Magnet Size

[Seyiwmz]

I seen an ad for larger magnets than the Dan's use in their book.  This magnet is 4x2x.5  grade 42 and has a pulling force of 290 lbs. Less than $20 a piece.   http://www.magnet4less.com/product_info.php?cPath=1_5&products_id=81

I'm thinking that the coil size would have to be bigger.  And could I use bigger wire for the coil.  Would a guy be able to handle more power and be able to utilize bigger blades and safely manage the extra power and heat.  Just wondering if this makes sense.  If I make another turbine, I wanna go bigger than what I already have.  Any ideas?

Guy

[bzrqmy]

I would say that these are all good questions for a guy that has built a machine before and wants to "Play".  The Dans have a good design that is proven.  I built one this year and I am still tweaking it to get it tuned in to my site.  I have plans on building a larger machine this winter and again will probably use their 17' diameter design with a few modifications for the lower summer winds that I get at my site.

My opinion is to build someting that has been done before.  Let the pioneers make the mistakes so we can learn from them.  If you enjoy raising and lowering towers, can afford to build several stator designs and have the machining and welding facilities and love to experiment, start from scratch and see what you can come up with.

We all would love to see whatever you decide to build.

Keep us posted and good luck.

[halfcrazy]

Basically you are asking if you can build a bigger turbine? essentially if you increase the magnetic material you will have to rework the coils for the proper voltage thus giving you more power. and therefore you will need bigger blades so it doesn't stall.

This is all doable you just need to do the math and proportion everything accordingly.

[Ungrounded Lightning Rod]

Stronger magnets means more voltage at a given RPM.  So you can go to fewer turns of thicker wire to keep the same voltage and get more current (and more load torque).

Thicker magnets means the optimum gap is wider, letting you put a thicker coil in, stuff in more copper, and pull out more power.  (Gap should be about equal to the sum of the thicknesses of the magnets on either side of it.)  Again you can use thicker wire for more current (and load torque).  You'll have to adjust the number of turns for the actual field in the gap - it just got more complicated when you changed the gap so it's not a simple expression.

Of course you need more horsepower from the turbine to produce more watts.  So you need longer blades (unless the current ones are in stall).  The optimum TSR remains the same but the circumference is greater so the RPM is lower, which lowers voltage, which needs more turns...

So you need to do a bit of algebra, and maybe build some trial coils, to adjust the design.