Getting parts on demand has been a manufacturer's dream for many years. Since 2005, there have been cries from the 3-D printing industry that additive technology would replace the need for injection mold tooling, that it would eliminate the need for machining, that casting would become obsolete.

Finally, that dream is becoming a reality.

While there have been success stories such as the use of Stratasys Ultem for aerospace parts and selective laser sintering (SLS) nylon for automotive parts, until today, these components have all had restrictions on where and how they could be used. Two of the biggest drivers for this have been slower production speed and the part cost.

Siemens, according to a recent article in Plastics Today, is using 3-D-printed fire-, smoke- and toxicity-compliant polymers to replace parts in trams, and they cite part availability as being the primary driver. The U.S. Marines have also recently experimented with printing replacement Humvee parts in the field.

What all these examples have in common is they are limited in scope by the 3-D printing technology restrictions. While the FDM process eliminates tooling, it is still 100 times slower than injection molding or machining, and while SLS material prices have been reduced, they are still 10 times more expensive than injection molding or nylon bar stock prices.

So, the extent to which these older 3-D processes can be deployed is still limited by cost and speed.

This is beginning to change. A new breed of additive manufacturers is arriving on the market who are focused on truly using 3-D printing to create production parts at costs comparable to injection molding and machining prices.

These "new age" additive manufacturing companies combine faster printing technology with engineering resources to convert and certify part performance. They have integrated quality systems to ensure material, process and part conformity. And they offer parts at competitive prices compared to injection molding or machining costs without the need for tooling, set up costs or inventory carrying costs.

An example, cited in a recent Reuters report, of one company taking advantage of this new age in additive manufacturing is Daimler Trucks, which has announced it will start offering plastic replacement parts printed at local service centers from a library of 3-D files.

These companies have developed much faster 3-D printing technologies that use faster curing and less expensive materials with all the properties of traditional polymers. With speeds that are 10 times faster than current SLS technology and material prices equivalent to injection-molded nylon or machined bar stock, they can now offer customers a wide range of new and replacement part solutions. Where precision tolerances are required, the companies use automated machining centers linked with the printers to provide finishing operations.

Without the need for tooling, customers can now order parts to print using their 3-D library or one provided by the service provider. The shorter printing cycle times mean that it is no longer necessary to hold more than 1-2 days of inventory for quick-use parts and less frequently used parts can be ordered as needed with zero inventory requirements.

For low order quantities (fewer than 10 parts), it has always generally been cheaper to 3-D print versus using traditional manufacturing. With the lower cost breakeven point of these new-age 3-D printing technologies, minimum order quantities (MOQ) of 500 or 1,000 will be converted to printing versus injection molding or machining. Customers already using SLS technology will see an immediate cost and turnaround benefit from switching to this new breed of 3-D printing technologies.

The benefit of these "new age" additive manufacturing companies is being immediately felt by the machinery manufacturers and end-users of such equipment. There is a significant cost benefit in current supply chains, PwC Strategy& estimates there will be a 20 percent gain in total cost of ownership (TCO) from 3-D printing replacement parts. It is estimated 70-80 percent of that can be delivered to the end-user.

Lower prices for spare and replacement parts are possible with peace of mind that the part has been certified for use. No longer are machinery manufacturers tied to traditional injection molders who retain tooling that cannot be easily moved. Parts produced offshore can now be reshored without needing to recreate tooling.

PWC Strategy& predicts German spare parts manufacturers will derive $3 billion in benefit from adopting 3-D printing. Additive manufacturing by its nature is not a labor-intensive process, and the new breed of technologies produces 10 times the number of parts in the same time lowering the overhead cost per part and making larger MOQ more attractive.

These additive manufacturing companies retain digital libraries and ship direct, on-demand parts in quantities of one to 1,000 in less than 24 hours. They do this by not only having faster 3-D printing technologies but also using automated transaction systems, integrated engineering and lean techniques to optimize printing uptime.

Whether it is Daimler deciding to print plastic parts locally to save warehouse, shipping and logistics costs or Siemens citing the increased ability to service multiple customers with parts on demand, times are changing for the benefit of producers and end-users. And to support the changing demands, these companies are turning to additive manufacturers who in turn are enabling U.S. companies to reshore production, improve turnaround time and lower part costs.

If you have dismissed 3-D printing in the past, it might be time to take another look.