3D printing technology

You continue to post thoughtful, intelligent comments and questions in response to my Era of Radical Change columns. Thank you.

This tells me we have a very savvy, active, and well-informed set of readers. I'm always eager to see what you bring to the discussion. Without your help and input, this column wouldn't be so successful (or nearly as fun to write).

Of course, the sheer volume of comments I get makes it impossible for me to address them all individually along the way. But I promise to keep doing my best.

With that in mind, let's tackle some of your latest queries...

Starting with a really interesting comment about 3D printing stocks.

Q: My background in materials strength and stress-strain analysis tells me we must expect a development period of some five to ten years until 3D-printing can become a real breakthrough in terms of manufacturing of mechanical parts. I would be cautious about investing heavily now in the hope of short or mid-term profits. ~ Al G.

A: Al, I can't compete with your knowledge of materials, and I won't even try.

But I do want to point out that we may be talking about two different aspects of 3D printing.

Clearly, there is a growing market for small businesses and consumers. These are lower-priced, entry-level printers. The cheapest mass market machine from a major company costs about $1,300. As Al points out, that's not going to give you solid, working metal parts that you might want to use in a car or a plane or for a lathe in a machine shop, for that matter.

However, many big companies are buying much more robust, expensive printers and putting them to good use throughout their supply chains. One publicly traded company for your radar screen is Stratasys Inc. (NasdaqGS:SSYS).

This firm is going after more of the upper end of the market - big outfits that can work this tech into their manufacturing lineups. As regards investing, you should always be careful. But I don't think it's too early to make money from 3D printing stocks.

And here's proof...