Epic adventurer - DIY paracord bungee that should outlast the polar caps

Making a home made paracord* bungee** to take my new and very small Gerber Dime® multi tool on any epic adventures I may set off on turned out to be pretty worth while. Claiming that it will outlast the polar caps probably isn't saying that much.

Oh well.

I wanted to make it so I could use my new little multi tool while it was still attached to my belt so I couldn't lose it overboard, but didn't want it dangling around my ankles when I let it go without re-clipping it. I figured if I wasn't actively using it, I'd clip it to my belt, but when I was using it, I could just it to still be attached. That would mean there was a loop of rope hanging down a foot or so from my belt, and I thought that might be annoying. I have a bungee cord with a hook at each end thats been sitting in water outside in the sun for 3 years and is still in perfect condition, but I have also bought a few dozen that didn't make it 3 months. I have no idea what brand the good one is, but even if I did, it's too think for my requirements.

The invention engine said I should make my own.

I started with some paracord and removed all the inner strands. If they are tight, just pull one out at a time until they come out with ease.

The mess should look something like this when complete.

The next step was to cut a length of inner tube into a strip thin enough to fit inside the hollowed out para cord.

I cut a length around 30cm long, and around 2mm wide

Try to avoid any nicks and rough edges as this is where it will break if stretched too far.

But we wont be stretching our too far so it wont matter.

I then threaded a thin wire through the hollow  length of paracord, bent a loop, and tied the strip of inner tube to it.

I attached to other end of the wire to my house because it was the only heavy thing I could find.

With the help of some pliers to grip the paracord, it was simple to pull the strip of inner tube back through the empty paracord.

I added a decent quality swivel from my fishing gear as an afterthought, but it would have been a lot neater to incorporate it into the knot so it might lie in a straight line to the DIY paracord bungee.

As it is in this pic, I can stretch it to around twice the relaxed length.

In later experiments, I discovered that if you scrunch the length of paracord bungee into a rough ball, then roll it around between your palms as if you were rolling a ball of dough, it gains extra creases and folds. This allows you to untie it, and shorten the length of inner tube inside, and as a result bunch up the paracord.

So now I can get a stretch of around 3 times the relaxed length.

To get maximum stretch, bunch up the paracord until it's still slack when you stretch it. This means the inner tube is the limiting factor. Then let a little paracord slip through your fingers until the inner tube is still fully stretched, but the paracord is also tight.

Tie it off, and you should be set. As long as you didn't stretch the inner tube too much before tying it off, the paracord should take any extreme force that's applied, and your rubber inner should stay intact for the next 25,000 years or so.

All in all this suggestion from the invention engine turned out well.

The short length of very thin and super strong DIY paracord bungee is ideal to suspend my new favorite tool.

120 Things in 20 years - Oh look, a post!

* strong, thin, light, multi strand rope you use to hang from parachutes
** rubbery rope you use to tie things to your roof rack, or tie your ankle to a bridge with when you are about to fling yourself off.

Aquaponics - Yabby farming

I'd really like to be able to grow yabbies for the plate, but they are a little too cannibalistic and need a lot of space.

After a lot of running stuff through the invention engine, I came up with an invention to save people who have fallen through ice.

But that's another story.

The stuff that came out on crustacean farming was a lot more interesting because I don't have the falling through ice thing to worry about where I live, and like eating yabbies.

I think I'll patent the ice thing after a little development.

In the mean time I think there's a way to grow a lot more yabbies in a lot less space.

In the past I mentioned a few ways this might be achievable based on some observations, and one was that if food came to the yabby, it would sit in it's hole all day and wait.

A yabby waiting in it's hole all day hardly ever eats another yabby also waiting in it's hole. The result is yabby utopia.

They would be free to move around if they felt like it, but wouldn't do quite so much of it.

Much more like cows in a rich pasture full of 20cm high green grass rather than a hen in a 30cm cube cage.

Or at least that's what I think.

So here's what you do...

You create a shallow tank that holds PVC tubes slightly longer than the crustacean and wide enough so that they feel safe and perhaps set at 45 degrees or vertical, or whatever it turns out yabbies like.

Not too wide. 12mm black poly pipe for new borns, 18mm black poly for when they are around 2cm-6cm, then thin PVC until maturity would be a guess. Actually thicker poly irrigation would probably cost less.

You set them in a gravel/scoria/clay ball media making sure there is a few feet thick of the stuff under the PVC tubes.

