THEOS 1.1.0 Release

Dear Supporters,

Over the past four weeks, I worked on integrating some pretty advanced klipper features into THEOS. Some of them you already saw here on Patreon in Action. Below is an overview of the latest developments:

🚀 New THEOS Features

This Release I focused on enhancing the Documentation to make it easier to install THEOS, Flash the Firmware to all MCU's and Connect THEOS to your Wireless Network. Also I've added an Feature overview section on github to give new users an overview of all the Features THEOS is capable of over a Standard MainsailOS

⚙️ Klipper Enhancements

1. Smooth Input Shapers

One of the most exciting features I’ve recently added to THEOS is the integration of Dmitry Butyugin’s Smooth Input Shapers. By introducing an S-curve component to conventional Input Shaping, these shapers help minimize mechanical stress at the start and end of movements, enabling higher maximum accelerations before the gantry stalls. Compared to the traditional input shapers this new implementation allows between 35-65% highers accelerations in the TEST_SPEED macro.

2. Synchronizing Extruder Motion with Input Shaper

In the standard implementation of Input Shapers, Klipper does not relay the movement adjustments made by the input shaper to the extruder. As a result, various artifacts can emerge—such as over- or under-extrusion—at the beginning or end of each extruded line. Traditionally, higher pressure advance values were used to compensate for this issue. However, by synchronizing extruder motion with the input shaper, the required pressure advance can be reduced from 0.03 to 0.021 without sacrificing surface quality. Lowering pressure advance also lessens stress on the extruder, enabling faster print speeds before the extruder itself becomes a limiting factor.

3. Non-linear Pressure Advance

In Klipper’s standard implementation, the pressure inside the hotend is assumed to increase linearly with speed and acceleration of the extruded filament. However, in practice, as printing speed goes up, the required pressure advance (PA) actually decreases. Setting PA too high at elevated speeds can itself introduce artifacts, degrading print quality.

With Non-linear Pressure Advance, you can define both a linear and a non-linear component for PA, paired with a damping function. This approach dynamically reduces the PA value at higher speeds. On my T250 printer, I have not observed a significant advantage over the linear approach—likely because it employs a very short Bowden tube within a direct-drive extruder. On the other hand, printers that use longer Bowden setups like the T100 benefit greatly from Non-linear Pressure Advance, seeing more consistent extrusion at higher speeds.

4. Sensorless Homing

I’ve introduced a dedicated setting for sensorless homing acceleration, allowing you to home at a specific acceleration instead of relying on your printer’s maximum acceleration. This leads to more consistent and reliable homing results. Additionally, the second homing pass now uses the same speed as the first, further enhancing the overall consistency of sensorless homing.

🧩 Configuration Improvements

1. Enhanced TMC Automatic Tuning Mode

I’ve introduced dedicated constants for all key TMC parameters, allowing you to lock specific values during the tuning process for more predictable performance. These parameters apply to both two-motor and four-motor configurations for the X and Y axes. The full set of parameters includes:

• xy_driver_TBL

• xy_driver_TOFF

• xy_driver_HSTRT

• xy_driver_HEND

• xy_driver_TPFD

• xy_driver_CS

2. Added Support for Auxiliary Fan Control in Orca Slicer

I’ve updated the definition of Auxiliary Fans to ensure full compatibility with Orca Slicer. Now, by enabling the Auxiliary Fan setting in Orca Slicer’s Printer Definition, you can customize the Auxiliary Fan speed for each filament profile directly within the slicer.

3. Fine-Tuned Configuration for the T250 Printer

I’ve refined the T250 configuration to include Smooth Input Shapers, an optimally tuned extruder motor setup, improved pressure advance settings, and an upgraded BD sensor configuration. I also enhanced the PRINT_START macro to minimize waiting times by leveraging G-code directives. The macro now checks whether the printer is already calibrated and, if so, automatically bypasses any unnecessary steps.

🛠 Try THEOS Today

I’m excited to announce the release of THEOS v1.1.0!

👉 Download THEOS v1.1.0

Thank you for your continued support and feedback. Your contributions make these advancements possible. Stay tuned for more updates on the T250 and THEOS – more features and improvements are on the way.

Best regards
Matt