Derelict Depot: Painting

A few weekends ago I got to painting my Derelict Depot, a mix of scratchbuilding, model kits, and 3D printing as described in the construction walkthrough:

The assembled Derelict Depot.

Colors

In choosing colors for the set I started with dark red and grey, mostly because I had spray cans of those laying around. But using those also meant these pieces would fit right in with my Medea Refinery board, adding a bunch of LOS blockers and scatter terrain to that collection. To add variety though I opted to do the big buildings here in olive green and some of the containers in red and yellow.

I used a lot of leftover white foam packaging in constructing this set, which some spray paints will melt. Generally I haven’t had a problem with that, but have had a couple cans that did eat such foam, so always test on a scrap piece first. To reduce the amount of spray painting on the white foam though, I brush primed those areas with two coats of black. All the other pieces got a good coat of spray black to start. Often you can just go straight to the base colors if you’re spraying, but the black coats better, adds another layer to help mitigate chipping, and if you spray the colors lighter and from a slight angle it creates some natural shading in the corners and recesses.

Unfortunately I had not previously used the olive green I picked up and it reacted badly with either the temperature on the day I was doing this, or the materials. On the trucks it cracked and broke, which would have been devastating on a normal model but worked great with the derelict theme. On the buildings though it fuzzed up a bit and became crumbly. Still not really a problem with the theme, but it made them feel funny and the paint a bit fragile to the touch.

Priming everything black.

Colored base coats.

Cracking on one of the trucks.

More Color

Following the base coating I wasn’t sure how much more time I’d get to work on these again before I wanted to use them. So I went with a technique I picked up watching my friend Sascha help paint the Medea Refinery, basically spray painting a bunch of details rather than brushing them. So mechanical boxes, doors, ladders, etc., all got sprayed in various colors without worrying too much about overspray—quite an affront to my OCD tendencies! Definitely wouldn’t work for all styles of terrain and isn’t to everyone’s taste, but it’s fast and I like the look of it for these kind of pieces. All the overspray just looks like rust, wear, etc., and ties everything together.

From there, still concerned about getting more time for this and feeling overeager with the spray paints, I went on and lightly oversprayed various colors across all the pieces. Having hints of the whole palette on each piece helps tie it all together visually, and lightly spraying this particular selection of colors also makes it all look weathered. Although I’d started off with a board previously painted, I felt it didn’t match this color scheme well so it got spray painted similarly. At this point I felt the pieces were all interesting and playable as-is even if I didn’t get back to them.

Multi-colored and somewhat weathered pieces.

Top of the garage.

Weathered truck.

Weathered plane.

Weathered console.

Site Designations

Fortunately I did wind up with more time to work on the set. So I sat down for a marathon overnight session of detailing and finishing. A key theme throughout this though was still facing a time crunch, trying to add a bunch of visual appeal under tight time constraints before hopefully using it in an event the next day.

So, thinking about quickly adding color and detail, first I added some site designations. Using some cardboard alphanumeric stencils, I spray painted “E 7” on a bunch of the buildings. A medium tip ink pen then let me quickly outline the lettering with thin, clean black lines. Of course the new lettering stood out against the weathering sprays, so it then got drybrushed appropriately to wear it back into the pieces.

Stencil masking the site designation on the silo.

Site designation after removing the stencil.

Outlining the lettering with an ink pen.

Drybrushing over the site designation to blend it into the weathered paint.

Hazard Stripes

Another quick way to add color and life to the scene was to throw a bunch of hazard stripes on various pieces. These were done real quickly by brushing on several coats of dark yellow, taping off the yellow stripes, brushing on black, and then drybrushing the whole stripe appropriately to weather and blend it into the piece.

Hazard stripes inverse masked on a solid yellow base.

Black part of hazard stripes painted on.

Finished hazard stripe.

Details

Still good to go on time, I set about with a brush picking out details. Some things were painted as normal and then drybrushed to blend and weather them into the existing paint job. For example, the tires and rims on the vehicles were painted black and silver and then drybrushed rust brown. The few organic elements around, like the duffel bags on the trucks, got painted a leather brown and then washed a dirt brown. Various dead light fixtures and computer consoles were painted black or dark purple and washed with the same. Other features were done solely with heavy drybrushing to add color and distinguish the feature but not break it out too much from the background, e.g., drybrushing a dark brown on the cabling or steel on the various scrap laying around. All the gravel and texture on the bases and the board itself also got drybrushed appropriately. Some metal edges and so on then got a hint of silver drybrushing to seem worn or jagged, like on the ends of the roughly cut scrap pipes.

