Discussion Board

Syndicate content
Live information from Fieldlines.com: The Otherpower discussion board
Updated: 58 min 6 sec ago

Re: Automotive alternator to PM alternator

Tue, 07/29/2014 - 18:35
Joestue,
The 36 slot stator will be wound 3 phase, 6 pole, wye. The rotor will be 12 pole. The bar magnets I am looking at are 1" long to match the stator length with a 1/4" square cross section. Skewed 11.5 degrees, and using one magnet per pole, this...

Re: The Little Box Challenge could shake things up!!

Tue, 07/29/2014 - 16:23
Designer keeps the rights to the design. And current technology isn't that far off from it already. My KW inverter is in a 31cu inch box, much of it open space.

Re: The Little Box Challenge could shake things up!!

Tue, 07/29/2014 - 16:10
I would think that you could sell the plans or demand a royalty for much more than $1,000,000. Seems like a pretty short sighted plan to win this contest.

Re: Automotive alternator to PM alternator

Tue, 07/29/2014 - 11:33
i would try 1/8th inch thick magnets.

1 inch wide magnets can get you an 8 pole machine if you have one magnet per pole.

one magnet per pair of poles means you only need 6 magnets for a 12 pole machine and there is nothing wrong with that.
even better...

Re: Automotive alternator to PM alternator

Tue, 07/29/2014 - 10:19
OK, I am ready to build the rotor to test the original alternator winding. Couple more questions. My slot width is .076" and tooth width is .166". Each coil spans 4 slots. Stator inside diameter is 2.75".  I am skewing the magnets approx. 11.5 degrees ...

Re: 5kw Poncelet Wheel Project

Mon, 07/28/2014 - 16:51
Sounds like building this on some sort of trailer that slides into a slot to hold it in place during operation is needed.

17 foot diameter information clarification.

Mon, 07/28/2014 - 06:20
I was reading the Homebrew Wind Power book for the umteenth time and I noticed a slight discrepancy between the book and the 17 foot turbine info on the website.  On Page 269 the book says the spindle housing is a 5 inch diameter pipe.  That would be p...

Re: F & P shaft size & hub mounting

Mon, 07/28/2014 - 04:28
Perhaps we could make a shaft for you

http://www.ecologieforum.eu/viewtopic.php?f=23&t=2566&start=480

Greetings Rinus

Re: F & P shaft size & hub mounting

Mon, 07/28/2014 - 02:06
The F&P gen is a washing machine motor with magnets arranged to fly around the copper in a cylindrical shape. 

Re: Load bank querry

Sun, 07/27/2014 - 17:28
Up until the 50's domestically and maybe still in third world countries, a salt water box was used to load test locomotive alternators. Below is a link describing the operation.

http://en.wikipedia.org/wiki/Liquid_rheostat

Re: 5kw Poncelet Wheel Project

Sun, 07/27/2014 - 11:16
Thanks for the advice Keith and Frank. I have thought about this in detail already and you are both correct.
 
The river bank is naturally rip rapped with small to large stones and very large tree roots help to bind it all together. An approx. 5 ton co...

Re: 5kw Poncelet Wheel Project

Sun, 07/27/2014 - 00:57
when dealing with marine hydraulics the forces grow exponentially at a rapid rate. Shorelines constantly change, when the slightest obstruction is added to the equation.
 A series of steel piles driven several feet into the ground using a minimum of a...

Re: 5kw Poncelet Wheel Project

Sat, 07/26/2014 - 23:39
If you had some way to determine how far down it was to clay, you'd have a better idea of how well your structure will hold.  It may be shallower than you think, but building on the aggregate is a recipe for failure.  If the large rocks are, say, in th...

Re: 300W to 1000W, 3 phase, 208+ volt: This type of windmill out there?

Sat, 07/26/2014 - 19:13
Perhaps a high-voltage AC "transmission" line might be practical.  Starting with the low-voltage AC from the turbine, step up to a higher voltage for the long distance wire, then step down again before rectifying.  It's been discussed before on the for...

Re: Experience with Heat Pump Water Heating

Sat, 07/26/2014 - 10:59
Wasted Attic Heat Being Put to Good Use

http://www.fortis.edu/blog/business-and-professional/wasted-attic-heat/

1. Heat during winter
2. Per-heat DHW supply during summer months

http://www.fortis.edu/blog/business-and-professional/wasted-attic-heat/

So...

Re: 5kw Poncelet Wheel Project

Sat, 07/26/2014 - 10:50
I started digging the riverbank yesterday and it is very tough going. Very little soil, lots of roots and rocks. It's unlikely that I'll be able to drive rebar down as there are too many rocks. In fact after getting down 18 inches or so I am hitting th...

Re: Perfect Windmill Design?

Fri, 07/25/2014 - 22:48
That being said are the motors that can be converted easily to generators without the use of a machine shop and still get at least 1kw at low RPM?

Re: Load bank querry

Fri, 07/25/2014 - 22:46
 I used to have access to a shop made load bank that could place a 150% load on up to a 1000 amp welder or load up to a 30KW 3 phase generator.
 Switching loads on DC was never done under load the resistance value would be preset then a very large knif...

Re: 5kw Poncelet Wheel Project

Fri, 07/25/2014 - 22:03
When sinking rebar into the streambed, consider the accumulated aggregate below.  My experience on both sides of the stream was interesting; one side was pure undisturbed clay, and the other was so many big rocks and gravel, down too far to dig it all ...

Re: Load bank querry

Fri, 07/25/2014 - 20:51
How about a few cooling fans.

Rather than planning an "overload", why not just plan for a maximum power level your equipment can possibly apply, and include enough resistors to do it?

Re-configuring the same load bank to operate at 240VAC or 120VAC or ...