I finally finished my Toshiba motor conversion!
I'm not kidding. I never finished it. I've been using it in my wind turbine for years, but it wasn't done. I knew it, but I didn't do anything about it. Until now.
Here's how its rotor looked in 2008 when I stopped working on it:
The magnets have slight offsets, but are lined up on the axis of the shaft and secured with screws only. No skew, no sealant. Then I moved on to do other wind turbine projects, built more motor-conversions, and used those for a long time. The Toshiba conversion sat on a shelf. Waiting.
Then in 2021, I did something stupid. While putting the blades on the shaft of the genny I was using at the time (a Baldor motor conversion) I neglected thread locking. Less than a year later, the blades wiggled themselves off the shaft. Surprisingly little damage, considering the blades flew free and fell 70 feet down (I was very lucky it wasn't a write-off). However, the Baldor genny was unusable. But I did have the spare Toshiba gen...
So the Toshiba was put to service at last, 13 years later. It's been running for years like this, with 10-foot cedar blades on it, working rather well. No - the real problem, which I have finally fixed, is that I never FINISHED the Toshiba conversion. On motor conversions that I finished after the Toshiba, I carefully bonded the magnets in place, and fastened them with screws. I didn't do that with the Toshiba conversion, probably intending to try various changes (I can't remember now).
Last month the Toshiba started making little grinding noises. Subtle at first, but impossible to ignore after a week. I shut it down, lowered the tower, took the blades off, and started inspecting.
Huh, at first I couldn't see anything wrong. So I put the blades back on, and gave them a free spin... grind grind grind. I had to dismantle the wind turbine a lot more to find out. The Toshiba was lifted off the mount, and brought into the shop.
Once I took it apart, this is what I found:
Several of those magnets have rusted. There are other signs that water got inside the case. In the winter, the water, in the form of frost, infiltrated all of the gaps and spaces between the magnets and the rotor. When corrosion started, the particles coming free stayed stuck, but CAKED in ways that lifted the magnets off of the surface of the rotor. The worst of the magnets (shown here) has a lot of magnetic particles packed underneath it, probably from repeated cycles of ice forming, expanding, rusting, and leaving the particles to pry up the magnet for the next cycle. Once the magnet was pried up enough, it started scraping on the stator.
So I took it all apart, cleaned it up best I could, and then bedded down the magnets with epoxy, and replaced all of the screws. Plus a few coats of paint to keep water from seeping in. While I did this I also DECOGGED the damn thing, too. I've been listening to it hum for years now.
With all that done, the shaft turns virtually cog-free, and it's being put back on the tower soon. Hopefully back in operation this weekend.
Topic: I finally finished my Toshiba motor conversion! (Read 60 times)
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