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Original Prusa i3 MK3/S/+ to MK4S upgrade kit
$ 649.00
Why our prices differ from Prusa
We have already paid the customs, duties, tariffs.
We make things that work better and last longer. Our products solve real problems with clean design and honest materials.
Shipping is already included in our prices.
We make things that work better and last longer. Our products solve real problems with clean design and honest materials.
Compatible Accessories
Why is our price different than buying direct from Prusa? Click here to read our article on our pricing.
This is the full upgrade that also contains the MK4’s new X/Y precise motors (400 steps, 0.9°per step). It’s the most expensive of all three, but last time you voiced your interest in a full MK2->MK3 upgrade pretty strongly, so we decided to give you a full MK4 upgrade as well. :-)
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
| MK3.5S upgrade | MK3.9S upgrade | MK4S upgrade | |
| High-Performance 360° Cooling |
No |
Yes | Yes |
| High-Flow Nozzle |
No |
Yes | Yes |
|
Build volume |
250 x 210 x 210 mm | 9.84 x 8.3 x 8.3 in | 250 x 210 x 220 mm | 9.84 x 8.3 x 8.6 in | 250 x 210 x 220 mm | 9.84 x 8.3 x 8.6 in |
| Mainboard | Custom 32-bit xBuddy electronics with STM32 | Custom 32-bit xBuddy electronics with STM32 | Custom 32-bit xBuddy electronics with STM32 |
| Stepper Drivers | Trinamic 2130 | Trinamic 2130 | Trinamic 2130 |
| Stepper motors | Regular 1.8° X,Y stepper motors | Regular 1.8° X,Y stepper motors | Precise 0.9° X,Y stepper motors (prevents VFA) |
| MMU3 support | Yes | Yes | Yes |
| Extruder electronics |
No |
Custom breakout board for connecting fans, thermistors and other parts. | Custom breakout board for connecting fans, thermistors and other parts. |
| Filament path | Aluminum heatsink, all-metal hotend | Aluminum heatsink, all-metal hotend | Aluminum heatsink, all-metal hotend |
| Drive system |
Direct drive |
Nextruder Planetary Gear System, 10:1 gearbox ratio | Nextruder Planetary Gear System, 10:1 gearbox ratio |
| First layer calibration | Manual adjust Z | Fully automatic (thanks to the Load Cell sensor) | Fully automatic (thanks to the Load Cell sensor) |
| Quick-Swap nozzle system |
No |
Yes | Yes |
| LCD screen | 3.5″ graphic 65k color screen | 3.5″ graphic 65k color screen | 3.5″ graphic 65k color screen |
| Bed calibration |
Automatic, Mesh Bed Leveling |
Automatic, Mesh Bed Leveling (only on print area) | Automatic, Mesh Bed Leveling (only on print area) |
| One-click Printing | Yes | Yes | Yes |
| Status LEDs | Yes | Yes | Yes |
| Input shaper | Yes | Yes | Yes |
| Filament Sensor |
Yes (IR) |
Yes (built-in Hall sensor) | Yes (built-in Hall sensor) |
| Loadcell sensor |
No |
Yes | Yes |
| Advanced sensors |
3 thermistors + SuperPINDA, fan RPM sensors |
Filament sensor, Loadcell sensor, Power panic, 4 high-precision thermistors (genuine Semitec) + fan motors RPM monitoring | Filament sensor, Loadcell sensor, Power panic, 4 high-precision thermistors (genuine Semitec) + fan motors RPM monitoring |
| Power panic | Yes | Yes | Yes |
| Ethernet connection | Yes | Yes | Yes |
|
Wi-Fi connection |
Yes | Yes | Yes |
| NFC connection | Yes | Yes | Yes |
| Prusa Link | Integrated | Integrated | Integrated |
| Print medium | USB drive / LAN / internet via Prusa Connect | USB drive / LAN / internet via Prusa Connect | USB drive / LAN / internet via Prusa Connect |
| Firmware update interface | USB drive | USB drive | USB drive |
|
Kit price |
249 USD / 279 EUR (VAT incl.) | 499 USD / 549 EUR (VAT incl.) | 579 USD / 639 EUR (VAT incl.) |
Frequently asked questions
What is the return policy?
Our goal is for every customer to be totally satisfied with their purchase. If this isn’t the case, let us know and we’ll do our best to work with you to make it right.
Are any purchases final sale?
We are unable to accept returns on certain items. These will be carefully marked before purchase.
When will I get my order?
We will work quickly to ship your order as soon as possible. Once your order has shipped, you will receive an email with further information. Delivery times vary depending on your location.
Where are your products manufactured?
Our products are manufactured both locally and globally. We carefully select our manufacturing partners to ensure our products are high quality and a fair value.
How much does shipping cost?
Shipping is calculated based on your location and the items in your order. You will always know the shipping price before you purchase.