Painting details on the garage. A layer of Modge Podge cures on the mechanical building in the background.

Painting details on the vehicles with my helper as dawn approaches.

Posters

I still had some minutes for detail work, so the finishing touch was to print up some signage and posters on cardstock. These were cut up, in some cases further filled out with ink pen scribblings, glued to various pieces either on the walls or crumpled up as litter on the ground, and then washed brown to age and grime them heavily.

Printed signage, posters, and litter.

Sealing

All these pieces are intended for public use in my local shop’s tournaments and such, so even if they’re not out all the time they still need to stand up to some abuse. The board and all the foam and cardstock surfaces therefore got coated in Modge Podge to seal them with a protective layer. This also resolved the problem mentioned above with the olive green paint having fuzzed up in the heat and feeling crumbly. Modge Podge can add a bit of a gloss sheen, but I knew the final steps would take care of that…

Covering the board in Modge Podge.

Carbon

Last up, I wanted to knock down the brighter colors and better blend the brushed details in with the sprayed “weathering.” So everything got quickly “washed” in carbon black pigment. Out of time, I didn’t try to do any real weathering here, caveat being sure to generally throw on the pigment low and then brush it upward so that it tended to collect and be heaviest toward the bottom of pieces. In some cases this “wash” dimmed the colors a bit more than I would have wanted, but overall I thought it really made the pieces feel more lifelike without hardly any effort. It also definitely made the sprayed and brushed details feel uniformly worn.

Once the pigment was on I just sealed it in place with dull coat spray. That’s not really sufficient to secure thick applications of pigment, but for a wash like this and even with some thin accumulation on the tops of a few pieces it was fine.

Fully painted tank.

Tank “washed” in pigment.

Play!

In the end, after working all through the night, at just about exactly noon I did the last batch of dull coat spraying, took a shower, and jumped in the car to head to the shop and get the board set up just in time for a 1pm Infinity tournament—success!

Critical to this was carefully staging all the various tasks so that I didn’t have any downtime. The ordering above is just notional, in reality the various steps were mixed up and interleaved across all the pieces so I was never just sitting around waiting. A prime example was doing the buildings first so I could Modge Podge the fragile parts and then work on painting the vehicles while that dried. All told this whole board got painted in about 16 hours of work: 2+ hours spraying one day and the rest leading directly up to the debut event. In hindsight I wished I had done the detail brush work and then gone back to do the weathering sprays, but it worked out fine in the end between drybrushing and pigment washing so this was an acceptable strategy to ensure I had pieces ready even if I didn’t get to work on them more.

A few of us played games in the newly built Derelict Depot in that tournament and it worked well. One modification needed was that it was immediately clear I needed to add some vegetation and such to make the railings and such provide overt partial cover, as planned in the construction writeup but not completed beforehand, so I did that afterward. The board definitely isn’t going to be loved by everybody, it’s more oriented toward narrative and aethestics than pure gameplay. Some of the details and unique shapes make placing figures, especially in cover, a bit more fiddly in a few places than standard MDF terrain. It’s also super dense if you put on all the pieces—very challenging for my own airborne-oriented squads! Realistically you could probably make two boards out of the collection with a more typical level of density.

But, it looked great, has a lot of unique details both mechanically and visually, and turned out very well. Gallery photos of the final product to come!

Don and Lovell fighting it out on the brand new board.

A Morat commands their troops from the mechanical building.

Derelict Depot: Construction

It’s been a long while since I wrote up a terrain project, mostly because I have a couple stuck in half completed limbo. But one is moving forward; I finished construction this weekend, and expect to have it painted up for my local shop’s next RECON+ Infinity tournament: The Derelict Depot.

Construction complete!

Planning

RECON+ is basically half the size of a standard Infinity match: 150 points, on a roughly 24″ by 36″ board. I really like the format and we play it often so I wanted to put a new, detailed board into the rotation. Major goals were that it work for Infinity, which has fairly different terrain considerations from 40k, and that it not look or play like the “MDF-box” cities that are somewhat ubiquitous in Infinity. I think the end result will fit right in with the Shantytown, Old City/Slums, and other unique terrain we run at the shop alongside the more standard MDF stuff.

The start was an actual, physical board I’ve had kicking around almost a decade now after I made some basic terrain for teaching 40k to the university gaming club. The desert colors brought to mind a scenery idea I’ve dreamed about for some time but not built yet: A vehicle graveyard. Simultaneously, some interesting packaging scraps laying around got me thinking about a fuel depot or similar. Putting the two ideas together I started building toward an abandoned vehicle depot.

