- Odyssey
- Gravship engine
- Zero to three to six to eight grav cores, depending on size of your saucer
- A mouse
- The planning tool found in the "Orders" architect menu
- Q and E keys, or equivalent

The starting substructure capacity of the grav engine is 500 tiles, with a potential maximum capacity of 2000 tiles, as such that amount will be the main target of this guide.

This capacity increases by 250 at a time depending on how many grav field extenders you have installed at once, up to a limit of six. Any further added will overwrite the allocated area of earlier extenders and leave the displayed shape as a mangled mess, however the added range is still effective as discovered in testing for The Leviathan variant, at least so long as substructure is connected soundly to eachother and close to the apropriate extender.

Because of the cramped space in gravships i would recommend using storage mods for your needs.

"Cargo Holds" adds neat floor storage, with some tradeoffs for movement speed and adjacency.
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3536708812&searchtext=cargo

For food specific storage with interesting features like forbidding animals from eating things or having wall structure fridges my pick is "Rimfridges: With Shelves"
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2898411376&searchtext=rimfridges

And for more decorative thematic storage options with a lot of depth then "Reel's Expanded Storage" is quite a nice option too.
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3237638097&searchtext=reel

To determine the size of your saucer you will need to take your measurements, i will make the initial layout intended for the largest possible one that can be made, but you can always size it down to your preference.


-Step one: Starting from the exact center of the engine, use the Q and E keys to change the draw shape with the planning tool to make a 25x25 box outline reaching out as our first corner.
Note that you can hold the CTRL key to force the tool to match dimensions on all sides as you draw.

-Step two: Now starting at the far point edge of that corner, draw a 49x49 box outline to the opposite corner around the grav engine.


-Step three: Add the missing axis lines to complete the base reference for all simple gravsaucer sizes from this point onwards.

To get a perfect circle on the outer edges of your saucer you will need the following.

Step one: Using the planning tool and starting at the center of the engine, draw an outline box 11 tiles wide by 10 tiles tall, i recommend using a different color from the tool as well.

-Step two: Starting at that new corner, draw a box 21 tiles wide and 19 tiles tall, this is going to serve as our placement reference for the grav field extenders.

-Step three: With six grav field extenders placed one in each corner, top and bottom you will get a shape like this for the substructure range, a little wider than it is taller, the reason for this stems from the overlap that the top and bottom ones have, allowing a circle to be drawn at the top but needing more tolerances on the sides.
You can also build this central box with the starting materials from the quest

-Step four: Change the planning tool shape to a full circle, and start drawing from the top corner of our outer 49x49 box, until you have a matching 49x49 circular saucer, it will make it to the very edge on either side. You can also go straight to ordering the substructure at this step.

Congratulations, you now have a 1941/2000 capacity saucer that can carry a whole colony, with some spare tiles for ornaments be it engine mounts, antennae, wings, whatever else your heart desires.

But what if your heart desires symmetry on the inner square of our plan?.

If you want to work with exact symmetrical numbers you can follow this for a very comparable result.

Step one: Use a new color on the planning tool to draw an 11x11 box outline starting at the engine.

Step two: From that new corner, draw a 21x21 outline box.

Step three: Now that you have a perfect square as the center of your gravship, you can proceed to install your six extenders on each corner, top and bottom highlighted in yellow. And draw or order your substructure placement at a 49x49 circle shape starting on the outermost corner.

Using a perfect centered square makes the left and right center points buckle inwards by one tile, highlighted in black, so you get a slightly pinched shape for your saucer, still really close to the max capacity. This variant has the advantage of a little more room at the top and the bottom for ornaments.

You can also build this central box with the starting materials from the quest

Congratulations, you now know how to make the two largest variants possible of perfect circular saucers, at least with the six extenders possible.

But what if you don't want to make a huge mothership?.

For my own use of gravships i decided to build a large solid saucer as an expeditionary vessel, meaning its intended to carry my mining crew and exploration teams composed of only a couple of pawns with a lot of mechs and animals.

I have found this layout to be exceptionally useful and it allows me to comfortably extract resources and return home loaded with stuff, as opposed to pre 1.6 where i spent thousands of steel and tens of thousands of fuel via transport pods while having to make temporary bases wherever i went.

