I would welcome any comments and suggestions. Should I use larger (thicker, at least) magnets? I have noticed a number of different methods being used to affix the magnets to the rotor. I think Zubbly had a nice method of filling around the magnets with resin, but he used circular magnets. If I employed that method I might have to use smaller magnets and leave some space between them.
I am expecting the rpm range of my set of blades to be between 100 and 400 or so. Without a rewind could anyone hazard a guess at what volts I might obtain from this setup?
Is it wired in Delta now? Changing it to Star will help, and might get it up to what you want.
Bar magnets will have a pretty large effective gap. Might try magnets less than half as long, and put them in like Zubbly would stagger his if he was using 2 per pole.
It is going to be a real treat getting them on there. I don't know how anyone would get that many magnets of that size next to each other. Be careful. G-[ Parent ]
If I have this right, according to Faraday's law of induction, the voltage produced is proportional to both the number of turns in the coil and the magnetic flux. Increasing either will help me reach my target voltage range. If possible I would like to leave it in a delta configuration to take advantage of the increased efficiency (less resistance). Also, I think star-delta switching might not work with the water pump controller we will be using which will hiccup if the V/f ratio changes.
The following mockup allows for more space between the magnets (that would presumably be filled with resin). There is also about a third more magnetic volume. Clearly, to answer my question about predicting the final voltage I need to spend a little time with Faraday's Law! Regardless, comments are much appreciated.
[ Parent ]
The smaller the air gap the better. Yes. I am not so good with software. Cut the top and bottom off a soup can to be the laminations. Use a pencil as the magnet. Skew the magnet (pencil) inside the laminations (can). The middle of the magnet is far from the lanimations.
Use a ruler as the magnet, and the edges make it worse.
I have a few concerns...
Do you have neo magnets? It will be VERY difficult to get them that close together with the proper pole up. The size of the motors or magnets is not clear to me, but I would not try it with bar magnets because it sounds somewhere between impossible and simply dangerous.
The air gap is important. However, if the magnets are that thick, I have concerns about completely or over saturating the laminations. It causes problems I can not explain. Too much flux causes problems.
Simply replacing the armature into the stator will be a dangerous task, requiring block and tackle.
Is this the first conversion you have done. This is not a good size to start with.
I believe you may be seriously under estimating the forces and violence involved. G-
So you are saying that I cannot simply use thicker disk magnets to increase the flux and thus increase the final voltage? Does the magnet configuration shown below look sensible?
Increasing the magnet thickness (some people call it 'length') will increase the voltage.
The big thick bar neos looked like it might have saturated the laminations, causing problems. (if you could have got them on there!) I had the problem a couple times. I can't explain it, but here is where it was explained to me... http://www.fieldlines.com/story/2006/8/23/144336/344 G-[ Parent ]
I don't think it would be a problem with round neos.
Setting the magnets into the steel rotor will short out the flux. They could go in a small percentage, but not much. Many people have machined the rotor, then used a pressed on aluminum cage dilled to hold the magnets. It's something I can't do.
This would work with a lathe, and a lot of time with a file... http://www.fieldlines.com/story/2007/2/2/55123/75010 [ Parent ]
