Thane Heins Perepiteia.

[aether22]

Well I have had my gen at 3,000rpm, but my magnets are attached by machine screw through drill holes.

That JB weld suff sounds good but if you can obviously screw or bolt on is the way to go.

Why am I not reporting results? Well I could only get a well balanced system to work with a sync motor and they never change speed, also there is no metal connection between the rotor and the axle.

When I get back from my trip I'll get to have fun with Thanes Gen currently on it's way to me, yay!

And then I'll be looking at buying a nice large pulley like the one above because it should allow running at higher speeds smoothly!

[gotoluc]

These Ryobi grinders can go up to 3,500 RPM. Thane has never allowed it to go anywhere close to that speed since he had a few magnets fly off in a demo once and ever since has been real careful. I just wanted to see what would happen at around full RPM. Now we know Thane is right. So be careful.

Luc

Is glue the only option for affixing the magnets?

No, Epoxy is an added extra to help hold. If you look at my picture of the plastic rotor, I had 2" holes right through the 1/2" rotor to hold the magnets in place plus the epoxy all around each side of the magnets on the rotor.

Luc

Take a look at these magnets.  Perhaps they will assist with safety issues at high speeds.


Dimensions: 5/8" od x 1/8" id x 1/4" id x 1/8" thick
Tolerances: ?0.002" x ?0.001" x ?0.002" x ?0.001"
Material: NdFeB, Grade N42
Plating/Coating: Ni-Cu-Ni (Nickel)
Magnetization Direction: Axial (Poles on Flat Ends)
Weight: 0.320 oz. (9.06 g) (per pair)
Pull Force: 22.67 lbs
Surface Field: 3010 Gauss
Brmax: 13,200 Gauss
BHmax: 42 MGOe

I can get bigger ones of course, but the idea is the same.  What do you think?

They are ok for low RPM, maybe up to 800 RPM any higher and the vibrations can crack them apart and now you would have multiple sharp pieces flying magnets around.  Maybe you can use them for a proof of concept mode and get a sheet of min. 1/8" lexan which you can heat and bend as a shield around your rotor for protection. The safer way is to have the magnets sunken in and epoxyed in the rotor. Also keep in mind that a magnet with a hole in the center is weaker.

An easy and safer way is to use these magnet cups holders here:
http://www.leevalley.com/wood/page.aspx?c=&p=32066&cat=1,42363,42348

Magnets and cups:
http://www.leevalley.com/wood/page.aspx?c=&p=58750&cat=1,42363,42348

Luc

[polarbreeze]

Ok, first all normal electric motors pull less current the faster they rotate.
But they produce less torque (less mechanical power)...

Aether, you're right about the current but I think you'll find that for an AC induction motor operating in a low speed regime (which is the case in all these experiments), torque usually increases with speed, it does not decrease as you state.

Also, torque and power are not equivalent as you seem to be implying. Power = torque x rpm.

In fact I question if you really live where you claim and I doubt you are who you claim because if you had experience in induction motors as you claim you wouldn't have confused it with a synchronous motor as you did earlier.

Well, it doesn't really matter where you think I live because I'm reasonably certain of that myself and that's what really counts. I do seem to be able to get back to the same house every night so I guess I'm doing something right.

As for the synchronous motor thing, I think if you go back to my posts you'll find that I proposed an idea to explain Thane's flux feedback mechanism and when I did that I was describing a synchronous motor. Then, in a later post I generalized it to apply to any sort of AC induction motor (but still excluded DC motors). I don't think there was any confusion but maybe you missed one of those posts?

Incidentally, the conceptÃ, of the generator back-EMF creating an ââ,¬Å"energy lessââ,¬Â synchronous motor effect inside the induction motor was originally proposed by Dr Habash, according to one of Thane's earlier posts, so I don't think the synchronous motor argument was so far out of line in the first place.

PB

[gotoluc]

Hi All,

here is a new ideal we got and just put together as a new rotor for the generator. It is a 10-3/4" Cast Iron belt pulley available at most quality bearing and pulley shops. We drilled through the spokes and installed screws with nylon lock nut to hold the magnet holders cups. The wheel is true and balanced. It is much heavier than the wheel barrel wheel but is an easy off the shelf precision piece. However, since it is heavier it accelerates slower but seems to give the same affect. We will be testing it more and will give an update.

Stay tuned.

Luc

Luc, thanks for sharing the blow up!  But the pictures are great in that I can see what and how you
are building. As you found out acylic is very brittle. lexan is stronger, along with delrin, but it is not
until you get into the special re enforced plastics that one can feel safer.

However you are not out of the woods yet with the new cast iron wheel. Again cast iron is a very
brittle material. Did they give you a maximum rpm limit? I would think 2000 rpm would be it.

Being a pulley would allow you to wind the vee grove with piano wire or 600 pound test SS fishing
wire, the groove say half filled and the wire ends brought out through a couple of small holes and
down to a clamp screw on the spokes.... could safely double your speed. Either that or a purpose
built steel wheel.....

OK, I'll just go back to counting flowers, lol

Ron

Yes i_ron, you are correct. Iron is brittle, the pulley is rated max 2,400 RPM and we will not be goin over that. We got this pulley to see if Iron would give a better magnetic coupleling effect than the carbon steel wheel. Also since it is heavy we can also see if flywheel effect is helpful.

Stay tuned for results.

Luc

[bitbeam]

Hi Luc,

Great to have you back on the board! Especially with all the cool info and pictures! 

Aaron