Two storage mods are included here, Cargo Holds first for general storage.
Machining research required, dependancy required.
Cargo Holds

And this for food specific storage, compatible with paste dispensers as hoppers, structure and wall variants, temperature tab.
Rimfridges: Now With Shelves

*EDIT*
I have additionally started using Reel's storage mod, it is quite nice. another option for you to add.
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3237638097&searchtext=reel

Features;
Large hospital barracks with rec and dining amenities
Kitchen for making paste my animals can use, or people.
Four massive cargo holds
Two shield generators and comm's console
Workshop with only basic manufacturing, but space for more
Fuel depot
Power generation
Exo bay
10 defense turrets

I have learned since writing this guide that the specific placements for extenders can be rather generous, as far as the original reach of the engine itself. For this reason the diagonal extenders have been moved to the outer edges in each direction. You can play around with it until you are comfortable.

Exterior hull is a 49x49 circle for reference with minor additions. Turret mounts on three sides provide fortified positions when landing in hostile environments.

The engine room is a 17x17 circle shape, with bow, port and starboard wings 11 blocks wide for my cargo holds and workshops. Two butchering tables with rimfridges along with some refrigerated cargo holds on the top left, hospital barracks with rec room on the top right. Really, you can outfit each of these spaces however you like.

On the stern is power generation, a barn for my mining animals, fuel storage with a couple of dedicated 1x2 fuel holds, and a massive hold amidst the tanks. Seven tiles down from the inner circular engine room is a 27 tile wide divider totaling three tiles in height at the edges to make space for my exo bay. Do be aware that i make use of four massive holds because i tuned them down to 20% capacity, a single unaltered one will have more capacity than you'll need for a good long while.

Includes orbital scanner, signal jammer, 14 transport pods and space for up to four shuttles, two 1x1 cargo holds specifically to have steel always at hand. Substructure lip for flare with the diagonal thruster distribution.

It has served me quite well, maximizing open space and function. I am sure it will work wonders for you too.

Maybe you don't want a gigantic ship but still want to fly a saucer, maybe you want a saucer with a lot of extra ornaments, maybe you just got the engine and have no extenders.
This is the section for you.


For a medium saucer that matches the default size of the engine area, you can draw a 37x37 square, or simply uninstall any extenders you own and order all of the default area to be constructed. You will need three grav field extenders back in place afterwards to cover the 1117/1250 substructure tiles.

For a small starting saucer, you can make it work with only the engine and the panels you get from starting the quest. Draw a 12x12 corner starting at the engine, and then a 23x23 box starting from that corner. It will hold a decent amount of stuff, will carry most amenities, a generous amount of fuel and will have you covered for a decent while. Feel free to copy my layout.

I continued experimenting and came up with a couple of new designs with variants, these more advanced designs have a lot more steps with more complexity, a colossal resource cost and will require wits on your end to make best use of them. Additionally, because of their features we will need to redo planning from scratch.

The first of them intended for large cargo and an acceptable secure farming and fishing area within the hold, naming it for this purpose The Evergarden. Thanks to DeathKnight in the comments for the idea.

Step one: Using the hollow box shape with the planning tool we will make a large outer layout starting with a 26x26 corner, and a 51x51 total area of reference.

Step two: We will make a second medium layout with a 14x14 corner, and a 27x27 overall area, this will serve as the hollow chamber within the UFO.

Step three: Lastly, a third small layout 10 tiles tall by 12 wide on its corner and 23 tiles wide by 19 tall overall. This will serve as our references for six grav extender placements in the top, bottom and corners.
You will have to build this bit of substructure in the following sideways H shape which we will modify later.

Step four: At this stage you can order the construction of your substructure in a 51x51 filled circle using the outer layout like so. Once in place, take the medium square layout as reference point and use the cancel architect tool for another filled circle to remove the inner tile blueprints, these will remain open for farming and fishing.
Once in place, take the medium square layout as reference point and use the cancel architect tool for another filled circle to remove the inner tile blueprints, these will remain open for farming and fishing.

Step five: Once constructed, you will be left with a saucer in this shape. Next steps are to remove the top and bottom beam substructure going across with the "remove foundation" tool in the architect menu and only leaving the tiles that hold a grav extender, as well as connecting the saucer substructure vertically through the engine. For appearance you can divide the hollow center in two or four sections to your preference.

Optional additional step one: Because of the additional space tolerances from a hollow center at a count of 1645, it is possible to build outwards all the way to the edge limit of the extenders, to make it work a vertical beam across the engine becomes a necessity and even then the maximum capacity is exceeded by seven.

Optional additional step two: To compensate for this, we will remove eight tiles part of the inner perimeter at these positions with the "winged" highlights of the planning tool, circled in black. This will permit a perfectly filled outer area, more of a berry shape. Fitting for The Evergarden.

Seeking to push the absolute possible limits of ship construction i made new groundbreaking discoveries that allow for a rather unhinged and even unwieldy design, This is by far THE largest possible circular ship you can make rivaling what would otherwise be a space station, with its highlights being a double saucer design and an astouding 63x63 outer perimeter.

