
RetroRig: Builder
Brings the retro BuildCraft Builder and Filler blocks into modern Minecraft, using FE energy.
Screenshots



About this Mod
FormForge is a standalone mod built around a simple idea: bring back the feel of the old BuildCraft Builder and Filler, but in a modern setup. (Part of the RetroRig mod suite)
The mod adds two machines:
- Builder, which reads a saved blueprint and places the structure for you.
- Filler, which can fill or erase a configurable area using a few preset shapes.
It also adds a Blueprint item for capturing structures directly in the world.
What It Does
The Blueprint lets you mark two corners, save the blocks inside that area, and keep that structure on the item. Once it has been written, you can name it so it is easier to sort through multiple builds later.
Put that blueprint into a Builder, load the machine with materials, give it FE power, and it will start placing the structure block by block. The preview can be rotated or shifted before you start, which makes lining things up much less annoying.
The Filler works a little differently. Instead of reading a captured structure, it generates a shape from its own settings. You can choose the mode, size, rotation, and offset, then either fill the area with the selected block or erase everything inside it.
Both machines render holographic previews before they do any work, support item and energy automation, and are built to survive chunk unloads, reloads, and normal world saves without losing their place.
Features
- Blueprint capture with naming support
- Builder machine for saved structures
- Filler machine for shaped fill and erase jobs
- Holographic placement previews
- Rotation and offset controls on both machines
- FE-powered operation with speed scaling
- Item and energy automation support for pipes and modded logistics
- Resume-safe machine progress across saves and reloads
Recipes
Builder recipe:

Filler recipe:

Blueprint recipe:
- 1 Paper
- 1 Lapis Lazuli
Notes
This mod is inspired by BuildCraft, but it is not trying to be a one-to-one remake. The goal is to keep the part that made those machines fun in the first place: setting up a job, watching the preview, feeding the machine materials and power, and letting it do the repetitive part for you.
If you liked old quarry-era automation mods and want a Builder/Filler style toolset in a current NeoForge pack, that is the whole reason this project exists.
Get Involved Suggestions, bug reports, and feedback happen over on the Discord: https://discord.gg/RJqPMHbUh3
Available Versions
How to Install RetroRig: Builder on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set neoforge Loader
In the panel under "Egg", select the neoforge loader and matching Minecraft version (1.21.1).
Install Mod
Open the mod browser in the dashboard and search for "RetroRig: Builder". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.1
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
RetroRig: Builder server crashes on startup – what to do?
Most common cause: wrong neoforge version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.1). You can switch loaders with one click in the panel.
Is RetroRig: Builder compatible with neoforge?
RetroRig: Builder officially supports neoforge for Minecraft 1.21.1. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with RetroRig: Builder – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if RetroRig: Builder consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
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Rent Modded Server
Install RetroRig: Builder with just one click on your server.