Wednesday, April 27, 2011

A stepper motor as a wind turbine?

I brought this little stepper motor from Oatley Electronics.

I had hoped that it would generate a decent voltage as it is rated at 24 volts as a motor.
I set about working out which of the six leads formed each of the two coils. Two leads were center tap ones and can be ignored. I found the two pairs in the end by drawing the following diagram and using a multimeter to record the resistance between pairs.
I hooked the inout shaft up to my battery drill and gave it a spin. I could get about 10 volts out, but only a few milliamps. Multiplying the two it didnt really equate to any decent output in watts.

It would be easy to make a little battery charger to charge very small batteries but I am after a lot more to charge my electric bike and such.

A good experiment.

Saturday, April 16, 2011

A maglev bearing for my VAWT

I came up with a simple way to make a bearing for my VAWT.

Two overlapping pieces of aluminium tube, a nylon bush (from a watering system joiner) and two opposing magnets.

Works really well.

A vertical axis wind turbine (VAWT)

I've wanted to build one for ages.

I found this nice anodised "Connect-It" aluminium at Bunnings and got to thinking that with some Corflute/Correx fluted plastic you could make some nice wings. I gave it a try.

The reality with these lift kinds of VAWTS are that they are hard to tune precisely if you use flexible material like Corflute. I think I will move to making a simple Horizontal Axis turbine instead. It's a more conventional shape.

Wednesday, April 13, 2011

Wind turbine hub from a chopping board

White polyethylene is really expensive when purchased as an 'engeering plastic'. But it's great when you get it from cheap import shops or from Kmart.

It's resistant to heat and chemicals, soft to work with, and it absorbs vibrations.So I had a go at making a wind turbine hub from it. It is the ideal material for the job - and cheap. I'd better replace ours before my wife notices...

Monday, April 11, 2011

Fisher and Paykel Axial Flux Alternator

My dad recently got his hands on one of these for me. The benefit was that it had already been rewired for wind power.

If you ever see a Fisher and Paykel that is 'broken' - grab it.They make heaps of power.
You can read more about using them at The Back Shed.

Sunday, April 10, 2011

A cheaper way to make Lenz VAWT wings?

I've like the idea of a Lenz II wind turbine for quite awhile - but the wings have struck me as being a little over complicated.

So I wondered if these garage wall hooks couldnt be used to make a simpler structure. I spotted them at my local hardware store (Bunnings) for $3 each. I prefer using premade components where I can.

Maybe in some future build I will give it a try....