Prusa MK4 Rumors Increasing?

By on July 6th, 2021 in Ideas, news

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Prusa MK4 Rumors Increasing?
Still on top, the Prusa MK3S awaits replacement by a future MK4 device [Source: Prusa Research]

Recently there seems to be an uptick in rumors of a possible Prusa MK4 desktop 3D printer.

Prusa Research is one of the leading producers of 3D printers worldwide, having had a series of highly successful products over the past six years. They’ve grown massively, largely due to a combination of top-notch products, service and marketing.

Currently their flagship device is the well-known Original Prusa i3 MK3S desktop 3D printer. It’s a machine that is proven to be reliable, is upgradable and it produces prints of outstanding quality.

But the MK3 was first announced way back in September of 2017, nearly four years ago.

Since then there have been some notable tweaks to the design, resulting in the MK3S and MK3S+. Perhaps the most important upgrade has been the replacement of the electronics with 24V power and an upgraded processor.

However, it’s mostly the same machine. Don’t get me wrong, it might be the best desktop 3D printer you can buy these days. But it has been quite a while since the machine was introduced.

In the interim Prusa Research has been quite busy developing other machines. They’ve introduced a new line of resin-based 3D printers, and made an inexpensive version, the Prusa MINI, which include a number of features not present on the MK3S.

Many in the industry been anticipating the elusive MK4 for years. Some have speculated on what features it might include, including myself.

Why the delay in bringing forward a MK4 design? I suspect it’s a combination of factors, including:

  • Resources diverted to development of other machines that capture new markets
  • Consideration of opening overseas offices
  • Tweaks to the design have been sufficient for most operators
  • They are still able to sell as many MK3S units as they can produce

Certainly the MK4 must be on the drawing boards at the Prusa Research offices, but there has been no public announcements thus far. However, there have been some hints.

For example, if you accidentally mistype a URL for, the company’s customer interaction site, it takes you to their 404 page:

Prusa Printers’ 404 page [Source: Prusa Printers]

Or rather, their “MK404” page. It says:

“We’re sorry, but this page belongs to our top secret printer coming in distant future.”

Some users are so anxious to see a MK4 we’ve begun to see “spy photos” of purported MK4 devices and prototypes. Here’s one I recently saw in a Reddit post:

Spy photo of an alleged Prusa MK4 device [Source: Reddit]

In this image we see what seems to be a Prusa MK3S, but the extruder assembly seems a little different. It’s almost certain this is not the mysterious Prusa MK4. If anything, it could be an extruder/hot end upgrade for a possible MK3S++ version, if I’m allowed to use even more “+” signs.

Similarly, a question on a recent Prusa livestream thread triggered this response from Prusa Research chief Joseph Prusa:

Jo Prusa responding to a question about a possible MK4 3D printer [Source: Facebook]

Of course, nothing was announced the following Friday.

What does all this mean? Do these bread crumbs mean Prusa Research is building a MK4?

My thought is that Prusa Research is indeed working on a MK4; it’s inevitable. The only question is timing. However, based on the bullet points above, they are taking their time. They have no reason to rush it forward because they’re already at the top of the hill.

But in the meantime they’re also having some fun with overly-anxious fans.

Via Facebook and Reddit

By Kerry Stevenson

Kerry Stevenson, aka "General Fabb" has written over 8,000 stories on 3D printing at Fabbaloo since he launched the venture in 2007, with an intention to promote and grow the incredible technology of 3D printing across the world. So far, it seems to be working!

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