Generator Project New Blog

As the generator has become a minor project of its own I have created a new blog to cover it.

http://dcgenset.blogspot.co.uk/

Any further updates will be posted on the link above.

Generator Update

The new drive plate has been made and fitted.

Once the drive plate and new support frame was fully bolted into place a final dial gauge test was done. On the end of the shaft there was 5/1000th of an inch runout. This shaft will be cut back on final assembly to about 11/4" (30mm) when the HRC90 coupling is fitted. This will reduce the runout even more. The coupling is designed to take way more runout than this.

This video explains better than I ever could how the taper lock system works.

New Genset Frame

This is the new frame I have made to do 2 jobs. 1st job is to support the rear of the engine. Previously the 230v alternator body did this. The new 12v alternator isn't designed to do this

This doesn't look much but it took several hours of head scratching and trying different things. There was 2 main problems / considerations in the design. The 1st and most important was the maintain all the original parts so it could be put back to original. 2nd, I wanted it all to fit back in the original sound reducing box.  The other minor problems were to ensure access and use all the original bolts and the exhaust pipe route got in the way. The final consideration was to ensure the new alternator could be fitted and removed as the pad mount lugs are wider than the diameter.

The pads of the alternator will sit flat on spacers on top of the flats of the bottom angle irons and bolted through 

HP Calculations

In reply to a comment here, I realised I hadn't shown my workings!

So is the 12hp engine powerful enough?

This would be the maximum output.  It's very unlikely my batteries could ever draw this much. The plan is to run the engine at 1500rpm, however it can be run faster if needed.  Why 1500?  well its very quiet at that rpm, but even at 2000rpm its a fraction of the noise at 3000rpm.

This is the horsepower required to achieve this.

This is what I am looking to achieve at 1500rpm

This is the horsepower required.

These calculations are of course in ideal situations with a new engine, however there is still about 33% to play with.

So time will tell, but I'm confident the engine will drive it.  Interestingly when I was considering a 1500rpm 4 pole 230v alternator it was calculated by the intended supplier that it could not exceed 3kw output.

US Alternator Has Arrived

The Ecoair alternator arrived today from America :-)

Just a picture quick entry this time.

Its big! and it's heavy 18kg!

In the interim I have been looking at drive options.  I have decided to make a new drive plate:-

Old drive plate

to which I will probably use a Fenner HRC Coupling or possibly a Fenner Tyre Coupling.

12DC Generator

I am sick and tired of my current 230v genset causing all sorts of problems with unstable voltage, poor quality sine wave and noise, (engine not electrical) although I suppose there is plenty of that too. My Victron doesn't like it and I have killed so many switch mode power supplies for mobile phones, iPads, even the power supplies in a Sky box, a DAB radio and a NiMH drill charger which actually caught fire didn't like it.

So why have I or indeed any boaters got a generator?  I think in most cases 99% + its to charge our batteries.  Of course we all have one bolted to the side of our main engine which by and large does an excellent job of charging the start battery for which it was designed for and a pretty fair to poor job of charging supplementary or house batteries via various methods of diverting surplus charge elsewhere.

When I did my alternator conversion the one thing I didn't expect to be as successful as it has proved was the ability to run my oven 2.2kw through the inverter and still be putting in as required depending on the SOC of the batteries up to 60amps of charge.  This set me thinking, why the hell am I making 230v to run my inverter charger to then charge the batteries at a maximum of 120amps when my new alternator on the main engine I have seen putting in over 180amps without conversion losses.  I have read somewhere that the Victron inverter on charge makes 800w of heat as well. Heat I really don't want. This I can well believe as I had to add additional fans to the inverter space under the stern steps in order to keep it cool enough to keep the charge rate up as it shuts down the charge rate according to the running temperature. 

So you might wonder where this is leading.  Well as I see it its simple. Use my current 500cc genset engine to spin a 12v alternator instead of running a 4000cc (4L) to do the same.  Big engines like this suffer from bore glazing running on tickover or low loads.  Google bore glazing its an interesting topic with many views generally eventually agreeing its not a good thing.

