Saturday, 12 January 2008


...or Make It Simpler, Stupid.

Forget the mangle, it doesn't need to be that complicated.

All that's really needed is a rectangular tube the size of a bottle, to store the squashed bottles in, closed at one end, with a crushing-flap and a sliding door at the other end. This'll be easier to explain with a picture:

(I used Google Sketchup to create this drawing - one of my favourite tools, and free!)

To use the crushed-bottle store, you pull up on the handle to open the hinged flap, place the plastic milk bottle onto the green panel, then close the flap gently on top of the bottle to hold it in place. Next pull the green slide panel out. If there aren't many bottles inside so far, the bottle will just drop in. Once the level of bottles reaches the green panel, new bottles will rest on top of the stack. You can now press down on the flap handle, crushing the new bottle (and re-crushing the ones underneath). While holding the flap pressed down, push the green sliding panel back in to trap the crushed bottles inside.

Emptying it could be a bit tricky. Open the flap and slide out the panel, and all the compressed bottles will shoot out. It might be fun! (once or twice).

If the entry hole in the bottle-bank were wide enough to take a bottle sideways, it might be possible to take the crushed-bottle store to it, open the flap, hold the end up to the hole and then release the green sliding panel, but the bottle bank hole is only wide enough to put bottles in long-ways. Hmm...

Tuesday, 8 January 2008

Recycling plastic bottles needs a lot of space

Kerbside recycling is pretty good where we live, but plastic isn't included yet, so we have to take plastic bottles to a collection point at the supermarket. It's mainly milk bottles, which get rinsed out in the kitchen, then get propped upside down in the garage sink to drain, before being crushed and stored in a big cardboard box until I take them to the recycle point.

Except that someone in the family (mentioning no names) tends to bung them in the box without crushing them, and I end up doing a mammoth crushing session in one go to make more space in the box. It gives me some exercise...

But the bottles don't stay crushed! They creep back into shape and fill the box even quicker.

It's like a pile of cuttings in the garden - there's not that much wood, but the sticks and twigs are all tangled and keep each other apart, leaving lots of space in between. Put them through the shredder and it turns into a much smaller pile of chippings.

If we could shred the plastic bottles, the chippings would take a lot less space, but would the recycling centre accept a pile of chippings? I think they're pretty fussy about not mixing different types of plastic, and a big pile of anonymous chippings is going to say "contamination", and "reject".

Plan B: what we need is something that squashes the bottles and then keeps them squashed. I partially achieve that by jamming the squashed bottles into the box, but that only works once there are enough to fill the box, and I want something that works right from bottle one.

I'm thinking of some sort of mangle-like contraption to squash the bottle, drawing it onto the top of a stack, which is stored in a rectangular tube with one wall that slides just far enough to allow another bottle in, but not enough to let the squashed bottles expand again.

The sliding wall could be held against the squashed bottles by a spring (would have to be a large one!) or a weight, or perhaps could slide on a mechanism connected to the mangle-handle.

The mangle rollers would need a bit more grip than those on a clothes mangle, as the plastic is a bit slippery. Maybe some little spikes (it wouldn't matter if the bottles were pierced).

Now, if the elves could just make me one overnight...

Thursday, 3 January 2008

Birthday robots

Jr (the larger) had his 11th birthday a couple of months ago, and wanted to have another "making" party. In previous years he's had a party making toy trebuchets with rice-filled-balloons for ammo, and before that, battery-powered racing cars made from card, empty drinks cans, straws, elastic bands, a motor, a battery and of course some duct-tape.

Daddy (that's me) had been toying with robotics a bit, and thought we could probably make some simple robots this time. Of course it turned out to be more complicated than I'd anticipated and I was tearing my hair out in the last week before the party when the prototype wouldn't work, but in the end it was ok, even if we did run out of time at the party and they had to come back another day to finish them.

Details, pictures, circuit diagram, construction details and firmware to come...

How to store the big stuff

The garage had to be cleared for the building work we had done, so they could demolish it to get the diggers round the back, so everything had to be packed up or discarded. I've missed several of the discarded items already... :-(

But the good thing was we had a clean slate to start with once the building work was completed.

We started with shelves on as many walls as possible. Mostly they're just those cheap wooden ones you assemble yourself, but they're fine for the large quantity of miscellaneous stuff to be contained.

Trouble is, it's only been a year or so and already it's getting difficult to move around in there again. It's all the larger items that don't fit on the shelves that are causing the problem.

The assortment of bicycles are the main space-takers. They're stacked against one of the shelves (blocking access to the lower half), and in size order, so if I want my bike out (the biggest) I have to shuffle all the rest out of the way first.

The roof isn't high enough to hoist them all out of the way. There's no free wall space left to hang them on brackets.

They don't take up all the floorspace, so it'd be ok for them to stay on the floor if it were just a bit easier to shuffle them out of the way when we need access to something.

So I'm thinking of some sort of trolley on wheels, so the whole lot can be wheeled aside to get to the shelves behind, and a separate bracket or post on the trolley for each bike or two, so it's possible to get one off the trolley without disturbing the others.

A bit of MDF for the trolley floor, some castor wheels, and some struts to lean the bikes against, one each side of a strut. What do you think?

Perhaps I'll mock something up in Sketchup first.

Leftovers from 2007

I had a few ideas last year. Some of them even made it out of my head and into the real world, which I count as a success even if I didn't finish them.

Here's a summary of those that I'm carrying over into 2008, and I'll fill in more details as and when (labels in brackets, which I'll use for further updates on each project):

Node zero (node-zero): a cupboard in the living/dining room where the wiring terminates and the A/V boxes live.

Living/dining-room lights (beam-lights): there are dangly wires where the ceiling lights should be...

The cold shower-room (shower-heat): Nice new shower-room, shiny new towel radiator, but cold in winter. :-(

Birthday robots (dodge-bugs): Jr had a robot-building party for his birthday. Definitely a case of biting-off more than I could chew.

Led sensors (led-sensors): used in the dodge bugs with some degree of success, but I've a feeling there's more to be done with this.

Garage storage (garage-storage): lots of shelves, which is good for the small stuff, but the garage is already full again, with large stuff that doesn't fit on shelves. Hmm.

Home network (home-net): lots of cat5 but not a lot plugged into it yet. Lots of plans though...

The Den (den): part home-office, part library, part hobbies-room, part a study for homework, part computer room, part games room... or "The Den" for short.

What's it all about?

So many ideas, so little time to realise them.

Perhaps if I publish an idea here, it will a) inspire me to develop it further, or b) someone else might pick up the ball and run with it.