The most complicated and complex of them all with over two dozen steps to follow including deconstructing and reconstructing parts to make it work and a grueling requirement of eight grav cores for extenders.

i don't believe this can be surpassed without mods. For this reason, i have named it The Leviathan.

Step one: We will begin using the planning tool with the hollow square shape to draw a 19x19 corner, followed by a 37x37 outline. This is the default range of the grav engine by itself.

Step two: Using the hollow circle shape, order the construction of substructure on the very edge of the engine range using the 37x37 plan box as your reference point, this will serve as our starting extender mounts but will be deconstructed later. Grav extenders can only be placed within the starting range of the engine, so this is as far as they will possibly go.
Connect this circle frame with vertical and horizontal beams.

Step three: Using the diagonal shape for the planning tool, hold CTRL to force a perfect even distribution and draw a "staircase" diagonally to the circular frame we constructed from the center of the engine, we will do this on all sides.
With all the staircases in place, you will build your eight grav extenders at the end of the horizontal and vertical beams, as well as the end of each diagonal staircase highlighted in black here.
I have discovered that despite grav extenders not visually displaying their added range beyond six, they remain effective, as such a full set of eight is necessary for this ship to work at all.

Step four: We will make a new box layout with the planning tool on the hollow square shape starting at the engine with a 21x21 corner, and a 41x41 total area. This is going to be the reference for the empty exclusion zone between the outer saucer and the engine chamber later.

Step five: We will draw the final outer layout with the planning tool and hollow square shape, with a 32x32 corner, and a 63x63 total size. This is as far as a circular shape can be made, however you can use this as a starting point for other colossal designs, be aware that at these dimensions hollow segments are always mandatory.

Step six: Using the filled circle shape, order the construction of ship substructure using the 63x63 outer square as your reference point, for a matching 63x63 circle. This will be the total size of our mobile space station.
However, this would far surpass three thousand substructure tiles so we need to prune it down. To do this, use the cancel tool with the filled circle shape drawing a 41x41 circle using the intermediate box as your reference.

Step seven: Once construction is finished, you will be left with a shape like this, but still exceeding the 2000 capacity of the engine, this being the case will will need to further trim the tiles in here.
Using the "remove foundation" tool from the architect menu in the hollow circle shape, order the removal of our original circular frame, take the inner 37x37 box as your point of reference.
Only substructure tiles that do not have a grav extender will be removed, you don't need to micro that part.

Step eight: Because we trimmed the starting circular frame, you will need to build a few more tiles to bridge each diagonal extender back to the outer saucer like so in order to maintain structural integrity.

Step nine: with the new spare tiles, we can build a small engine chamber for the piloting computer and other things, draw an 11x11 hollow box around the engine with the planning tool, you can eyeball this by going three tiles out in each vertical and horizontal direction like this. Follow it with the build order of an 11x11 filled circle of new substructure. This is going to push us five tiles above capacity.

Step ten: To compensate for the engine chamber, we will remove one tile on each of these "winged" highlight spots of the 41x41 box, circled in red and totaling eight.

This will put us at three tiles under capacity which you can rearrange as you please, i decided to put two in the back as part of my engine mount, and one in the front as a nose.

Step eleven: As the final result, you will be left with a saucer the size of a mobile space station with an enormous secure internal perimeter for crops and fishing, connected via single tile beams in a crossed pattern. I tested this in space and pawns will climb over the extenders no problem, its not a risk for them to become stuck or fall into the void.

However, if you feel this is too precarious, or merely want more options there is an alternative layout i made by removing the top vertical and horizontal beams from the grav extenders towards the engine chamber, rearranging those tiles for a single broader walkway from the bottom, placing the handful of spares next to the diagonal extenders and one to either side of the walkway base, all highlighted in green. I call it The Panopticon.

After this whole ardous process, you will be able to take to the skies with the largest saucer vanilla Rimworld has, The Leviathan.

"There go the ships: there is Leviathan, whom thou hast made to play therein"

While developing The Leviathan's substructure in such a manner that it could fly at all i did anticipate that actually using it would be more than a little awkward, not just being able to land it in places with its unwieldy proportions but also being able to efficiently use the internal space as a home rather than an expeditionary vessel.

It is a trade-off from having the enormous secure inner perimeter to fish and farm with tremendous efficiency as merely a fish or two are enough nutrition to make a meal, capable of harvesting hundreds from an ocean map paired with the ability to grow fields away from danger meaning that even children can participate and learn their passions for the future of the colony.

Thus, i racked my head to figure out a way to make it work, thanks to Ash in the comments for the suggestion. This is my layout for The Leviathan.

