Large Ceramic 3D Printer

In the fall of 2019, the professor who worked with me on the small ceramics printer got a grant for us from her department to build a large-scale 3D printer for ceramics and various other types of materials that can be made into a consistent paste form (take paper pulp as an example). With the experience I gained from working on the small printer, I came up with a design mostly from scratch, with some inspiration drawn from some pre-existing ceramics 3D printers (mainly the printers from WASP). With a bill of materials, we ordered some essential parts and started building version 1. I also invited Jacob Sorscher E'21, a friend of mine who is also a mechanical engineering major, to join the team.

By the time both of us graduated, we have completed the mechanical build, the electronics system, the initial firmware configuration, and a few semi-successful test prints. While we were unable to deliver the printer as a complete project, we hope that with the foundation we built, future students could quickly get up to speed and make large, beautiful ceramic prints with it.

The Design

Fall 2019

I started by making some preliminary sketches on my iPad. One of the largest issues we have on the small ceramics printer is that if the power is cut off or a soft reset is triggered, the motors will be allowed to spin almost freely; with the weight of the extruder filled with clay, the print head will fall and hit on the unfinished print on the build plate. So after some thought I decided to replace the timing belt with a long lead screw.

I also decided to build the main frame with 8020 aluminum extrusions and 6061 aluminum plates made by online waterjet services. Here's a link to the bill of materials I created that are still under minor revisions.

Design sketches

CAD renderings

Initial Fabrication

February 2020

To reduce the overall cost, we ordered 6 feet 8020 aluminum extrusions and machined them to desired conditions ourselves. Mainly, we used the band saw to cut the horizontal and vertical short pieces, drilled large holes on the side for the anchor connectors, and tapped the ends of the rails with 1/4''-20 keys.

Single Axis Test

February 2020

Partial tests are a necessary step in the prototyping process. Therefore, I quickly assembled a small portion of the printer's mechanical structure - a single axis with one lead screw mounted with one NEMA 23 Motor. I uploaded the Marlin firmware to the electronics board, wired up one-third of the printer, and did some quick calibration tests to make sure the mechanical design is working. I also tested the motor's strength by attaching appropriate weights to the axis (about half of the expected load, which in the final design will be split between 3 identical axis). Based on the initial test, the design proved to satisfy out requirements.

Initial load test

Assembly Test

March 2020

We recently assembled the main structure for the first time. We have not yet placed the orders for the aluminum plates, and are substituting the aluminum plates with laser-cut plywood of the same thickness as temporary placeholders. This way we can double-check to make sure that the design does not have any major flaws when we place the big money order for custom fabrication.

As a comparison, my height is about 5'8'' :)

What the printer looks like in March 2020 right before school closed due to pandemic

FEA Analysis

March 2020

After completing the assembly, we decided to add more supporting structure to the main frame in order to make the printer more stable. To find out what structure does the best job, we created a simplified model in SolidWorks and ran some preliminary FEA analysis on the structure coupled with different support structures. For each scenarios, we added both torsional and horizontal load for a more well-rounded evaluation.

FEA results - original design

FEA results - long cross beam on the side

FEA results - side panel on the top

Metal Plate Fabrication

January 2021

We finally got access to continue working on the printer after the lockdown. The first thing we did was to double-check the design and ordered aluminum structural plates from BigBlueSaw in 0.25'' 6061 aluminum. after a few weeks of waiting, the plates arrived, and we immediately started assembling the main structure.

Tapping and counter-sinking the metal plates

Wiring up the Electronics System

Assembling the extruder

Sheet metal cover fabrication