Saturday, April 12, 2014


I like to have a reliable way of lighting a fire on me at all times. The most durable firelighting system is a ferrocerium rod, but these tend to be a bit large and don't hide well from Australian airport insecurity staff. So I invented my micro-tinderbox, that is extremely lightweight, works after a thorough soaking and drying, and strikes on a TSA-approved blunt nailfile or the file on your multi-tool.

Take a 3mm ring crimp terminal and shave off the insulation. Widen the wire inlet with a spike until you can fit a lighter flint into the hole. Then crimp really, really tight. There's the world's smallest ferrocerium rod!

To catch the spark, make a wad of charcloth, which you hold next to the flint when striking. Put the whole lot in a little baggie - with a spare flint - and hide it away for a firelighting emergency.

Friday, January 31, 2014

Homemade Fogging Fumigator

Looper caterpillars invaded our tomatoes. This is an act of war, and so I needed a way to disperse toxic dust particles (Derris Dust) amongst the plants in a thorough and pervasive manner - though I should imagine the same technique could be used to fog with any dry powder. It certainly beats heck out of the little pepperpot holes on the end of the derris tub. Here's a shot of it being tested; it's more impressive when a lot of powder is used and great billowing clouds come out.

We have an air compressor system in the workshop, so I dragged an air hose outside to provide the puff at 80 psi. On the end of the hose went the air gun fitted with a ball inflator needle. That pokes into a piece of plastic tube on a 13mm (1/2 inch in old money) barbed T joiner from my hydroponics plumbing box. Into the upright of the T goes a piece of 6mm i/d stiff PVC pipe, wrapped with tape to fit. This only goes half way up the T. Blasting air through the needle causes entrapped air to be sucked up the 6mm tubing and blown out of the open end of the T, together with any dust it may have sucked up. Cool, eh?

Derris dust is organic, but so is hemlock so only use it when no cold-blooded things you want to see alive are around, mask up, and don't muck about with it. Testing of the fogger was done with plain flour.

Saturday, January 18, 2014

Recycled raised planter frame

Suz said she wanted a big planter, raised off the ground so she could tend it easily. We have no actual dirt except for a small strip under the factory security fence which we've already planted with hundreds of peas and beans. So she needed a large planter to grow crops that don't like hydroponics.
The planter, part-filled with tubs.

I scavenged 8 x 20l polythene cooking oil containers (couldn't find the lids, buggerit) and hacked the tops off with a skillsaw. A couple of 10mm holes 50mm up from the bottom provide drainage, and a load of river pebbles hold a reservoir of water at the bottom of the container below the drains. The rest gets filled with potting mix. Planting tub x 8; 150 litres of soil where none stood before.

OK, so now we have a large plantable area, but it's not raised up off the ground. So I dismantled a couple of palettes and with the 2x4 from them and a length of preserved 2x4 from a previous project, built basically a bed frame. Suz didn't like the yellow colour of the tubs, so the frame is enclosed with scavenged timber. The bottom is slats, allowing drainage, which would have been hard to arrange without using the tubs.

The tubs also allow herbs with wandering roots to be kept separated, and things to be moved around individually if needed. I'll try to score some more identical tubs as backups.

As you can see, it needs a bit of wood preservative, but otherwise looks fairly functional. Another recycled success story!

Sunday, December 29, 2013

Hydroponics Upgrade

We've rebuilt the hydroponics system using a 75 litre nutrient tank and a 100W pump on a timer. The runs are a mix of sizes, held in place by a framework constructed from recycled palettes. Tip: When designing a hydroponic system, start with the tank, then design the drains as that'll tell you where everything has to go.

This is what it looks like after a month or so of serious growing:
As you can see, or not, the tank is hidden under the foliage on a palette. A block of three new runs stands behind the enveloped one, and the bare framework for our 3rd block - which will have 3 metre rather than 2.5 metre runs - stands on the concrete in the distance.

The runs are made from a mix of 50mmx100mm and 75mmx150mm rectangular section drainpipe. Some of our runs are over a decade old and have been restructured many times. We drill holes every 200mm-ish, depending on the intended crop and the size of the little pots. Pots are filled with either clay beads or vermiculite.

We used to get the endpieces from Switched On Gardener and the plumbing from Mitre 10, but we now print our own pots, drains and endpieces using a DiamondMind V2 3D Printer from Diamond Age PLA filament.

 The endpiece has slots in in which you fill with bathroom silicone sealant and smack on to the end of the tube.

You can just see the purple 13mm barb fitting on the bottom of the drain sticking out the bottom with the yellow nut holding it in place. This gets a bead of silicone round it as a gasket before assembly.

The hydroponic pots are then filled and loaded into the holes in the run. The yellow thing on top is a hydroponic plug that is used to cover the inspection hole above the drain so that algae do not grow inside the trough.

Once the silicone has set up, that run will go in the new framework and we can plant another 14 little weed-free wonders to feed us in the Autumn and Winter.

Tuesday, July 2, 2013

This One Really Sucks

We're getting a 1.2m x 1.2m CNC, probably by early next week. In preparation I have assembled a dust extractor. It has a 2kW motor and more suck than the NSA.

I did intend to experiment with it in the following configuration as a jet cart, but the womenfolk did not agree...
 It would've been fun though. Ⓥ

Friday, June 7, 2013

Long reach nail punch

Just a little something I knocked up from a 6", sorry, 150mm nail and a piece of aluminium tube. The point of the nail is ground off and notched to engage with a smaller jolt nail head, and the aluminium sleeve keeps it on target when you whack the nail into otherwise unreachable places. The sleeve still slides a bit, so you can thump the nail all the way home and the sleeve obligingly moves out of the way.

Friday, May 24, 2013

PLA Filament Ear Plug

I've got an ear piercing that needs a reasonably-sized plug in it, and I thought I'd use my own company's PLA 3D printer filament to make one. So I took a few samples of 3mm PLA (just hit Diamond Age up for freebies folks!), held them lined up in my fingers, and applied a small blowtorch flame to the free ends to soften them. When they went soft, I squeeze them together and they weld nicely. When you get the temperature right, it welds to itself into a glorious technicolour ribbon, not to your fingertips - practice and keep a bowl of nice, icy cold water handy!

When warmed and soft, the PLA ribbon can be cut with scissors, wrapped around paintbrush handles, squished against flat glass surfaces etc. and generally worked over. So now I can make ear plugs of whatever size I need, depending on how my piercings stretch out.

I've been wearing a cruder version for a month, and the PLA has shown no sign at all of degradation when worn against my skin, so premature biodegrading is not an issue . In fact, the PLA plug is cleaner and my ear more comfortable than the titanium plug in the other ear. I'm wondering what else I can make with it. Ⓥ