My initial research lead me to a 220amp automotive alternator
but this would need spinning at 5000+rpm so gearing would be required.  I had considered running a 3kw 230v alternator at 1500rpm (4 pole) but again this still had the electrical conversion losses but in preparation for this I managed to con my current genset into running at 1500rpm by removing a slow run cutout relay.  At 1500rpm its as quiet as a sewing machine.   But then I will need to have made for me a drive pulley set and this will have additional frictional losses and belt slip reducing the limited power the genset engine has.

So having bought the 220amp automotive unit 

220amp Automotive alternator

I did some more Googling  and found a slow speed 12v alternator from the USA. 

The Ecoair company  make probably exactly what I and every boat owner needs, and a 24v version also.

325amp Slow spin alternator

After exhaustive discussions with one of the directors I have purchased one of the 12v (14v) units with the option of becoming the UK / EU importer distributor.

So having stripped my current genset:-

Vetus genset with cocoon

The 230v armature still to be removed

Armature and coupling removed

Flywheel end of the engine

This seems to be a 6 hole fixing with 200mm PCD so I will need to look up the SAE of this fixing.

This is an ongoing project so I might start a separate blog on this conversion.  In the meantime if you want to follow it make sure to bookmark it of check back regularly 

Making Keel Cooling For A Friend

A very good friend of mine had a new engine fitted recently.  The boat was an ex hire boat and only had a 35hp engine which is fairly normal for a hire fleet boat. The hire companies do this deliberately as they want to control the speed the boat can achieve and they probably govern the engine as well.

The beauty of these boats is they can be bought for very reasonable price, they come well equipped with quality fittings to stand the riggers of hire and the hulls are well built.

So the internal skin tank was set up for a 35hp engine, a fact the professional boat company installing the new 52hp engine somehow overlooked?  Hmm?! IMO the first thing to work out when fitting an engine is how to cool it.  If you can't cool it you can't run it.  Well you can but so long as you don't call up all the horses or want to destroy it. 

The problem only manifested itself when Sue needed to punch against the flow on the Thames, which of course needed more horses than poodling on a canal which she had been doing since the new install.

There were 2 options to solve this, another internal skin tank linked to the original which would require the engine bay to be cleared of things like the errr! engine!  The other option an external skin tank, or keel cooling which is really what a skin tank is requiring just 2 holes made and welded in the hull.  No engine removal and just a few hours work in a dry dock.

There's a well regarded formula for working out the cooling area / engine hp.  It's HP divided by 4, so a 52hp engine needs 13sq/ft of surface area.  The most compact way of doing this is with tube, in this case 80 x 40 box section which gives 1sq/ft of surface area every 16" of length.  To further compact this a serpentine patten is the norm.

This is it.

So this is what I came up with and made for Sue & Vic.  See the links below as she takes up the story on her blog.  Read backwards from here:-  Sadly I wasn't able to fit it for her, but the local floating dry dock did a great job.

If you like boating blogs, you will love Sue's.  Her's is constantly ranked in the top 10 UK boating blogs, its has a great balance of travelogue, opinion, and lifestyle showing the good and not shy of speaking about the not so good. Always punctuated with great photos and on the sidebars masses of excellent links, tutorials and resources as well as a massive list of fellow boater blogs.

Comfy Seats :-)

About a month ago I made some templates for the seat cushions to finish the seats on the stern deck.

After a lot of hunting around and reading reviews I decided to place the order with Caravan & Boat Seat Cover Centre.  I liked the name to start with as it said exactly what they did and following a few chats and emails with John I was convinced it they were the right people to make them.  Its true what they say in sales, "people buy people" and so it was with John.

So here they are in all their glory!

They have been beautifully made and so neat.  I'm not sure of the density of the foam but they are surprisingly heavy, very comfortable and supportive.

Thanks 

Its War On Mozzies

Why should we swelter with 26c -30C heat in the evenings when we have windows that are fully removable?

