If you have an MK3.5 printer, there is no product in our e-shop with the direct upgrade to the MK3.5S. However, purchasing the parts to turn your printer into the MK3.5S separately is possible.

On PrusaSlicer, the MK3.5 and MK3.5S have the same profile.

The parts added will be the new Wi-Fi board and the new NFC board.

You will need:

El-box-cover printed or from the e-shop (1x)
MK4S-Wi-Fi-cover printed or from the e-shop (1x)
M3x12 screw (3x) (a set can be found is the e-shop)
ESP-Wi-Fi (1x)
NFC set (coil+cable+adhesive film) (1x)

The upgrade is similar to the MK4 to MK4S connectivity update.

Upgrading

Opening the electronics

To start the upgrade, the printer's electronics need to be accessed. Open the xBuddybox-cover and the El-box-cover. Set them aside as they will be used again later. Remove the Heatbed-cable-holder, the Wifi-cover, and the ESP board. They will not be used anymore.

Assembling

Assemble the Wi-Fi, and install it on the x-Buddy.

Connect the NFC antenna by fitting the connectors together and pressing lightly until you feel a click.

Prepare the NFC coil.

Install the NFC coil on the new Electronics box cover. Then connect the NFC coil cable to the board by fitting the connectors together and pressing lightly until you feel a click.

Attach the cover to the xBuddy Box with two M3x10 screws.

Arrange the NFC coil cable to the rightmost side. Close the xBuddy box cover with four M3x6 screws.

You should be left with the old electronics box cover, the old Wi-Fi cover, the ESP-01S Wi-Fi module, and the heatbed cable cover. You can discard them or use them in other projects.

Original Prusa MK3.5S

Assembly manuals

Original Prusa i3 MK3S/MK3S+ to MK3.5S upgrade (1.0)