Pit Row Dyno: The Mechanical Chassis

Open Source Reference Design for Small Engine Dynamometers

This repository contains the CAD files, DXF cut patterns, and fabrication details for the Pit Row Dyno physical chassis.

⚠️ LOOKING FOR THE ELECTRONICS? The wiring diagrams, firmware, and sensor specs have moved to their own dedicated repository. Go to the Pit Row Controller OS Repo Here

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The Barrier to Entry (Read This First)

I'm not going to hold your hand, but if you are capable of finishing this project on your own, you don't need me to.

I'm no expert at any one part of this project, so don't judge the CAD file too harshly.

To build this chassis, you will need to:

• Cut, Drill, and Weld: This is a steel fabrication project. If you don't have a welder or a grinder, you are in the wrong repo.
• Understand FreeCAD: You will need to navigate the provided CAD files to get dimensions, part locations, and hardware breakdowns.
• Source Mechanical Parts: Bearings, axles, load cells, and raw steel.

If that sounds like a reasonable enough barrier to entry and you still want to build one yourself—you are exactly the reason I am open-sourcing this project. I'm proud of you.

The Form Factor

The finished dyno has a 16" x 16" footprint It weighs a little less than 50 pounds. It is designed to be easily transported to a track day with your friends, or just live in the corner of your shed without taking up valuable real estate.

What This Chassis Can Do

I honestly couldn't tell you the physical ultimate limits of this design—a lot of that comes down to your craftsmanship and weld penetration.

• Engine Class: Designed for Predator 212, Clone, Briggs LO206, and similar small engines.
• Capacity: The reference design is robust enough for modified kart engines.
• The Electronics: While this repo covers the steel, the system is designed to pair with the Pit Row Controller, which handles data acquisition up to 25,000 RPM.

DIY Data Acquisition

This chassis is designed specifically to mount the Pit Row Controller.

• Automated Runs: Connects to a laptop for professional graphing.
• Portable Power: Runs off 5V USB-C (power bank compatible).
• Touch Interface: Designed for a 7" Sunton Touchscreen.

Get the Wiring & Code for the Electronics Here

Don't Want to Weld?

Don't want to be hassled with sourcing steel, laser cutting plates, and jigs? Let alone the work of putting it together?

Never fear, you can buy the chassis pre-built or as a complete turn-key unit. Go to www.pitrowdyno.com to check it out.

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