Very very preliminary ideas.

Garage

I quickly settled on the defining piece being a garage of sorts. Our Infinity group doesn’t play many interiors so I thought it’d be neat to force some inside action. I liked the image of two teams shooting it out across a garage while huddling behind small humanoid doorways on the sides. Cutting big vehicle doorways on both sides to make it a pass-through garage was a simple way to make the interior playable. You can fairly easily move figures around inside through the large openings on either side.

Sketching out cuts on the garage.

Initial cuts forming the garage.

One quirk about nearly all Infinity “MDF-box” terrain is the little walls on the tops of the buildings, sides of walkways, and so on. They provide obvious, extensive cover opportunities and straightforward gameplay. But it’s a little weird that nearly every little roof and walkway has short solid walls. Most roofs I’ve been on you can just walk off, most walkways have railings, fences are more common than walls, etc..

So rather than put unnatural little walls all around the roof of the garage, I put a bunch of large-ish features that an infantry model could get partial cover behind while prone models could easily duck below and move around safely provided they watch their angles. The turbine ventilation units are stolen off baby food pouches, while the other brightly colored bits here and throughout this board are 3d printed pieces I designed for this kind of assisted scratchbuilding. For this construction I had to rely on pieces I had laying around already as my printer is currently fully occupied churning out another project. Many of them are already available via my Thingiverse profile.

Testing details on the roof to provide some cover.

With the basic openings and roof features selected, I spent a while adding trim and details, just whatever I could think of and had on hand or could create quickly. Just one side got a ladder, in keeping with the idea that Infinity boards shouldn’t be that symmetric, built using a technique I use often. Both sides got outcroppings to provide some cover along their faces. The roof got an additional pile of junk “metal” to make a small cover nest, and some tubing hooked up between the mechanical boxes for flair.

“Front” of the garage (the front and back faces are essentially the same).

Side of the garage.

Final rooftop details of the garage.

Fuel Reservoirs

Next up were some fuel reservoirs made of supermarket mushroom containers. The key feature here is some kind of large pump that I imagined keeping the fuel moving around and cooled, or a giant fan for ventilation. These are big enough to provide cover, but I also added some railings on the sides. By themselves these are too slight to reasonably obscure any models enough for protection. However, once painted I plan to add overgrowth all across the board to give it an abandoned, unmaintained feel. Vines and plants draped over these railings will solidify them visually and make it clear that they provide cover, without having just stuck on some solid walls.

Primary components on the fuel reservoirs.

To create some vertically overlapped space on the board, a distinctive feature of much Infinity terrain, I made a walkway out of polystyrene strips and sheeting to go between the fuel reservoirs. The garage I think is too big for it to really feel like two planes of combat despite having two levels; the roof and interior can’t interact enough. Sizing for the walkway is dictated by having just enough clearance for a 40mm base to definitely fit on it. Overgrowth will provide models some cover while crossing, but mostly only from one direction—one side has already been blasted away! I frequently lose a trooper or two to missile and rocket fire while hiding on walkways by my deployment zone, and I wanted to capture that kind of story vignette here.

Finally, each fuel reservoir got a ladder, and some lights and vents were tacked on. Unusually for my terrain there’s no functional hint, no obvious interface for actually getting fuel in & out of the reservoirs. But I thought they looked fine at this point, I wanted to move on, and that lack of grounding is certainly not out of place in miniatures gaming. Maybe these entire buildings are cooling circulation units for a huge underground reservoir, interfaced through the pipes and fittings on the other pieces?

Ladder and walkway.

The mushroom containers are unfortunately very thin and compress too easily, the main effect of which is the features could pop off due to the plastic flexing under them. I’m going to address that by filling the undersides with expanding hard foam.

With the core concepts of the garage and fuel reservoirs nailed down, everything kind of took off. After almost a month of sitting on my hobby table getting poked at every now and then, the rest of the board got built pretty quickly over a couple nights. To those three pieces I added a mechanical building, silo, liquid tank, and a segment of blast wall to provide some additional large elements blocking line of sight. A variety of vehicles, containers, and scrap pipes then filled out the board with scatter terrain.

Mechanical Building

The mechanical building was inspired by realizing some sports drink canisters I had fit perfectly over the hole in a piece of plastic electronics packaging that I wanted to put on a wall somewhere. I started thinking it could be the broken output pipe from some giant pump. Later I realized this idea is a bit of a rehash, it basically combines the pump station and pipeworks pieces from my Medea Refinery build, but that’s ok.

