Original Prusa i3 MK3/S/+ to MK4S upgrade kit

Before you order the upgrade, please check which PSU your printer came with and which version of the heatbed connector is installed. This kit only works if you have the black power supply and not a silver power supply. Your heatbed must have screws and is NOT solder on.

This product is supplied as a kit - you must assemble it yourself!

Printed parts are NOT included! Please print them before you disassemble your MK3S/+! The filament is included in the upgrade package.

Important: The black injection-molded spool holder is not part of the upgrade package. If your printer didn't come with it (early revisions of MK3), you can purchase it here.

Here is a closer explanation of the difference between the MK3.9 and MK4 upgrade packages: the only difference is in the stepper motors. The MK4 uses higher-precision stepper motors that help eliminate VFA (Vertical Fine Artifacts) – these are tiny surface artifacts that are visible if you closely inspect a printed object. In other words, the motors in the full MK4 upgrade are the cherry on top – if you’re chasing the highest possible level of quality, they will come in handy.

This product includes:

• 32-bit xBuddy board (same as MK4)
• Metal xBuddy case (and cover)
• xLCD screen (same as MK4)
• Nextruder parts (including E motor)
• Cables for Nextruder, Heatbed, xLCD
• 10 mm smooth rods (Z-axis)
• X/Y/Z motors
• Expansion joints for Heatbed
• New belts for X & Y axes
• Fasteners and other accessories
• PCCF printed parts
• Injection molded parts (PG cover and xLCD cover)
• WI-FI module
• NFC module
• High-Performance 360° Cooling Fan and Fan shroud
• High-flow Prusa CHT nozzle - 0.4 mm

Parts kept from your MK3S/MK3S+

• Frame and extrusions (new MK4 has just a different look)*
• PSU** (same wattage/voltage as MK4)
• Heatbed MK52 24V (thermistor and power cables will be changed) *
• X/Y rods and bearings

*Frame and heatbed are not included upgrade, because replacing these parts brings no funcional advantage and would only increase the price of the upgrade. If for some reason you still want a new frame (it has hexagons on the other side), it will be available on the eshop as a spare part.

MK3S/+ Upgrades Comparison