The more tubes you want to set per square area, the more depth of media you need. 500L of media can support around 12kg of life. (depending on how much you feed it)

Put something under the media or run a stack of PVC pipes with slots cut in them so you can collect water from all over the bottom.

Add a pump to collect water from the bottom. An air lift would be better because it's a zero head lift and they run at a tiny percentage of the cost of a water pump.

Next you add enough water so that your tubes are covered by only about 4cm of water, plus half the length of your crustaceans at the stage of life they happen to be. Adjust as required, but this can be pretty vague.

You fill the tank with duckweed and pump so it draws water from the bottom of the media and expels it above the media pointed in such a direction as to set up a gentle movement all through the tank.

A round tank would probably be best, but square would work.

Add yabbies.

The yabbies sit in their holes.

The duckweed's 3-4cm roots float past.

The yabby grabs one, pulls it down and eats it.

The yabby grows. And excretes stuff that is either ammonia, or becomes ammonia.

I eat the yabby.

Duckweed can eat ammonia directly which is probably why it can choke rivers and lakes so brilliantly.

Duckweed has crazy mad Fu.

Most plants require bacteria to turn the ammonia into nitrites, then another bacteria to turn the nitrites into nitrates which the plants then consume.

When a plant can eat ammonia, it will always get first crack at the available nutrient. It also floats so it causes a blanket of shade at all the plants that live underwater. So duckweed gets the double advantage of all the sunlight, and all the nutrient.

The tank would definitely need a glass lid because yabbies love to escape, and a glasshouse would make both the yabbies and the duckweed grow well.

You would need to supplement the nutrient by adding duckweed from another source if you had a lot of yabbies, or adding some peas or brussels sprouts or something. Yabbies eat everything.


That's it.

I'm pretty sure it will work.

Thinking - wasabii

note to self. when you lost one lens of your glasses and you put a tissue over the lensless bit so you could see ans then you ate food with wasabi and then you used a tissue as a napkin they are not interchangable

throw all tissues away under such circumstances

eBike - Electric bike lights

Mrs 120ThingsIn20Years pulled up in her eBike only to grab a hand rail and detach a bit of tendon that should have never been detached.


She's under the Plastic & Re-constructive Surgeon's knives, scanners, and other bits of kit as I type. So this is part blog post, part self distraction.

We are so lucky in the west to have access to all these amazing experts who learnt all this amazing stuff from all our amazing universities, then went on to work at places with amazing tech that can do amazing things.

Head transplants and so forth.

Sometimes medical staff (oneofmyformerelderlyGPs) forget they didn't get there on there own, but rather because we wanted them to be put there so found the cash to teach them, and that perhaps the poor people in the hospital where they used to work were poor because they were sick or something, and not just because they loved daytime television.

But more often than not they are an awesome bunch of people.

So thanks medical type people everywhere. If it wasn't for you, I would have been dead ages ago, many times over.


Tail lights and indicators had nothing to do with this mishap, but I cant help feeling it might be nice to not have to take your hand off the front brake (right hand) to signal a right turn across traffic (we drive on the left). If you don't signal you run the risk of getting killed, and if you do, you will almost certainly be killed.

Especially by that loony driver who was driving on a moonless night with their lights off. Thanks loony driver for near missing me. A near miss is always better than a light graze.

Anyway, I thought I'd make some indicators and brake lights and things.

I figured I'd use a PICAXE programmable chip to make everything work.

I further figured the feature list should be ...

  • Headlight control so I can set strobe, always on, hi/low beam or whatever. This way I can add my own light directly to the eBike power supply at some stage, and turn the world into daylight if needs be. When we are on the road, a strobe headlight is always a good thing so you don't get lost amongst all the other white lights. But we have a lot of cycle tracks in Adelaide Australia, and when you're on the tracks, being able to see is more important, so you want solid bright light.
  • Turn indicators with a handlebar mounted three way thumb switch with off in the centre, and some kind of beeping sound that reminds you that they are on. Maybe a auto cancel function after 30 seconds (with an extra beep to let you know or something).
  • A brake light that does something dramatic to draw attention to itself, and when it's not being used as a brake light, should just go about acting like a normal tail light.
I think it's important to have a solid red light (most bike tail lights here strobe) to give the indicators a point of reference. It's will be difficult for a driver to tell if your indicator is the left or right without a red light reference point I think. 