Two blocks of foam covered entirely in cardstock make up the shape of the mechanical building. Again I used chunky details to provide cover rather than just solid walls. One railing is included though, which will get vines and ivy just like the fuel reservoirs to make it actual cover. As on the garage, I especially enjoy the tubing connecting some of the mechanical boxes to the wall inlets as a neat functional hint. The canisters on the front are glued on to break up the wall surface and provide cover straight down its length as the broken pipe does on the back. A short ladder at the back provides quick access the the mechanical boxes on the roof, but I purposefully did not add a second to the top roof so that it would take some extra climbing to get there.

Front of the mechanical building.

Back and roof of the mechanical building.

Silo and Tank

To create some more big LOS blockers, I made up a silo and a fuel tank out of coffee and vitamin containers. Loops of masking tape and polystyrene strips combined with the foundation pieces hopefully will break up the recognizability of the shapes just a bit once painted. I did not add ladders or platforms to the silo, though I might think about that some more so that any models on top are more accessible to close attack. Hopefully players will know to not place the tallest terrain piece in either deployment zone and let a model just deploy on top unreachably. I also plan to add a lot of built-up overgrowth to the top to make it difficult to place infiltrating snipers there.

Tank and silo (left and right).

Details

Finally, I made a whole bunch of scatter terrain: Several vehicles, lots of containers, and some piles of scrap pipes. The shipping containers are 3d printed designs I made that have been super useful on several boards. One variant is on Thingiverse. The other containers are wood pieces I got in bulk a while ago and use everywhere. The scrap pipes are sports drink tubes hacked up, and in one case wrapped with tape to make the ends look fitted. I like them being see-through laterally, making the ends tough to use for cover even as the sides are excellent for it.

The vehicles are 1/48 models. For 40k that works for some tanks and is arguably maybe “correct” if you incorrectly consider its miniatures to be 28mm scale models rather than the artistic, loose 28–32mm gaming pieces they are. But for these and most vehicles 1/48 is too small to look right in Warhammer. That’s one reason I never built my original vehicle graveyard idea. For Infinity though, as the figures are generally fairly accurately proportioned and mostly closer to 28mm scale, these models look ok. Next to heavy infantry or such they look small, but they should—those are big warriors in giant suits of armor! Compared to unarmoured troopers and similar the models look fairly plausible, particularly the earlier figures before Corvus Belli started creeping up the scale. Comparison pics to come once the terrain is painted.

I greatly enjoyed clipping and physically smashing down the really broken truck and airplane. I don’t know what kind of backstory justifies a biplane in an Infinity setting. Maybe this depot is on some neglected backwater planet and they use very low-tech vehicles for civilian tasks as they’re easy to build and maintain? I have no idea, but it looks pretty cool in the garage-hangar and is a neat piece of scatter terrain cover.

Broken down truck and Volkswagen. Original Volkswagen Beetles have their engines in the rear so that vignette with the hood off will be misread by a lot of people thinking it reflects working on the engine, but it’s still plausible.

Abandoned biplane in the garage.

Looking out from inside the garage.

Diagnostics console, supplies shelves, and other equipment inside the garage.

Shipping containers: The true hallmarks of far future war.

American-Style

That about wraps up the tour. There’s definitely enough pieces in the depot for the dense “American-style” boards we generally play in my Infinity scene, much to the sadness of my airborne troops. Big models have enough to hide behind, and there’s plenty of ways to prevent overly long firelanes and lots of partial cover over which to advance cautiously. Variety in heights should create good reasons to go up or slink around. Boards made with these pieces will definitely not be symmetric, an important property required to give meaning to the choice between initiative or deployment zone selection. On the flip side, the board is so dense that it should be difficult to inadvertently leave one side overly exposed. Finally, the pieces have a good level of detail, but easy playability and only a few features here and there that look particularly amenable to breaking, so I think it will hold up ok to public play.

Next up is painting, hopefully to be completed for next month’s tournament!

Top view.

Left airborne view.

Right airborne view.

Ground view left.

Ground view right.

3D Printing Tutorial: Modeling & Making a GR-75 Cargo Pod

Jedi, Sith, starfighters, walkers, whatever. No one could argue that the true hero of the Star Wars universe is the homely GR-75 medium transport. Cheap, poorly built, cargo literally simply floating in the void, well past due for retirement, clean lines marred by all manner of greeblies, hull panels invariably burned through… I love it.

A GR-75 evacuating Rebels from Hoth, escorted by X-Wings.

