Micron Precision Printer

2024 – 2025 Senior capstone ±1 µm target Mesa + LinuxCNC

Overview

A senior capstone build of a research grade 3D printer targeting ±1 micron. Preloaded ground ball screws, 1 micron linear scales, and high torque steppers under LinuxCNC. A pneumatic extruder lays down a silver filled polymer, so it can print conductive traces onto the part.

My team handled the XYZ stage, so the materials group could focus on the printing itself.

My contributions

I designed and implemented the electrical and control hardware: the Mesa 7i96 and 7i85 stack, the stepper drivers, the encoder and linear scale inputs, the limit switches, and the pneumatic valve control, plus the diagrams the team built from. Ferrite beads and a star ground layout keep the noise down, which matters at this level of repeatability.

Block diagram of the control signal chain, from the Raspberry Pi through the Mesa cards to the stepper drivers and back from the linear encoders — The control signal chain: a Pi 5 into the Mesa 7i96 for step and direction out to the DM556T drivers, with the linear encoders coming back through IBV 650 interpolators into the 7i85.

Schematic of the encoder output connections: three RELM linear scales through IBV 650 interpolators into the Mesa 7i85 — One sheet of the set: just the encoder output connections, three RELM linear scales through their IBV 650 interpolators into the Mesa 7i85.

Technologies

LinuxCNC on a PREEMPT-RT kernel
Mesa 7i96 motion controller
Mesa 7i85 encoder board
C5 ground ball screws, zero backlash nuts
Heidenhain 1 micron linear scales
DM556T stepper drivers at 128x microstep
Pneumatic extrusion of conductive polymer

Results

What it did

Test moves confirmed ±1 micron repeatability over 100 mm of travel, and the printer deposited conductive traces successfully.