mrrrk.net

Yet another narcissistic load of old cobblers that no-one will ever read.

The Day of Erection

19. February 2018 mrrrk Chacmool weather station (1)
What?  Erection is a perfectly normal and suitable word.  Stop sniggering.  So, now it's time to put up the wind turbine that will help power my Chacmool project.

Here's a step-by-step idiots' guide.  As in, you're probably an idiot if you do this like I did.

First, I soldered 3 m of extra cable onto the short leads that come out of the bottom of the turbine flange.  I haven't really soldered for years.  I found I need glasses to do it now.



Then I added heat-shink tubing 'cos I thougt it'd be nicer than wrapping it in tape.  I added extra tape in the end 'cos my soldering is awful and there were sharp bits where strands of wire stuck out as I'd mashed the two ends together, willing them to stay still long enough to accept my molten fixative.



I then bolted the flanges together, the other flange being the tube clamp wall plate.  I added a solid-neoprene spacer between the two faces (bought off Ebay and cut to size with scissors.)  The bolts look excitingly chunky.  Looks like proper engineering.  The reason the nuts are upper-most (rather than the bolt heads) is that the washers won't fit on the other side 'cos the tube clamp collar is too wide.



Next, the blades need bolting onto the hub and the hub is tightened to the spindle using the hex socket in the middle:



Then I added the shorter tube and snapped on the nose-cone to complete the upper assembly:



You might notice the notch I needed to cut near the bottom, with drill and hacksaw (and filed off aterwards), to allow the wires to branch sideways into the shed:



Now I needed to assemble the bottom tube and brace it to the shed.  I decided to reinforce the shed panel from the inside with a sheet of MDF.  I then drilled some holes and fixed the tube, the base plate and the T-piece in place.  I'd done all this already without taking pictures as I went but you can see the results below.

Now comes the idiot step.  I seriously wondered if I could manage this without help (my wife was in Leeds that day) and I probably shouldn't have tried.  Undaunted (well, a bit daunted, actually) I managed to climb the stepladder, carrying a turbine weighing too-many kilogrames swinging around on the end of a 1.3 m steel pole.  Finding myself in this new precarious position, I needed to feed the yellow wires round 90° through the T-peice and into the shed while simutaneously supporting the unweildy, top-heavy turbine and myself - without falling and breaking several bones or rupturing internal organs in the process.  There's no way I would have comtemplated this if there'd been any wind - but there wasn't any.  Anyway, got there in the end.  The tube found it's way home with a statisfying thunk and I'm pretty sure I managed not to trap any wires.  Do not try this at home kids.  Or at least get a grown-up to help you.

One thing to note is that the wires need to be shorted together if they're not connected to the charging controller.  If it's windy (presumably very windy!) it's apparently possible for the turbine to spin so fast that it damages itself.  Shorting the cables stops this becuase any generated current will create an opposing magnetic field in the coils and will resist the turning.  You can feel this when you try and turn the blades - it's not locked up but its quite stiff to turn.  Once connected to the controller, it should handle all of that sort of thing automatically.

Anyway, here are some pictures of the final assembly:








At the time of writing, the blades haven't turned an inch on their own yet.  I did mention it wasn't windy though...

It isn't easy being green

14. February 2018 mrrrk Chacmool weather station (0)

None of my wind turbine and mast components actually need painting since they're made from either plastic (possibly glass-fibre reinforced) or galvanised steel.  However, the thing will be hoisted 3.5 metres in the air and be in full view of me, my wife and various neighbours and so I spent some time last weekend painting the wind turbine and the tube clamps to make them stand out less.  As you can see, this is truly a green energy solution:


 

Rather than paint the tubes, I wrapped them in brown PVC electrical tape:

 



The instructions on the paint tin specified a temperature range of 15 °C to 25 °C for application.  The painter himself would have appreciated a temperature in that range too but the paint and I had to put up with a mere 5 °C along with splashes of rain carried into the garage by gusts of unwelcome wind.

The plastic parts were sanded over with some roughish sandpaper to provide a key and given a couple of coats of primer followed by a couple of coats of green gloss.  I gave the blades more coats since they'll get the most punishment.  It'll be interesting to see how well the paint stands up.

Here's a scruffy diagram of what I'm trying to build:


The tube is split into two sections to be joined by the T-piece.  This is so I can man-handle the tube plus turbine section and make it easier to erect.  The wires will also run through the T-piece and into the shed.


The bottom base plate will be fixed to concrete with self-tapping concrete bolts.


I'll also be adding some MDF reinforcement inside the shed on the other side of the T-piece + base plate since this will be taking quite a lot of lateral force and torsion when the wind blows hard.  I did wonder about trying to calculate some of the wind loads - but then I reasoned that the shed is basically an enormous sail - and it's still standing.  It can handle a bit of extra push.  I hope.

It's a dirty job...

4. February 2018 mrrrk (0)

Have a look at this picture from around the back of the shed.

You'll notice a few things:  1) The weather is awful, 2) the crazy angle suggesting your author is possibly drunk and 3) a couple of large, cylindrical objects.  The first point is irelevant, the second is simply due to a lack of wide-angle capability on my phone's camera and the third is a problem for Chacmool's wind turbine.

I want to site the turbine mast in line with the centre of the shed and unfortunately that means the shorter cylinder - the composter - needs to move.  It's unfortunate becuase it's big, heavy and full of rotting compost.

So I set to work and a couple of dirty hours or so later the composter was in a new position approimately 1 metre to the left.  I wanted to spend a bit of time after that working on preparing the turbine mast components and stuff - but after that (and some other pressing tasks like cleaning the bathroom), I frankly couldn't be arsed.

Getting a closer look at the compost was interesting.  We usually just chuck compostable stuff into this thing and hope for the best.  No turning-over or other composty maintenance for us.  It just seems to look after itself.  On closer examination (which I could have done without), the compost contained quite a lot of still-pristine egg shells, an alarming number of un-decomposed wine corks along with quite a bit of biodegradable plastic which hadn't done any such thing.

A couple of days later, after all that digging, I got this twinge in my shoulder.  My lovely wife suggested a trip to the osteopath.  I shrugged that off in my usual manly, medic-averse manner - which was painful becuase it hurt to shrug.  Surely it would fix itself in a day or so?  Three or four days of miserable aching, ibuprofen guzzling and sleepless nights later however, I found myself at the osteopath clinic and a few quid lighter.

Digging sucks.  Don't do it kids.