A GR-75 evacuating Rebels from Hoth, escorted by X-Wings.

container-tokenNot unrelated, wargaming is all about supply containers and cargo bits. “Buck up, soldier, we’re shipping you across the galaxy to fight horrible monsters over… some oil drums… and maybe a weapons crate.” So in crafting missions for our Molokh Gambit X-Wing Miniatures narrative campaign event, of course there’s going to be a Supply Depot scenario.

Just like the shuttle mission, that means we need cool tokens for the mission. A couple good 3D printable options already exist. There’s a great 3D rendition of the art on the Den of Thieves scenario tokens that come with the Millenium Falcon (remixed here to be printable w/ no supports). At a larger size is the Class A container from the X-Wing and TIE Fighter video games, which has also been made into a BFF-1 Bulk Freighter.

Neither of those worked for me though. I wanted something that could be printed without needing to cut supports or glue halves, was small like the container token to minimize impact on the basic game dynamics, and ideally had fewer Imperial associations. So I modeled the cargo pods on the underside of FFG’s GR-75 model.

This tutorial is a walkthrough of that, in hopes that newcomers to 3D modeling and printing might learn from seeing the process of constructing this simple artifact. These designs have also been uploaded to Thingiverse as a free download. In addition, I have a previous article up more generally introducing 3D printing for miniatures.

It's a hunk of falling-apart junk, so of course the Rebels would decide the transport could do double duty as an assault ship...

It’s a hunk of falling-apart junk, so of course the Rebels would decide the transport could do double duty as an assault ship…

Shape

Fantasy Flight’s GR-75 model is really fun. There’s a ton of detail, and just enough color to really draw the eye onto them. Most captivating is the underside, with a whole mess of tiny cargo pods sprinkled with bright colors. It’s exquisite.

Fantasy Flight's GR75 model.

Fantasy Flight’s GR75 model.

Pods filling the underside cargo bay of the medium transport.

Pods filling the underside cargo bay of the medium transport.

Fortunately for my task here, these pods have a distinctive but really simple design:

  • The core shape is basically a central box with two large angled wings;
  • The wings are themselves top and bottom triangles with a thin central box;
  • There are recesses on the top and bottom of the wings;
  • The front and back faces have pads with slightly angled corner cutouts;
  • The top is textured with two boxes and two circles.

Easy. The one detail I opted to skip is that the front and back faces have slight angles to their top and bottom halves. This feature would be a hassle for me to model, the loss of it wouldn’t really impair the look, and it’s probably largely a production requirement. Vertical faces of plastic injection molded parts have to be drafted (swept back) so that the piece doesn’t get stuck in the die or the metal scrape across and mar the surface as the two halves of the mold are pulled apart and the component ejected. That’s probably the primary driver of why these faces are angled. This isn’t a concern in 3D printing however, as the part is formed in place with no encasing mold.

Cargo pod deconstruction.

Cargo pod deconstruction.

Scale

With that shape deconstruction, the next question is “How big?” I decided to upscale my cargo pods to 1/270, the nominal scale of X-Wing’s large and small ships. The huge ships, like the GR-75, are done at a mix of scales to tradeoff between manufacturability, cost, gameplay, and look. As you might guess, this is a whole huge topic area online that dives way deep into the “correctness” of FFG’s models versus previously published material, with many lists around cataloging the variances.

In this case, there are no concrete canonical measurements for the GR-75. Length, width, etc., are not published in its starwars.com data bank entry, and they’ve never been given in authoritative roleplaying books, video games, and so on. A well established baseline though, derived from comparison to other ships and as reported by Wookieepedia, is that the “real world” transport is 90 meters long.

It fills me with no little joy that so many people have produced such serious documentation for so many Star Wars ships. #seriousbusiness!

It fills me with no little joy that so many people have produced such serious documentation for so many Star Wars ships. #seriousbusiness!

FFG’s model is 225 millimeters long. Given the 90m length, that means it’s at exactly 1/400 scale (225mm/90,000mm = 1/400). If the model were done at the same 1/270 scale of the smaller ships, it would be 50% longer, 333mm. No doubt FFG decided that would cost too much to manufacture, even if the gameplay was reasonable—there’s only so big you can make a ship and still have it fly around on a kitchen table.

Moving on to the pods, I started by taking precise measurements of the overall extents as well as the vertical & horizontal central boxes. The pods were a little tricky to measure in place, and they no doubt vary a bit due to minute differences in cooling and plastic shrinking rates as they were cast, but some basic numbers are easily attained. Sampling a bunch of them, I came up with a range for each dimension. Those were roughly averaged and then upscaled by the trivial formula (observed * 400) / 270. That output I adjusted ad hoc to produce nice numbers. This isn’t rocket science, and it’s a lot easier to work with a 17mm wide piece than 16.59mm.

