Jump to content
UltiMaker Community of 3D Printing Experts

How can I define extruder endstops?


Recommended Posts

Posted · How can I define extruder endstops?

Hi everyone!


Before I start off:  I am working with an UM2+, Cura 4.3.0 on Windows 10 and the tinkergnome UM2+ firmware.


I am currently working on a university project. The aim is to convert the regular UM2+ into a printer which can do both regular and bio-printing (bio-printing is in short words the printing of hydrogel in which you can implement cells, so you can print organic material in every desired form). To achieve this I already designed and printed a syringe pump which is driven by more or less the same stepper motor the current extruder is using. This makes it possible to switch from regular to bioprinting by unplugging the extruder motor and plugging in the syringe pump. This leads to my question: In order to keep the syringe pump from crashing every time the syringe gets empty, I want to include two endstops for the extruder motor. I already took a look into TinkerGnome´  s Firmware and I could imagine that it should be possible to include the endstops within the definition of the regular endstops. The desired reaction would be to pause the current print until the material "is changed".

What I am asking for at this point is experience. Has anyone ever tried to do this and could maybe even help me out with some code advises? I have some programming experience, but mostly with Java and Python so I could really use some help. Especially as the firmware is pretty huge and I am not sure which files have to be edited to make this work. Also I am not entirely sure how to compile and upload the edited firmware. I tried setting up the regular Marlin firmware (the way it was explained in a YT tutorial) but all I got was a huge bunch of errors on the Arduino IDE, mostly Index out of bounds... 

I know I am asking for a lot and I could totally understand if nobody is willing to put that much effort into a stranger´  s project. But I promise if you can help me and I should ever run into you in real life I will buy you a couple of beers!


  • Link to post
    Share on other sites

    Posted · How can I define extruder endstops?

    By the way, I also discovered that there is an option to include "virtual endstops".  This sounds like a pretty good solution as well, especially as the hardware modification would not be needed anymore. If this means I have to sacrifice a little bit of extra safety I would be fine with it.

  • Link to post
    Share on other sites

    Posted · How can I define extruder endstops?
    3 hours ago, properN00b said:

    The desired reaction would be to pause the current print until the material "is changed".


    Detection of endstops is usually disabled during printing, but this sounds very similar to a simple "filament end detection".

    Support for such a function was added to the tinker-firmware in 2015. This would need a simple switch that connects two pins on the Arduino board when the syringe reaches its end position.

    It was originally meant to be used with a more complex sensor, but it turned out that this was all what it needs:



    There are some instructions and pictures about the cable connections as well - and it's easy to test with a (pair of) wire.


    The firmware does not do much more than this part:



    Hope that helps!


    • Like 1
    Link to post
    Share on other sites

    Posted · How can I define extruder endstops?

    Finally got to try it out and it does exactly what I hoped for. I really start loving your firmware more and more. It´  s also great to see that much support in the community. Big ups to you!

    • Like 1
    Link to post
    Share on other sites

    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now
    • Our picks

      • UltiMaker Cura 5.3 stable released
        In this stable release, Cura 5.3 achieves yet another huge leap forward in 3D printing thanks to material interlocking! As well as introducing an expanded recommended print settings menu and lots of print quality improvements. Not to mention, a whole bunch of new printer profiles for non-UltiMaker printers!
          • Thanks
          • Like
        • 21 replies
      • Here it is. The new UltiMaker S7
        The UltiMaker S7 is built on the success of the UltiMaker S5 and its design decisions were heavily based on feedback from customers.
        So what’s new?
        The obvious change is the S7’s height. It now includes an integrated Air Manager. This filters the exhaust air of every print and also improves build temperature stability. To further enclose the build chamber the S7 only has one magnetically latched door.
        The build stack has also been completely redesigned. A PEI-coated flexible steel build plate makes a big difference to productivity. Not only do you not need tools to pop a printed part off. But we also don’t recommend using or adhesion structures for UltiMaker materials (except PC, because...it’s PC). Along with that, 4 pins and 25 magnets make it easy to replace the flex plate perfectly – even with one hand.
        The re-engineered print head has an inductive sensor which reduces noise when probing the build plate. This effectively makes it much harder to not achieve a perfect first layer, improving overall print success. We also reversed the front fan direction (fewer plastic hairs, less maintenance), made the print core door magnets stronger, and add a sensor that helps avoid flooding.

        The UltiMaker S7 also includes quality of life improvements:
        Reliable bed tilt compensation (no more thumbscrews) 2.4 and 5 GHz Wi-Fi A 1080p camera (mounted higher for a better view) Compatibility with 280+ Marketplace materials Compatibility with S5 project files (no reslicing needed) And a whole lot more  
        Curious to see the S7 in action?
        We’re hosting a free tech demo on February 7.
        It will be live and you can ask any questions to our CTO, Miguel Calvo.
        Register here for the Webinar
          • Like
        • 18 replies
      • UltiMaker Cura Alpha 🎄 Tree Support Spotlight 🎄
        Are you a fan of tree support, but dislike the removal process and the amount of filament it uses? Then we would like to invite you to try this special release of UltiMaker Cura. Brought to you by our special community contributor @thomasrahm
        We generated a special version of Cura 5.2 called 5.3.0 Alpha + Xmas. The only changes we introduced compared to UltiMaker Cura 5.2.1 are those which are needed for the new supports. So keep in mind, this is not a sneak peek for Cura 5.3 (there are some really cool new features coming up) but a spotlight release highlighting this new version of tree supports.  
          • Like
        • 22 replies
    • Create New...