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.
So..
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.
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.
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.
But...
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...
lacklustre
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.
Anyway...
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.
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.
But...
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...
lacklustre
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.
Anyway...
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.
Maybe.
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.
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.
Maybe.
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
So...
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.
Whatever.
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.
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.
Whatever.
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!
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.
(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!
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...
Winsome!
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!
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.
Awesome.
Yesterday I was cold for a bit.
Awesome!
120ThingsIn20Years... No really - Awesome!
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.
Awesome.
Yesterday I was cold for a bit.
Awesome!
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.
Tricky.
Yabbies are so delicious that they tend to eat each other.
Yum!
Tricky.
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...
http://www.fish.wa.gov.au/Documents/aquaculture_yabbies/how_to_grow_bigger_yabbies.pdf
"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.
Which is nice.
So now I have to farm them.
Tricky.
Yabbies are so delicious that they tend to eat each other.
Yum!
Tricky.
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...
http://www.fish.wa.gov.au/Documents/aquaculture_yabbies/how_to_grow_bigger_yabbies.pdf
"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.