For the brake light drama, I'm thinking along the lines of a rapidly increasing strobe that flashes faster and faster, then settles on solid bright red light. The flashing stage would take perhaps one second and should continue even after you take your hand off the brake, so you can use it as a "HERE I AM, LOOK AT ME" kind of thing. Just touch the brake when you think people need to be reminded of your being made of soft squishy stuff that goes all rancid when all your blood falls out, and then you can get back to escaping from them.

Then one last feature should be a "strobe everything" function in case of emergency. I might also attach that to the warning device.

My current warning device is a bell, but it's soon to be upgraded to a container ship's fog horn, and a baseball bat with a nail through the end of it.

Actually I think I might start a campaign that says a green flashing light on the end of a flexible fibre glass rod that extends two feet into traffic means that there is a diamond on the tip of the rod ready to gently (without disturbing me in the least) draw a line down the length of your car's paint if you get too close.

120 Things in 20 years thinks that the emergency "strobe everything" function would be best voice activated by a scream.

Thinking - Not time like the percent

I wonder if our current wacky time system has any psychological side effects. If humans think $4.99 is still in the $4 range, then perhaps we think something odd about time.

Perhaps a stopwatch showing 1:50:00 is a bit close to one and a half hours or something. Perhaps that's why I leave it until the last minute to get into the shower before going to a restaurant. Perhaps I still think I have half an hour up my sleeve when really I have only ten minutes.

It's stresses like these that make people drink 1.02110316 × 10^-54 cubic Parsecs of Tequila with a slice of lime and a pinch of salt, over and over until comfortably numb.

Personally, I think we should go with the Parsec for everything. Or...

We could make everything very very simple.

Some time ago, I remember asking mum why we (Australians) were so historically insane as to have once had one Australian Pound be made up of twenty shillings, which were each subdivided into twelve pence.

She thought I was over-reacting.

People often do.

Until you ask them to do some calculations.

Perhaps a currency like that made it a simple task to buy things with the weights they were using at the time... lets see... there were sixteen ounces to the pound, fourteen pounds to the stone, and eight stone to the Hundredweight.


If it cost one Pound, eighteen Shillings, and eleven Pence to buy one Hundredweight of paraffin, how much would it cost to buy four Pounds (no, the other Pound) and thirteen ounces. Obviously that would depend on which kind of paraffin. There's a 2/11th discount on the impure stuff, but not on the pure stuff. So lets make it simple and work it out for the pure stuff.



I tried to explain why I thought it was insane, by attempting to teach her to count in a way that started in base 12, then rapidly insaned into base 20 for the next digit (or digit like thing), before settling out into base 10 the subsequent digits (I presume).

I got very confused.

Imperial units are funny.

People must have just tried to avoid calculations that involved all the "layers" (ie pounds, shillings, and pence) It seems odd, but I guess people chunked their prices into easy to calculate amounts.

Quarters, halves - that sort of thing.

I'm guessing shopkeepers just made up prices as they went along as well. Who's going to check?

For a modern day example for people living in a metric world, without thinking too much, on paper, in your head or with a calculator, try adding ...

11:44:29 hours, minutes and seconds to
03:19:51 PM

Not so difficult, but it hardly trips off the tongue.

It makes me think that perhaps we avoid doing it. Perhaps it's just too hard, so we only use the easy chunks of time. Quarters, halves - that sort of thing.

We need a new metric clock.

Our current clock is loopy.

Anything where your first digit is in base ten, then your next isn't, should be shot in the foot.

How do you even write a time calculation?

I think a semicolon would be more appropriate.

    1/2 ; 3/12 ; 19/60 ; 51/60 ; 00/100
+        11/12 ; 44/60 ; 29/60 ; 81/100
=                                    ##:##:##.## am/pm

Perhaps percentage of a day might be better.

So 6pm would be 75.00 o'clock

It would be easy to learn, would allow easy calculations, unlimited resolution if it mattered, and the Swiss would love the economic stimulus.

It would save the world a few lines of code when designing stopwatches as well.

120 Things in 20 years thinks no sleep yet and 6am means it's time to buy a new internal clock.

Aquaponics - Selective yabby breeding

I still have my yabby brood in a small aquarium sitting on my desk. As I type I'm watching them going all crazy for some fish food flakes.

Some are much, much bigger than others. Originally the difference was only 10% or so, but now some are three times the size or more than the smallest.

I get the feeling that people would always selectively breed from the fastest growing yabbies so that they might get a more productive farm over a few generations, but studying their behaviour up close like I am, I'm starting to wonder if that might be a bad idea.

The big ones are always the aggressive ones.

No doubt they got that way because they are getting more than their fair share of the food supply, and perhaps by eating one or two of their brothers and sisters along the way.