I use two mods heavily to make it happen.
General use storage particularly for raw materials, be aware some of these slow movement.
Machining research required, dependancy required.
Cargo Holds

And this for food specific storage, compatible with paste dispensers as hoppers, structure and wall variants, temperature tab.
Rimfridges: Now With Shelves

Features;
Archon Grand Throne room
Archon bedroom
Eight double bedrooms of average space
Greatly varied rec room
Kitchen
Workshop
Research lab
Nursery
Ideology temple
Anomaly ritual chamber/Hospital/Deathrest chamber
Power rooms
Exo bay
Orbital scanner
Signal jammer

Now, i originally began working with the exact shape out of the Leviathan segment but it was turning pretty ugly and mangled, so i decided to make the internal secure perimeter into a proper circle shaving some more of the "garden" substructure which ultimately makes the main highlight of this ship even grander.

To achieve this you will need to draw a 23x23 corner, followed by a 45x45 square which will serve as our inner wall reference point, order the removal of any scattered substructure which in the process will bring the total close to the 1900s, we will leverage this later.

You can draw the outer wall via the 63x63 square from original planning, use circle shape as well for convenient wiring. Whatever is not highlighted with the inner or outer circle was filled in by me for aesthetics.

On the bow we have a grand throne room which can meet royal needs with one large sculpture of decent beauty in addition to the regular requirements for structures. Eight bedrooms hugging the outer wall allow for a hallway that is a tighter curve, each with 13 space or more to avoid negative moodlets. Two exits as it is always useful to be able to leave the saucer from multiple angles.

Planning shapes for reference to scale. You could bring 8 to 16 crew depending on relationships or if they mind sleeping together. Could even do two individual beds if need be. Extra outer substructure as turret mounts.

A bit of a messy shape but you can use the spare space for fermenting barrels or other things, notably any sort of gear you wish to keep should go into an outfit stand to preserve space.

On the port side we have a small kitchen room using rimfridge walls as well as one refrigerated cargo hold, you'll be able to cook and store food on the same spot, just make sure rimfridges has vacuum sealing enabled. Also be aware that refrigerated cargo holds slow down pawns considerably so just one in the corner or none is preferable.

Additionally, a paste dispenser with an extra fridge wall separates that side's entrance from the upper and lower decks, a massive cargo hold serves as a place to store all the random stuff you come across, most often raw resources.

Recreation room has a combination of furniture fridges and wall fridges, as well as a megascreen tv, poker table, pool table, dining table, chess table, bookcase, and even a sneaky horseshoe pin hugging the inner hull.

For size references, the outer length of the wall by the storage is 13 and the inner length is 11. Also note the exits pointing outdoors to preserve as much internal space as possible both on the inner and outer perimeter. Four more turrets to cover that angle. Directly below is a nursery for any babies and children on the ship.


On the starboard side we have a royal room meeting the needs of one Archon pawn with layout reference, some more space for fridges to hold stuff like psilocaps or beer or similar, and a workshop with a refinery to make chemfuel on site, a smelter to scavenge steel from slag and a machining table, two immediate 1x1 cargo holds to keep your basics for manufacturing like components or organics, two tool cabinets to get the most out of room bonuses and a fabrication bench for your advanced crafting needs.

2x2 cargo hold next to it for rarer materials like gold and plasteel supported by the massive cargo hold on that side. Same proportions for outer and inner wall lengths and four more turrets to protect that approach. Research room directly below with an advanced bench, analyzer and bookcases for speed bonuses.


Finally, on the stern of The Leviathan i placed an ideology temple with seats and lectern as well as an anomaly ritual room which can also function as a hospital with beds placed there, also viable as a spot for deathrest caskets if you have a sanguophage.

Power generation and fuel storage is located here as well, with 3000 fuel loaded at all time and two 2x1 cargo holds dedicated to fuel.

An unroofed exo bay allows for three shuttles and six emergency transport pods to be used, thrusters mounted outwards in this use case as i like having entrances in all directions, if you prefer, sealing the stern with proper doors and mounting thrusters facing to the gardens is possible, leveraging the bridged grav extenders with some more substructure, up to your creativity.

There is space here for telescopes, as well as a scanner, a jammer and little nooks for 1x1 cargo holds to place steel and spare components to quickly rebuild transport pods, small substructure "lip" added for flare.

In total, this layout carries six autocannons and six uranium slug cannons, potential for more with spare substructure. temporary barricades when landing suggested.

With all of this, you will be able to land and fish and farm and thrive wherever your home is at the time.

If you enjoy UFOs i hope this guide has been useful to you.
Have fun exploring the rim on your new saucer, and remember.