Ed Poore

I wouldn't worry about it - I spent the last year of my degree heavily immersed in automotive alternators and still know bugger all about them. Worrying since that's what my Master's project was about , although I'm quite interested in an aspect that Si (simonr) pointed out about the project which basically means it could be adapted to improve battery life...

Even more pedantic mode on - an induction machine is anything that operates by the process of electro-magnetic induction. A synchronous machine is a special case of an induction machine and an alternator is a special case of a synchronous machine. I'm not denying that you can't get more power from alternators by spinning them faster (in a non-automotive application) it's just that with all the extra electronics built into the ones installed on vehicles the way that the voltage is regulated is by PWM regulation of the field current. Therefore they are tuned to produce maximum power at a particular rotational speed, which is usually a fast-idle as mentioned in other posts.

Don't think that's correct for the majority of vehicles (I say majority because there are no two Land Rovers the same and therefore what normally applies doesn't normally apply if you get my drift ). Most alternators are designed such that they can generate maximum power at more or less idle speed. Basically* the alternator is an induction machine and therefore one fundamental property of it is that as you increase the rotational speed then the output voltage also increases, the current that it outputs depends on the electrical load attached to it. So to prevent damage to batteries, lights etc then this output voltage must be regulated. The method for doing this is to disconnect and reconnect the circuit rapidly. The duty cycle (i.e. the ratio of time the circuit is on to off) therefore controls the average voltage seen at the other end. The reason you see a DC (smoothish) waveform on the alternator is due to the filtering properties of having a massive inductance (the alternator) and a massive capacitance (the battery) - they're literally a low-pass filter. To simplify matters the field current rather than the stator current (i.e. the little rather than big cables) are chopped since it's cheaper to deal with low currents (MOSFETs that can deal with ~10A are pennies whereas MOSFETs that can deal with ~100A are more like £50 a pop). So the underlying fact of the matter is that as the alternator speeds up the input current (and therefore output current) is chopped and therefore some power is "lost", or rather not generated in the first place. Therefore as rotational speed increases the power that can be generated decreases. That's a rather simplified view but hopefully justifies why they're tuned for lower speeds. There's some pretty clever electronics / physics going on in the physical design of the alternators to make changes in rotational speed matter less and the like. The reason alternators may not output maximum power at idle is due to the electronics controlling them - basically if you wallop a 100A load onto the alternator then it in turn will load the engine - this may not be desirable as it gives a rather rough lumpy response. In fact one of the alternators I've worked closely with actually stalls some amateur rally cars when they switch on all the floodlights and heated windows! During my Master's project I built a test-rig for work on alternators and this was a 4.5kW DC motor driving said alternator (150A tiny Denso thingy) and if I switched on my load-bank (~1.5kW of halogen bulbs ) then smoke would start appearing from the belts and invariably blew several fuses on the motor-driver and reached the limits of a single-phase supply. At the moment I'm tidying up this project etc for the Uni so they can use it as a demonstration in the labs and will be wiring into a three-phase supply to make it a little more reliable. Going back to the original comment - if the batteries are severely discharged then the alternator will try it's best to deliver the power in order to recharge them because the lead-acid batteries will draw a substantial current initially. I haven't noticed it on my 110 because of the torque that engine produces but certainly on the little <1L Suzuki I used to drive if you switched on the head-lights while the engine was ticking over you could hear the engine note drop as the alternator produced more power and therefore loaded the engine. *because there's a lot of mathematical gubbins behind the actual operation of them which I can't be bothered to explain and more importantly because I can't remember it off the top of my head...

Well I had the benefit of having the old guy and therefore having the digger (him being my father and all...) . Was the first proper "toy" I got to play with as a 5 year old since in the middle of a field there was very little damage you could do...

I used one of these when removing my Series drive-train. Had the benefit of being able to do it all in one piece as well.

There are some British stockists of the Sparkfun stuff as well: http://www.proto-pic.co.uk/ http://www.oomlout.co.uk/ Are the two I remember off hand

I'll find out on Saturday for you - will be doing some lanes around that area and Sarn Helen is one of the ones on the list if it's open.<div><br></div><div>Ed</div>

I've seen a few big ones in my time...