Measuring the pods.

Measuring the pods.

Working notes of observed measurements and calculations.

Working notes of observed measurements and calculations.

FFG’s 1/400 scale pods are about 11mm x 8mm x 5mm. Converting that to 1/270 scale, we get pods that are 17mm x 12mm x 8mm, with a 5mm central horizontal box, and a 2.5mm middle vertical box. In real life these would be 4.48m wide, 3.2m deep, and 2m tall. That seems inefficiently small for an interplanetary modular freight system, but not ridiculous. Those dimensions are just slightly bigger than the cargo space of a 15′ box truck (a meter is 3.28 feet). Regardless of real world issues, as a sanity check, that lines up with drawings and other representations of the GR-75 and how it gets loaded.

A GR-75 being loaded.

A GR-75 being loaded.

Modeling

For a small project like this for 3D printing (as opposed to, say, laser cutting or injection molding), I’m a huge fan of TinkerCAD. It’s browser based, so unlike most CAD packages it works well on my Linux laptop. The interface is intuitive, and the feature set plenty for simple pieces. I was able to do a lot with it very quickly, and highly recommend the app. It’s free for non-commercial use, so you can try it out easily.

The first step in modeling the cargo pod was checking the overall dimensions, in case they needed to be fudged for gameplay or aesthetics. To start I made a base to exactly match the core set Container token. I wanted to keep that as the normative playing piece, with pods merely decoration. After making a box from the dimensions calculated above, I could see that it would be a reasonable size to put a couple on the base. In addition, I imported an X-Wing sized TIE Fighter model to see how the pod would look against a ship. It looks a bit small, but I think that’s an artifact of almost everyone picturing jet fighters and star fighters as much smaller than they are. This is especially true for the TIE Fighter, even setting aside FFG’s arguably upsized take on it.

Roughing out the dimensions with an appropriately sized box.

Roughing out the dimensions with an appropriately sized box.

From there I blocked out the basic shape, creating three boxes capturing the overall dimensions of the center box and wings. The same was done for a wing, and then the top and bottom of it replaced with a wedge.The sizes for all of these boxes, notably implicitly defining the angle of the wings, were taken directly from the scale calculations above. Of course, I only needed to model a single wing in detail. As they’re the same left and right, when it was all done I could just duplicate and mirror that side.

Breaking the overall shape up into the central box and side wings.

Breaking the overall shape up into the central box and side wings.

Deconstructing the wing into the middle box and two halves.

Deconstructing the wing into the middle box and two halves.

Replacing the top and bottom halves with wedges.

Replacing the top and bottom halves with wedges.

With the basic shape arranged, I made a checkpoint copy to keep in the background in case I decided to start over from this point, then started on the front pads. The center is simply a box slightly smaller than the center box itself. To make the side pad, I grouped the three components of the wing, duplicated the amalgam, shifted it forward, and scaled while maintaining aspect ratio. Both of these pads were sized and positioned to create a 0.5mm border around and between the pads.

The pads also stick out from the body 0.5mm, but they’re modeled 0.75mm deep and extend into the latter. A major issue in CAD system implementation and use is numerical precision. In particular, when shapes are combined to make a single solid, if two faces meet but are positioned apart by an infinitessimal decimal difference, the system may not realize they’re completely joined. It doesn’t typically matter much for this kind of casual modeling, the final printed piece would usually look the same either way. However, it could affect the efficiency of the print. It also quickly becomes an issue if you use a combined shape with such a gap as a hole to make a cut: You’ll be left with an extremely thin slice in the middle of the hole. I find this issue arises often in TinkerCAD, so whenever possible I extend parts into each other a bit to make absolutely clear that they should be a single solid when joined.

Another detail is that the 0.5mm visible pad depth is not an arbitrary value. Much below that and many home printers, including mine, would not have the resolution to be able to reliably produce the outline. Further, even if it could, the detail would be lost with all but a very careful paint job. The pads are also hanging in space, creating an overhang that might need external support to be printed. However, a 0.5mm overhang is easily managed by many or most slicers and printers. There’s little enough material that the overhanging region can be largely supported from the body.

Front pads made by copying the center box and wing, then scaling down and positioning.

Front pads made by copying the center box and wing, then scaling down and positioning.

