Automated Fencing Dummy

The brief

Designed a purely mechanical fencing training station capable of simulating an opponent’s attack, so fencers could practice defensive technique without a live partner.

The problem

University projects often suffer from weak management. In a team of five friends, we stayed stuck in open-ended ideation. With two weeks left and no CAD started, the project was at real risk.

I stepped in, produced a technical roadmap, and split the machine into buildable subsystems so everyone could execute in parallel.

Some suggested hiding the original note I sent the team because the tone was blunt. I keep it in the story because it shows how I take charge when a group needs direction. We shipped the full system in under two weeks, earned an A+, and the team stayed friends — they said the clarity was what we needed.

Stalled project → delivered in 2 weeks

MCG 2101 · University of Ottawa · Winter 2022

Hard constraints

Hold a standard foil blade and mimic human arm motion.
Adjustable height and reach to fit roughly 95% of adults.
Perform fencing movements: forward/back steps, lunges, and parries 2, 4, 5, and 6.
Generate unpredictable sequences of five attack actions.
Operate using mechanical mechanisms only — no electronic controllers.

Parries reference

Standard guard positions — the mechanism targets four corners of the tip workspace for parries 2, 4, 5, and 6.

1 Pronation Prime
2 Pronation Seconde
3 Pronation Tierce
4 Quarte
5 Pronation Quinte
6 Sixte
7 Septime
8 Octave
9 Neuvieme

Mechanical concept

Tip workspace & syringe actuation

Parries 2, 4, 5, and 6 map to four corners of a square in foil-tip space — two orthogonal motions are enough to reach them. Pairs of syringes (hydraulic coupling) drive X and Y motion at the wrist; a spring return balances pressure where needed.

Lunge & reach

A scissor arm provides lunge extension (motor- or syringe-driven). Reach is set with a simple pin-in-rack (“gym rack”) adjustment so fencers of different sizes can use the same base hardware.

Rotating barrel cam

Five stacked plates on one shaft each drive a subsystem: wrist left–right, wrist up–down, scissor lunge, one forward step pulse, one backward step pulse — triggered by cams, syringes, and contact switches. Each plate is divided into five 72° sectors; each sector encodes one five-step attack phrase, so timing stays repeatable while combinations feel varied.

SolidWorks drawing sheet: assembly views, scissor arm, wrist detail, movement disks, and wheel drive — Drawing set — full assembly, arm, wrist, cam disks, and adjusters (replace with your exported sheet).

3.1 Automated fencing dummy

System integration & results

Complete system

The integrated machine uses one electric motor to spin a barrel cam that mechanically sequences every subsystem. As the barrel turns, plates push and release syringes and contact switches in order — producing unpredictable-looking attack phrases without electronics, sensors, or code.

The hard part was believable randomness from a purely mechanical controller; the multi-plate cam barrel was the compact answer.

System capabilities

Four defensive blade positions (parries)
Forward and backward stepping
Lunge attack via scissor arm
Unpredictable five-move attack sequences
Adjustable reach and height
Single motor, zero electronics

Leadership takeaways

Unblocked a stalled team

by providing clear technical direction
Broke complexity into subsystems

making the problem tractable for the group
Delivered under pressure

from stalled to A+ in two weeks