Perhaps that's not a good way to run a farm. Where some of your cows are eating the others, or at least stealing all their food.

One of my batch of yabbies seems to not be part of any of this. It's on the large side of medium in size, and seems to spend most of it's time grazing algae from the surface of a sheet of gutter guard (plastic mesh to keep leaves out of your house gutters). Mostly it's left alone, and more often than not leaves others alone when they occasionally venture onto it's bit of turf.

I think this kind of beast might be a better candidate to breed from.

Not quite as big, but a lot more sociable and a bit less cannibalism.

And who knows, perhaps without the aggressive ones, this type would be just as big.

I'm going to try to find out.

120 Things in 20 years went to a lousy seafood restaurant, but now wants to eat more crustaceans.

Thinking - Easter - moving mountains is easier than you think

It's Easter.

Now I know Easter is really all about some Pagan thing and not so much about a Bible, but..

Traditionally, Easter is a time when all Australians get as many people together as they can, and drive around in boats very fast trying to do as much damage as they can to the river banks.

It'sThat's all well and good, it's not the speed that does it, fast boats and skiers just skip across the surface. But humans make these things that make wakes so your skiers can do jumps. It looks like amazing fun but it will destroy the river in no time.

When I was a kid of seven years old or so, we would visit an Aunty and Uncle living in a place called Port Noarlunga. The beach boasted a very cool reef full of interesting fish, and a little way away, the worlds highest sand dune (I think it might have actually been the worlds highest sand dune, and not something that simply seemed that way to a kid). A small shop would sell the normal crud that shops sell to people doing stuff at the beach, including small plastic balls with a tiny hole in them. I asked the shop keeper why there was a hole in the ball, and he told me it was to let the water out that I was complaining about that entered through the small hole.

That's when I knew there was a problem with the world.

But for a few years, this shop also hired out little wooden sleds/sledges/sleighs and sticks of wax to ride the sand dune. This dune was tall. So tall we rarely bothered to climb it all the way to the top for it was hard going walking up it.

Now it's not so tall, and the river at the base of the dune is wide, and shallow.

This image search reveals what it looked like about half way through the damage.

I put that mountain into the river.

Me and a couple of friends.

Even kids can move the largest mountain given time.

It only took 20 years or so to turn it into nothing special at all.


That's the seasonal biblical mountain moving reference out of the way.

Now, lets all try not to destroy the River Murray like I did the Onkaparinga River when I was a kid.

Speedboats and skiers don't do a lot of damage, but wake boats will eat the rivers of the world given half a chance.

120 Things in 20 years thinks we should dredge all that sand back up there.

Epic solar boat adventurer - deep cycle battery performance

I put my sweet looking battery to the test today to see what would happen running the motor at half speed.

Fresh looking isn't it.

I decided to run it on speed 3 of 5 to see what kind of range I might get without any sun.

I should get around four hours of full sun in spring on the mighty River Murray on a fine day.

Or so I'm reliably informed.

Much of the country on the lower half of the river is effectively desert so there should be plenty of sunny days.

As I move further upstream (to the right) the weather will get more and more overcast. The beginning of the river is in dairy cow country I think. The middle (shown here) is more like that kind of country that's good for growing a goat... maybe even two goats. A few meters either side of the river is nice (in an Australian kind of way), but this is a very, very old land, and this river has dug out a trench to run through so it could ignore the vast parched land surround it and just on with doing it's own thing.

 I have no idea what that being upstream will mean to my levels of sunshine at this stage.

But I wont be in any hurry, so I don't really care.

Today's test involved running the motor, and writing down some numbers every half hour. I also turned the motor off for a minute, then wrote down some more numbers.

Amp Hours
less than 1
Volts under load
Volts after 1 minute rest

After the test I waited an hour and the voltage had bounced back to 12.31v.

I turned it on for another 10 minutes and the voltage dropped rapidly to where it was before the hour long rest.

Final numbers after the additional 10 minutes were 10.36v under load, 12v after a minute rest, and 26.54 amp hours used.

I think what all this means is perhaps my battery might be good enough. I'm hoping to keep it almost full all the time with only a small amount of use for a little light.

That should put me within range of humans for 80% of my journey, but there will be a few sections where I might not see people for a few days.

To be honest, I have no idea. 

I hope I don't die!

120 Things in 20 years hopes I don't die.

Epic solar boat adventurer - Stress testing my old battery

I've had this big old deep cycle battery for years, and I don't know enough about it so I thought I'd learn some stuff.

