Meet the maker: Josef Prusa

“I was playing with music and I started to build my own controllers,” says Josef. “So I needed to make knobs and faders, and that’s when I found 3D printing. So I went ahead and started to build a RepRap. And because I’m a lazy person, I found it really complex. I wanted to make it easier and simpler during the process.

“When I shared it back, people started to use it instead of the original design. It became my hobby, and after two more years, when people were constantly asking me to build a printer for them, I turned it into a business. And from there it’s grown.

“I went full time in, I think, 2012, so six years ago. I dropped out of college and started a company.
“A lot of people in Czech use me as an excuse, ‘Hey, he also dropped out, and look at them.’ But you have to have something before you drop out. If you just don’t like studying it’s a bit tougher.”

Printing with ultraviolet

You could say that things are working out OK for Josef; his company has sold around 100 000 printers so far, with most of that coming in the last three years. So what’s next on the horizon?

“We acquired an SLA resin printer company and, for last year, we were working on making a new one, the Original Prusa SL1. That’s a resin-based 3D printer, which is a completely different technology than we were doing before. It’s pretty exciting.”

Resin printing sounds a bit sticky, but according to Josef, the process is similar to using a traditional material such as PLA. The only difference is that you use light rather than heat:

“PLA is a thermoplastic, so you heat it up and then you lay down the layers. But this uses liquid resin: when you shine a specific UV light on it, it cures

into hard plastic. So the layers are not done by melting the plastic, but by putting light in specific places, and it cures the resin.

“It’s pretty similar to a lot of UV coatings. You put on a coat of varnish and then you harden it with the UV light. If you could put the varnish in a specific space, cure it, put down another layer of varnish, cure it, put another layer of varnish, cure it, you would have 3D printing.

“It has a different use [to PLA], it’s high resolution, and in some instances faster, and it’s usually used by jewellers.
“Basically if you want to do something that’s very small and high-detailed, this technology is for you.

“If you want small detail, like you have on your glasses, these things, they would be very hard to print on FDM; they would not be as detailed. But on SLA you can print them with no problems.“

The poster child of 3D printing

3D printing is growing up: “It’s interesting to see the change in the last year, year and a half. There were a lot of companies who were small, but at some point the market started consolidating, and I’m very happy that I started to invest in development a lot a couple of years ago, so we do our own slicer, our own firmware, we can develop new stuff. If you are a company just building Marlin [firmware] and Cura [slicing] compatible machines, and if you are just building printers to be compatible with these, you are never going to make something new. So you know, it’s market disadvantage. At the end of the day, we are open-source and everything, but if I need to push the company forward, you need money, you need the sales.”