The original design works well for single terrain sets, but can be improved for building multiple terrain themes efficiently.

In the original system, every tile requires its own base, and each base uses 8 magnets. So if you want 3 terrain sets (forest, mountain, and dungeon) of 14×14 squares, you need 49 bases per set — a total of 147 bases, which comes out to 1,176 magnets. And if you add even more terrain types, the number grows fast.

To solve this inefficiency, I redesigned the base system so that one set of bases can be reused across all terrain types.

What’s new?

I added a central magnet pocket to the base and placed a matching center magnet inside each terrain tile. This single connection point lets any tile securely attach to any base.

With this system, each base now uses 9 magnets, and each tile uses 1 magnet. But you only need 49 bases total, no matter how many terrain sets you have.
Using the example above, this reduces the magnet count to 588 magnets 

• 441 magnets for the 49 bases
• 147 magnets for the tiles (3 sets × 49 tiles)

Material savings

Besides the huge magnet savings (which only get better as your terrain collection grows), you also save filament. Each redesigned base weighs 7.8g (including the cover) instead of the original 5.02g, but since you print far fewer bases, the total filament used goes down dramatically.

For the same 3-set example, you only print 382.2g of filament instead of 737.94g when printing 3 full sets of standard bases.

Getting Started

For each base you will need:

• Print the base file (“base with middle magnet.stl”).
• Print the base cover (“base_cover.stl”).
• 9 magnets (5×2 mm).
• Glue to attach the base cover.

After placing the magnets inside the base, glue the cover on top to keep the magnets securely enclosed.

Step by step:

1. Print the base and it's cover

   

   

2. Place the 9 magnets into their pockets inside the base.

   

3. Apply glue on the top surface of the base

   

4. Press the cover onto the base and hold it in place until the glue sets - I use kitchen clips, but a small weight book work fine.

   

5. Thats it! Once the glue is dry, your reusable OpenForge base is ready to use!

   

For the tiles

Make sure each tile has a 5.5 mm diameter, 1 mm deep center hole.
You can also use terrain sets that already include this hole and are compatible with this universal base.

• Forest
• Mountain
• Dungeon Stone
• River
• Swamp
• Road
• Modular House

After printing the tile, glue a 5×1 mm magnet into the center hole using super glue.

The magnet orientation does not matter because the central magnet in the base has enough room to rotate and automatically align itself to the correct polarity.

Elevated Terrain Bases

There are also special bases for elevated terrain:

• “base with middle magnet for elevation 5 ft.stl”
• “base with middle magnet for elevation 10 ft.stl”

These elevation bases are used as tiles placed on top of regular bases, which is why they include a center hole for a 5×1 mm magnet.

Note: The center hole on these bases requires supports.

For the best visual and structural result, place these elevation tiles next to a tile with a wall (see the mountain terrain set for an example).

Converting Other Tiles to Work With This System

You can easily make any OpenForge tile (or any other modular tile) compatible with this reusable base system.
All you need to do is add a 5.5 mm diameter, 1 mm deep hole in the center of the tile. Then glue a 5×1 mm magnet into that hole.

Demo

If you’d like to see the system in action, I made a short video showing the final result with the tiles, bases, and magnets in place:

Feel free to ask any questions in the comments or send me a message - I’m happy to help!

Magnets that I have used:

• 5X2mm - for the base cover - https://www.amazon.com/dp/B0CCXY6WBR
• 5X1mm - for the tiles -  https://www.amazon.com/dp/B082PN5BLN

Glues that I have used:

• For the base cover - https://www.amazon.com/Weld-Acrylic-Plastic-Cement-Tube/dp/B00R5NYM7M 
• For the tile's magnet - https://www.amazon.com/dp/B00342VCGM