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Specialty HVAC tool

EEV Thing

$149.00 pre-order · ships in 1–2 weeks

Here's a cool Thing I made. See below for details.

✓ Ships in 1–2 weeks · ✓ 1-year warranty · ✓ Covered by The Pledge

Category: Available Products
The story

Why this exists.

Pre-order — ships in 1–2 weeks. Order now and yours comes out of the first production run. You'll get a tracking number the moment it leaves the shed.

Yes, these photos were taken in a hotel room. I'm at a convention, the tools are real, the lighting is not. The engravings aren't finalized yet either, so the one that shows up at your door will look a little more polished than what you see here. It will definitely have better lighting.

The EEV Thing is the fastest way to find out whether an EEV motor is actually dead. Instead of digging out the needle probes and poking pins one at a time, plug the valve into the EEV Thing, hold the button to scan, then tap to cycle through the resistance of all 4 coil windings. It shuts itself off when you forget to. Which you will.

A failed winding can sometimes take out the control board along with it. Cut the plug end off the dead EEV, wire it into the other side, and now you can plug the EEV Thing into the board and confirm it's putting out 12 VDC to every winding.

There are devices out there made to drive EEVs, but the windings still had to be checked the old-fashioned way. The EEV Thing is the perfect companion to an EEV driver, or a standalone diagnostic tool on its own.

Works with 5- and 6-wire unipolar stepper motors with 2.54 mm connector pitch, which covers the vast majority of EEVs in VRF equipment.

This is the production version of the Founder's Edition: same job, fixed design, a little smaller, and no hand modifications required this time. The Founder's Edition buyers paid for the R&D. You get the version where I already found all the mistakes.

Specs
the important bits.
Works with
5- & 6-wire unipolar steppers
Connector
2.54 mm pitch
Reads
All 4 coil windings
Also verifies
12 VDC board output
Battery saver
Auto power-off
Case
PCTG · USA-made filament
Status
Pre-order · ships in 1–2 weeks
why PCTG? Higher chemical resistance, durability, and temperature range than PETG. Costs a little more. Worth it. Made in the USA.
From the field
“These "Things" are pretty cool.”
MADISON · INNOVATIONS ★ THE PLEDGE ★ EST. 2025
MADISON · INNOVATIONS ★ THE PLEDGE ★ EST. 2025
The Madison Innovations Pledge

Tools that work.
Or I make it right.

Tools need to work right every time. If one of mine breaks, send me a picture and tell me how — I'll replace it, and I'll use what went wrong to make the next batch better.

01
Made in the USA
Everything is designed by me. All 3D-printed parts are made in-house with USA-made filament.
02
Right to Repair
Replacement parts will always be available. If I ever stop making a product, I'll open-source the design files.
03
Print your own parts
STL / STEP files for printed enclosures available on request. Customize, repair, reprint — go nuts.
04
Built on feedback
I take ideas seriously and refine designs constantly. Send me an idea for a Thing that would make your job easier.