Engineer-for-hire · Castle Rock, Colorado

Mechanical design meets intelligent automation.

MechaNexus designs, builds, and automates the systems small manufacturers and hardware teams don't have an in-house engineer for — from a single custom bracket to the workflow that quotes it automatically.

Engineering & Manufacturing Solutions AI Integration Business Automation

What I build

SHEET 01 / SERVICES
01

Design & Rapid Prototyping

Custom mechanical parts, brackets, fixtures, and mechanisms — modeled in CAD, refined for real-world manufacturing, and coordinated through 3D-printed or CNC prototypes so you get a physical part in hand.

CADDFMPrototyping
02

PLC & Automation Retrofits

Troubleshooting and upgrading the mechatronics on your line — ladder logic, motor/sensor integration, and mechanism design for equipment that needs to run itself more reliably.

PLCMechatronicsControls
03

AI Integration & Business Automation

Workflow automations that remove manual busywork — auto-generated quotes, inquiry routing, order syncing, and simple AI-powered tools built on Zapier, Make, n8n, and the Claude/ChatGPT APIs.

Zapiern8nAI Workflows

Who's building it

SHEET 02 / PRINCIPAL

Principal Engineer

David Pettingill

Education

B.S., Mechanical Engineering Technology

ECPI University — ABET-accredited · 2025

M.S., Engineering Technology in progress

Mechanical Engineering concentration — ECPI University · starts Oct. 2026

  • U.S. Navy — Hospital Corpsman, Dive & EOD-trained
  • Precision troubleshooting & schematic analysis background
  • CAD, mechatronics, PLC/automation

MechaNexus is built on a straightforward premise: most small manufacturers and hardware teams don't need a full-time engineer — they need one for the problem in front of them. A bracket that doesn't exist yet. A line that stalls without warning. A quoting process that still runs on spreadsheets and memory.

That's the work — mechanical design and fabrication-minded engineering, grounded in a Navy EOD background where precision and safety weren't optional. It's also the reason the business is built to grow toward the second half of its name: as automation and AI integration become part of nearly every shop floor, MechaNexus is the connective layer between the mechanical work you already trust and the automated systems you're only starting to adopt.

Based in Castle Rock, Colorado, and working with clients across the Front Range and remotely.

Ongoing project

SHEET 03 / ACTIVE WORK
FIG. 02REV A

Automatic Mower Access Door

PROBLEMA robotic mower needed to pass unattended between front and back yard through a fixed gap.
SOLUTIONA 2ft × 2ft track-guided rollup door, RFID-triggered at ~5ft range, driven by a small gear-motor and tied together with a PLC-based controller.
OUTCOMEDesign in progress — full mechanism, RFID integration, and weatherproof enclosure spec underway.
STATUS — ACTIVE PROJECT

How a project runs

SHEET 04 / PROCESS
STEP 01

Scope call

A free 15-minute call to hear the actual problem — no obligation, no pitch deck.

STEP 02

Concept & quote

A concept sketch or CAD model within days, with a fixed-fee or hourly quote before any commitment.

STEP 03

Design & build

Full CAD, DFM review, and — if needed — a coordinated 3D-printed or CNC prototype.

STEP 04

Delivery

Documented files you fully own, plus an honest read on where automation could save you time next.

Start a project

SHEET 05 / CONTACT

Response within one business day. If it's not a fit, you'll hear that too.

Good first questions to send

  • What's the part or process, in plain terms?
  • Do you need a concept only, or a physical prototype in hand?
  • Roughly what's it costing you today — time, scrap, downtime?
  • Any deadline this needs to hit?
Email David →