WaterWheel

It was around July 2005, that I happened to mention to the Director (highly qualified mechanical engineer amongst other things) of one of our customers (An Engineering company who specialise in water/oil transfer/control equipment) my plans for the water wheel, to which he replied, "No, you´re going about it all wrong. Let me help you". Who was I to say no!.. So after a few meetings and white boarding sessions, we decided to built a ´prototype´ water wheel to ´see´ just what the potential in the creek was. Of course we did do rudimentary calculations by throwing floats in the creek and timing them along 10m stretches, but that isn´t enough to determine the actual power the creek can create.

A couple of weeks later, we had a fully operational / rotational CAD drawing on our email that consisted of a fully laser cut, A-Frame based water wheel with low friction sealed bearings, solid aluminum keyed axle and PVC pipes cut in half and slotted in for paddles. (A hell of a lot better than the bike wheel based prototype i was going to build!)

So.. After a few more weeks the wheel was built and had its first construction in the Engineering Factory over in Melbourne. (You will notice throughout all documentation I refrain from mentioning the company, as they have explicitly told me that they never want to do this again!).. It was larger than I originally expected, being 3m High and 10m in diameter, and weighing approx 300kgs.

So we packed it all up and off to Tassie it went. We went about installing it first off by assembling the whole thing on the banks of the creek and winching it into the creek. This proved to be a pain as it caused the frame to twist, and the wheel to run awful close to the supports. But we got it in and made measurements of 1.5kgs to stop the wheel from stationary. In January 2006 we took the wheel back to Melbourne, as the untreated steel was starting to rust. It was then bead blasted and painted gun metal grey with a zinc based paint that would prevent future rust etc from occurring.

Back down to Tassie she went and reinstalled again.

We built a proper channeling system consisting of 6 to 1 concrete / sand/rock mix and built sandbags up to funnel all the water directly into the wheel. (Fish etc can still travel freely beneath the wheel). We now require over 7.5kgs to stop the wheel and a full rotation now takes 11secs flat. I also attached a ´hub-o-meter´ to the wheel that measures the distance the wheel has travelled in miles (very interesting).. it was averaging about 14miles per day when we first got it installed.

The WaterWheel Gearbox was designed in November 2006 to be a 200:1 spur gear / oil bath based system, with chain drive off the main shaft with different sprockets to achieve different ratios. The F&P Motor then runs on the shaft as pictured below.

Because the F&P motor generates 0.8W per RPM loaded, we are hoping to achieve 400RPM on the F&P motor which will give us about 320Watts loaded.. but remember.. thats 320Watts x 24hours a day = 7.68KWh which is HEAPS!
Lets hope we can get that much ! - We have to remember however that after taking all the inefficiencies / cable length losses etc into consideration we will probably get a LOT less than this figure.. BUt ive got my fingers crossed, because I just dont know yet..

June 2007 Update : Gearbox ended up being a 33:1 gearbox and we installed it on wheel. the BEST we could get out of it was .25A @ 24v loaded, and that was doing about 220RPM.. so we are planning on changing ratios in gearbox and on shaft, and different stator wirings etc as well to achieve more out of it..

October 2007 Update : A new version of the F&P motors have become available (7 Phase hubs) so after re-wiring stators into 7phase configurations and still using a 1:1 ratio we can now generate about 1.9A @ 24v into the battery bank - when the creek is flowing.. obviously when theres no water the wheel dosent even turn.. we now are going to build a proper funneling system too, as the sandbags are already cracked and water is getting through them.