The backlash over my  3-D printing article last month was quite pronounced.

Industry insiders, those who make a living from designing parts, company reps, and a few stray trolls all made sure to get their shots in. Then, after a few weeks, the admission emails started to arrive from people who had actually bought one.

One small business owner told me he felt "duped" by a MakerBot model that ended up collecting dust in a back closet. He bought one on a whim and thought it would provide some utility down the road; then, the whim faded.

Others admitted there are some serious problems because the parts were not always that useful and some didn't quite work, even after a few tries.

In case you question whether there's a problem, remember that the most popular 3-D printing company  is in a downward spiral. The stock price of the parent company has plummeted. More important than those two factors is the experience you have using one. I've tested several models over the years, talked to countless manufacturers, seen demos, watched Yoda heads print at tech conferences, and followed the industry closely. My most recent experience, testing over several weeks printing out classic cars, cup holders for bikes, a keychain for a Volvo, and many other plastic parts made me wonder for the first time if there could be some holes in the 3-D printing ship.

My main realization came when I wanted to print a part that would be useful.

I've covered all of the details in the previous piece, but I'm still waiting for someone to send me a cup holder for a Saab. A few offered, no one has done it. It's not that difficult, but it points to a problem with 3-D printing because it should be easier. Someone should make this part, offer it for free, and allow anyone to print it.

To say there are some complex parts available is missing the point. The complex part I needed wasn't available, even though a Saab is a fairly common used car. (That's because it's incredibly reliable, which is something Makerbot should have replicated.) The Saab part is one example. Since that story posted, I've thought of a few more. I tested a Husqvarna Automower recently, and one of the side panels is scuffed up. How about a replacement? Yet, the part doesn't exist because Husqvarna would prefer I buy direct, which is their prerogative. Also, it's probably too big.

In fact, looking around my office, I can see multiple gadgets and office accessories that have parts I could replace but, after checking Thingiverse, they are nowhere to be found. What will you find? Keychains, cup holders for bikes, toys, and Yoda heads. Yet, even these items are a letdown. I printed a Darth Vader statue and it looks like something you'd design in middle school shop class using free Google apps. 

I did have high hopes for an iPhone case. I imagined printing one out for friends and family, creating elaborate designs and printing in unusual colors. Here's where things really went south. There are iPhone cases on Amazon for $5. In my area, you can have one delivered in 30 minutes for free. Please explain to me why I would ever print one myself. It's insane. Sadly, the industry insiders are so committed to the cause they can't seem to admit that many of the parts you can design and produce are available for much cheaper online and without any of the hassle. Sadly, the industry is dying because the entire concept of printing at home is totally suspect.

So, what will save the industry? It's the same thing that saved the graphics and photo-editing industry about two decades ago. Remember Kinko's? It still exists in some form (as a FedEx shop), but back in the early days of laser printers, design software, and desktop computers you'd go to the shop and request help from technicians to make a color brochure. It was partly a hand-holding exercise, partly a way to get design help, but mostly a solution to a mass production problem.

Recently, I've heard of 3-D printing shops like Blu-Bin in the Bay Area doing what service bureaus did back in the 90s. The people who work there know how to maintain the machines. They understand that the customer almost always has unusual requirements. As a business, these shops have no interest in making plastic toys and keychains. They are making parts that are useful. They're professionals.

What has really killed the 3-D printing industry is that it was positioned as a DIY machine for the home. Industry experts said anyone could create a design and produce an object. They were wrong. Not everyone is a designer. There was a disconnect between what was available on Thingiverse for fun and what people really wanted to do, which was create more complex and useful parts.

As I mentioned, I'm not against the industry. I want 3-D printing to succeed as much as anyone else. But it is my job to cry foul when companies insist that a 3-D printer can do "anything" you want, that there is an "unlimited" archive of parts, that you will buy one of these expensive machines and it will be humming along night and day and change your life. During my longest test, it was humming along all night...making one part. Yet, I never warmed up to the idea of owning and using one for anything around my house--e.g., the lawnmower part, the case for my iPhone.

Eventually, I'd like to have a 3-D printing shop work like Amazon Prime. In a 10-minute chat with a technician (or maybe a chatbot), I'd ask about the Husqvarna part. They'd design one that doesn't infringe on a patent. It would arrive that same day for $5. Done. Now, scale that up to thousands and thousands of people asking for the same replacement parts, useful items for home, iPhone cases, and maybe even keychains. Once anything that's broke in the home can be printed, it could rebound. Once anyone can request a part for a prototype and see the results quickly, 3-D printing could become viable. For now, it has a long, long way to go before your neighbor up the street buys one and starts printing out parts all day.