Random Writings

I’ve had a very good day today. It started auspiciously at Screwfix, when they had all four of the things I wanted, and therefore clearly the gods of DIY were looking favourably on me…
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I now have a working inverter/charger on the boat! Back at Easter I started a big electrical upgrade of the boat, fitting new batteries and some new internal wiring. But I was hamstrung by not having the right terminals on the cables to the inverter. I called around Cambridge’s extensive range of electricians’ merchants (”electrical wholesalers” to use the jargon) and eventually found one firm, Hedley & Ellis, who were prepared to help. Unfortunately, their giant crimping tool (a thing about the size of a large pair of boltcutters or a tree lopper) was out on hire. It returned yesterday. Today I cycled into town with about 10kg of copper cable in the bike panniers, got the terminals crimped on for the princely sum of £5, and then this evening I’ve wired it all up.

And it works! The batteries charge quite rapidly, and I can now run the generator in economy mode (where it adjusts the throttle according to the load) which should hopefully save me quite a lot in petrol.

Probably next weekend I’ll fit the SmartGauge battery monitor and split-charge system so I can charge the domestic batteries from the engine, and after that I’ll have to do something about the wiring spaghetti on the kitchen wall!

Simulink is a companion to Matlab which purports to be a time-flow simulation package. This post is going to get quite technical, so if you’re not into either communications system design or Simulink in general, look away now.

I’ve used Simulink before, in my third year at York, but that was following a well-structured lab script where the lecturer had partially set up the models in advance. This time I’ve been doing a course (I’m obliged to do one of Leicester’s engineering MSc modules in my first year) simulating communications systems in Simulink, and the lab script is much vaguer. I’ve spent a lot of time banging my head against a brick wall in Simulink, and here are some important gotchas that might save other people going through the same level of auto-cranial damage.

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The long bank holiday weekend over Easter is traditionally time to begin big DIY projects (and then leave them part-finished for most of the next year!) and I decided that it would be an ideal opportunity to do all the electrical work that I’ve been planning since virtually the day I bought the boat.

The new battery tray, with two new domestic batteries and the engine battery

So, what’s been done? Well, I fitted the four new batteries I bought back in November, replacing the one old and knackered one that’s been on its last legs since I bought the boat. They’re all connected together with heavy-gauge cable, and the plan was to connect them up to a Victron Phoenix MultiPlus combination inverter/battery charger. The Phoenix unit duly arrived (although I ended up buying it from a more expensive supplier as my first choice cheaper supplier mucked me about) but once it was mounted on the kitchen wall it became clear that I had a problem.
The manual recommends very heavy 70mm2 cable to connect this unit to the batteries. The cable I had ordered in from Barden UK, and because the manual didn’t specify any kind of connector, I went for bare ends on the cables to the inverter. Opening up the unit, however, reveals that the cables should have a crimped terminal fitted to them. Unfortunately, once these terminals are fitted to the cable, the terminal is too big to go through the strain relief gland on the bottom of the inverter. I’ve now worked out that I can take the glands off the bottom of the Phoenix, thread them on to the cables and then take the cables down to my local electrician’s supplier who have agreed to crimp the terminals on for me - you need a special hydraulic crimping tool, as the terminals are massive! Unfortunately their tool is out on hire, so I’m hoping for a call at some point this week and then I can finish that job. Once fitted, the Phoenix will give me mains power from the batteries and also act in reverse to charge the batteries when the generator is switched off.

The Victron inverter and chaotic wiring on the kitchen wall

Other jobs involved assembling the new office desk and filing unit in the office area, and wiring 12v and 240v power through to the desk. I’m now sat at the desk with my PC, which is marvellous! I still need to sort out the floor, though, which is messy - some old ceramic tiles need to be lifted and I need to lay some consistent flooring over the whole office area.

The office desk

LED spotlight for the office - very bright blue-white light - came from Screwfix!

Dreaming of a white Easter - it got worse than this, about 4cm fell in total!

I’ve just migrated the website to a new hosting firm (www.xilo.net), so please bear with me if bits of the site are broken. Do let me know if you find some part of it that’s stopped working in the move!