Hows about a brushes used for cleaning shotguns?

I'd contradict that if you're not very experienced in programming - 'The C Programming Language' is a reference book rather than a tutorial. I love the book (although everything is committed to memory now). However, since I didn't learn C first-hand (I knew about four other programming languages prior to C) then it was a concise guide and needed little else. More for the OP: People have covered most of the bases here about various concerns about safety etc but one area that does need attention is the power supply side of things. You can buy off the shelf stuff that deals with buck conversion but just make sure the ratings are appropriate because the electrical systems in vehicles are horrendously noisy. A very worthwhile read is this application note: http://www.littelfuse.com/data/en/Application_Notes/an9312.pdf, the main point to highlight is that if your winch motor stalls then you could see the battery voltage plummet and any regulators you have need to be able to deal with this. Another point to highlight is that the winch I have (a cheapo Champion thing but does what I want) switches about 8A through the wired remote and thus you any MOSFETs you have to switch those currents (easy to source from RS and Farnell but not "bog-standard" transistors. Pay attention to wire size as well since this is where most things fall down, particularly important as I'm also toying with the idea of building my own solid-state controller to replace the solenoids. I say toying, I have the design but deciding whether to shell out and buy some MOSFETs at ~£50 a pop. Reckon I can build the MOSFET control for up to ~300A for <£200 but we'll see.... If you want to make sure you comply with all the necessary laws for automotive use (not particularly applicable in winching applications) then I can dig up some documentation I had when I did my final year project (was improving fuel efficiency through intelligent control of the alternator).

If you define for ever as a year then yes... If it's a draw then it'll pour.

When they come out in leaf

Very much like Wales... Most changeable day I've experienced in the last few years was supervising a Duke of Edinburgh Expedition around the Sarn Helen area and had snow, rain, sun, sleet, thunderstorms, fog, more thunderstorms and finally "April showers" all in the space of 12h

Don't quite apply down this neck of the woods (very South-West Wales) since we tend to deal with most of the stuff off the Atlantic. However if you're sufficiently high up you can usually see what tomorrow'll be like . On which note it looks like it might be dry for the rest of the day so that'll mean off down to the woods in the 110 to join the digger, tractor and dumper truck to make some mess in the various lanes we're rebuilding...

Eh? Where the hell do you see these "forecasts" they're unknown to me?! All the BBC and ITV seem to show is what the weather was like yesterday / earlier in the day, and they usually get that wrong for my neck of the woods... I did once see this legend of a forecast which informed me what the weather may be like in a few hours but to be honest I could tell that by looking out the window. If only they could tell me what it's going to be like next week...

After day one of some lane clearing on the farm. It was considerably dirtier but unfortunately I haven't taken any photos and the rain today seems to have done a reasonable job at clearing the lighter splatters off. Due to the state that the vehicles and ourselves have been getting into with all the chopping, chipping and digging haven't been taking a lot of photos. Had a wonderful time yesterday when after cutting down trees that were blocking tractor and dumper trucks' passage Dad managed to disconnect one of the tracks on the digger in a bog. That was entertaining getting a metal track for a 3.5t digger back on in 2ft of mud and water...

West Wales - essentially border between Carmarthenshire and Pembrokeshire, not local to you I'm afraid... Been busy on other stuff (like retrieving the 110 this afternoon, got it slightly stuck on the way back from cutting some trees down in one of our forestries) but if the weather holds out I'm going to be spending as much time outside as possible doing work on the land and then if it begins to rain will have another look at the gearbox.

Get a few large friends to sit in it - measure the gap between the tyre and the arch and then go for a bouncy drive and re-measure. Simplest method for testing whether it works.I thought the self-leveller might have been working a little but after fitting a set of normal springs to it I no longer bottom out on the shocks as easily going over speed-bumps with a load.

