Another Water wheel project

[Cliff top]

I have made another spout and other minor tweaks since all these photos. In flood it does rage over both sides of the wall 6" deep without damaging the machinery.

Its time I took some more pics.... watch this space

[Cliff top]

Ok, I have finally taken a few more pics to show where ~I've got to so far.

This is what the current setup looks like with the splash cover removed.



A close up of the gearbox/ generator....yes I know I need a bit more oil on the chain
I still can't help feeling I am losing perhaps half my power at low water just driving the 23:1 gearbox with oil in it. If it fails, I will redesign it with a system of 1/2" chains I think, to lower friction.


A close up of the sluice. Because the taper starts halfway, it doesn't run as smooth as I would like. I may try to do as someone suggested and make an insert that's parallel to keep a more lamina flow


I have lifted the whole wheel up 2" to give easier clearance of water from underneath in times of heavy runoff.

 At this low water level its only giving ~25watts, barely enought to make the meter go back
For the 3-4 days after a decent downpour I get perhaps 1-2 units a day. So far therefore I reckon its saved 50 units since november- which equates to about £12 given that its on the garage supply and the first few units are 24p ea to cover the standing charge
So outlay cost ~£1000....payback time at £6/month =  14years ... assuming the kit will last that long.

As Dick Strawbridge says.... It' s not easy being green....

And finally a 15sec video of it in operation.
http://www.pfmrs.plus.com/waterwheel/wheel09.mov

[Other-Power]

Thanks for the update.

That is a great DIY set up.

I agree with the suggestion that your gear box is taking half the power.

It may have a long payback but that is a great resource you have made great use of!

Keep up the good work, please let us know if you change the set up and how it works

Thanks again

Jonathan

[guydewdney]

Clean, good, correctly tightened, lubricated, aligned chains are very efficient. Deviate from this - and the efficiency drops rapidly.

Gearbox is probably very good - replace the oil with very light oil - diesel even - might help. Align shafts as best you can - thin the rubbers in any couplings to bare minimum. Rubber has a high hysterisys - which saps power.

Any way you can build a leat of sorts to increase wheel diameter?

[Cliff top]

I did consider putting thinner oil in the box, but was worried that there may not be enough lubrication and that would lead to premature wear, since under heavy load you can hear a whining/grinding from the first set (relative to rotation speed of input shaft)  I have at present in there the gbox oil from the old box that failed and red hydraulic fluid (roughly 50:50). Given the sub zero temps too won't help the viscosity.
Based on your suggestion I might try some heating oil instead.

As for the rubber coupling on the shafts, that seems to stay under the same tension as the shaft rotates and the shafts are dead in line.

As for increasing the wheel diameter....thats not easy.  A leat or pipe from further back would have to come from perhaps 50m outside our land...permission probably won't be a problem, but a big diameter pipe or channel would be a fair investment.
I could move the wheel 30m forward/downhill and gain perhaps another 2-3 feet of drop, but again a decent channel/pipe would be needed - we would be extracting virtually all the water from the riverbed for that distance and the wheel would be visible to all much nearer the roadway...something I didn't really want to publicise.
If/when the wheel needs rebuilding I will probably raise the dam wall another 6-12 " and dig a deeper wheel pit perhaps 10 foot in front of the other to gain another foot there- possible wheel size would then be 1.4m instead of 1m...so ~40% more power...


As a postscript to all those reading this thinking of having a go at a project like this....there is a lot of trial and error here to get this far...don't let me put you off, but it seems likely you will not get anywhere near the expected power outputs calculated due to a number of things lowering your efficiency on a small DIY build like this.  It also takes a LOT longer than you might expect.

[mespilus]

You can maintain adequate lubrication by adding dispersions of the 'solid lubricants' graphite or molybdenum disulphide, to the gear box oil.

Check that the 'oil' in the dispersion is compatible with the gear box oil you choose.

Traditionally the 'solid lubricants' were dispersed in the cheapest mineral oil.

These days they are also available in improved VI (Viscosity Index) mineral oils and synthetics.

Molybdenum disulphide (MoS₂) has traditionally been used in gear boxes.