Not the most exciting post this one, but…

Last weekend I took the boat to Cambridge to “do the tanks” (fill the fresh water tank and empty the foul) and so I offered some friends from church a ride on the boat on the return journey on the Sunday. So, faced with having guests, I cleaned and tidied, which was long overdue. I also bought more storage boxes - some to improve the storage efficiency under the bed, and two recycling boxes from Homebase to store kindling and coal for the stove. Previously I’ve just put the coal bag on the cabin floor, which leaves coal dust all over everything it touches…

Recycling boxes adapted as wood and coal bins

I also discovered that by tidying up and removing the nasty folding chairs that came with the boat (which I only ever use to dump stuff on anyway), I create enough space for me to get six of us around the dinner table, and after folding the table back to the dinner-for-one size, the cabin looks positively spacious!

I took some pictures to prove that the boat is occasionally tidy!

Tidy cabin, looking forward

Tidy cabin, looking aft

My improvement plans are moving forward. I’ve ordered a corner desk and filing unit from Mrs Flatpack and hope it’ll be delivered before too long. I’ve got the long weekend at Easter planned for the Big Electrical Upgrade (new batteries, new split charge, new inverter/battery charger) and so I’m about to place a very large order for all the parts so that I can check them all whilst I have time to order anything I’ve forgotten.

Oh, and whilst it’s been incredibly windy (50mph+ gusts), the boat’s been fine so far. Martin’s new concreted bollards are much more effective at holding the boat in position than the mooring pins were!

One of those awkward self-portraits done with a self-timer…

I’ve upgraded to the latest version of WordPress to solve a problem with the blog being displayed in reverse order, so sorry if I’ve munged your RSS feeds in the last few days. I’ve also finally managed to make OpenID work for comments, so LiveJournal users should at last be able to enter their LJ URI in the “website” field and get approved for comments quickly and easily.

I’ve had a weekend of DIY - it started on Friday night when I discovered that the Big Maplin on Newmarket Road was open until 8pm (gosh, I have an exciting life, don’t I!) and so I bought the bits and pieces for a job I’ve been meaning to do for a while - putting extractor fans in the bathroom and kitchen. I did the kitchen fan on Friday night, and in the process discovered that most of the wiring for the kitchen lights is just held together with insulating tape…

On Saturday I had a tidy-up and a clear-out of unwanted junk, and then did a recce for some wiring work I want to do fairly soon. In the process, I found myself looking at the woodwork in the dinette area, which I’m planning to rebuild into an office and wardrobe area. I ended up ripping out all the unwanted timber, which turned out to be slightly non-trivial. Anyway, it’s done now.

Today I’ve done the wiring for the bathroom extractor, which I’m hoping will reduce the amount of damp and condensation in there.

I finally have my Matlab package, it arrived yesterday, by DHL from Dublin. I thought the saga was over, but little did I realise what was in store for me this morning. David (the head of Engineering) appeared in my office with a printout of Monday’s blog post about Matlab. It turns out that the post was picked up by someone in MathWorks’ head office in the USA, and went all round their management before being sent to the UK office. They admitted fair comment on their customer service, but objected to my giving away the level of discount they offered us on the product, which should have been confidential. I’d not been told this, but had I been less frustrated and more rational that day I’d have realised that suppliers’ prices are jealously guarded things. Anyway, I’m shortly going to remove the offending figures from that post.

I am now, apparently, quite well-known within MathWorks…

On Tuesday night, at around 10 at night, the generator, which had been running happily for three hours or so, suddenly stopped dead. I went out to investigate, and found that it still had fuel in the tank and wouldn’t restart. I cursed it mildly and packed it away for the night. It was dripping wet from the thick fog we were having, and it occurred to me that the last time it had died it had done so after Cambridge had experienced torrential rain.

Some preliminary investigations revealed that the oil warning light came on as you pulled the starter, which had also happened the first time. As the guys at Elliotts (who’d repaired it last time) had said there was water in the fuel that time, I thought I’d investigate this first. In the back of the owners’ manual it explains how to drain the carburettor, which seemed like a good thing to try. Water is heavier than petrol, so it sinks to the bottom of the tank, where it goes down the fuel line and into the carburettor. To drain the carb, open the side maintenance panel (the one surrounding choke lever) and pull out the three lengths of clear plastic tubing that are tucked into the casing - they’re not attached to anything at the bottom. Put them into a container of some sort (I used a large jam jar) that you can use to catch the water/petrol when it drains. Make sure that the engine switch (which is also a fuel valve) is turned ON and then undo the screw on the bottom of the carburettor by a few turns, and the fuel should start to flow. About 200ml of fuel should drain out, and you should be able to tell if what you have is water or petrol.
Mine was definitely petrol and not water!
If you disconnect the HT lead from the spark plug and pull the starting handle, you will pump fresh fuel from the tank through into the carb - you can empty the whole tank this way if you have enough patience.