It's a conventional, unsealed, 100ah lead acid, deep cycle thing.

At least I think it's 100ah. That's the kind of thing you'd think someone would emboss onto the side rather than adding it as a stamp. That and the voltage.

At least they went to the trouble of embossing the + and - marks.

So with this kind of battery, it seems they don't mind being run down as much as, say... a car battery might. Car batteries hate it when they are run down, and it shortens their lives in a big way.

A deep cycle battery (also called a flooded battery apparently) is a bit more forgiving, but they still see damage with every bit of use. The lower you allow the voltage to get before recharging, the less charge cycles you get from them before they need replacing. 

As I understand it, 11.8v is considered "empty", but that's at rest 6 hours after you stop using it.

I need to know what "empty" is when I'm cruising along drawing 20 amps or 35 amps (that being the amount of juice the motor pulls from the battery at speeds 4 and 5 of 5.

So my education for today turned into more questions than answers. It looks like it's business as usual.

120 Things in 20 years thinks the Internet might not know something I need to know.

Epic solar boat adventurer - Watt meter?

Not so long ago I bought a watt meter online and it arrived as described.

I love it when that happens.

The best part isn't that it actually works, and works as advertised (which IS nice), but it tells me my Epic Solar Boat Adventure might actually work. 

I have 360w of solar, and it turns out my motor draws about that same amount of juice when running flat out. 

Hopefully that means I can cruise for a few hours a day at speed  4 of 5 on a sunny day, and still end the day with a full battery in case of snake bite, internet use, phone use, wanting to shine floodlights into the eyes of the local wildlife in that way that we humans tend to enjoy... whatever.

In all these years, I've never really known how much power my trolling motor uses on full power. My multimeter couldn't handle the amperage my motor draws, so I only knew the values for the first 2 of 5 power settings. 

Today is a happy day.

My trip is going ahead.

This stuff is going to work!

120 Things In 20 Years is a little surprised that the math(s) worked

Epic solar boat adventure - Extension poles

Part of the latest design plan is to be able to raise the solar panels when my little boat is going on an epic adventure, rather than just a day trip.

During transit on the tralier, I want my solar panels as close to the deck of the boat as I can make them so they dont fly of in a direction of their choosing. I want them to be a little more under my control that the wind might, so keeping them low means I get a bit less wobble. If you don't know what I'm talking about, get a neighbour's kid (don't use one of your own) and see how much more they move about if you lift them up high on a post.

That's physics at work.

Or something.

But anyway, if you built a carport on 300ft long broomsticks, it would fall over in the first stiff breeze. But the same carport would hand it just fine if the broomsticks were only 4 foot tall. (I presume you drive a Ferrari)

So I want my solar panels to sit atop their low rise roof in 110 kph transit, but be extended to a more convenient height when I'm on an epic adventure. I don't mind stooping a bit to get under cover, but it will drive me nuts if I have to crawl under the panels if I ever need to sleep on board.


The in the low rise version (road transit, and day trips) the solar panels will sit at around 400mm high.

In high rise mode, they will sit at more like 1200mm high.

In order to move from low to high mode, I figured I'd mount the entire frame on hinges so I could add the extension tubes first to one side, and then to the other by lifting the frame with one hand and adding the extension tubes with the other.

But I have a problem. I cant wrap my head around Newton and his pesky rules...

If I mount a 1.8m cube of grow house frame so that all four of it's legs are hinged to enable it to tilt around an axis running front to back of the boat, will it fall down, or will it's integrity be maintained by the structure of the top.

I realise the answer is going to start with "it depends", but arggggh!.

I want my old brain back.

120 Things in 20 years wants to start using the invention engine again. It's always worked much better than this brain thing.

Thinking - Roots... and that

Sometimes you think it might be nice to chat with the CEO of a multinational company and tell them some stuff about what's going on within their company, but you think it will be a pointless exercise.

But sometimes, when you spend the few hours tracking them down via their old bookface accounts or whatever, then take a punt on the most likely email account they might own within their company network, they turn out to be way interesting.

I just had a very (way) interesting encounter with a young upstart/startup that might prove to be something I can work with on an ongoing basis.

You never can tell from where (whence?) the next opportunity might come.

That last line is probably worth reading again no matter who you are. Unless the grammar is all messed up. Then it's probably only worth reading the once.

But it's definitely worth reading the once.

120 Things in 20 years thinks that stuff is probably worth reading at least once.

Thinking - Flat Earth gravity

I had someone cancel an appointment today so found myself browsing youtube with no particular direction and found something interesting.

