Quote from: OilBarren on May 14, 2008, 10:15:25 PM
MY SUGGESTION - FOLLOW LARRY'S ADVICE ABOUT THE CORE MATERIAL.

Thane

Well not really possible since Larry created an Oval shaped core to replicate a cylindrical core.
And I am trying to do something utterly different with square cores.

One very easy to answer question: Thane, in the microwave based video (http://www.youtube.com/watch?v=K7PBavkMGwI ) are the HV and HC transformer coils still on the original transformer laminations?

Or did you make up a new core from pieces bought from a hardware store or the likes?

I can now partially reply to my own question.

I picked up 2 microwave oven transformers (herafter called MOT's) and one had a secondary coil of 150, the other was 95.
So now I have 2 which are within a few ohms of 100 ohms and will together be pretty close to 200 ohms total.

So I took the 150 ohm MOT as the odd man out and applied my angle grinder, turns out the I bar is easily removed by grinding the weld that holds the I bar in place, after doing just one side I was able bend the I bar up easily and the welding on the other side broke.

Now I have an E with a primary and secondary on it, the HC primary is on last in all cases and that seems to agree with Thanes video.

While I would have enjoyed clarification what seems to be the case in Thanes video is that the coils are still on the center bar of the E that they came on and still in the same order.

It also appears that Thane has cut off the sides of the E leaving something like a T.
This cut is the one I am a little wary of as you must cut through the whole piece of steel and if you go .2 of a mm too far you will have killed the secondary coil.

I could ask Thane if making this cut is really required, however I guess I am unlikely to get an answer I like since the only answer I would like is "I tested it with them on and it worked so for fun I cut them off anyway".

But feel free to speak up!

I guess the outer corner is the best place to attack as the wire hopefully won't be in the outer corners.
But the safest would be to cut in between the primary and secondary as there is a spaced gap between the coils, but that will only take it off part way.

After writing the word safest above (in relation to angle grinders) my mind welt to the subject that I pulled the guard off my angle grinder years ago, so figured I'd research the subject and sure enough I will be positioning the disk away from me and seriously consider if the $20-$30 cost of buying a new one is worth the danger!

Thane then has some I shaped steel pieces he is using as laminations to act as a bridge between the 2 microwave coils, however if this is required is unclear since there is a gap of 3 or more mm between the coil cores and the bridge, so first I will try it without this bridge unless Thane indicates it is required.

I can't see any reason not to get the microwave version together tomorrow, although my time estimates are not that trust worthy.


BTW RCH, hope you have not left the thread? (admittedly I went quiet far longer)

Quote from: aether22 on May 15, 2008, 04:24:34 AM
I could ask Thane if making this cut is really required, however I guess I am unlikely to get an answer I like since the only answer I would like is "I tested it with them on and it worked so for fun I cut them off anyway".

Does that mean you would prefer and accept a likeable untruth, over an unlikeable truth? 

no, it means I'd rather just assume it needs it and cut it off risking damage to the coils than increase the odds of failure.

Quote from: aether22 on May 15, 2008, 05:58:51 AM
no, it means I'd rather just assume it needs it and cut it off risking damage to the coils than increase the odds of failure.

Interesting, I also wondered about the complete process of getting the MOT ready. What's keeping the coils from sliding off the E, so you could cut safely? If they don't, you can use a hacksaw for the final cuts.

Also, on your rotor you may be able to get the cups more even by varying there depth according to the wobble position.

Can you post any pictures of your rotor/motor?

On these MOT's it seem they will require cupped rectangular magnets with MOT's at rotor angle to take full advantage.

Larry