S-Line Window

Well until now its because the mozzies win. We shut all the windows and suffocate. You see, we are unfortunately, the type of people that come out in massive lumps when bitten.  So its WAR!

First off I made some fly screen replacement windows with the help of my friends with a CNC router.  They cut the frame parts for me, all exactly the same of course, scanned from a pane of glass then modified to suit.

The mesh is the same material Tutu's are made from I think its called dress net.  This was doubled up .

If you look closely you can see the Moire Pattern 

So now we are sitting with a nice cool through breeze with one of these each side of the saloon and just in case any pesky mozzies do feel lucky we have a death chamber waiting.

Should we still manage to get a bite we now have one of these each as well which we tried at a friends boat and they really work!

Amazon link

Cool It

As I went up the stairs the other day I was hit by a waft of heat coming from the back of the fridge which is a built in one.

When I felt the element on the rear of the fridge I was shocked by just how hot it was.  Out came my trusty digital thermometer and showed 65c!

Knowing the bilge air is much cooler I decided to add some 12v fans to draw air up from below and push out over the back of the fridge.

After a bit is probing with a multimeter I found the compressor feed and wired in a 240v relay to switch the 12v fans only when the compressor is running.

The result is now a much cooler 37c.  So hopefully this will save some battery power.  The total load of all 4 fans is about .5 a/h.

Underwater Prop Change

I've always had a suspicion my prop was undersized for the boat and the type of waterways we do and intend to use it on. The engine never seemed to be "working" which is not ideal for a diesel and is only really used at the lower rev range.

I did some research into the very black art of prop calculation, at first online with various web based calculators then with about half a dozen UK based prop manufacturers.  In all cases the maximum diameter I can swing is a 21" so this was a definite as too was the max RPM, HP, and gear ratios and the hull size and weight.

All online and all manufacturers calculations came up with the same pitch within an inch or 2,  with most pitching at the mid range of 21.  So it was decided a 21 x 21 and still a 4 blade. Up from 21 x 16.

Old and new props side by side

The initial plan was get a lift out and the back the same day at a local crane day, but the more I looked at it and them more advice I sought I decided it would be worth at least trying to do it under water. If this didn't work or something serious happened the crane was still an option.

I'm fortunate that the weed hatch on the boat is quite large and access good and Garth at the boat yard had the necessary prop puller on hand.

Weed hatch

The prop nut on a Vetus shaft is a flange nut so there would be no problem with either lining up a nut and split pin hole or having to drill a new one.  The only down side was two 2mm thick SS flanges had to be hack sawn off and hack saw movement was limited.  This part of the job took a quite painful hour or so, but once done the nut was easily removed.

Prop nut showing the flats where the flanges lock

Old prop, nut removed

Then getting the prop puller on was a bit of a fiddle but about half an hour of adjustment had it ready to start winding on the pressure.

Lots of lines attached so as not to lose anything

After a bit more tightening that sweet moment the taper broke.  The prop was off. :-)

This lot was removed and the new prop offered on the the shaft and measurements taken to establish the key wouldn't be too proud for the new prop.  I was undecided that the prop would sit entirely on the taper and not the key.  In the end I decided it was probably fine but removing .5mm would do no harm so I did this gently and ended up, once it was flat and square again, at .7mm removed.

Then it was time to fit the new prop.

All complete with shaft anode refitted

In all it took around 6 hours, and of course the only part dropped was the non ferrous prop nut which required the donning of  the wet suit and snorkel and a short dive to the river bed about 4' down to retrieve it.

All in all a good days work and a worthwhile experience. 

The purpose was to load the engine a bit more at as the 16 was not making the engine work and would easily reach max RPM of 2500 which is never needed or used. Also I wanted the fast cruise RPM to be at the top of the torque curve at 1500rpm.