Ironically it was fourth gear that was the quietest when it was on the road, third was substantially noisier than the others. I'm wondering whether there's something slightly amiss with the layshaft since if I've understood correctly it's a direct drive (like on almost all Series / Defender boxes) and therefore doesn't use the layshaft. There's a local company who specialise in rebuilding gearboxes and a friend of ours recommends them so may take the bits there and see what they think and depending on cost will either do things myself or just get them to.

Yet another vote for FTDI - they're stuff is stupidly simple to use and very reliable.If it's any help our company (small family business, i.e. Dad and Mum and I help out with the difficult software side of things once in a while) uses them a heck of a lot with data acquisition systems among other things. In terms of reliability these things are meant to run for years on end or at least many many hours at full pelt. The only issue that has been brought up is if you want to tweak the driver for your own use (i.e. when you plug in the USB cable then it'd appear as Megasquirt in your case) then there are a couple of driver signing issues with Windows 7 x64 but we were investigating cheap methods of doing the signing.We've also got all the necessary fab facilities here for prototyping / production and I know Dad quite enjoys fun projects for vehicles - he's built a very successful power steering unit for amateur rally cars that allows them to adjust the level of assistance.Oh - definitely not computer illiterate given I've worked professionally as a software developer and am now have an MEng in Electrical and Electronic Engineering. Likewise don't have a V8 vehicle or Megasquirt but have been contemplating for a long time to fit a V8 to the 88"...

Thanks. Managed to get it off in the end by driving a small screwdriver bit in one side and managed to get a claw hammer to grip a lip through the clutch housing. Almost winded myself when it eventually came off and whacked me in the stomach. Bearing is noisy (one in the bell housing) and there's a substantial amount of play but looks in reasonable condition bizarrely.

Does anybody have any suggestions on how to remove the primary pinion cover and oil seal assembly on a suffix D gearbox for a 1983 Series III? I've been tracing down a nasty grinding in the gearbox (notably when idle) which is definitely originating from by the rear of the bell-housing. Given that the 88" has done very little and was sitting for almost a decade in a garage before I acquired it I suspect the main input bearing has gone. It certainly sounds like it. Now my problem is that so far all the gaskets have required the large version of Land Rover's Special Tool #1 and a sharp screwdriver to break any gaskets to separate various components. Due to the shape of the bell-housing I can't get this technique to work (although I will persist in trying) to break the gasket between the bell-housing and the pinion cover. Having said that - looking in the workshop manuals, the green bible and various other sources it does look like I need to remove the securing nut on the layshaft to remove the bell-housing, I assume this is correct? Many thanks Ed

Just a quick search has revealed this: http://webarchive.nationalarchives.gov.uk/+/http://www.dft.gov.uk/pgr/roads/environment/research/cqvcf/tyrenoise/tyreroadnoisereport.pdf/ via http://www.the-ace.org.uk/tyre-noise-regulations.html

Not trying to put anyone off (I'd have a go if I had the opportunity) but does anyone honestly thing they can better Land Rover's own traction control systems? Haven't tried a Defender with TC / TerrainResponse but did get to drive a Disco4 last year and it's truly incredible what the traction control on that thing can do.

I don't know about the HD springs but I did fit (for exactly the same reason) some standard (van-back) springs to my 110CSW since I've now got a gun cabinet permanently installed in the back. The dampers (technically the springs are the shock-absorbers) are cheap generic 110 ones and standard-length, they have been replaced in the last 20k since they were weeping. Now something that did happen with putting the "normal" springs on was that the vehicle now rides ~1" higher than before because the original CSW springs were sagging, i.e. it's back to almost normal height now. My understanding is that all springs should be the same "height" just have different levels of stiffness and therefore how much they can be compressed by as opposed to how tall they are. Although I'm not a definitive source on it I would have said that there are two possibilities - 1) the dampers are too short or 2) the springs are not "standard height". I'd go with 2) which basically means that the HD springs are in fact ones with a lift. If you want I can see if I remember to measure the height of the van-back ones on my CSW tomorrow when I bolt the tub back on (hoping to be able to separate the rear x-member a bit to do some preemptive painting on it to stop rust but doesn't look like jacking it up is a simple job).