cut-in speed for a 10'

[milltech1]

Hello all,

     Just finished my stator for the new 10'er and did a test run on the stand with the cordless drill. I hooked up 3 rectifiers and checked the output at different rpms. I am going with a 24v system and the cut-in rpm I get at 24 volts dc is 165. Is this going to be too high for a 10' prop or will I be ok? The book calls for 140 rpm so I'm a bit over. I have the air gap quite tight too, can't get it much closer.

Thanks for your time,

Eric

[Janne]

Hi, if you live in a average wind site, the bit higher cut-in wont hurt you much. In fact, you might have some overall performance gain, as you will propably stall out less in high winds.

[Flux]

That should be fine. Anything below 180 rpm should be ok.

With very low cut in you gain a few watts on low wind days but you loose performance due to stall in the more useful winds.

The best trade off depends on your wind region and your power usage, If you get many hours of consistent low wind each day the low cut in may be better but if as here the low wind days only give you a few hours of a few watts then raising the cut in and increasing output in the 12 to 15 mph region will get you more energy capture.

Flux

[milltech1]

Thanks for the reply's, That is what I needed to hear. Hopefully I'll have the new genny up and flying in a few weeks, just need to give everything a paintjob and get it in the air.

Eric

[Goahead]

Hi Eric

I'm just beginning winding the coils for a 24v machine to.

Could you tell me size of magnets, wire and how many turns did you put in to achieve  24V at that RPM?

I have 2x1x1/2 N50, using 2 in hand of 1.2mm and aiming to 75 turns (or more if it can fit it in.)

Happy Easter

Goahead

[milltech1]

Hi Goahead,

     I used the same mags that you are using, 1"x2"x1/2" grade n50's. I used #13 wire and each coil has 1 strand of 60 turns.

Eric