AIM Stocks – what to watch out for....

My own professional expertise covers one particular area of minerals and metals processing.  Note, however, that I'm not a financial adviser.... do your own research.

  

The Alternative Investment Market (AIM) is a UK market for shares in smaller, more risky companies.

You've spotted a start-up company that's reporting great things – they've recently floated on AIM to raise £100m and the financial press is full of its potential – and so you've also bought into the marketing spiel and you now own a fraction of this company – they either have a new production process that's going to revolutionise an industry sector or else they've specific oil, gas or mineral rights to a particular piece of land or sea and therefore everything looks rosy, yes ?  

Wrong ! 

Why ?  Read on....

So, this fantastic new company has, say, the oil or mineral rights to a particular piece of land or sea.  What does this mean ?

Well, it means exactly what it says.  The company has probably agreed to acquire the sole and exclusive rights to extract whatever mineral they specified from under this piece of land or sea, but usually only for a finite length of time to commence, i.e. some government or other has given them maybe five years to build a full-scale production operation, or at the very least to commence 'meaningful works' – if your company fails to meet this deadline, then this (very expensive) option lapses and is up for grabs again and anyone else can then bid for the future rights.

So, your AIM company with a market capitalisation of £100 million wants to develop, say, a mineral minesite. 

Dead easy, yes ? 

Wrong again !

Have you any idea of the sort of financial and regulatory frameworks with which it's required to comply, even in so-called third-world countries ? 

Firstly, there's the initial cost of acquiring the option, let's say a lowly £20m, then they may need to confirm that the resource is exactly as rich as it's claimed to be, maybe £2m in further testing etc, then there's a series of feasibility studies required, eventually up to a level that would be acceptable to future equity partners or lenders.  Let's say £1m in total as a ball-park figure.  Then there's an Environmental, Social and Impact Assessment study (ESIA) into the proposed development, let's say £500k and which may well be on the low side.  Then there's survey & planning fees, consultation with local residents, possible relocations, public relations etc, let's say another £1m just for starters, if you're very lucky.  

Homemade Axial Flux Generator - Part 1 - The Mechanics....

Late last year, I'd thought I'd have a go at building an experimental generator which could be used with a wind turbine, either a new-build Savonius vertical-axis type or else utilising my spare set of home-made blades for our existing horizontal-axis machine.     

I'm starting small, at only around 150 mm (6") overall rotor diameter but I've a couple of worn front brake discs lying around in the workshop from my old MGF (long gone now....) which could possibly be used for a larger version in the future.

After first looking around at what others have done on YouTube etc, I came up with a slightly different design to most of the others and then set to work.    At this stage it's intended to be a 3-phase alternator and so with 12 magnet poles we'll need 9 coils cutting the flux during rotation.  This will give the required 120 degrees of phase separation during operation - there's several animations available on the web which show moving graphs of the voltages induced in a 3-phase alternator.

The generator coils will be static, i.e. will form the 'stator', and the magnets are fixed to steel plates and rotate, i.e. the 'rotor'.  The assembled rotor comprises two parts, the outer and inner.  The rotor shaft rotates in ball-bearings in the housing, to which the stator will be fixed in position.

I bought a couple of profiled steel plates from eBay, for the rotor discs.   I already had several pieces of aluminium round and square bar in the workshop from which to machine the bearing housings and shafts etc.

bearing housing, temporary central bolt,
rear bearing, rear stub shaft and bearing spacer

There are two bearings fitted in the front of the housing, so the generator shaft can rotate independently, and a third at the rear which will support the direct connection of a turbine blade set via a stub shaft.   The entire blade hub / generator assembly could then be retained by a single M10 central bolt - I've just used a length of studding for the moment, turned down to 8 mm diameter at the rear end so I can fit into the cordless drill chuck for testing.

There's only one way to remove a tree stump....

With apologies to Jasper Carrot and his old '...there's only one way to kill a mole..' comedy routine....

We've five tree stumps on our new piece of land (all conifers) that are quite large and in a difficult spot for removal by digging, and I know from experience it's also back-breaking work exposing the stumps down to a level where the roots can be cut.  Hiring a stump grinder for a weekend also seems a very expensive option.

In anticipation of acquiring the land, we'd cut the trees down to just above ground level around 9 months ago (they'd already been cut to below head-height by someone else in the past) and then we killed them off using Bayer's chemical tree stump killer (glyophosate), which seems to have done the trick since there's been no new growth and the bark on the stumps has already started to soften and can be pulled off easily by hand.

Land acquired.....

It's been quite a while since I last posted, what with work commitments and Christmas etc, but some sort of celebrations are in order !   

Our purchase of additional land adjacent to our house went through in November of last year.  It's a strip of 5 metres width and around 35 metres in length.   We had first expressed an interest in buying this land back in February 2011, and so the whole process took around 20 months to complete....

We won't frighten you with the costs, but adding legal, survey and planning fees it came to an awful lot of money for a simple extension to the gardens.

