the rotor:4pole 4x 10x10x25mm N52(!)neos on a 10x10mm square shaft
the stator:iron tube,id 40mm,od 55mm with alusheet(0.5mm,1mm,2mm)or coppersheet(1.5mm)
on the inner side.The gap between magnets and iron tube was about 2.5mm
in all cases
speed :only one speed 90rpm,15rps.
it was a mistake to think that power would vary lineair with the speed like
voltage of a generator.But at second thought I realised this probably would be
;more like square relationship.I should have checked this.
At the moment I was working on it I found it it quite a hassle to change the
belt from the drillpress(out of my reach).But most of the work was changing
the sheets in the tube(very close fitting).I should do it over at different
speeds.
I measured the force generated at a known radius from the axis,which make it possible to have the power generated with the formula
Power(watts)=2*pi*radius(meters)*rps(rotations/second)*force(newton).(Is this right??)
first some pics,results at the end
The stator tube with the different 'absorber'sheets and the rotor on the foreground
How I worked the sheets in the tube
The stator can rotate freely around the shaft thanks to this weird construction from
rollerskate wheels and rollerskate bearings
my testrig looked like this.forces are read from the diy dynamometer
results:
tube with nothing :6.5 watt
with 0.5mm alu :21 watt
with 1mm alu :35 watt
2mm alu :52 watt
1.5 mm copper :45 watt
Well, this is the output for 0.64 cubic inch of N52(is it really?)neo
I don't know if this is bad or good for a generator.
Anyway it 's far below for what I want for a testbrake for my future vawt-test setup
Finally I gonna try with a mechanical brake.
cheers,
stonebrain
Stone;
I don't know what you did posting this but it is full of erroneous characters [about 200 non breaking space codes] like maybe you wrote it in a word processor then pasted it in. There are so many of them I finally gave up trying to fix stuff. Try "preview" it will help catch this stuff.
