I dabble in 3D modeling, but more for artistic reasons. I don't have any actual training in the field (I can model, somewhat, but not texture, or code individual parts, so I make more like 3D sculptures of sorts; and even so, they're more hi-poly count anyhow.
Here's a sample of what I can do with my limited skills. I really wish I had more experience and skill in the field, because design jobs like this is what I'd like to do, preferably. Not processing images, or having people bug me about doing web design for them.
Here's a couple images I already uploaded for Creative Projects some time ago (I gotta finish them, after I recover the lost data on them; Most recent models were lost with the old HDD). Naturally, they're incomplete works, and between work and my laziness, I don't know when I'll finish them. I gotta regain my old habits that made me come up with ships by the boat-loads.
Basically, it's a relatively medium-small scale frigate which balances on 4 VTOL engines with a counter-recoil engine block on the backside (not pictured). It's a customizable craft, the model shown being a rather standard-build; but other designs could look more exotic, fewer, but more higher-calibur round cannons, and so forth. It's more a weapon of fear and intimidation, but despite being intimidating, their VTOL blocks are powerful enough to ambush from within canyons, caves, and alcoves within much larger vessels and buildings/super-structures. Despite some design flaws, they are surprisingly capable, and skilled pilots are a force to be reckoned with, others rely too much on the mask shielding to the point of becoming cannon fodder, however. But to fulfill their role as intimidation, take over a city, disarm it, and have some of these guys surrounding the land from the outskirts, and it'll keep places from starting an uprising, lest they watch buildings and streets get leveled "when the eyes glow".
Primary Bridge
Secondary Bridge on top
Topside
Bottomside
For an idea of scale, think of one of the primary wings as being about the size of a football field. And yes, on my crew's downtime, they can also play football on the wings. Pictures only show 1/3rd of the entire ship.
This was made a good 8 years ago. (Holy crap. That long ago? Previous images were made last year.)
More of a personal design of an airship I would love to fly (actually did in one of my dreams, and it kicked serious ass). It's supposed to be 1 of a set of 3 ships of the same class (the others being the Caladbolg and the Kusainagi). Basically, think of a battleship, with a bit of customization to also support a small wing of craft to support it (mostly dropships (another model design I had in mind modeled after a barracuda with it's own set of variant classes) and some interceptors). But this is not just any ordinary battleship; it's what can be summarized as an extremely broken thing to fight against. It's supposed to support a large engine block on the back for primary propulsion, and on the front wings, it also has a unique engine block design that permits the engines to snake into a trajectory to adjust accordingly (it's a more freestyle engine block that is not just for VTOL flying, but also altering the full trajectory, from assisting the front engine in speed, to being able to make the ship fly like a rally car in the sky, and even have the power behind it to do maneuvers similar to a fighter jet). To make things even zanier, I sorta had this designed with barnstorming in mind. Yes, a barnstorming battleship, barrel rolling while launching fighters like they were missiles; and to top it off, it has a mess of weapons, from a fixed-beam forward battery (when not firing energy beams, it also doubles as a railgun), along with a series of homing beam weapons, and it's just decked out in auto-cannons. It will pulverize just about anything in it's path, while matching fighters in maneuverability and speed.
When I said it was a broken ship, I truly mean broken. If physics doesn't break it first (despite an inertial dampener/meta-dimensional distortion field generator (not pictured)), then I doubt much else could, especially considering said generator. Basically, I just wanted to make a hot-rod in the sky that is just absurd in scale, and yet, follow enough aerodynamic laws to somewhat get away with it. But really, how often do you witness a half-kilometer battleship barrel roll, or buzz a suburb, and shatter all the windows as it buzzs overhead at a low altitude upside-down at mach speeds?
Looking back, maybe I shouldn't engineer ships.
Both ships were designed in Blender. I also had a Bladeship in the process (a multi-role aerospace fighter in the shape of a Sai), along with an entire fleet of similar types of ships (bladeships) I wanted to model; but I lost them to the hard drive crash as well. Basically, the culture that produced and flew those ships had ritual aerial melees. Yes, they crash into each other, swordfighting in the sky with aircraft. Also doubles as a secondary attack method. When they intercept, they'll rip you apart with their own ship, and due to their construction methods, can take out a squad before the ship starts feeling the effects of wear and tear. Oh yeah, and their capital ships are just as capable of ramming into things, and coming off with not much damage, due to hitting with the blades first. Not the lightest things to fly, but when they hit, you will feel it; provided you're not cut in half on impact first.
Of course, naturally, they also have guns, and they do use them. Melees are mostly ritual in nature, and also a good means of last-resort. But kudos to ritual combat, kamikaze maneuvering is actually pretty standard, and rather a force of habit, so they'll run you down, and gun you down in the process. My advice, don't play chicken against them; they won't swerve.
EDIT:
Added reference image for Excalibur.