Anyway, we've now got the land and are very pleased with it.  The neighbouring farmers also bought the remainder of the available land for sale, as additional grazing for their livestock.

So we've already taken down the existing fences and hedges, and hired a mini-digger and operator for a day to clear out one particular area which must have been used as a dumping ground for hedge and grass trimmings for the last forty years or so.

the northern end, before clearance.....

and after....

Some of our old hedge trunks were very substantial and so we've added to our stockpile of logs for the fire.   They need to season for about a year first though, to dry them out properly, so they'll be good for next winter.  The rest of the tree and hedge cuttings went on several bonfires.

Home-made Solar Panels - Part 2 - Operational Data, Costs & Economics

This is the promised second part of the Solar Panels post.  In this, we'll take a look at Operational Data, Costs & Economics.

Operational Data

The first panel was commissioned on 03 May and the fifth on 20 June.  Operational data was collected on a daily basis from the time the first panel was in place, and so at the time of writing we've exactly six months' worth of data. 

This summer has been very much a mixed bag in terms of weather - May wasn't too bad, June was very poor and the beginning of July only a little better, but since then it's been more typical of what we can generally expect around here.

Graph 1 below shows the total cumulative energy from the array since the time of hooking up the first panel.  The curve starts off rather shallowly and then gradually steepens as more panels become live, but the gradient is not as high as expected since the weather worsened through the commissioning period.  

Note that all of these graphs shown here represent net AC energy provided to the house grid, i.e. all the losses and inefficiencies in the grid-tie inverter during rectification and transformation from DC to 240V AC are already accounted for.  The light red line on the graph is a linear trend line.



Graph 1

(click on any of the figures for a larger image)

Going off-grid... Part 1 ... Musings on the possibilities....

Firstly, my apologies for what is quite a long post without any pictures to break up the text....one of the advantages of writing this blog is that, for potential major projects like this one, it focuses my ideas and also forms a written Design Basis & Facilities Description for me to refer to in the future, and is a basis for comparison after completion....

I think it would be very good for the soul if we could be totally independent of our electricity supplier and run the entire house off-grid.

How can this be achieved ?  Let's look at the possibilities....

Paper logs & briquettes – Solid fuel for free ?

Like most households, the amount of paper regularly pushed through our letterbox is astounding.   Every week, we receive reams of local advertising material within what are laughably called 'free newspapers', plus flyers for local take-away food services, insurances, garden clearance, roofing, TV aerials and just about anything else you can think of.

Even the postal service gets in on the act, routinely delivering one or two pieces of junk for every real letter which is actually addressed to us.

The addressed mail we receive, from bills to further targeted marketing guff, also eventually needs to be disposed of – anything that has our names or address on it gets shredded as a matter of course.   The remainder of the junk paper is all just dumped in our blue recycling bin and collected by the council every fortnight.

At least until recently.....

We have an open fire in our living room, fronted by an Edwardian cast-iron insert with a mahogany surround that we bought very cheaply on eBay when we were renovating the house.  We replaced the old cracked picture tiles with new picture sets of the wife's choosing, gave the iron frame a good wire brushing and a fresh coat of high-temperature paint, extended the depth of the fireback with some thick steel sideplates and then installed it.  The fireplace in the chimney breast had been blocked up years ago but we opened it up again, enlarged it and brought this great feature back to life.

the fireplace....

We're lucky enough to live in an area which is outside of the urban smoke control zones, and so we can burn wood and coal etc in an open fire.  If you're within a smoke control zone, then you can only burn these materials in an 'approved appliance', usually an enclosed wood burner or similar.

Anyway, back to the story.... 

We buy coal in 25 kg sacks (currently £5.80 each) from a local merchant and we've literally a shed-load of logs from an ash tree bough that broke in high winds last year, and also from the trunks and branches of our own hedge and tree removals.

Last month, I was searching on eBay for an old & cheap hydraulic press for the workshop, and one of the items on offer that struck me was a hydraulic paper-briquetting machine.  This started me thinking, and so I then searched specifically for those manual cross-handled presses I'd seen years ago.  Still plenty of companies selling them, but the cheapest on offer was around £13 delivered and I'd no idea what the build quality would be like – from the photos, they don't appear to very substantial and might damage easily.

Now, you might think £13 is not a lot of money, but in this context it's very significant.  I could buy 56 kg of coal for that money, and even burning all the paper logs we could realistically make in a year probably wouldn't produce the same heat output as that mass of coal.  Coal is a fabulous fuel with a high calorific value and it burns very hot – it's little wonder that Britain's prosperity was built on it.

Still, even low-grade fuel from waste paper is a tempting prospect if it's completely free – we don't even have to go out to collect the waste paper, it gets delivered to the door !    So we just needed to work around the requirement to buy a machine to compress it...

So, here's a couple of ways we came up with to make the logs, just using things we already had to hand :-

Mastic Gun – we've a few mastic guns and several old cartridges with contents that are well past their best and should have been thrown out ages ago.

