Fit the roll, reduce the bulk.
Earlier: The bag compartment was too small in some prototypes and larger than needed in others.
My direction: Refine the space around a commonly available bag roll, keeping the carry size as compact as possible.
Summer 2026 · Internship Project
DWG-003 · NYC INTERNSHIP · SUMMER 2026
Iris Pet Waste Collector
A twist-operated iris and integrated bag supply rethink pet-waste pickup for city walks.
INDEPENDENT CONCEPT & DEVELOPMENT RHINO CAD · 3D-PRINTED PROTOTYPING · FIT REFINEMENT
FIG 01 · PRINTED PROTOTYPE
SEC 01
A Different Kind of Pickup设计起点
LESS DIRECT CONTACT. MORE REASON TO CARRY IT.
What if you could place a tool over the waste, then twist?
A plastic bag separates the hand from dog waste, but not from the sensation of its warmth and shape. I wanted a compact alternative to the bulky scoops and tongs I had encountered—an object designed to belong on a city walk.
During my summer 2026 internship in New York, I independently developed the concept, mechanical interaction, form, Rhino models, and printed prototypes. The result is a working exploratory prototype with a manual iris and integrated bag supply.
WATCH THE PROTOTYPE Explore the design decisionsSEC 02
See the Twist真实操作
FIG 02 · DEMO AT 2× SPEED
White printed iteration. Pickup uses a substitute object, not actual dog waste. Silent video; action descriptions available in captions.
REAL PARTS. REAL HAND INPUT.
One rotary action drives the overlapping blades.
The camera-aperture-inspired opening makes the mechanism visible. Grip ribs give the fingers purchase and carry the same repeated geometry around the body.
WHY NO MOTOR?
I chose manual operation to avoid adding a motor, battery, and their associated weight and cost. The aim was a simpler tool designed around everyday carrying.
SEC 03
Refining the Interaction设计迭代
PACK SMALLER. MAKE THE ACTION CLEARER.
Each print raised another question about using it.
I was designing for an object that could be carried at the waist or in a pocket. That goal shaped the space for the bags, the opening action, and the connection between parts.
I used the prototypes repeatedly and passed them to colleagues for informal handling feedback. Their comments on the fit helped guide further adjustments.
Make the opening action clearer.
Earlier: A separate operating lever had to be turned to open and close the iris.
My change: Move to turning the outer grip directly. I wanted the action to read as “place it over, then twist.”
Balance release and retention.
Earlier: The connection could feel too loose or too tight; an earlier connecting structure also wore down with repeated operation.
My change: Revise the connection structure, then refine its mating features through printing and handling.
Retrospective account of prototype development. The selected prints below document the work; individual problem states were not photographed.
FIG 03 · PHYSICAL DEVELOPMENT
The white lever on the leftmost prototype shows the earlier control approach. I later moved to direct rotation of the outer grip.
A CLOSER LOOK / THE REFILL CONNECTION
How I judged the fit
The connection should stay attached while the product is carried, but still be easy to open for refilling. Too little resistance risks accidental release; too much makes opening difficult and risks damage if forced.
- 01 / OBSERVE
Try it, then ask.
I used the assembly myself, then let colleagues try it and tell me whether the connection felt too loose or too tight.
INPUT · MY USE + COLLEAGUES’ FEEDBACK - 02 / ADJUST
Change the contact geometry.
Revise the depth of the recesses and how far the matching protrusions extend, then print the revised parts.
VARIABLES · RECESS + PROTRUSION - 03 / CHECK
Use the next print.
Reassemble and try again, checking the feel against those two goals: staying attached during carrying and opening without excessive effort.
CHECK · INFORMAL HANDLING FEEDBACK
FIG 04 · WHERE I ADJUSTED THE FIT
WHAT I CHANGED
Small features. A difference felt by hand.
- A Recess depth
- The receiving geometry at the lower edge of the inner body.
- B Protrusion extent
- The matching geometry inside the removable bag compartment.
I adjusted these features together and judged the result in the assembled print. This drawing identifies the features in the current design.
DESIGN TAKEAWAY
The connection is part of the user experience. A CAD assembly alone could not tell me how the printed parts would feel to take apart and put back together.
SEC 04
Inside the Mechanism机构拆解
FIG 05 · EXPLODED CAD
NINE MODELED PARTS · FIVE FUNCTIONAL GROUPS
The mechanism shapes the object.
HOVER / TAP A PART TO HIGHLIGHT IT IN THE CAD
FIG 06 · IRIS DETAIL
FIG 07 · HOUSING CUTAWAY
Blue-gray: complete inner body. Bag supply is not modeled.
SEC 05
A Working Starting Point阶段成果
FIG 08 · LATEST APERTURE
FROM MY INITIAL QUESTION TO A PHYSICAL MECHANISM
A carry-oriented concept made tangible through repeated prototyping.
The prototype demonstrates manual iris actuation, access to the bag compartment, bag handling, and pickup with a substitute object. The intended pull-and-tear bag workflow keeps the next bag available without opening the base each time; replenishing the roll still requires access.
NEXT VALIDATION
Real-waste and outdoor trials, cleaning, durability, and usability with dog owners remain to be tested. The project has not been commercialized or validated for production.