A while ago I talked about what I thought gravity might be like with a flat thing on a spherical Earth, but today I discovered on Vsauce what it might be like to live on a flat earth.

As long as it was thick enough to have some gravity, as you approach the edge, the amount of Earth behind you would add a stack of gravity. The closer you get to the edge, the more it would be pulling you back to the centre. So a bit like the billiard table I described, a ball dropped anywhere on the surface would roll back into the centre. The closer you get to the edge, the more gravity you would feel, and the more it would be attracting you toward the centre of the disk. So it would feel like you were walking uphill, AND there would be more gravity.

But my new favourite bit is what would happen when you actually managed to climb up to the edge of this flat Earth.

Nothing special.

You could just keep walking to the other side. You would step over the rim and just keep strolling along the thickness of it. The gravity would be strong, but at least you wouldn't be walking uphill any more. Once you got to the edge of the other side, you could step over it onto a downwards slope and walk to the centre.

In fact other than the centres of each side, the thickness bit (the bit that looks like the surface of a tire that touches the road) would be the best place to live and ride bikes because it would be so nice and flat.

I feel slightly safer.

120 Things in 20 years would dig a hole through at the centre so everyone could enjoy zero gravity.

Electric Bikes - My second electric vehicle

We bought some electric bikes!

Way cool.

Aside from sailing and messing about in boats, there is nothing so normal feeling as riding a power assisted bike.

You stick a battery and an electric motor onto a normal everyday bicycle, and you get an uncanny resemblance to the feeling you get when you go sailing.

Something just feels right about it all.

I thoroughly recommend it.

I bought mine from a company called Dillenger, but so far, I have nothing good to say about them.

That's not to say I have anything bad to say about them yet, but I've had a few problems due to damage to my delivery in transit, and it will be a while before I get an impression of the company as a whole.


I started work on Mrs 120ThingsIn20Years' bike first, because I knew if I built my own bike first I would just drive away into the sunset and it would be weeks before getting around to building hers.

But there were some problems.

So I started work on my bike.

There were some problems.

In the end we spent a few hours at a local bike shop called MiCycles owned by a thoroughly decent human being who made my bike work.

Thanks MiCycles.

We'll see about thanking Dillenger if they finally figure out how to do customer service without being...


If they turn out to be a publicly listed company, I might buy a share so I can go to their annual general meetings and bang on about how poor their problem resolution is.


electric bikes are awesome, you should buy one if you can.

I know I sound jaded, but I today I rode a lot without drinking enough water, so really I'm a bit "near death" is all.

I see everything once, just like Yossarian.

120 things in 20 years has spent the last three days on the phone so hasn't posted anything.

Aquaponics - Yabby stocking density

I've been thinking about stocking density, and it isn't even close to the holiday season.

I've had a clutch of baby yabbies (freshwater crayfish like things) drop from their mother, and for the last week or two I've been watching their behaviour through the glass of their small aquarium.

They spend most of their time running the boundary and bumping into each other for a quick fight, then moving on.

The result of all this watching is that I've had an idea.

The popular numbers I hear for yabby stocking density are that you need one square metre of lake per adult yabby if you want to farm them to eat (and have them grow to a decent size), but I think that might not necessarily be the case. I think that perhaps you need a linear distance of boundary per yabby rather than an area.

I have a feeling that in a lake, the yabbies might also run the boundary, bump into each other, and fight for a bit before moving on. This would mean that a large normal shaped lake might hold less yabbies than a long thin lake that took up the same area. I'm trying to stop them fighting and to give them the illusion of having a decent patch of lake to call their own, so maybe, the longer the boundary, the more yabbies you can keep.


If this turns out to be true, a long thin lake with a series of baffles might prove to be the better bet.

Or not.

Who knows.

If it works I hope it makes a stack of yabby farmers a stack of money, or helps someone who depends on their yabby farm to eat eat a bit more, or perhaps it could help someone like me to grow some yabbies in their aquaponics system.

Who knows.

120 things in 20 years doesn't know.

Epic adventurer - Solar boat - Nobility of metals and becoming unhinged


 I'm building a framework to hold some solar panels to power me the length of the mighty Murray River, and I figure I should mount the entire assembly on hinges so I can lift one side at a time to add the extension tubes to raise it up high when I'm on a long trip so I can use the space under it to sleep or whatever.  

The panels were originally going to be mounted on hinges as well so I could tilt them to the sun as required, but I figured I'd keep it simple and see how much cruising time I have per day without moving them. I can always add hinges later.