A minute detail from the original piece, I then made very thin wedges to cut angles out of the corners of both pads. This is quickly done by making one wedge, then using the align and mirror tools to flip it into each corner. Those are then grouped together, switched to a hole, and grouped with the pad.

Wedges used as holes to cut corner angles into the front pads.

Wedges used as holes to cut corner angles into the front pads.

The recess on the wings could be made by scaling down the body similarly as the pads. However, a small tweak can be made to afford a critical difference. The front pad on the wing has a small border all around it. However, we can model the recess to only be on the top and bottom aspects. This is actually how it is on the FFG model: The side face of the wing body is aligned with the side extremity of the front and back ribs.

Modeling the recess this way is a significant boon to 3D printing the piece. By not recessing the side of the wing body, the side of the piece presents a completely flat plane. It’s also big enough to stand stably on the print platform. The piece can thus be rotated 90 degrees and printed on its side.

This is great news, because it entails no supports will be needed. If the piece were printed in its natural position, sitting upright, the wings would create an overhang requiring support. The issue is that the wings grow out to toward the sides at too shallow of an angle. The printer can’t print in thin air. Most start needing a support structure at anything shallower than a 45 degree overhang, and the wing rise is much less than that. Support structures are a pain to cut off or dissolve, assuming your printer even has the latter capability, so they’re best avoided whenever possible. They’re especially difficult to work on small pieces, and in this case the detail of the wing recess would be lost cutting out a same-material scaffold as required on a single-head fused deposition printer (the most common kind) on such a small piece.

Similarly, printing the piece on its front or back would risk losing the detail of the pads and their angle cuts. Although very small, the pads would create slight overhangs that might not be rendered as precisely. Even more likely, physical effects and common settings for the initial print layer(s) against the build plate, such as fatter and thicker material deposition, would probably cause the small recessed border around the pads and the detail of the angle cuts to be flattened, absorbed, or otherwise lost.

In contrast, by putting the piece on its flat side, no detail will be lost and the wing angles grow vertically very comfortably within printer tolerances. Combined with the point above about the front pad overhangs being kept well within tolerances, this means the piece can be printed without supports, and a whole mess of hassle and loss of detail avoided. As a bonus this mimics the original FFG piece as well, though it would otherwise be a tradeoff of printability versus accuracy well worth making anyway.

To preserve that flat side and create a solid print foundation with no supports needed, the wing body can’t be simply scaled down. Its body has to extend to the side extremity. So, rather than scaling, the original 3 piece wing construction was duplicated and ungrouped. The top and bottom wedges were then simply moved vertically toward the center, creating a border recess parallel to the top and bottom lines of the front and back ribs extending all the way to the side edge. The center box was then just downsized to this thinner space.

Similar to the pad, creating the wing recess by lowering the wedges and downsizing the middle box.

Similar to the pad, creating the wing recess by lowering the wedges and downsizing the middle box.

Next I added simple shapes above the top of the center box to give it texture, just like the FFG model. Another bit of minute detail is that the one circle appears slightly smaller relative to the other on the original model, and I kept that here. Like the pads, these details are again sized keeping in mind the capabilities of many home printers. Mine has a 0.5mm nozzle, which is fairly common. That means it more or less produces a 0.5mm wide path. It’ll try, but it can’t realistically and reliably print features below 1mm resolution, essentially a wall made by a path going out and back. So that’s my usual size threshold in making small details like this, the smallest circles and boxes are 1mm. That turns out to be fine though for throwing in vague details like these.

Once that was done I duplicated the front pads and full-size wing rib and shifted the copies to the rear. From there I grouped all the pieces of the wing, duplicated them, shifted them to the other side, and mirrored them.

Adding bits on top for texture.

Adding bits on top for texture.

Copying the pads and full size wing rib from the front to the back.

Copying the pads and full size wing rib from the front to the back.

Duplicating the wing to the other side.

Duplicating the wing to the other side.

The modeling of the piece is now essentially done. All that remains is to create a hole on the bottom for a flight stand peg to hold the pod off the base, and group everything together to form a single solid.

The hole is simply a cylinder center aligned on the central box, switched to a hole, and grouped in. One small note here about TinkerCAD is that it doesn’t have many convenience functions. For example, there’s no functionality to choose a reference for an align action or to lock one piece down for aligning against (the button to lock pieces unfortunately—oddly—also prevents it from being used to align). So, if you select two displaced objects and center them, they’ll both move. Assuming the moving piece is smaller, the pattern is therefore to first align the piece that can be moved against the far extremity of the piece you don’t want to move, and then center them. Since the moving piece is now within the extent of the larger piece, the latter won’t move. In the next picture, this means aligning the cylinder against the right edge of the body, and then centering it. If the moving piece is larger then you need to position it manually or craft a more elaborate temporary construction.

