Prusawire 2025.B1.1 (BETA 1.1) Square Nut Hot Fix

What Makes a Prusawire?

• A Prusawire must contain the following elements:
  • Core XZ motion system
  • Linear rods on Z
  • Linear rail on X
  • F623 bearings
  • Panels covering wiring

3D Viewer

You can now view the full Prusawire assembly from within your browser!
No CAD software required.

Go to the 3D Viewer

Who This Printer is For

Pick one of the following:

• You have an old MK3, MK3S, or MK3S+, and you want to teach an old dog new tricks and are on a budget
• You upgraded from MK4S to a Core ONE, and have a leftover frame. You are okay spending money on building a new printer with that hardware.

Additionally, the following says this printer is for you: 

• You want to take your first steps into RepRap beyond Prusa, and Voron is an exciting route.
• You are comfortable working from a CAD file as your build guide
• You respect the Frankenstein-y nature of this April Fool's joke printer

Want to Support the Project?

First of all, a big thanks to everyone who has built the project. Ella Fox mostly self-funded her build with support from Levendigs and LDO Motors. I was graciously given a MK3 by KB3D and have mostly used hardware I had on hand.

• Buy me a Ko-Fi - Ella's Kofi
• Support Positron3D to fund future endeavors

Build Volume

• X: 250mm
• Y: 210mm (220mm for Core ONE build plate)
• Z: 185mm

Technical Support

Prusawire, technically, does not count as a Voron Switchwire. We ask you kindly not to nag the Voron Design team for technical support.

Instead, please join the Positron3D Discord for support with your build, and maybe share your progress over there too.

Serial Numbers

We are accepting serials over on the Positron 3D Discord. Please submit your request to the #prusawire-serial-request channel over there.  

As of September 21st 2025, there are 7 issued serial numbers.

Bill of Materials

An almost complete BOM is now available. We will continue to update it with suppliers as time permits.

Link to BOM

KB3D BOM Hardware / Fastener Kit - Prusawire - Beta 1 (Affiliate Link)

West 3D BOM Fastener Kit (Affiliate Link)

Upgrading the Einsy Rambo to Klipper - Read this!

Installing Klipper on the Einsy Rambo board is possible, with extra steps. Follow the guide published by the awesome folks at MyRigs3D! We recommend Method 2.

Github Links

All documentation and links will be found on out Prusawire Github

Please check out the GitHub Klipper repository for a convenient starting point for getting setup with Klipper.

Credits

Many thanks to all the awesome people and companies that have made this possible. Notably:

• Prusa Research - Cheers, Josef and the team for the MK3/4 platform on which this was built upon!
• Voron Design - Switchwire
• Positron 3D Team - Too many to name, you know who you are <3
  • Early development team:
    • Nomad's Galaxy
    • Koosh
    • Birb
• Jason @ LDO Motors - Part sponsorship
• Levendigs - Part sponsorship 
• KB3D - MK3 Sponsorship, Filament Sponsorship, and the best stickers
• Early access testers:-
  • Killa_Prints
  • LinksLab
  • Safe
  • Silicon
  • TheNexusAvenger
  • torsten

Release and Revision History

• Ella released Beta 1 on July 27th, 2025.
• Safe releases Beta 1.25 on September 22nd 2025.
  • Fixes square nut thickness issue
  • Adds links to KB3D hardware kit
  • Adds links to Prusawire Github for Hardware

FAQs

I have been answering a number of questions with a high frequency. Here are some of them:

• How much is it going to cost to build Prusawire
  • This depends upon where you are starting
    • For a Prusa MK3/3s/3s+ the current estimate is the Prusawire will require $200-300
    • For a Prusa Mk4/4s the current estimate is $250-350
    • When building the Prusawire from the spare parts obtained during the Mk4S to Core 1 upgrade is $400-500. 
• What's the thing behind the toolhead?
  • It's a door puller/Keyback that's used to hold the gantry up
• Why use Stealthburner?
  • The decision to use the Stealthburner toolhead stems from a number of considerations some of which are as follows:
    • Cost - When starting from the MK3, SB with CW2 is the least expensive toolhead
    • Ease of Assembly - for beginners SB is a very forgiving toolhead
    • Classy Printer - I don't think anyone will argue that SB looks clean and iconic.
  • A number of folks have complained about using the SB and its performance with PLA.
    • As of writing there is a very good profile issued by Ella which performs great without any tuning. 
• How long should it take to build?
  • Assuming you start with a completely disassembled MK3, you should allot 6-8 hrs to build this printer assuming this is your first DIY printer. Note that this does not include the Klipper configuration and tuning.
• Why no multi color system?
  • As of right now, the current development goal is to provide a better build experience. If you wish to add one of the many wonderful systems, go for it.
• Why does the toolhead sickout so much
  • To provide enough clearance for the tall Stealthburner, the X carriage was extended. thus far it has not proven to be too big of an issue. The goal of the Prusawire is to be a fun build, not to be the most rigid machine.
• Can I print my parts from PETG?
  • It's possible you can print your parts in PETG, though it's not recommended. PETG has a tendency to deform under sustained stress and temperature. The non-structural parts can be printed in PETG though.