A few test results

[christopher]

Finally got back to my 9/12 dual rotor, 12" disk, 1X2X1/2" mags.  If you remember from my last post I had used recycled wire four in hand and brought out the 24 leads hoping to get 12, 24, or 48 volts.  Here is a picture of the coils before potting in resin:

Here are my peliminary results:

           48 Volt Configuration

       50 open volts DC at 118 rpm

           24 Volt Configuration

        24 open Volts DC at 120 rpm

           12 Volt Configuration

        12.5 open Volts DC at 125 rpm

            Amps into 12 volt battery

          5 amps at 150 rpm

          10 amps at 180 rpm

          15 amps at 200 rpm

These rpms were visually counted so are probably off a percent or two.  I was trying for a cut in speed to match from Alton's Blade Calculator a 10' TSR 6.

Would sure appreciate any thoughts on wether you think this will make a good match before I start carving the blades.  Thanks in Advance,

Christopher

[Flux]

Would be ok for a very low wind area but you will have to furl very early.

Cut in is ok, but for normal winds I would not have gone that slow for 10 ft.

Resistance is very high and seems to be near 0.4 ohm in the 12 v case. It will be near a perfect track for a 10ft prop at tsr 6 but you pay the price in efficiency.

You will reach 50% at about 350W and I think you will have to hold it down to about 600W to prevent frying.

It looks as though you could have used more strands in parallel but it does become difficult with large numbers. I wouldn't have made the coils with radial sides, just kept them rectangular and saved a fair length of wire and resistance.

If you are happy with about 600W maximum output and excellent low wind performance then it will be fine.

You give no idea of number of turns , coil thickness etc, but I suspect the coils are quite thin to have filled the space with so little wire. For those magnets the stator can be 5/8" thick, that leaves coils about 9/16 with a bit of room for resin and glass.

[christopher]

thanks flux,the stator was 1/2" thick with 38 winds per coil i think i will be happy at the low wind end with an early firl

[Flux]

Have you decided which voltage you are going for?  The higher voltages with less rectifier and line drop will do better than the 12v.

Nice looking windings by the way. good luck

Flux

[christopher]

at the start i will be using it at the 12 volt as i only have a 12 volt inverter. i also have a 48 inverter but in need of repairs at this time.