In days gone by Ford found they could forego the expense of the last 3% of machining of gear wheels
by including MoS₂ in the first fill.

The resulting swarf from the first couple of hundred miles was removed at the compulsory gearbox oil
change at the first service.

[Cliff top]

I have some graphite powder/lubricant.

What do you reckon to mixing that with heating oil for a thin oil?

[mespilus]

Minimal benefit I would expect.

The advantage, (and cost) of the 'solid lubricant' dispersions is that the particle sizes are
normally sub micron, and each particle has been wetted by the 'oil'
so the solid lubricant particles remain in suspension, even when diluted by the gear box oil,
until deposited onto a metal surface.

Your powder will most probably float on the surface of your gear box oil.

Re-read your previous post.

Be wary of adding heating oil.

28 sec heating oil (kerosene to some) has virtually no lubricating properties.
35 sec is similar to red diesel, but again has less lubrication than one would need.

Pre-'City' or 'ULSD', (Ultra Low Sulphur Diesel), diesel owed most of its lubricating properties to the sulphur
containing contaminants not removed at the refinery.

As we all now know sulphur in fuels leads to acid rain.

Refineries were modified to remove the sulphur.

The resulting diesel was found to have inadequate lubrication properties.

A sensible solution was mooted and adopted.

Bio-diesel, (hopefully made from used cooking oil), has enhanced lubrication properties.

So all pump (fossil) diesel currenly has 2.5% biodiesel added to it to ensure adequate lubrication
of the injection system.

Not advocating you use bio-diesel in your gear box, as the vegetable derived molecules are prone to
crosslinking and oxidation under continued extreme pressures of your contained system,
compared to (idealised) once through system of a diesel powered vehicle.

[Cliff top]

I would of course like to find the thinnest oil I can that will offer some protection.
Is hydraulic fluid on its own ok? 

[Taffyboy]

Fill it up with WD40?

[mespilus]

I would of course like to find the thinnest oil I can that will offer some protection.
Is hydraulic fluid on its own ok? 

Which hydraulic fluid?

Any trade name, references, 'Complies with xxxx Specification'?

[wdh]

You can maintain adequate lubrication by adding dispersions of the 'solid lubricants' graphite or molybdenum disulphide, to the gear box oil.
...

Wouldn't it be worthwhile to have a rootle around the local Halfords or equivalent?
There are all manner of high lubricity potions.
I recall (many years ago) watching a race-engine-builder carefully wiping all bearing surfaces with neat STP as he was assembling things.
Gearbox oils are typically much lower viscosity than motor engine oils. BUT oil viscosity is hugely temperature dependant. The point about 20/50 was that even though it was 50 at high temp and 20 at low (better lube and easy starting), its still much thicker at the low temp. Just not quite as thick as it would be if it was a monograde.
I expect the gearbox runs rather cold. Or does it get heated by the 'lost' energy?

Meself, I wonder about the bearings for the wheel itself. What are they like?

[mespilus]

You can maintain adequate lubrication by adding dispersions of the 'solid lubricants' graphite or molybdenum disulphide, to the gear box oil.
...

Wouldn't it be worthwhile to have a rootle around the local Halfords or equivalent?
There are all manner of high lubricity potions.

Holt Lloyd (if they are still trading) used to supply Halfrauds with a 3% dispersion
diluted down from the 40% supplied by the manufacturer.

[Cliff top]

mmm not sure what sort of hydraulic fluid....  maybe auto transmission fluid...blagged it from a small garage out of the bottom of his tub.  red coloured.

Main bearings are lovely and smooth running.
The slow speed of the wheel won't be the friction loss, its obviously the smallest output gear whizzing round in treacle which is cold and doesn't seem to be attaining any noticeable heat from the losses.

worth trying something thinner though, thanks for the input.
Cliff

[guydewdney]

Ill second the 'dont touch heating oil' statement above.

thin lubricating oil - 0w5 synthetic car / motorbike oil? WD40 isnt good for gears - its a penetrating oil. Hydraulic oil is good - its designed for use in gear pumps - which are gears Talk to Rocol (the only people who bothered to email me back when I asked about lubrication for somthing else).

diesel?


mate says 3 in one...