LA NPDT — LA New Product Development Team

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Outdoor Gear Design: Fall Arrest Hunter Safety Device

A tree stand fall arrest device taken from a hunter's idea to a manufacturing-ready product that was licensed to an established manufacturer.

  • INDUSTRIAL DESIGN
  • MECHANICAL ENGINEERING
  • MECHANISM DESIGN
  • PROTOTYPING
  • TESTING & VALIDATION
  • DESIGN FOR MANUFACTURING
  • LICENSING SUPPORT
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Outdoor Gear Design: Fall Arrest Hunter Safety Device
Konstantin Dolgan

Written by Konstantin Dolgan, Ph.D., NPDP

Founder & CEO, Product Development Engineer

Published August 30, 2026

Project snapshot

James McMaster came to LA NPDT with an idea: hunters fall from tree stands, and construction fall protection is not built for them. We designed and engineered the Fall Arrest device, built and tested multiple prototypes, and delivered a manufacturing-ready product that McMaster licensed to an established manufacturer.

The LA New Product Development Team delivered Outdoor Gear Design: Fall Arrest Hunter Safety Device, covering industrial design, mechanical engineering, mechanism design, prototyping, testing & validation, design for manufacturing and licensing support. Our in-house team handles concept design, engineering, prototyping and manufacturing readiness under one roof in Ruston, Louisiana.

Services applied
INDUSTRIAL DESIGN, MECHANICAL ENGINEERING, MECHANISM DESIGN, PROTOTYPING, TESTING & VALIDATION, DESIGN FOR MANUFACTURING and LICENSING SUPPORT
Fall Arrest, by McMaster Outdoors, is a personal fall arrest device for hunters who work from tree stands. It straps to the trunk above the stand, pays out line freely while the hunter climbs and settles in, and locks the moment the line runs out at fall speed — so a slip ends with the hunter hanging in a harness instead of hitting the ground.
James McMaster came to LA NPDT with the idea and nothing else. Our team took it through concept design, industrial design and mechanical engineering, designed the internal braking mechanism, built and tested successive prototypes, absorbed several design pivots along the way, and finished at a manufacturing-ready design. Rather than tooling up himself, McMaster licensed the finished product to an established manufacturer in the hunting market. It is one of several outdoor and hunting product development programs run out of our Ruston, Louisiana shop.

The Brief: Construction Fall Protection Does Not Fit a Hunter

Falls from tree stands are the most common cause of serious hunting injury, and bow hunters are especially exposed because they climb early, climb in the dark and move around at height with their hands full — a pattern documented across published trauma reviews of tree stand fall injuries. The engineering answer already exists in construction, where self-retracting lifelines are standard personal fall arrest equipment governed by OSHA 1926.502. The problem is that a construction unit assumes things a hunter cannot provide.
  • The anchor is a tree, not structural steel. The device had to clamp and strap to an irregular, moving, growing trunk and stay put across a season.
  • It is carried, not installed. Weight and bulk are budgeted against what a hunter will actually pack in before dawn along with a bow, a stand and a pack.
  • It is used one-handed, in the dark. Attaching, paying out and detaching had to work by feel, with gloves on, without reading anything.
  • The field is not a job site. Cold, rain, mud, sap and a full off-season in a garage all had to be survivable.
  • It has to stay quiet. Anything that clicks, rattles or shines costs a hunter the animal, which means the device does not get used.
Bow hunter seated in an elevated tree stand connected to a Fall Arrest device strapped to the tree trunk above him
In use: the unit straps above the stand and stays connected while the hunter climbs, sits and shoots.

Engineering the Braking Mechanism

The heart of a fall arrest device is a brake that ignores slow motion and reacts instantly to fast motion. We designed a centrifugal mechanism: shoes carried on a rotating hub are held inward by springs, and the drum turns freely while the line pays out at climbing speed. In a fall the drum spins fast enough that centrifugal force overcomes the springs, the shoes swing out against the drum, and the line locks.
Sectioned CAD render of the Fall Arrest centrifugal brake showing shoes, return springs and friction drum
Sectioned view: shoes, return springs and the friction drum they engage.
CAD render of the assembled Fall Arrest centrifugal brake unit with carrier plate and pivoting shoes
The assembled brake as it sits inside the housing.
Two numbers set the whole design. The engagement threshold has to sit above the fastest speed a climbing hunter will ever produce and below free-fall, or the device either locks on every step or fails to catch. The arrest itself then has to be soft enough not to injure the person it just saved, which is what the energy-absorbing lanyard below the housing is for — it stretches under load and spreads the stop over distance instead of stopping the body in an instant. Spring rate, shoe mass, pivot geometry and friction material were sized together against those two targets, then re-checked against cold weather, where springs stiffen and grease thickens.
Top view CAD render of the Fall Arrest brake showing three pivoting shoes and their return springs around the hub
Three shoes and their return springs set the engagement threshold.
Exploded CAD render of the Fall Arrest brake assembly showing fastener, washer, shoe, friction pad and drum
Exploded view — a short part count, chosen so it could be assembled quickly at volume.

Prototypes, Testing and Design Pivots

A safety device cannot be argued into existence on a screen. We built working prototypes, dropped weights on them, and used what happened to change the design — several times, including pivots the client asked for once he had a unit in his hands. Each round tightened the same short list: does it lock at the right speed, does it survive the shock, does the housing hold up when it is dropped, and can a hunter operate it wearing gloves?
James McMaster holding a working black prototype of the Fall Arrest hunter safety device by its carabiner
A working prototype — the point at which a drawing becomes something you can test and argue with.

From Working Prototype to a Product a Manufacturer Would Take

The last stretch was design for manufacturing: converting the tested prototype into moulded parts with sensible draft and wall thickness, standardising fasteners and springs to catalogue parts, cutting assembly steps, and packaging the drawings, bill of materials and test results into something a manufacturer could quote and build without redesigning it first. Where a client wants to make and sell the product themselves, the same package feeds our low-volume manufacturing line instead.
Angled render of the Fall Arrest device showing the tree strap routing through the back of the housing
The strap routes through the housing so the unit sits flat against the trunk.

The Outcome: A Licensed Product

McMaster Outdoors ended the project holding a proven, manufacturing-ready design rather than a garage full of inventory. That package was strong enough to license the product to an established manufacturer already selling into the hunting market — the fastest route to shelves for a solo inventor, and the outcome we aim at whenever a client would rather collect royalties than run a supply chain. Similar field-gear work includes the Bait Bunker and the DropTine scent dispenser.
  • Industrial design and CAD. Housing, strap routing and control geometry, modelled and rendered for review and marketing.
  • Mechanism engineering. Centrifugal brake sized to an engagement threshold, with an energy-absorbing lanyard for a survivable arrest.
  • Tested prototypes. Working units built, loaded and revised across several rounds, including client-requested pivots.
  • Manufacturing package. Mouldable geometry, catalogue hardware, drawings, bill of materials and test results.
  • A licensable product. De-risked enough for an established hunting-market manufacturer to take on.
Working on outdoor, hunting or safety gear and want the same path from idea to a licensable product? Talk to our Ruston, Louisiana team or start with our product development process.

Capabilities used on this project

  • Low-volume manufacturing

    Bridge tooling, short-run production and supplier management for first commercial batches.

  • Rapid prototyping services

    3D printing, CNC machining, urethane casting and functional prototype builds with published materials, tolerances and lead times.

  • Concept design

    Sketch exploration, form studies and CAD concepts that turn an idea into a buildable direction.

  • Prototype design and engineering

    Design for the prototype itself: CAD, tolerance stacks, material choices and assembly detail before anything is built.

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