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This page is about the Mass Fabricator added GregTech 5. For other uses, see Mass Fabricator.
Mass Fabricator

ModGregTech 5
TypeTile entity
Tooltip textUUM = Matter * Fabrication Squared
Blast resistance10

The Mass Fabricator from GregTech 5 produces UU-Matter used to replicate elements in the Replicator. It may be supplied with UU-Amplifier from an Amplifabricator to increase its speed and efficiency.


Like every electric machine in GregTech 5, the Mass Fabricator comes in 5 variants, one for each voltage from Low to Insane.


The Low Voltage Mass Fabricator produces 1L of liquid UU-Matter every 160 seconds, unless UU-Amplifier is supplied. When UU-Amplifier is supplied via fluid pipes, the time is shortened to 40 seconds. 1L of UU-Amplifier is consumed for each 1L of UU-Matter produced. Since the LV Mass Fabricator consumes 32 EU/t, it may require 2 amps of power if it is supplied via cables due to power line loss.

Because it does not require any material input, the Mass Fabricator operates and consumes energy constantly. The Machine Controller cover may be used together with a Lever to fit the machine with an on/off switch to conserve power.

Like most GregTech machines, higher voltage tiers of the Mass Fabricator operate with doubled processing speed and quadrupled energy costs:

Tier EU/t Time for 1L UU-Matter in sec Time with UU-Amp in sec EU per 1L UU-Matter EU with UU-Amp
LV 32 160 40 102880 25720
MV 128 80 20 205760 51440
HV 512 40 10 411520 102880
EV 2048 20 5 823040 205760
IV 8192 10 2.5 1646080 411520

Each tier effectively doubles the energy cost per unit of UU-Matter, making higher tiers of the Mass Fabricator less practical until the late game, when energy is abundant.

Since the Osmium needed to make the Mass Fabricator is usually rare in GregTech 5, it is often first used to replicate more Osmium. A complete processing chain consisting of an LV Mass Fabricator, an LV Replicator, and the Elemental-Scan: Osmium Data Orb (which uses 1 Osmium Dust to create) will cost 7 Osmium. This first Osmium can be obtained by processing Iridium Ore, or by processing large amounts of Chalcopyrite or Pentlandite if using GregTech 5 Unofficial.

Osmium has an atomic weight of 190, so 190L UU-Matter is needed to replicate a single Osmium Dust. An LV Mass Fabricator needs 19,547,200EU over 8h29min to produce one dust. If also supplied with 190L UU-Amplifier, only 4,886,800EU over 2h8min are needed.

UU-Amplifier Efficiency

In an LV Mass Fabricator, 1L UU-Amplifier saves 77,160EU.

An LV Amplifabricator produces 1L UU-Amplifier using 9 Scrap and 5120 EU.

A Recycler produces 9 Scrap using (on average) 72 items and 3240 EU.

Subtract the cost of running the two other machines from the amount of EU saved by 1L of UU-Amplifier and divide by the number of items recycled: each item recycled will save (77,160 - 5,120 - 3,240) / 72 = 956 EU. To produce one Osmium Dust using UU-Amplifier requires 190L of UU-Amplifier, which will consume 13680 recycled items.

Inserting an Integrated Circuit (any configuration) into the Mass Fabricator will prevent it from running unless it is supplied with UU-Amplifier.

GregTech 5.09 Changes

In GregTech 5.09, the Mass Fabricator was changed to use 256 EU/t (32V at 8 amps) at LV tier, and all tiers can now accept up to 10 Amps. Before 5.09, the LV Fabricator used 32 EU/t and accepted up to 2 Amps of current.

This increased the cost of generating UU-Matter by eight times, which makes Amplifier even more important. This change was made to bring up the GregTech energy costs to equal the original IndustrialCraft 2 costs. At every voltage tier, 1L of UU-Matter will cost 823,040 EU to create, or 205,760 EU if supplied with UU-Amplifier. Thus, 1L of UU-Amplifier is worth 617,280 EU, and each recycled item is worth 8,457 EU.

Higher tiers of Mass Fabricator now maintain the same power efficiency as lower ones: Each tier doubles both energy cost and processing speed (rather than quadrupling energy cost as most other machines do). Every tier of Fabricator can accept up to 10 amps, allowing you to supply a high-tier machine with many amps of a lower-tier voltage, in addition to supplying the low-tier machines with many amps of the appropriate voltage.

Tier EU/t Seconds With Amplifier
LV 256 160 40
MV 512 80 20
HV 1024 40 10
EV 2048 20 5
IV 4096 10 2.5