Life at the end of the road

January 28, 2020

OK for another year :-)

Filed under: boats, daily doings, hydro — Tags: , , — lifeattheendoftheroad @ 7:34 pm

Well, my outdoor thermometer says 2 degrees but I’m sure it’s lying, certainly the bitter east wind makes it feel that way. I’m just back inside for a warm and more coffee, having given up on some early morning pottering with my ‘Stream Engine’ in the shed.

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I didn’t leave the house until 8:00am right enough, the Storr being shrouded in cloud and even the hills of Harris having a dusting of snow.

The ‘high’ of, not only completing my annual ‘self assessment’ for HMRC yesterday before the 31st deadline but also TWO VAT returns!!!! Sure one of those was three months late and one a week early but I almost tore into the 12YO malt in celebration. I didn’t do that though cos I’ve not had a drink this year, well not since the ‘first footing’ at least Smile

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Anyway, I really must get back outside or I’ll be stuck in the toasty house all day admiring the view and taking pictures of the Trotternish ridge all day.

Stream Engine Hydro

The first job I tackled was my ‘Stream Engine’ https://microhydropower.com/ hydro turbine that had died the best part of two weeks ago. Stupidly I didn’t even go and have a look at it as soon as I finished work a week ago. Nope, apart from checking the water input the night it failed and checking phase voltage at home I left it alone. Hardly surprising really as it resides almost half a mile away from Sonas, through a wood, down a cliff and almost on the sea shore. Ten years ago, I’d have been down there like a shot with head torch, clad in oilskins, carrying all my tools and followed by a muddy wee dug. Nowadays I seldom stick my head outside when it’s dark and certainly not after work in the pishing rain.

It was yesterday when I finally got around to it, after yet another visit to Brochel on ‘generator duty’ Smile 

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Leaving the Kawasaki Mule as near as I dare to the turbine, I could hear straight away that all was not well. Even though still is still quite a way from the turbine I heard the rumble of duff bearings or a ‘lost phase’ and as soon as I got down there I could see the problem, or at least its cause.

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One of the three hoses feeding the various nozzles had split, spraying water onto the wall mounted isolator. This in turn had shorted out causing two or more of the wires from the alternator to melt together and make the turbine vibrate. The two weeks inaction on my behalf sealing the fate of the bearings.

There was no point investigating any further so I removed the whole assembly and took it home, easier said than done,

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it’s steeper than it looks Smile

Taking it back home I gave it an inspection and found it to be very rough and stiff as a result of the shorted phases and worn bearings. Removing the melted wiring improved matters dramatically so I tested it on the bench using a cordless drill to drive the alternator.

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All voltages were around 60V at the same drill speed so all was peachy with the windings. There was a little play accompanying the roughness so I ‘dug deeper’. The Stream Engine is built in Canada but infuriatingly all the threads and sizes of the fastners are ‘Imperial’ so if you loose any nuts or bolts the chances are you won’t have any spares. Same with the Allen screws, they all have ‘Imperial’ heads and of course I didn’t have a 1/4” one so had to file down a 6mm one to fit!! The bearings are a really common size (6203), there are three of them and the replacement procedure is well covered here https://cdn.microhydropower.com/wp-content/uploads/2012/08/BEARINGrepSEa.pdf

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Luckily, perhaps by design, they are also the same bearings as in the Harris turbine http://harrishydro.biz/ and even some of the Navitron Chinese ones. As I look after a couple of these I had some spare.

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Interestingly the bronze ‘Turgo runner’ was quite worn, not enough to justify replacement yet, but perhaps in the near future. The ‘head’ on this setup is 40m and the water quite dirty, even so it’s surprising how much damage water can do.

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The image above is the ‘Stream Engine’ Turgo after ten years at 40m head (left) and a ‘Harris’ Pelton runner after just two or three years at 90m head, notice the holes in it!! I replaced that one some years ago with a stainless steel one. https://lifeattheendoftheroad.wordpress.com/2012/04/25/a-runner-for-harris/

Anyway, that’s my new 6302 bearings on the shaft now with some Loctite 638 to hold them there and the monk fish casserole is just cooling out of the oven so I’ll just leave you with some images from the rest of the day Smile

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Brochel Bay and the ‘White Face’ from ‘Calum’s Cairn’, not that you can see much of it for the mist.

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Snow at Sonas and Brochel Castle yesterday.

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Two very serious boats at the Skye Bridge on Sunday, only the military could afford propellers like that and these ‘secret’ boats are so streamlined even the anodes are recessed in the hull.

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Who else would want to put these in an aeroplane Smile

3 Comments »

  1. In the ringing wet, very adverse environment of a cliff-bottom on Scottish island, the Stream engine hasn’t done so bad to last this long without the need of a major repair! Just goes to show that the built-in redundancy in Your off-grid power system is up to the job!

    Comment by Mark James — January 28, 2020 @ 8:43 pm

  2. Are you working for the Russians? Should be in the tower for giving away our secrets:)

    Comment by ex Quarryman — January 28, 2020 @ 9:11 pm

  3. Aye those Stream Engines are tough little machines.

    Comment by Dan Grey — February 1, 2020 @ 9:19 pm


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