Position of the carburettor drain screw

Of course, this didn’t solve my problem, which left me thinking that the problem was electrical - some damp mucking with the electrics and preventing the engine from firing. So, last night, seeing as it was clear and breezy, I left the cover off the genny to help it dry out.
This morning, when pulled over, it spluttered briefly into life and then died. Further fiddling made it start about one time in twenty. At this point, encouraged that the thing wasn’t entirely dead, and with assistance from my landlord Martin and his daughter Sabrina, I took the whole thing apart for further investigation.
This is slightly fiddly, but easy when you know how. Now that I do know how, I’m sharing that knowledge, as there seems virtually nothing on the internet about how to fix these generators, which gives an idea as to how reliable they are!

Anyway, first drain the fuel tank - this isn’t totally essential but is recommended on safety grounds. Next, remove the side maintenance cover and unscrew the grey plastic end covers (one around the sockets, one around the exhaust) - they both undo with four screws each and then pull off. To take the rest of the casing off, first peel back the rubber surround around the fuel cap on the side nearest the sockets - you’ll find a small brass circlip which you need to prize off. This is a bit of a fiddle, and even more so to get back on again unless you have circlip pliers.

The circlip under the fuel filler surround

Now undo the screws on either side of the socket panel - there’s one on each side. They’re not captive, so remove them completely from the cover rather than dropping them on the ground when you tip the unit on its side! Roll the unit onto its side, with the starting handle downwards, and undo the screws in the handle and the base. You’ll need a Philips No 3 screwdriver (PH3) and if your unit is like mine, the screws will be very tight indeed. You should now be able to lift off the plastic cover and get at the insides in an ordered fashion. Alternatively (as I did), split the cover in half whilst the machine is upright, and watch everything spill all over the floor!

Anatomy of an EU10i - from back: engine/alternator block, fuel tank, inverter, socket panel

I was looking for the ignition system wiring, which is buried at the bottom of the casing underneath the engine and the inverter unit. This turns out to be a bit below Honda’s usual high standards - the ignition wiring has lots of connectors (some multipole and some bullet crimps) and none of them are very well waterproofed. What eventually solved my problem was getting at the engine switch, which is actually a small black microswitch just below the edge of the maintenance panel. It’s pressed in by the white plastic rod that’s turned by the engine switch knob itself. It’s a proper pain to get at, as you have to unscrew it from the cover from the inside, which involves moving everything else out of the way. Anyway, having unscrewed it, I was able to trace its cable back to a two-pole connector covered in muck and sludge, which I disconnected. Having done this and cleaned the connector, I pulled the starter carefully, and the engine sprang into life. Of course, it wouldn’t stop, as I’d disconnected the ignition switch (oddly, the switch closes to stop the engine) and so we had to stop it by pulling the HT lead off the spark plug.
I decided at this point to clean the water/oil/petrol/WD40/grime out of the casing and electrics, and to waterproof the ignition system connectors with self-amalgamating tape. Thanks to Helen for buying me some whilst she was in Cambridge!

The engine microswitch

Reassembling the generator was a bit fiddly, too. Firstly, reassemble the engine mountings - the rubber disks and metal shafts - there are two in the bottom and one in the handle.

The generator with one side removed. Note the three round engine mountings

The inverter unit (the slim aluminium unit) and the fuel tank have to fit together quite tightly, and there’s a rubber spacer that holds them in the right position:

The inverter (top) and fuel tank (bottom) with the rubber spacer between them
Reassembling the case is fairly easy as long as you have the inverter and fuel tank located correctly in their mountings. You may need a second pair of hands (thanks Sabrina!) to hold the casing together whilst you get the circlip back on.

Anyway, I now have a working generator, and am going to take more detailed steps to stop it getting wet in future - but I hope my experience will help anyone else who suffers similar problems.