PROJECT 03 / PROTOTYPING

Mini RASSOR

Additive manufacturing and bucket-drum design for a 15 kg excavation robot based on the 65 kg RASSOR rover.

Purpose

Mini RASSOR is a smaller version of NASA’s RASSOR regolith excavator, developed for educational programs. My work took components from printed prototypes through fit checks, assembly, and actuator testing.

My Contributions

3D printed ABS parts on Ultimaker printers and checked tolerances on wheels, chassis, bucket drum, and actuator housings.
Designed a 3D-printable bucket drum that reduced part count to seven parts and simplified assembly.
Revised CAD and reprinted parts to address warping and fit issues.
Designed a 3D-printable test rig for the T-shoulder actuator.

A bucket drum designed for 3D printing

The original Mini RASSOR bucket drum was not designed for 3D printing. I developed a printable version with four sections and seven printed parts, simplifying assembly and using the same material as the other components.

CAD model of the redesigned bucket drum — **Design:** A printable bucket drum divided into four sections and seven parts.

Completed white 3D printed bucket drum — **Built hardware:** The printed bucket drum, with spiral sections for collecting regolith.

Printing & fit checks

ABS prints could warp or shrink relative to the CAD geometry. I checked hardware and mating-part fits, adjusted the CAD, and reprinted components where needed.

Printed chassis with hardware installed — **Chassis:** Test fitting the printed chassis with hardware.

Printed wheel with actuator pod — **Wheel integration:** Checking the fit between the wheel and actuator pod.

Assembly

The bucket drum sections interlock through tabs bonded with PVC cement. The presentation documents the printed sections coming together into the assembled drum.

Interlocking tabs on printed drum sections — **Joining sections:** Tabs align the sections before bonding with PVC cement.

Assembled bucket drum standing upright — **Assembly:** Joined sections form the bucket drum.

Actuator testing

I designed a 3D-printable rig for the T-shoulder actuator. The team also set up a motherboard test bench to support component testing after assembly.

CAD model of T-shoulder actuator test rig — **Test fixture:** A purpose-built, 3D-printable rig for the T-shoulder actuator.

Actuator connected to electronics on the test bench — **Bench testing:** T-shoulder actuator and motherboard test setup.

Next project: IPEx Suborbital Flight Experiment