For competitive reasons, General Electric (NYSE:GE) won't reveal the exact dollar amount it'll be investing in 3-D printing in the coming years, but investors can piece together a series of data points and determine that GE's investment in the technology is truly unprecedented. After all, General Electric has plans to 3-D metal print 45,000 fuel nozzles a year for its upcoming Leap jet engine and has more than 130,000 3-D printed fuel nozzles in its order backlog today. No other company's 3-D printing commitment even comes close to this.

Part of an even bigger plan

In an effort to keep up with booming aviation demand, GE Aviation has pledged to invest more than $3.5 billion between 2013 and 2017 toward manufacturing plants and equipment worldwide, of which the majority will be spent here in the U.S. General Electric's 3-D printing investment falls within this greater investment plan, which Bloomberg believes will reach the "tens of millions" range.

To get a better sense of GE's scale, I recently had the opportunity to speak with Steve Rengers, R&D manager at GE Aviation's Additive Development Center, or ADC, who helps oversee GE's 3-D printing research and development. According to Rengers, the ADC and GE's Lean Lab are the two facilities that handle General Electric's 3-D printing operations, and each house about 50,000 square feet of floor space. In the next 18 months, General Electric has plans to triple that floor space, and over the next three years, the company will fill it out with new 3-D printing equipment.

As far as how many 3-D printers this equates to would be anyone's guess. Rengers explained that in order to meet its annual production target of 45,000 fuel nozzles a year, General Electric would have to purchase more than 100 machines based on today's direct metal 3-D printing technology -- not a very practical or cost-effective approach when each printer can easily cost upwards of $500,000.

However, in the coming years, it's expected that a host of 3-D printing companies will introduce direct metal 3-D printers with significantly larger build volume and throughput to handle the needs to large-scale manufacturers like GE. This would allow GE to consolidate the number of machines it needs to meet its 45,000 fuel nozzles a year production target and likely save on costs at the same time. In other words, it's a pretty safe bet that General Electric is waiting to significantly ramp its 3-D printing capacity until these next-generation machines hit the market.

A sizable investment

Although General Electric has yet to release any fuel efficiency data related to its 3-D printed fuel nozzles, it's clear that the performance gains over a conventionally manufactured fuel nozzle are significant enough for the company to move forward with expansion plans that'll triple its 3-D printing capacity. Coupled with more than 130,000 3-D printed fuel nozzles already in General Electric's order backlog, it's likely going to take a rather sizable 3-D printing investment from the manufacturing giant in the years ahead.