On Monday, February 5th, we started to ship the Original Prusa MK3.5 upgrade kit, so the first units are already on their way to their new owners! The MK3.5 is a major upgrade with many useful features taken directly from the MK4. One of the biggest changes is the hardware-based support for Input Shaper and Pressure Advance to give your MK3S+ a massive speed boost. It’s the most cost-effective way to get many of the MK4’s features on your MK3S/+.

Speaking of the MK3S+: please note that we’re ending the production of the MK3S+ assembly kits on February 15th February 29th (extended due to popular demand) and we’re planning to end the production of MK3S+ assembled printers – we will sell them only until the current stock lasts. But we will, of course, hold spare parts in our warehouse. So, if you’re looking to expand your MK3S+ print farm with the same models (instead of switching to MK4), now would be the time to do it.

Back to the MK3.5! Most of the new additions are possible thanks to the 32-bit embedded xBuddy platform, which also allows us to add a full-color LCD panel with useful things like print file preview, easier configuration and navigation, and more. Plus, you get built-in support for remote printer management via Prusa Connect.

The upgrade process is completely straightforward, so you don’t have to worry about taking half of the printer apart. We estimate it takes around 2 hours to install it – check out the assembly guide in case you want to see the entire process for yourself. 😉

Supercharge your MK3S+!

Thanks to the 32-bit xBuddy board and its support for Input Shaper and Pressure Advance, the MK3.5 is up to two times faster than the MK3S+.

The actual speed will always depend on the size and complexity of an object, but the good news is that the larger the object is, the more time you save. For the purpose of this article, we compared several objects, from statues to handy improvements (such as cases and storage boxes) and the results are pretty decisive across the board. An iFixit Mako Frame would take 7 hours and 7 minutes on the MK3 while it takes only 3 hours and 23 minutes on the MK3.5, that’s 2.1 times faster! We used the 0.20mm SPEED profile, PLA, and a 15% infill. Another popular model that takes full advantage of the higher speed is the wonderful Rugged Box (Parametric) by Whity which can be printed up to 2.2x faster in PLA or 1.8x faster in PETG.

Similarly, we sliced the popular Darth Vader bust and went for the 0.15mm Quality/Structural profiles. The MK3S+ required 1588 minutes (26 hours) to print it, while the MK3.5 did the same job 778 minutes (12h 58 minutes).

On the other hand, with small objects, the speed differences are less significant. A small-sized low-poly Pikachu model took the MK3S+ 36 minutes to finish while the MK3.5 did it in 33 minutes.

Model MK3S+ (minutes) MK3.5 (minutes) Speed increase
iFixit Mako Frame 427 203 2.1x
Darth Vader (without base) 827 455 1.8x
Rugged Box 425 197 2.2x
Torture Toaster 800 384 2.1x
Dragon Egg 171 86 2.0x
Low-Poly Pikachu (20%) 27 24 1.1x
Modern Spiral Planter (two pieces) 940 487 1.9x

All objects in the table above have been sliced with 0.20 SPEED profile, Prusament PLA, and with a 15% infill. Pre-release print profiles were used in combination with PrusaSlicer 2.7.1.

Easier and more convenient

With the new larger full-color LCD panel, operating the printer is easier and more convenient than ever before. Enjoy useful additions, such as print file preview – when you select a G-code from the USB drive (no more SD cards!), you will also see a thumbnail of the sliced object. Perfect for all of those who love to name their G-codes as askdfjhs.gcode. 😉

The larger screen makes all calibrations and configurations a breeze. And you can even customize the footer of the main screen with useful information about various parts of your printer. You can also flash firmware from a USB drive or remotely via Prusa Connect.

As always, the upgrade kit comes with detailed assembly instructions and a new 70-page 3D printing handbook to get you up to speed!

Built-in network features

The MK3.5 can easily connect to an existing network via ethernet cable or Wi-Fi. This step is completely optional and just like our other machines, the MK3.5 can be fully operated offline without any drawbacks.

With the built-in network features, you can connect your MK3.5 to our remote print management system, Prusa Connect. This gives you the ability to manage your printer remotely and send print files directly to your printer. We made extensive changes to the network code and Prusa Connect to boost the network speeds. With the introduction of “Instant Printing”, the MK3.5 starts printing only seconds after you upload your G-code to Prusa Connect. This is possible thanks to a new binary G-code format and data streaming features and using the MK3.5 this way is much more convenient. Plus, you don’t have to look for that pesky SD card reader every time you want to print something. Prusa Connect can do much more, though! Check out our recent article covering its features.

Printer Overview

You can also enable “local Prusa Connect” called PrusaLink. This creates a simple local server on your MK3.5 in case you don’t want your data transferred via the internet.

Out now!

The Original Prusa MK3.5 is now available in our e-shop. The package includes everything you need to give your trusted workhorse a massive refresh.

With the addition of Input Shaper, the printer becomes crazy fast – even with the original extruder! In case you’re looking for a bigger upgrade, take a look at the MK3.9 Upgrade which also includes the entire Nextruder with its Loadcell technology for an always-perfect first layer. And since there was a huge demand for an MK2->MK3 upgrade, we also offer a full MK3 to MK4 upgrade.

Happy printing!


Q: Are the plastic parts included?

A: There is a small PETG filament spool included for you to print the parts.

Q: Which MMU unit is compatible?

A: Our latest MMU3 unit is compatible with the MK3.5. To get MMU3 for your MK3.5 printer, you can choose from the following options:

Q: Is the Wi-Fi ESP module included?

A: Yes, the Wi-Fi ESP module is included.

Q: Is the Revo compatible?

A: The Revo hotend is a third-party addon. As of firmware 5.2.0, there might be issues with running the REVO hotend on the MK3.5. During testing, we discovered that due to the strict checks built into the firmware, the initial self-test will fail. It is possible to start the print, although we recommend waiting for the upcoming releases, which will extend the support for 3rd party hotends. Please see the release notes for more details.

Q: Is OctoPrint compatible?

A: The MK3.5 has the same base level of support for OctoPrint as the MK4 and XL. We’re still looking into some features. More details can be found in the release notes.