What will it do?

My machine will extrude and 3d print consumer objects made from clay. Ideally, clay bricks and clay components for architecture.
This project is intended to provide a viable extruder head for 3d printing in clay. My main focus will be the extruder assembly, and motion control will be provided by Kuka KR10 robotic arm or a KR30. If there’s time, I will build a 3 axis gantry CNC machine.

Who's done what beforehand?

There are several projects that have done this. The first one that inspired me was fabclay by students starsk lara + nasim fashami + sasha jokic on IAAC. This machine just uses pneumatic pressure from a compressor. Another very good reference is CBA’s own Jake Read, who did the Claystack machine. From Mr Read's design I have learned a lot particularly regarding aluminium chassis and machining tolerances and ideas. Also, there's potterbot, which is one of the designs that use plungers for pressure. Potterbot uses real clay instead of slip which is watered down clay. Extruding clay is much harder because you need a lot of force to compress the material. There's an open source kit that is just the extruder, which has both a plunger system, but it also has an auger pushing system. This was made by a company named Stoneflower3D . Further, theres's one that uses earth materials and needs a lot of force, hence it uses a hydraulic actuator again, by IAAC

What will I design?

The whole extruder assenbly will be based of on other projects, however I will adapt it to available parts to me. My specific contributions will be:

• 1. A custom interchangeable extruder head that has a moveable trowel controlled by a stepper motor.
• 2. A universal mounting system for attaching device to Kuka KR30, KR10 and KR150 robotic arms.
• 3. A control system to talk to the Kuka robots. I’ll start with the KR10 as it’s the easiest robot to connect to. Kuka control needs to be pre-programmed for now for simplicity.

Also, to get things organized I have developed categories or assemblies that will be useful in developing the project.

• 1. Trowel extrusion mechanism
• 2. Screw/auger clay pusher
• 3. Plunger/pressure system assembly

Materials and Components

This is the current Bill of Materials (BOM). It details vendors, price, and quantities. Will be updatedd as the project progresses.

What parts and systems will be made?

I have set up several systems that I will make:

• 1. Extruder feeding system based on an auger and plunger or syringe pump. This assembly will have a plunger type extrusion system based on 3d potter assembly. Clear Acrylic tubing will allow to see the mixture of the paste. Plunger will be 3d printed first to prototype. NEMA 23 motor will be used. It’s the biggest NEMA with integrated lead screw I could find.
• 2. Extruder trowel nozzleassembly for contour crafting. This assembly will feature a small stepper motor that will control rotation of a 3d printed trowel. This trowel will give the printing process a unique look that has not, to my knowledge, been made with clay.
• 3. Chassis assembly to hold it all together using CNC milled ¼in aluminum. This chassis assembly will hold all the bearings and motors in its place.
• 4. Control system for all parts. I’ll have to provide a way to securely control both motors(trowel and plunger) . The stepper motors will not be a problem, however my main concern is the communication with the Kuka control unit. This will be done using the robot’s digital outputs, which hopefully will be an easy way of connecting to the kuka control unit.

What processes will be used?

I will mainly use 3d printing and CNC machining for the custom parts of the chassis and the trowel assembly. I will have to make a breakout board for the kuka side, and then make the controllers and drivers for the motors. Hopefully the stepper drivers will be easy to make using PCB milling.

I may have to use molding and casting for the trowel heads. If not, then I will make the trowel heads by 3d printing and mold and cast a housing for electronics.

2D design: files for the CNC machining, templates and logos for stickers.
3D design: the whole assembly will have to be modelled. Some parts parametrically.
Additive processes: 3d printing trowel parts, bearings and some connectors
Subtractive processes: CNC milling of chassis assembly.
Electronics design and production: design and produce boards for control of motors, maybe sensors or encoders.
embedded microcontroller interfacing and programming. Programming controller to interface with kuka robot. Application for generating gcode or shapes perhaps???

What questions need to be awnsered?

I will need to awnser many questions regarding the whole project. These are the ones I have now:

• What is the best clay to use?
• What is the best and easiest way to connect to the Kuka Robotic arm?
• What is the best method, air pressure and auger pusher, or plain plunger and tube assembly?
• How will turns and rotations of the trowel will be handled?

How will it be evaluated?

Bottom Line, the success of this projecct is to get a 3d printedd clay object that is usable. Further credit or success would be to hace consistent printing and characterization of the settings to print quality prints. Extra success would be to actually have it used by others in the lab.