PitStop 2 Extruder

The 3D printer extruder with quick-swappable hotends.

Last updated on June 28th, 2022.

Project Status

This project is older and not under development anymore.

The last version of this project was in Beta stage, accessible to my Patreon supporters.

Printer Support

Due to the extruder layout, printers require frame changes in order to use the full build volume.

Supported printers:

  • Prusa MK3(S+) with adjusted Bear frame.
  • Ender 3 and CR-10 V2 (and mounts for a few other Creality printers can be added).

For the far future I intend to switch to a custom printer frame for the extruder and support for the printers above will be very limited.

Hotend support

Several hotends are supported already:

  • V6
  • Volcano
  • BMO
  • Rapido HF
  • Rapido UHF

Is it for you?

Yes, if:

  • you own or can buy multiple hotends;
  • you want to swap hotends when they require maintenance, so the printer can keep running;
  • you don’t mind modifying your 3D printer significantly;
  • you use various nozzle sizes;
  • you have experience sourcing parts and modifying 3D printers;
  • you like tinkering with your 3D printers;
  • you’re comfortable identifying and fixing issues on your 3D printers without assistance;
  • you like the project despite it not being actively developed.

No, if:

  • you don’t have time or experience sourcing parts and modifying your 3D printers;
  • you’re after improving printing speed and want a lightweight extruder;
  • your printer works great and don’t want to risk making it worse;
  • you have a favorite extruder already;
  • you’re looking for a drop-in extruder replacement;
  • you need reliable printers and don’t want to spend time debugging potential issues;
  • you only use one nozzle size (per printer);
  • you require long-term support for the extruder;
  • your extruder and hotend are reliable and never had issues with them.


No runout sensor integrated in the extruder (can still use a filament sensor mounted on the frame). I might add support for a runout sensor at some point.

This extruder uses a full size motor (not geared) which makes it heavy compared to some other extruders. This aspect will be addressed with the future PitStop 3.

Due to the flat back mounting, compatibility requirements for the EngineSwap, and full size motor, there’s a significant nozzle offset compared to other extruders, further away from the carriage. This means that printer frames need to be altered in order to use the entire build volume, and motion problems can be amplified by this offset. These will be addressed in a future version.

This extruder is not backwards compatible with PitStop 1, and PitStop 3 will likely not be compatible with PitStop 2, requiring further frame adjustments.

Why I designed this extruder

PitStop 2 is a 3D printer extruder designed from scratch, featuring quick-swappable hotends. It’s part of the larger EngineSwap project that makes automatic hotend swapping for affordable multi-material printing without the typical waste. It also aims at hotend management and is designed to integrate with may 3D printer models. While the EngineSwap project is nowhere near completion, it is under active development and I designed the PitStop 2 extruder specifically for it. Many 3D printing enthusiasts have shown interest in the PitStop 2 as a standalone extruder due to its ease of swapping hotends and therefore nozzles, reason why I’m releasing it. The project is NOT under active development as I'm already working on a newer design. I’m the sole developer of the project.