I-RONS

[i_ron]

Here is the start of my replication.

Nice work both of you!

Having seen enough of the ryobi, I dug out the old 5 horse RV
and stuck the T rotor on it. It does 1740 RPM so is still way to quick for this (maybe) at over 500 Hz...

I wanted to do some tes ting of core material so clamped a couple of samples of mot cores and recorded drag and temperature rise in five minutes. The pieces did show some slight differences as if to indicate different grades but for 400 Hz the laminations shouldn't be bigger than .005 thou (inch). These were .019 thou lams (.45 mm) so way to big for this Hz.

They averaged about 30 watts drag per sample and temperature rise in five minutes was from 20C to 40C.

I should add that the unit without a core runs at 47 watts.

For comparison I dug out a Somaloy core (tubular) and it ran on 4.2 watts and the temp rise was from 20C to 27C in five minutes. So there is a major design factor to have the RPM, the number of magnets and the right core material all in place.

Ron

[wattsup]

Guys, guys, no more pictures please. My mouth is watering and I can't breath. lol
Geez, that's virtual water-boarding. lol

@baroutologos

In your first picture please describe that fine green roll of wire. What type is it? Looks like twisted multi-strand. If so is each wire insulated.

@hydrocontrol

Nice wheel with good inter magnet open spaces should give you some great zero-full-zero passage over the coil(s).

@i_ron

You are doing exactly what I had suggested to @TH many months ago. Good work, plus under RV. That will be very interesting. Is the wheel you are using the same one you had sent to @TH.

For the RV side, do you have a switchable capacitor bank?

Also, can I ask you how you managed to secure those magnets. Are they safe?

[i_ron]

@i_ron

You are doing exactly what I had suggested to @TK many months ago. Good work, plus under RV. That will be very interesting. Is the wheel you are using the same one you had sent to @TK.

For the RV side, do you have a switchable capacitor bank?

Also, can I ask you how you managed to secure those magnets. Are they safe?

Gee wattsup, I hope you mean TH, lol

Yes this is the #3 rotor, the first two were purchased by Mr T. This one doesn't have the slots in it that the first two have.

This one does the 3K plus on the Ryobi, so 1740 is no sweat.
The rotor design followed on from Mr T's open wheel barrow wheel on which the Lee Valley cups were welded on. As you can see in the pic the cups that hold the magnet are pocketed, so are quite safe up to 10 K. I never made a cap bank as it was always a fight to scrounge up enough caps. I find that if one stays somewhere within the window that tuning is not all that much of a problem. I just keep a two MFD on jumpers that I use to check if the tuning needs tweaked.

Anyway, thanks for the kind words, I somewhat hesitate to post my pictures so as not to discourage those without a shop. I should let them see my early wood and tape models!

Ron

[i_ron]

Having seen enough of the ryobi, I dug out the old 5 horse RV
and stuck the T rotor on it. It does 1740 RPM so is still way to quick for this (maybe) at over 500 Hz...

Ron

Correction:  The formula says two poles times the rpm.

Thus: Frequency = NP/120

where N is the RPM and P is the number of poles.

so... 1740 X 18/120 = 261 Hz

On the frequency meter it says, 298 Hz so in the ballpark.

So for core size, compared to 60 Hz, would be 298/60 = 4.966 so the 298 Hz core can be 5 times smaller than the 60Hz core.

Ron

[minde4000]

Its nice to see things moving on there ron hydro baruotologos. Here are a few parts I have gotten for my project already. Rotor plate and magnets should arrive this week. No word on laminates yet. GL