User-Centered Design · DFM · Mechanisms

Soccer Shots

A two-player spring-powered tabletop soccer game engineered for elderly couples and former athletes, taken from napkin sketches to a working all-3D-printed prototype.

Design Project · MEEN 210, Texas A&M (Group 24) · Jan–Apr 2025 · College Station, TX

Finished goal with blue truss backboard, orange triangular end stands, and suction-cup feet — The finished goal: a diagonal-truss backboard on triangular end stands with suction-cup feet.

2 playersHead-to-head play

All PLA3D-printed build

~$43Sourced parts budget

Any tabletopNo fixed field

Who it's for

The design started from the user, not the mechanism. We were designing for elderly couples, especially former athletes, so every decision traced back to their needs: reconnect them with a competitive past, keep their hands and minds active, and give them something to do together.

Understand the user

Reconnect former athletes with their competitive past through a fast, familiar head-to-head game.

Define needs

Improve dexterity and fine-motor control through the grip and spring resistance, and give couples a shared activity that eases loneliness.

Design to fit

Keep the product cheap and simple so it stays approachable and easy to set up anywhere.

Concept → CAD

We generated hand sketches, then grouped and scored them against our criteria to down-select a single concept. That concept became two SolidWorks assemblies: a spring-loaded launcher (the "shooter") and a goal with a pivoting goalie.

Early hand-drawn concept sketch of the tabletop soccer game — Early napkin concept sketch.

Hand-drawn final-assembly sketch showing the launcher, goal, and goalie together — Final-assembly layout: launcher, goal, and goalie.

Hand-drawn sub-assembly sketch with dimensioned fits and tolerances for the shooting mechanism — Sub-assembly fits and tolerances for the shooting mechanism.

SolidWorks CAD of the shooter assembly with grip body, twin guide rods, plunger block on a compression spring, and suction-cup base — Shooter assembly: grip body, twin guide rods, plunger block on a compression spring, suction-cup base.

SolidWorks CAD of the goal assembly with diagonal-truss backboard, triangular end stands, goalie post, and sliding goalie block — Goal assembly: diagonal-truss backboard, triangular end stands, goalie post and sliding goalie block.

Design for manufacture

The build is almost entirely 3D-printed PLA, with parts spread across a Creality K1, K1 Max, and a Voron 2.4. The only sourced items were interchangeable compression springs and suction-cup feet, which kept the whole project under budget.

A PLA part printing on an enclosed Voron 2.4 3D printer — A part printing on the enclosed Voron 2.4.

Sourced compression springs in two stiffnesses alongside suction-cup feet — The only sourced parts: springs in two stiffnesses (Home Depot) and suction cups (Amazon).

Tolerancing & iteration

The first prints did not fit. The guide-rod bores came out too tight, and the end caps and handle would not seat in the launcher. We sanded parts to size and enlarged the holes. Tolerancing the poles and holes in the shooting mechanism turned out to be the key to an accurate product.

Close-up of a printed block whose two guide-rod holes came out undersized — Two guide-rod holes printed undersized.

Gray launcher body with the plunger handle inserted during a fit test — Fit test: plunger handle inserted into the gray launcher body.

Printed end block held to the camera showing its two bored holes — An end block showing its two bored holes.

Assembled launcher sliding on its twin guide rods — The assembled launcher on its twin guide rods.

Smooth, accurate slide

Enlarging and sanding the bores gave the plunger a smooth, accurate slide on the guide rods. That is the difference between a toy that jams and one that shoots straight.

Finished product

The result is a working game with a smooth goalie pivot for easy blocking. We deliberately chose not to build a fixed field, so the two pieces play on any tabletop at any distance, versatile and customizable to whoever is playing.

Finished shooter with gray body, finger grips, orange plunger head on springs, and suction feet — Finished shooter: gray body, finger grips, orange plunger head on springs, suction feet.

Finished goal with blue truss backboard, orange triangular end stands, and suction feet — Finished goal: blue truss backboard, orange triangular end stands, suction feet.

SolidWorks3D printing (PLA)DFMTolerancingSpring mechanismsUser-centered design

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