I pumped out the remains of an old sealant cartridge and cut the end off it.   I also made a rough blanking plate from a scrap piece of thick plastic. The blanking cap shouldn't be a tight fit in the cartridge – it must let the water past –  and so it can be quite rough.

We experimented first with material from the shredder bin.   This was also an excuse to get rid of all those eBay invoices, old bills and other papers that were piling up on the shelf, and so the process began with a shredding campaign. 

The shredder bin was tipped into a washing-up bowl filled with water, mixed and allowed to soak.  The mash was loaded into the cartridge with the blanking cap at the bottom, pushing the mash down with fingers several times and adding more until it was as full as possible.  The cartridge was then loaded into the mastic gun, and the gun pumped as firmly as possible....note that water escapes from both ends, since the gun driving washer is not a tight fit in the cartridge.

shredded paper in the mash...

We left it for several minutes under pressure to consolidate, gave the gun trigger a final few squeezes, and then removed the cartridge.  Using a piece of wood as a mandrel, we held the cartridge and pushed on the blanking plate and, hey presto, out popped a damp paper cylinder. 

very simple - cartridge, rough blanking plate
and a log made from it....

in the mastic gun under pressure....

We made a few more using the mastic gun press – they were a little fragile at the wet stage when removed, but we laid them out on an old cloth for a few days and then placed them directly on top of the central heating radiators in the workshop for a few weeks.  At this time of the year we use the heating sparingly and only ever in the evenings, and so the log drying time was prolonged. 

However, the end result was paper fuel logs which were dry, hard and of sufficient strength to be handled quite roughly without falling apart.

Home-made Screw Press – I had a piece of thick-wall aluminium tube lying around in the workshop, but although it's ideal as a log mould I didn't want to damage it because it's valuable and bound to come in useful for something more profitable.  Any design I could produce therefore required the aluminium tube to be a passive component, with no cutting or drilling.

So, I made a simple screw press from a length of 8 mm steel bar that I threaded at both ends, one end with quite a long thread length.  I made a threaded end plate and loose-fitting piston for the tube on the lathe, using some plastic barstock – I appreciate that most people don't have a lathe, but you could still make these items using just a hand saw and a few scraps of wood, they don't have to be precision engineered.   Threaded steel bar is also available from DIY stores and those hardware & tool traders we see at car boot sales, but obviously if it's more than a few pounds to buy then it defeats the object of making such a press yourself. 

So now we had a log mould of roughly twice the diameter and twice the height of the mastic cartridge, i.e. eight times the volume.  Exactly the same paper preparation process as before, but this time compressed by tightening a nut and washer against the piston within our aluminium tube.

screw press - twice the size of the cartridge...

Again, our first tests were with shredded paper.  When we pushed these longer formed logs out of the tube, they generally fell into two or three pieces but we just gave each piece a consolidating squeeze by hand.  The presence of the central screwed bar also made the wet log removal process a bit trickier, and contributed to the breakages. 

However, these breakages actually turn out to be an advantage, as they produce shorter log lengths that are more suitable for the size of our fireplace. 

first batch of logs for testing....

We also made some logs from newsprint, but for these we didn't bother shredding the paper.   We just pulled the newspaper into separate sheets, folded them and laid them in the bowl of water.   After experimenting a bit with them, it seems easier to soak them for quite a long time, maybe even overnight, and mix them around the bowl by hand until you've a wet and grey muddy pulp that's barely recognisable as paper.

In this form, although they're a bit messy to handle, they make dense logs that hold together – if the papers aren't wet enough, they tend to decompress a bit and open out slightly when removed from the press, although they still dry out and burn OK.

newsprint logs - the left one was not soaked enough and has
sprung open, the right one is from fully pulped paper

In conclusion....

We found the type of paper used had a big influence on the log making – I've since shredded several old confidential client reports that were produced on a thicker-quality paper, and these logs didn't hold together nearly as well as those made from newsprint or more run-of-the-mill printer paper.   I think the trick will be to mix the thicker stuff together with the thinner when doing a shredding run.

Those logs produced using the screw press were noticeably denser than the ones made with the mastic gun.  This is to be expected, because it's possible to apply much more compressive force on the mash in the tube using the screw.

All the logs we made eventually dried out very well to make usable fuel.  So, I think we've found a couple of ways to make some totally free fuel logs.   However, they're a little fiddly and time consuming to make with these types of home-made presses – if you intend to be serious about it, maybe come up with something that's easier to load and press, for a quicker turnaround time.  If I see one of those cross-handled manual formers on an eBay auction for a fiver or so, I might even buy one.

So how well do the paper logs burn ?  They're a bit like wooden logs in that they need to be added to an established fire, but they held together and burned well enough.  They didn't leave much residual ash in the fireplace, unlike burning loose pages of paper which produces flying ash and needs a lot of cleaning up afterwards..

three paper logs on the fire...

An added benefit with these home-made paper logs and briquettes is that they're clean to handle when dry – after all, they were made from clean paper – and therefore you can store them in any indoor cupboard, unlike either coal or timber logs...