Centering a cylinder to become a hole for the stand peg.

Centering a cylinder to become a hole for the stand peg.

The hole grouped into the bottom of the center box.

The hole grouped into the bottom of the center box.

That’s it! The cargo pod is now done.

The completed GR-75 cargo pod.

The completed GR-75 cargo pod.

Printing

The next step is making a test print of the pod, base, and a simple flight stand peg. My printer is a Lulzbot Mini, which has been phenomenal to work with. Though I’m not an expert on current market offerings, it seems to strike a very good balance between cost, ease of use, reliability, print quality, print size, and time. An important observation is that it seems there are many printers now offering high enough resolution to print miniatures of acceptable quality. Some are even very low cost, down to ~$300. But it seems one of the biggest tradeoffs made in achieving that is that they print much more slowly. That’s probably fine to download and print parts, but in developing new parts from scratch could seriously slow down design iterations.

In any event, one of the cost tradeoffs made in the Mini is that it does not have an SD card reader and/or internal high level controller, it must have a computer connected to drive the print. So I use Lulzbot’s CURA distribution to slice objects into G-Code printer commands, and send that file to a Raspberry Pi running an Octoprint server which actually executes the job and can be monitored remotely.

Slicing the test print.

Slicing the test print.

Another logistical point is that I currently have my printer set up by a window, with fans to draw and push air out of the room and ventilate my workspace. Although there doesn’t seem to have been much study yet of health effects of 3D printers, ultimately fused deposition modeling is melting plastic to form a part. That typically creates toxic fumes, so I’ve been erring toward an abundance of caution as I use it heavily.

My current printer setup.

My current printer setup.

I’ve been exclusively using eSun HIPS filament for miniatures work, to great success. The resulting product has great resolution, is hard and strong, is easily cut and sanded, and takes paint great. A kilogram spool runs $24–40 on Amazon and can be shipped same day Prime. A part like the cargo pod and its base only uses literally a couple grams of material, so you can print an awful lot of miniatures bits per spool.

As referenced above, caveat upgrades, the Lulzbot Mini has a 0.5mm nozzle. After a fair bit of experimentation tuning settings for this kind of project, most of my prints are at 0.18mm layer height; 0.54mm bottom/top thickness; same initial layer thickness; 100% initial layer width; and 20% infill at 0.5mm shell or 10%, 15%, or 20% at 1mm shell. Those settings have struck a good balance between speed, quality, and strength, with very acceptable dimensional accuracy (mostly a challenge in the initial layers).

In the end, the first test print came out excellently! The part came out very cleanly and definitely looks like the cargo pods. The only changes made were to raise the top details from 0.25mm to 0.5mm tall so they’d not be lost in paint, and to increase the flight peg diameter to 3mm. I’d expected to have to do that, but was hoping in vain that the thinner 2mm would magically work. It looks good and would be perfectly fine for at-home play, but I need these pieces to work in a public event setting where they’re not being babied, so I had to accept the 2mm pole would be too easily snapped. I also ran the test with a separate flight stand peg so that in case it was useless, the base would still be useful somewhere. However, the final design integrates the peg and base to make a solid connection with no gluing required.

First print: Success!

First print: Success!

Conclusion

After that was just making a few bases with different numbers of flight pegs, and the project was all wrapped up. I now have a sweet 3D cargo supply container token that matches my beloved GR-75 in 1/270 scale, and have started printing out piles of them.

Again, these designs have been uploaded to Thingiverse as a free download. Drop a line if you make use of them, or have any questions about this walkthrough!

Final design mockup of a cluster of cargo pods; prints are made as one base piece (red) and a bunch of pods (orange) that fit onto the pegs.

Final design mockup of a cluster of cargo pods; prints are made as one base piece (red) and a bunch of pods (orange) that fit onto the pegs.

Print layout for a stand of 4.

Print layout for a stand of 4.

Printing an initial batch of tokens.

Printing an initial batch of tokens.

Cargo pods and their mothership under attack!

Cargo pods and their mothership under attack!

Supply depot.

Supply depot.

Extreme closeup. These parts have not been cut, trimmed, sanded, glued, or otherwise cleaned up in any way yet, this is straight off the printer just popping pods onto pegs.

Extreme closeup. These parts have not been cut, trimmed, sanded, glued, or otherwise cleaned up in any way yet, this is straight off the printer just popping pods onto pegs.