Open Workout system!

OPEN WORKOUT SYSTEM

Open-source your fitness stack. Have full control of your fitness and data.

You can learn more about our project on our website: https://www.openworkoutsystem.com/

Open Workout System is an open-source ecosystem for fitness and health devices and applications. The entire project was born out of the pandemic when we were all stuck inside. I was looking for a device exactly like this and couldn’t find anything close for any amount of money. I needed something compact enough for an apartment yet powerful enough to do basically everything I wanted.

Enter the Digital Weight device—the spark that created Open Workout System.

This has been a prototype journey. We’re now on our 9th prototype and 5th major revision (hence V5). We’re taking it to the next level and refining the project so it’s more accessible as a DIY build, a kit, or a complete product for people both inside and outside our direct community.

At Open Workout System our guiding principle is simple: build devices and services that let people connect and share their fitness stacks in the most bespoke, personalized way possible—so everyone can find their own unique inspiration and drive. And we want users to feel true ownership of their devices. What better way than to open-source the entire thing?

Digital Weight V5 is a powerful, compact, ultra-versatile resistance trainer for strength training, rowing, and paddleboarding. The hardware is fully open source and available to download and DIY-build today from our GitHub.

Here is a video of it being used last year at Open Sauce.. This was our older V4 unit. Not the V5 you see below.

https://www.youtube.com/shorts/1E-ZTYqPVzk?feature=share

Here is the older V4 unit being used with a wall mount.

And here is the newer V5 Digital Weight and the Highlights:

Replaces a full cable system / functional trainer

Supports hundreds of strength-training exercises

Weighs only 12 lb and is roughly the size of a half-gallon milk carton—ultra compact and portable

Monitors and controls rep speed

Includes an expansion port so it can act as a general-purpose actuator for whatever other DIY projects the community dreams up

Here is the current V5 cleaned up

Here is the V5 we presented at Open Sauce 2026!

Here are a few members of our open workout system community presenting at Open Sauce this year.

And here is a picture of Josef Prusa using our device!

What's next after our V5.. Well V6 of course!

This one is special. Its the device we will run through DFM and step further away from off-the-shelf components. This comes with a development cost and so here is where we are now looking for sponsorship and further support from our community.

Future V6 PROJECT ENGINEERING LEVEL DESCRIPTION

This project is broken down into several parts

48V LiFePO4 batter pack
Battery management system with soft power switch and safety monitoring MCU
Touch display and rotary knob input
USBC
Main controller with WiFi connectivity + LAN and POE
Motor controller
BLDC motors
Spool + Strap
Expansion port
General frame/assembly with device mounting capabilities

Here are a couple more pictures of our CAD work.

48V Battery Pack Module:

This battery pack requires a custom PCB to organize / tidy the wire harness for monitoring each cell and will also have the soft power and PMB unit on it.