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Hard drives can be a lot of fun!
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25,000 rpm HDD with a simple FET drive, and 3.8Mrpm

February 17th, 2020, 19:32

I was messing around and wanted to see how fast I could spin the platters using a very simple square wave generator and a single FET (no brushless motor driver/etc), turns out it was 25,000rpm because my power supply was limited to 20V
https://www.youtube.com/watch?v=SRk651ThM0k&t=

For the hell of it, I wanted to see how fast I could spin a object, turns out it was
3,808,800 RPM, 63,480 RPS, 1338mph, 2153kph, 24.3M G's
https://www.youtube.com/watch?time_continue=1&v=ZQE05T-3680&feature=emb_logo

How about Ultimate Acceleration! 0 rpm to 3.2 million rpm in 25ms! 130,000rpm/1ms
Info here https://www.rcgroups.com/forums/showthr ... 000rpm-1ms

And some of my drone flying here
https://www.youtube.com/watch?v=uHoFfpLSb2g

Re: 25,000 rpm HDD with a simple FET drive, and 3.8Mrpm

May 18th, 2020, 11:38

You did not mention the hardware over here in the post.
It would be good if we get some more information on this page itself.
This would make us more susceptible to click on your links and view this information further.

Re: 25,000 rpm HDD with a simple FET drive, and 3.8Mrpm

May 18th, 2020, 11:57

RuskinF wrote:You did not mention the hardware over here in the post.
It would be good if we get some more information on this page itself.
This would make us more susceptible to click on your links and view this information further.


Fair enough :)

More info on the 25K HDD. A hard disk motor is 3 phase, some have a 4th wire (some call this 4th phase). These motors have a microprocessor controller and driver (brushless electronic speed controller). I figured I could drive this type of motor with a simple single FET (I used IRFZ44N) and square wave generator.

I knew it would have a few limitations using such a simple drive circuit:
I know it would not be self starting (need three poles for that),
limited on acceleration,
limited on torque.
Of course I could just use a RC ESC and pwm servo tester, but that would be easy and way more costly.

The 3.8 million rpm is a completely separate project, all the info is in that video.
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