One of the problems I have is that I'm using three or four different metals in a potentially salt water environment. 

Metals hate that kind of thing. 

They have a problem with nobility. 

It turns out that if you arrange a stack of metals in a particular order based on something called their nobility, and you pick some that are a decent distance away from each other on that list and try to build a boat out of them, you get a battery, and some stress.

I already have the stress, and the battery doesn't even exist yet. 

And by the way. Where're not talking about some awesome battery that will be useful, but the kind of battery that used to be around in the 70s in your transistor radio left in a cupboard in your room, and that was left un-attended for too long and decided to go all acid all over the shop and make your mum angry because you didn't own clothes any more. It seems when you stick two metals that are far from each other on this table of noblenessso they touch each other, and then wet them with some electrically conductive liquid...say... salty water, they get all crazy and dissolve each other and basically ruin your boat. 

Sometimes ruining your boat includes letting go of solar panels while you're driving to the water at high speed, and that is the very thing I'm trying to avoid.

I have stainless hinges, painted iron grow house tubes for a frame, nickel coated nuts and bolts, and aluminium frames on my solar panels. 

Lucky me!

I bought some rubber grommets because the guy at Bunnings told me to, and said everything would alright. He was the one who sold me the hinges, the nuts and bolts, the grow house (two years before) and all the tools I needed. He was very reassuring. 

But just in case he had no idea what he was talking about, I paid some drunk guy with a boat shaped voodoo doll to make everything better, so I should be good. 

At least he claimed his boat shaped thing was a voodoo doll. 


I'm sure everything will be fine.

120 Things in 20 years needs all the magical help it can get to prevent becoming unhinged, and/or zombieism.

Epic adventurer - Think steering, and kill switches

I built a more sturdy frame to hold the solar panels.

It sits quite low to the back half of the boat.. On my epic adventure, I'll add 4 extension tubes so that I can get under the frame and use the space (and perhaps even sleep under if), but when I just go our for a day trip, I'll leave the tubes off, and keep it low. It needs to be low so it can travel on highways on the trailer without shaking to bits, or catching too much wind. 

I'm mounting the entire assembly on hinges so I can lift one side at a time to add the extension tubes before I set off.  

The panels were originally going to be mounted on hinges as well so I could tilt them to the sun as required, but I figured I'd keep it simple and see how much cruising time I have per day without moving them. I can always add hinges later.

The frame looks a bit like this...

 (you might recognise it as my old aquaponics growhouse with some bits re-aranged), but I might cut some more bits off to shorten it a little. It's around 200mm longer than the solar panels, so the rest is just excess weight. 

120 Things in 20 years thinks it might actually happen. Some of it already works!

Competition winner!

So according to Mrs 120 things in 20 years (also known as Mrs Bullwinkle, and also by her actual name in non-digital real life, the winner of the amazing solar charge controller competition - based (apparently) entirely on effort rather than anything else is ....

brbrbrbrbrbrbrbrbrbrbrbrb boom tish!

Mike Creuzer who suggested I hold a comp to get new ideas to learn or something.

To be honest I lost track a little :)

I don't really like prescription opiates, or competitions, and it turns out I hate hosting them.

Some ideas I've had are better than others. 

But I do like winning them, so if Mike is anything like me, he will like the fact that Mrs Bullwinkle thought his thoughtful thoughts were...


So congratulations Mike you seem to be the winner. I hope you put it to good use, or perhaps even better, I hope you hold a similar competition on your own blog and pass it on to someone else :) (not really - use it).

Please keep in mind I was conned when I bought it as it doesnt do the claimed 24v solar to 12v battery, so there is a slim to fare chance that it's filled with nothing but exported industrial waste rather than MPPT circuitry. 

Winner beware!

Pass the final test - guess my email address and send me your postal address and I'll send you your awesome prize. 

Why did Mrs 120 Things In 20 Years have to pick the post distant entry from the other side of the world instead of the guy I would have picked in my home town with the "most unfinished projects" entry, or my friend that suggested the cheese eating comp? I could have just handed it to either of them.

At least it will finally find a good home.

120 Things In 20 Years Congratulates it's most recent prize winner. Most of the rest of you are insane!

Epic Adventurer - Thinking - something actually happened

Something actually happened!

I did something.

I secretly fed a duck and a turtle in a park near a hospital (Where there are "please don't feed the wildlife" signs, but I picked at the bark and leaf litter on the ground, and fed other bits of the wildlife to the other wildlife, so I figure...

