Converting a washing machine to hydro turbine
 

This is a pretty cool conversion! 600W generation and not a crazy amount of modification and fabrication. I'm pretty impressed.

https://www.youtube.com/watch?v=0ieFZI4-6K8

Yay, it's a Whirlpool Cabrio / Maytag bravos HE top loader in the USA. I service and trade washers and dryers in my spare time, and I love those units. A major cause of failure with those things is the tub bearings. The shaft seal is directly above the bearings, so when it fails, the wash water weeps right down onto the bearings and washes the grease out. The units get louder and louder, and at a certain point, the dragging bearings affect the spin cycle. If the owner doesn't fix or get rid of the washer when it starts getting loud, they do when it throws codes for an unbalanced load.

The bearings and seals for those units can be had for around $20 or so on ebayzon, and the repair is about like changing a wheel bearing. Not super simple, but not too difficult as far as mechanical repairs go.

Pretty much all of the direct drive front load washers in existence have the same basic drive in them. Rotor is a magnet ring flywheel, stator very similar to the video. Same basic failure with the bearings and seal happens, but not as often as the Cabrio washer. The motor control and the washtub support "fidget spinner" have the tendency to fail before the bearings and seal do. With the mod in the video, the spinner and the motor control are not used, so there are a lot of people giving away front load washers that could be repurposed this way.

Great info Jeff. Thanks!

Just got a PM for more information on the subject, so here's my tidbit for the curious:

The older washers had a stator with 42 poles in them. Factory wired as 3 phase star, 14 poles per phase. Max rpm for the old ones is around 800, and each phase puts out close to 500VAC peak at max rpm. Some stators were wound with heavier wire than others, so they can source more current. I've heard that the 1mm wound units can source up to a kilowatt.

When Whirlpool got involved with the design, they "optimized" the motors, reducing the number of poles and the wire size. Nearly all of the direct drive washers since the 90's have a 36 pole 3 phase star stator. These stators develop the same output voltage as the 42 pole stators, but not as much output current. Depends on the wire gauge used for the windings.

In the factory wound configuration, the easiest way to get power out of the thing is to use a step down transformer and rig up the stator however the transformer wants to be fed. The common connection for the star is right next to the connector for the individual phases, so it's pretty easy to change the stator to a delta if that's what the transformer wants. I believe I used a 480 to 24 volt industrial control transformer on one I wired up. Since there's more stuff between point a and point b, a little bit of power is lost during the journey.

The max power extraction factor is achieved by rewiring the poles on the stator. Each pole can develop around 20 to 25 VAC unloaded, about 2/3 of that loaded up good. Most people who rewire the stators want to power a 12 or 24 volt load, so they wire all of the series connected poles in parallel. At first glance it looks more difficult than it is.