How Do You Scale 3d Printed Terrain Pieces For Your Games?


I have backed several Kickstarter.Com campaigns that had, as their rewards, a series of 3d printer STL files for model buildings and structures. The STL file is the computer file that contains the 3d description of what the final model is. You would load that STL file into a slicer program (like Ultimaker Cura) to generate GCODE files that the 3d printer then uses to print the model.

But if you’re making a model house, how do you know what size that house is going to be? I don’t want a house the size of a house! Luckily, that’s not possible. The slicer program will ensure that your 3d model will fit within the confines of the printer’s build capacity. If it’s larger, it will throw a warning to tell you that the model is too big. It’ll even show it on the screen, with the part that can be printed in a solid color and those parts outside the build area shaded with a stripe pattern.

To scale a 3d model, use the Scale button on the slicer to resize the model. To know what size to scale to, use a comparison item. If you are printing a model car, place it beside a model person and see if they look right together. Scale up or down to correct and you will have a good match. Use a scale ruler from Thingiverse.Com to help you gauge relative heights.

What Is a Game Terrain Model

Game terrain models are the models that you use to flesh out your playing space, that aren’t the playing pieces. So, in a wargame, things like trees, buildings, bridges, roads, sign posts, garbage cans, cars parked on the streets and even airplanes on an airfield all good examples.

You can design your own 3d models of these objects, but I’m not that talented. I purchase 3d models from great designers on Kickstarter.Com or from WargameVault.Com. I search for the search term ‘STL’ to find those campaigns or products offered with STL files in them. I have backed several Kickstarter.Com campaigns for World War II buildings for Western Europe, to print for my miniatures games.

Here are two different designers’ collections from past Kickstarter.Com campaigns:

Each of these campaigns contained a series of buildings and accessories to dress up a miniature battlefield. I’m concentrating on buildings that would look good for the Normandy region of France, in 1944 (for the Allied invasion of France against the Germans, the start of the end of World War II).

How Do You Know How Big a Game Terrain Model Is To Start With?

The designers should state in their description how big the model is without modification. The designer for WoW Buildings states that his buildings are sized for 28mm (or 1:56 scale) without modification. I play my games at 15mm (or 1:100 scale) so I needed to make mine smaller.

The designer for 3d Print Terrain states that his models are designed for 20mm to 22mm scale. He recommends using a size reduction to 73% for 15mm games. For 28mm games, you’d have to upscale the models to 127%.

How Do You Scale Without Having To Print and Compare Terrain Models?

The best method I’ve found is to download a height checker model. This is a stair-step tool that shows you, at scale, how high something is. You can download GrooveDachschund’s excellent 28mm Height Checker from Thingiverse.Com here:

28mm Height Checker from GrooveDachschund on Thingiverse.Com

It’s scaled for 28mm, but you can change the size in your slicer by adjusting this like any other model. Load the model that you want to make (like a building, car, tank, whatever it is), and then load the Height Checker. Adjust the Height Checker to the scale that you need and move the Height Checker model up against the object you’re checking. You can visually compare how big to scale the original model, now.

Don’t worry, you won’t be printing the Height Checker. Once you’ve got your original model to the size that looks good to you, delete the Height Checker from the slicer, and then slice the original model. Take a note of the percentage scale that you’ve settled on, in case you want to use it again. You may want to print the same piece again, or other pieces from the same designer (assuming that the designer used the same scale each time he created a model).

To scale the Height Checker model, GrooveDachschund recommends the following chart for each desired scale:

Desired Scale Percent Adjustment of Height Checker
10mm 36%
12mm 43%
15mm 54%
20mm 71%
25mm 89%
28mm 100%
30mm 107%
32mm 114%
35mm 125%
40mm 143%
54mm 193%

How Do You Decide On a Scale to Commit To For Game Terrain Pieces?

For illustrative purposes, I printed the same building three times, each time using a different scaling in my slicer. The building comes from 3d Print Terrain’s World at War 5 Kickstarter.Com campaign. The building started as a 20mm to 22mm building.  I play games in 15mm. According to 3d Print Terrain, I should scale this building to 73% for 15mm.

The result on the right (the largest of the buildings) is the 73% version. I see why he suggested this size, as it would fit two stands of my 15mm infantry (these are based for Battlefront’s Flames of War wargame). The designer felt that two stands of infantry (representing eight to 10 soldiers) would fit on each level of the building. You can see from the picture that two stands fits nicely in the upper story of the building.

Two infantry stands per floor at 73%

Originally, I didn’t pay attention when I printed this building, and thought it was designed for 28mm games. So I printed at 54% to get it to 15mm, in scale with my figures. The building looked very small to me. I can place one stand of infantry in the upper story, but not two. This seemed to be too small. Of course it was! I had made an incorrect assumption on the initial scale of the building before modification.

One stand of infantry at 54%
Again, one stand of infantry, but at 65%

The Front Door Test For Game Terrain Buildings

I find that the best way to figure out if a building looks right for scale, is to put the figure in front of it, and compare it to the size of the front door. This is a subjective test, but that’s okay. I’m not making an engineering model. I’m making art for my games, so subjectivity is called for.

My 54% building looked too small when compared to the 15mm figures in front of it. My 73% building (the scaling that was suggested by the designer) looked too big. It fit the two stands on a floor, but it just looked too large compared to the figures. I tried 65% (somewhere in the middle between 54% and 73%) and I liked the look.

Infantry in front of 54% building’s front door.

At 65%, I can still only get one stand of infantry per floor, but as a retired Army officer, I wouldn’t send more than half a section to each floor of a building of this size. So that’s just me convincing myself of my decision to stick to 65% with some possibly outdated but maybe valid thinking and experience! It’s art; you can’t tell me I’m wrong!!

The same infantry, in front of the 73% building

Scaling your terrain pieces to fit your figures and your mental image of how it should look is important. Just as important is to be consistent in scale between your pieces, so that they look good together as a collection. If you make a village, it looks best if the buildings are all scaled appropriately and consistently between them.

I liked the look of this one, in front of the 65% building

Happy gaming!

Related Questions

How do you scale down a 3d model?

In your slicer, look for the ‘Scale’ button. Select a model that you’ve loaded into the slicer (or a series of models, if you’re printing multiples at the same time) and hit that ‘Scale’ button. Enter a value as a decimal. So, for 54%, you would enter 0.54. You’ll see that the model changes size. You can then move it around to best fill your build area. You can select a previously scaled model in the slicer and hit that same ‘Scale’ button to see what scale it has been sized to.

Can you 3d print miniatures?

You can! In fact, it’s pretty much the only thing I use my two 3d printers for. I print miniatures (both historical soldiers and vehicles) and fantasy figures and monsters on my DLP resin printer. On my FDM Filament printer, I print buildings, bridges, fences and the like to provide terrain pieces for my games and battles. You can find many of these objects to print at Thingiverse.Com. Check out this article for other places to find models, too: https://home3dprints.com/3d-printing-and-preparing-gaming-figurines-for-the-tabletop/.

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