Sentrybot project - I was happy with the end result. :slight_smile:

Nov-A - The walking element is the biggie. I’ve attached a render of the first part of the concept I’ve started modelling - the leg (see below). Hopefully by adding a pivot point on the main horizontal structure (on the right), this will enable the leg to perform an additional sideways movement, allowing the thing to walk? It breaks the visual flow of that shape a bit, but it’s quite an important detail I now see! Why tiny hydraulics on the legs? I want this robot to look a bit awkward - a bit like these bugs that have huge oversized bodies, and spindly little legs. I wanted a ridiculously over-sized weapon on it - something that almost makes it look so top heavy that it could just tip over - my intention is to make it look a bit odd. Not necessarily ‘cool’. But, I’m glad you like it overall. I’ll hopefully work out some issues as I model, which I’ll update here.

Thanks for looking.


Are 6 legs enough?



6 is definitely better.

absolutley love that last concept sketch, it’s got a real “chunky-ness” to it ( i know you said you wanted to steer away from that)

anyways, looking forward to this, your stuff is very nicely polished from what i’ve seen so far


DaezD - Thanks. Perhaps a variant and more refined version of the design you commented on could be one of my future robot projects :slight_smile: . I just didn’t want to do the usual big-fat-legs-and-body robot design that are too common (as much as I like them!).

Anyway, here’s a tiny update, as I’ve not been able to do much at all on this. I still need to adjust the proportions and make the top of the leg a bit chunkier, but thought I’d show the (minimal) progress.

Thanks for looking.


Slight update. I’ve built up the body more, and beefed up the top of the leg, as well as giving it a different joint design (still needs refining on the top to allow the leg to pivot sideways).


I’ve started modelling the upper body; the main ‘head’ shape is now formed. Now I’ve got most of the important bits blocked out (excluding the guns), I can see that the mid-section of the legs don’t resemble the proportions of my original concept sketch, so I’ll work on making this ore accurate. I think doing this will help balance the top/bottom portions of the robot out better, giving it a more stable and wider stance. I might also raise the height of the head a bit (extending the pistons and front beam) as it also looks a bit more sunken than in my sketch.

Let me know your thoughts :slight_smile:


I’ve just re-worked the gun detailing, ready for when I start modelling. It was lacking a bit of flair. Opinions of the new design?


Before I get on with modelling the guns (which I’ve just temporarily blocked in in 3D for the moment), I’ve had a messy play around with the concept sketch to see if making the gun less round and slightly smaller will work better. Input needed please! :slight_smile: Thanks.


Here’s a WIP of the guns. I still need to refine the shapes slightly, and will work up the detailing further. But here it is as it currently stands.


Some more detailing on the gun. I’m going to change the shape of the main vent now that I see it as a render - it doesn’t work…


sweeeeeet !!! I like the small but clear details on this machine.
cant wait to see more


Weiluntsai - I appreciate the comment. I’m trying to add as much 3D detailing as possible before I start with the textures (and bump maps).

I’m resisting adding cabling (ala Robocop’s ED-209 arms) as I’ve never understood why an enforcement droid would have exposed areas that are vulnerable to being disabled with a bolt cutter.

Anyway, a bit more detailing has been added, and some elements re-shaped/edited. It’s a slow, fiddly process…


whow! can you show wires?
and I like the way you draw concepts before modeling.very cool.


Love the design Jamie! And as I’ve said in another thread of yours, I love the execution and the presentation of your models. Its very clean and professional.


ConceptStingray - I’m happy you like it. Here’s quick wire view. It looks horrible, as I’m using a lot of intricate boolean cutaways for the panelling, resulting in a very messy mesh!

Innovator - That’s very kind of you, and it’s great you like the design - that’s the important bit to me! But you might take the “clean and professional” comment back when you see the wires below! :slight_smile:


Ha, hey I’ve seen messier wires :-)…hell I’ve made messier wires

I’m all for the philosophy ‘if you can get away with it (especially hard surface models) you don’t need your topology to be perfect.’

lookin great man, can’t wait for more updates