Where's the crime?

anyway... they looked hungry and made pleading sounds, so I fed them some other things

but I guess I DID feed them things that (if I could read exoskeleton facial expressions) looked very frightened, and screamed in utter misery the entire time...

But anyway...

after that, and more importantly, I have more stuff in my brain that I did the other day.

and that feels a little odd

It's been a while.

I've had a tummy ache.

They thought C17H19NO3 might help so gave me lots of it for ages.

Lately it feels like there's been a eighteen month slow leak of stuff from my brain rather than the thing I was going to say but forgot a bit...

So I've got that going for me.

But today I continued on from the other day, and actually finished some work on my solar boat that may have actually got me a little closer to something.

Which is nice.

It doesn't sound like a lot. To anyone who hasn't tried to make a trailer's wiring communicate with a car's wiring it wont sound like a lot, but if you have, and you know either something, or nothing about electronics, you'll know that having your brake lights strobe when you turn left is actually a reasonabe outcome. At the very least, the person behind you knows that something is about to happen, and they should probably change lanes and get as far away as they can.

Not such a bad outcome as far as safety is concerned.

But what works even better is a system that uses the correct lights where they are appropriate!

Who knew!

But the best part, is that I wired it up, hot glued it in place, plugged it in...

And it actually worked.

Today at least, physics does my bidding.

120ThingsIn20Years - Bam!

Epic Adventurer - Solar Boat - Bullwinkle III

I made some progress.

Actual progress!

I have a plan, some drawings, and newly found personal temperature control.

Which is awesome.

If you haven't had personal temperature control for a decade or so and then you get it, it's pretty much the most wonderful thing you could imagine.

I no longer need ice packs under my hat and in my pockets.


Yesterday I was cold for a bit.


120ThingsIn20Years... No really - Awesome!

Aquaponics - Yabbies!

I just raised some baby yabbies. Yabbies are a freshwater crayfish that call Australia home.

Which is nice.

So now I have to farm them.


Yabbies are so delicious that they tend to eat each other.



The problem is they they each want a stack of space to call their own.

They also take their time growing, but I just found this from...


"Separating males and females by hand is time-consuming and prone to mistakes. To make this
easier and more accurate, a hybrid has been discovered that only produces male progeny (by
crossing male WA yabbies Cherax albidus with female Cherax rotundus yabbies from NSW)"

According to the Western Australian Government fishy people, "Monosex culture provides a 70 per cent increase in gross return to the farmer."

I've had my first batch of yabbies drop from their mother, so I'm now a little obsessed with high stocking rates. I have the entire clutch in a very small 30 litre tank. So far they don't seem to be hurting each other, but they are very vulnerable when they shed their crunchy outer shell to make room for the next bit of growing they plan on doing. Shedding your armour also turns your pincers into mushy things that are no good for pincing.

No good at all.

I put the berried (that's what we yabby farmers call yabbies with eggs stuck to their undersides) female in a cage made of gutter guard (a plastic mesh to keep leaves out of your house's gutters) so the delicious babies would fall through and wouldn't get eaten by their mum. It seemed to work. Babies would let go, spend a minute or so near their mother, then drop to the bottom and never return.

For high density raising, I have a bit of a moral problem with battery hen style conditions even though (or perhaps because) I did some work on a design a few years back. But now I have an idea that I think might work for an IBC.

Basically its a 3D zig-zag of shade cloth that works it's way down a container like a staircase...kind of, so that there is a minimum of 5cm and a maximum of 8cm between each level. I'll attach a stack of PVC homes on each level that get larger and fewer as they get to the top. All of them should point downhill a bit so food and waste don't get stuck, and the basic plan is that the bigger you are, the higher you rise in the yabby high-rise (with me being at the very top). There would be gaps around the edges, so the smaller yabbies and babies would be able to find their way down with ease. They can sort it out among themselves as to who gets the housing at the top nearest the biggest food.

Watching my adult yabbies, I see that when they eat they let a lot drop. They leave a lot of crumbs. They make Cookie Monster look like something best described with words like "refined". They are also bottom feeders, and are not opposed to eating a meal that has already made its way through somebody else's digestive tract. Or more than one somebody's digestive tract.

So my hope is that I can add fish feed, or even veggie scraps (yabbies aren't fussy) into the top, and draw nutrient rich waste water that has been munched into very fine particles from the bottom to add to my growbed.

120 Things in 20 years needs to learn stuff. It's been a while.

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