RPM             Speed MPH

                   Previously 16".          Now 21".
  800            2.6                          4
1000            3.5                          4.8
1200            4.5                          5.5
1500            4.8                          6.5    Turbo now heard working
1800            6.0                          7.8    And speed building

I suspect given all the right conditions 8.5mph would be achievable.

The conditions were wind on against 2 mph (ish) flow.

Observations so far are noticeably less rudder judder throughout the range, more rudder authority, less rudder input to keep on line, turbo heard working, acceleration much better (not really required) stopping massively improved prop walk slightly more pronounced, engine ran 5°c hotter on prolonged 1800+ test but this returned to normal 85°c very quickly at 1500 and maximum rpm now 2200 so slightly over propped as expected. No black smoke at any point on the test.

In conclusion I think this has been worthwhile. I can now cruise very nicely at 1000 and fast cruise at 1500 and gallop at 1800.

These are only preliminary tests on deep water so like all things boat there are infinite variables.

The predicted all round performance/economy improvement was 20% which I think is probably about right.  Someone else can do the calculations for me if they like.

Next stop 100,000 page views?

Sneak Preview Of Current Project.

This is what I'm up to at the moment.  Seats and storage boxes for the rear deck.

More next time.

New Central Heating

Last Tuesday I set about installing a new central heating and hot water boiler.  Although the Mikuni MX60 originally fitted has done sterling service for 2 winters, it did run hard and long which is actually good for this type of heater.

I decided the replacement would be a Hurricane SCH25 as it has more function and control.

I gave my self a couple of days to do this.  First job of course was to remove the Mikuni which took about 2 hours.  

With that safely removed and packed away the next job was to drain the engine calorifier coil as I would also be installing a flat plate exchanger to recover engine heat into the radiators which the SCH25 control system is able to do.

 20 plate 44kw heat exchanger

This is placed in series with the calorifier coil. The left hand (blue) pipes are from the engine the right hand (white) go the the central heating system and the SCH25 calorifier coil.  

Once the engine water has reached 70c this aquastat switches on the circulation pump and feeds the harvested heat into the CH system but without firing the SCH25.

This of course can be used in reverse to preheat the engine from the Hurricane but this would need another pump.  There is a small amount of thermo siphon already so I might consider putting in a 1 way valve to stop this as heating the engine without the option is wasteful.

Once the system was up and running I was getting (from the engine alone) 56c of water through the CH system.  Basically free heat when cruising or charging.

Reading taken from the towel rail

After 3, yes 3 days! I had all the plumbing done, and the heater installed and the wiring put through.

I had to cut a larger hole for the exhaust.  The old one was 1 1/2" and the new one is 2".  I didn't want to put yet another hole in the boat so how to do it?  My plan was to clamp wood either side of the hole and run a new pilot. But no there's a much better way shown to me by Garth at Ely Boat Yard.  This has to be tip of the year so far. So obvious really!

Use the previous hole saw as the pilot
 by mounting both on the arbor   

How neat is that?

New exhaust fitted

As always putting in wiring neatly all takes time.  The previous room stat had only 1 pair of wires the new one needs 3 pairs + I heft a spare for an extra frost stat but probably won't be needed.  This involved taking down one of the kitchen cupboards, the one with the most stuff in it of course!

Followed by the wiring back to the control box.

There are 3 extra wires here too, one for the GSM remote for the controlling the heater by TXT, one for the extra but probably not needed frost stat, and another for a room stat in the bedroom if it proves necessary.

Then finally all connected.

And with permission from the manufacturer in Canada the GSM remote wires soldered on to supplement the  switch on the system remote panel.  Special permission to not void the warranty

.

And here with the panel switch off but the GSM switch on, system working.

So that was that.  It was a bigger job than I expected and if was presented with a bill for the time it took me I would be questioning very seriously.  I would think it probably took me 30+ hours.

All I need to do now is learn how to program the room stat/timer controller.  It's too cleaver for it's own good so they provide tutorial videos on the Heatmiser website.

To come:-  The new prop has arrived.

And some new seating and storage for the stern deck.

This is the template to build to