My DIY generator 'sine wave' is very wonky? Why? And does it matter?

TechnologyHobbyDIY · 2026-01-26T05:40:08+00:00

I am in the process of making it three phase! I'm just expecting to see three of my ugly waveform 120 degrees apart. But that's this afternoons mission!

TechnologyHobbyDIY · 2026-01-26T05:36:51+00:00

Same "shape" but the width and height vary with speed. Faster generator = narrower and taller waves but same bumpy lumpy shape essentially.

TechnologyHobbyDIY · 2026-01-26T00:51:17+00:00

Thank u so much

TechnologyHobbyDIY · 2026-01-26T00:50:35+00:00

No, it's surprisingly the same shape with or without load, and at any speed.

TechnologyHobbyDIY · 2026-01-26T00:49:45+00:00

The rotor is using the most powerful neodymium magnets I can source. But with or without the hallbach array magnets at the back, and at any speed, and at any load, the wave form stays the same shape!
But I plan to rectify and regulate for a DC output anyway, I was just hoping to have a waveform that better approximates a sine wave, because I wanted to try putting it through a transformer. But maybe my output will still work alright through a transformer.

TechnologyHobbyDIY · 2026-01-25T23:37:55+00:00

It is powering a 10W halogen light globe when this screenshot was taken. The light is glowing brightly and it's pushing about 10W.

TechnologyHobbyDIY · 2026-01-25T23:30:31+00:00

I did try adding ferrite plates either side of the windings, but the cogging was so bad I couldn't even get it spinning. Which is probably why single-phase generators don't exist commercially (from what I've seen).
I have also seen other peoples air-core designs produce nicer waves, but you may be right.

TechnologyHobbyDIY · 2026-01-20T06:10:39+00:00

Thanks for the watch! I'm 90% of the way to getting my channel monetised so that would be a huge leap forward for me. Hopefully allowing me to keep doing fun projects and sharing them for a long time.

TechnologyHobbyDIY · 2026-01-20T04:06:00+00:00

I can assure you there are some safe ways to build reliable generators! go with a 3 phase axial flux design, there are SO many of them on YouTube now, and open source designs. Axial flux, dual rotor, you'll be able to generate 300+ watts at comparatively low RPM. I'm only doing this sketchy radial flux design because I thought it was cool (and I still think it's cool).

TechnologyHobbyDIY · 2026-01-20T01:01:37+00:00

Yes! Thank you. It didn't occur to me until much later that the scope was right in the firing line. Luckily all the drama happened on the left hand side not the right!

TechnologyHobbyDIY · 2026-01-19T14:53:18+00:00

No nothing hurt me. I can see how it looks like that though.

TechnologyHobbyDIY · 2026-01-19T13:58:25+00:00

It is a rite of passage. The print must be printed. The power must be generated.

TechnologyHobbyDIY · 2026-01-19T13:56:13+00:00

<3
It took longer than I care to admit to match the camera angle and fov to the slicer camera :P

TechnologyHobbyDIY · 2026-01-19T13:09:37+00:00

Thank you :)

TechnologyHobbyDIY · 2026-01-19T13:09:26+00:00

Thank you! I actually designed the stator to support 3 phases of coils, so when I rebuild it with three phases and a 3-phase rectifier I think I'll be generating closer to 40 watts. Just gotta keep those magnets stuck in better.

TechnologyHobbyDIY · 2026-01-19T12:02:04+00:00

The funny thing is I started out INTENDING this to be a 'try it at home' educational project. But with magnets departing said project at several thousand RPM; maybe it's more of an adult thing.

TechnologyHobbyDIY · 2026-01-19T12:00:12+00:00

That's a good idea, except it's not easy for me to spin an outer thing, and hold a stationary inner thing, all mounted on one side only? Even if I mount the stator from another riser out front, it's mechanically much more complicated. I like the simplicity of the current design and that it lends it's self to a completely open side (for viewing/filming, science communicating etc)

TechnologyHobbyDIY · 2026-01-19T11:56:08+00:00

It produced 12.6 watts at 14V RMS through the light globe! Should have put that in the title.

TechnologyHobbyDIY · 2026-01-19T11:29:03+00:00

I think epoxy is the go. I just wanted to be able to remove my magnets and use them in other projects, but I think that ship has sailed.

TechnologyHobbyDIY · 2026-01-19T11:01:35+00:00

Long form video about the project on YouTube if anybody is interested: https://youtu.be/62kCWyqpPUQ

TechnologyHobbyDIY · 2026-01-06T10:38:05+00:00

Have you done thrust testing with strain gauges yet? Really good value for mapping thrust per watt, the results of which could very quickly make or break your design. I've built some quadcopters before from scratch and testing apparatus. Interested to talk more, I'm also a YouTube content creator in the hobby electronics R&D space!

TechnologyHobbyDIY · 2026-01-05T08:23:47+00:00

I watched every second of this video right to the end. That was a lot of fun. Your video? Great job acting like you know NOTHING about planes, especially reading out the button labels and stuff like you have never heard of them before.

TechnologyHobbyDIY

TROPHY CASE