“I bought a tool, not a mold,” says new 3D printing entrepreneur

squarehelper 3d printed

Necessity is the mother of invention. But in the old days — pre-3D printer days — the invention never came to realization, with most people getting stuck right at the “Gee, I wish I had a …” moment. The idea was always thwarted by the complexity and cost of producing a prototype, a mold and then mass producing the idea. As most of us all now know, those days are over, thanks to 3D printing.

A beautiful case in point is Chris Milnes. He’s a singer in the band Mucky Pup, and as any of you who perform know, you’d got to sell CD’s, shirts, and anything else you can to try and make a venue pay. Well Chris did this and in fact automated the sales process by using something called the Square credit card reader, which is a small mobile card reader that you plug into your device’s standard headphone minijack. In Chris’ case, and I assume for most traveling small vendors these days, that device is an iPad or iPhone. He simply pulled the Square reader out of his pocket, popped it into his iPad, and started swiping credit cards.

But like most things, not everything was perfect: the card reader would spin around on the male pin, making it sometimes difficult to get a good swipe. It needed to stay in place without moving. With a little tinkering with his kid’s Lego blocks, he was able to create a prototype of sorts that attached to the iPad and kept the reader from spinning. It worked so well that he thought about making it a product that he could sell to others who use the Square card reader.

The classic next step would be to have an injection mold made, but that was going to cost him $4,000 – $6,000, plus the cost of each product run. And if he ever wanted to change his design, he’d need to make a new mold. This is where most small inventor’s dreams die. Until 3D printing. Chris realized he could bypass the mold making AND the mass production runs with a $2,000 Makerbot Replicator.

As he says in the video, “I bought a tool, not a mold.” That is a profoundly powerful statement.


With the Sketchup 3D modeling program and his 3D printer, he was quickly able to create his first SquareHelper, which fits neatly on the iPad while holding the card reader while letting it spin. Once he found he had a winning product, he scaled up. He tells the story in his own words:

“I started off with one Makerbot machine. and I did my calculation and I figured I could pop out 100 a day, and even if I run it seven days a week I have 700 pieces. So I have purchase orders coming and I figured it out. and this will do me right now for this moment. What do I do when I have a purchase order for 2,000 pieces, 3,000, 10,000? I scale up. You just add another bot next to it and, as you call it, it’s a bot farm. It sounded funny when I did the computations — I’m going to be running this 24 hours! But I actually do run this 24 hours. It is always running. I even have a little D-Link video camera on the platform, so whenever I am, on my iPhone, or on a web browser, I can see if its done, and do I have to clear the platter and start it again? But the machine, since I’ve had it, is at an average of 20 hours a day, which is crazy!”

The Chris Milnes manufacturing plant, in his home office.

Chris sums up the space in which he finds himself quite nicely: “I live right at the point of prosumerism. It’s not consumer and it’s not professional grade. I’m right in the middle where I can really get the most bang for my buck.”

He bought a tool, not a mold. And so will a million others and the world will change as we know it.