At Actuonix, we often see our actuators turn up in applications we never originally designed them for, and 3D printing is a good example. Most of the attention in a printer goes to the obvious motion: the print head crossing the bed and the platform shifting on the Z axis one layer at a time. Running alongside that are smaller motion jobs that only get noticed when a print goes wrong.
Two of them stand out. One controls material feeding. The other keeps the build surface level. Neither looks like much, but if either one is inaccurate, the part is ruined. That is why both require precise, repeatable motion.
Use of Actuators in Material Feeding Control
Most desktop printers pull a single filament through a single extruder, and that setup is relatively simple to drive. Production lines and multi-material machines are more complex. They often use more than one feeder to print multiple materials in the same job.
On one customer build, the feeding system used two PQ12 micro linear actuators, one per feeder, with each actuator driven independently to select from one of two materials during printing.
That independent actuation is what makes multi-material printing practical. Each PQ12 controls its own material feed path, moving material into the feed path when required and retracting it when another material takes over. A shared drive can only present material according to a fixed mechanical sequence. Using a dedicated actuator for each material feed allows the printer to select the required material in any order without relying on a shared indexing mechanism.
The PQ12 earns the role on size and control, not force. A few reasons it fits a feeder include:
- It is the smallest and lightest unit Actuonix builds, so a pair adds minimal mass.
- The slim body allows two actuators to sit side by side in a compact assembly.
- Each actuator is a complete, self-contained motion device rather than a motor that needs separate mechanical packaging.
- The position feedback option makes every feed stroke repeatable, helping each cycle deliver consistent material movement.
Actuators in Automatic Bed Leveling
A heated build plate is never perfectly flat, and it does not stay fixed during operation. Thermal expansion, a slightly bowed sheet, or a thumbscrew that loosens over time can all change the gap between the nozzle and the build surface.
Manual leveling with a feeler gauge or a sheet of paper can work for one print. It does not hold up as well across repeated jobs. More importantly, it is less reliable and more time-consuming than automatic leveling.
Automatic bed leveling removes the manual adjustment from that process. The printer checks the plate at multiple points, records the height variation, and uses those readings to maintain a consistent nozzle gap. On machines that physically correct the bed rather than compensating only in firmware, small actuators mounted under the platform raise or lower the bed corners on command. These corrections are small and repeated constantly, so the actuator has to return to the same position without drifting.
This is where a stepper actuator has an advantage over a geared DC unit. The Actuonix S20 resolves motion in steps from 0.01 mm down to 0.3 microns with micro-stepping and holds its position when power is removed, provided the applied force remains below the back-drive force rating on the datasheet. This helps keep each bed corner exactly where the firmware placed it.
What a leveling actuator really needs comes down to a short list:
- Step resolution fine enough that a correction does not overshoot.
- Position holding with power off, so the bed does not creep during a print.
- A 100 percent duty cycle, since correction may continue through long print jobs.
- A compact body that fits under a crowded build platform.
The S20 covers all four. If the bed assembly is heavier, the P8 stepper provides even finer precision with more force in reserve.
Related Article: How Precise Are Micro Linear Actuators?
The Motion You Never See on a Spec Sheet
Material feeding is one 3D printing application we have supplied directly, but it is not the edge of the list. A printer can hide motion in many other places, including filament cutters, tool changers, automated part removal systems, and enclosure vents. If you want the groundwork on the components themselves, our explainer on how linear actuators work covers the basics.
The Actuonix comparison chart also lines up every model by force, speed, stroke, and control type. If something in your build has to move a short distance with precision and keep doing it reliably, there is a good chance one of our actuators already fits. If you are not sure which model is right, it is worth a conversation before committing the design to the wrong part.
Frequently Asked Questions
Will the heat from a heated bed damage the actuator?
It can if you mount it poorly. The S20 is rated for ambient temperatures up to 40°C and the P8 up to 50°C, while a heated bed surface can operate at much higher temperatures. Keep the actuator away from the hot plate using standoffs, shield it from direct radiant heat, and ensure it operates within its specified ambient temperature range. Within those limits, both actuators can run continuously at a 100 percent duty cycle.
Do I need position feedback, or will open-loop stepping stay accurate?
For most material feeding and automatic bed leveling applications, open-loop stepping is sufficient. The S20 and P8 hold position by counting steps and remain in position even when power is removed, provided the applied load stays below the actuator's back-drive force rating. If your application operates close to the actuator's maximum force capacity, consider adding an encoder or selecting a higher-force model to avoid missed steps.
How fast can these actuators move?
The PQ12 reaches speeds of up to 28 mm/s, making it well suited for the short, rapid strokes used in material feeding systems. The S20 and P8 stepper actuators prioritize positioning accuracy over speed, with movement determined by step frequency rather than a fixed linear speed. For automatic bed leveling, the required movements are extremely small, so precision is generally more important than maximum speed.
Can Actuonix actuators be used for other functions in a 3D printer?
Yes. Besides material feeding and automatic bed leveling, Actuonix micro linear actuators can be integrated into tool changers, filament cutters, enclosure vent systems, automated part removal mechanisms, and other compact motion systems where precise, repeatable linear movement is required.
Find the Right Actuator for Your 3D Printer Application
Whether you're designing a material feeding system, automatic bed leveling mechanism, tool changer, or another precision motion assembly, Actuonix offers compact linear actuators engineered for reliable, repeatable performance. Use our Actuator Selector Tool to find the right model, or contact our team to discuss your application or OEM requirements.
