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Posted by z on March 30, 2008, 11:00 pm
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>
>>
>>>
>>>> Yup!
>>>>
>>>> Today I spent some time trying different nozzles just to see if I
>>>> could wrangle out those last few RPMs needed to get past 12 volts
>>>> ..
>>>>
>>>> I bored two out to 3/8ths and dremmeled the crap out of them,
>>>> finishing the interior with some fine gauge steel wool wrapped
>>>> around a dremel shaft and polished it till the battery died on the
>>>> tool. I made sure it was a smooth angle to the tip and got rid of
>>>> all the scratch marks from the drill bit.
>>>>
>>>> Put them in and just ran the hydro with a multi-meter and was
>>>> getting around 7 volts with a single jet. Pretty sweet .. the most
>>>> I ever got before was around 5.5. With both jets on and with some
>>>> fiddling with the angles I hit 13!!
>>>>
>>>> So I turned connected them to the batteries and whadya know.. its
>>>> charging. The battery bank is at 12.4 and when I hit the switch to
>>>> complete the circuit the alternator comes under load and keeps on
>>>> spinning!!!
>>>>
>>>> So thats that then. Now just have to keep tweaking things to gain
>>>> more performance. I might bore some out a bit bigger and see how
>>>> that goes. The nozzles i'm using don't have much room left .. any
>>>> larger bores and i'm risking going through a side wall, but they're
>>>> only like 2 bucks each so its not a huge deal if I screw one up.
>>>>
>>>> speaking of which think i'll have to get to town and buy a few more
>>>> to play with.
>>>>
>>>> Hey
>>>>
>>>> I can't thank all of you enough for the advice and telling me i'm
>>>> doing something bone headed once in a while -- its been a huge
>>>> help.
>>>>
>>>
>>> With the nozzles bored out to 3/8 inch, unless youve increased the
>>> feed tubes 2 or 3 time in diameter, you are probably losing a lot of
>>> velocity in the feed tubes. What you need from what I read is
>>> velocity, to spin the wheel faster.
>>>
>>>
>>
>> its interesting I did a test with some smaller nozzles and although
>> the velocity is faster, they do not turn the wheel as fast as those
>> with the larger bore.
>>
>> There must be some kind of relationship of the wheel to the water
>> such that the larger bore catches the wheel better or something like
>> that -- maybe the area (stream size) must be a certain volume in
>> order to impact its force uppon the wheel ??
>>
>> In any case, these new bores show the greatest RPM compared to the
>> other so i'll stick with them I guess.
>>
>> But like I said in the other post, the windbluepower guys are going
>> to install a different stater that should get me in the right voltage
>> range given the RPM i'm getting now.
>>
>> hopefully that will get me into the juice before summer comes!!
>>
>
> Without a doubt, the stator change sounds like an excellent
> approach. It
> should, if properly done, enable you to get signifacantly more power
> out at the lower speed you are attaining. Looking at the charts of the
> two generators, it looks like you are getting slightly more than 1000
> rpm. That looks like the new generator curve will put you exactly
> where you you want to be voltage wise, according to the pelton wheel
> design theory described by others here.
>
> The larger nozzle will definately give you more torque, which
> should result
> in more current at any given speed. The no-resistance speed will be
> higher with faster water speed, which will be somewhat dependent on
> the size of the feed tube. If the feed tube in insufficiebtly larger
> than the nozzle, the resistance which reduces speed will be higher.
> When optimizing this system, that would be something to look at.
>
> The fact that your larger nozzle made a big difference in the
> unloaded
> voltage suggests to me that the friction and other losses in the
> generator are significant. These are probably going to decrease as the
> generator "breaks-in".
>
> I have a hose "blaster" nozzle I acquired many years ago which could
> be a good prototype for an adjustable nozzle. It has an internal
> rubber tube outlet nozzle which can be constricted by turning an outer
> adjustment. It would produce a solid stream as big as 1/8" in
> diameter, and adjust down to a single jet so small as to be
> practically invisable. It's great for party tricks with the small jet.
> IF such a thing is made in a larger size, it could be very good for
> optimizing water flow for seasonal water supply and power needs.
>
> As always, I'll be looking forward to your next report.
>
> If you were nearby, I'd bring the homebrew.
>
>
cool. Yeah I had thoughts about using some kind of ajustable nozzel.
In any case my ISP has been giving me fits so sorry for not answering so
fast.
I did invest in a Frelon sleve bearing for the shaft which may let the
thing spin a bit better, rather than the simple bronze one I have now.
It also fits the support better so once the altnerator comes back it'll
be testing time again.
cheers -- another week or two and we'll find out!
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