Wednesday, 30 May 2012

The Power of Projects (Pointless or Purposeful)

I've had these thoughts about projects bubbling around in my mind for the last few weeks; sort of since my crystal growing project. I've realised over the years that devising and journeying through a project build gives me the impetus and drive to learn the new skills or knowledge required to complete them. What I've sort of realised in the last week however is that sometimes the project doesn't always have to be actually achievable or even have a point for the learning and self development to take place. If you are following me on twitter (@concreted0g) you may have picked up on the fact that I have become a little obsessed with “CubeSats”. CubeSat is a defined and accepted open source design specification from Cal Poly and is a platform for small 10 x 10 x 10 cm fully functioning satellites. Now if anyone builds one out of NASA approved materials and if it passes all the NASA tests and you have some cash and contacts with someone with a rocket you can (and amateurs have) get these into a low earth orbit (heck current trends/developments in cubesats is that companies are developing small propulsion systems so these things can go interplanetary). Now...I kinda want to build one....not helped by this wonderful artist and amateur satellite builder....

Now back to the point of this much as I feel the era of personal satellites may be coming...I realise that this is a ridiculous project for me that would never be completed let alone ever see space... but do you know what? Even if I gave this an hour a week the skills I would develop would be really interesting and possibly benefit my other areas of work/hacking/making and inspire other thoughts. I certainly am drawn to developing some engineering and fabricating skills and also would love to get into using a 3d modelling environment like google well as taking a big step forward in my electronic engineering. So watch this space, feel free to mock and berate my foolish ways but remember if you see posts about satellites - it's all about the journey not the destination! If nothing else reading about this technical stuff is a better brain workout than sudoku or crosswords.

I'll finish with a quote attributed to Dr Robert Twiggs who is the man responsible for the entire cubesat project that I feel links nicely:

“I hope the CubeSat is like the personal don't know what the heck you're going to do with this little box when you build it or what markets will be enabled. But it's so cool, you've got to do it.”

Thursday, 24 May 2012

I grew a microphone

So the image above is one of a few hundred crystals I grew from readily available kitchen ingredients in my kitchen the other night. It is a crystal of 'Rochelle' salt and is made by doing a bit of home chemistry with some cream of tartar and some sodium bicarbonate (both of these are available from any shop that sells baking stuff). The interesting thing about these crystals is that they are piezoelectric in nature meaning that if the are made to vibrate the produce a voltage. This is the exact principle in play with contact microphones and so with a bit of fiddling to clamp the crystal between 2 conductive plates (bits of tinfoil folded round a bare wire!) these crystals can be used to make this

I originally got the idea when I saw this video on Collin's lab ages ago.....

......but in the video Collin uses cream of tartare and sodium carbonate which I could not find...I wondered though if he could have made a microphone out of his crystals that he grew.....however like many thoughts I filed it away and promptly forgot about it. That was until I saw this post from the mighty Leafcutter John (I was perusing his site looking at his hydrophones...another thought on the great todo pile). In this post Leafcutter John provides the answer that if you bake sodium bicarbonate for an hour at 150C it turns into sodium carbonate...and he had indeed managed to get his crystals working as a contact mic.

So the other night I turned my kitchen into what I imagine a meth lab looks like and managed to grow some crystals and make the contact mic as seen above, now they are pretty low output and the mic preamp on my tinkering/hacking mixer didn't lift it much and I needed to attach the mic to a battery powered amp and then record the output. I attached this to my diy street sweeper bristle kalimba and had a plink around and here is the result with no effects but a bit of the top end hiss rolled off!

Sunday, 13 May 2012

Making things more playable!

In between kid wrangling, lawn cutting and all those other things that happen, I found some time this weekend to do a spot of tinkering. I've been feeling the need to make BLARP my cmos modular a bit more playable. So I've made a start by building a small keyboard....Yeah thats right a whole 6 keys!! I salvaged the buttons of a circuit board out of an old cd player (one of those old Yamaha "Natural Sound" ones..a good deck in its day!) I've had a couple of jams setting up the keyboard to control/trigger the envelope generators on BLARP. It's cool but it's made me realise I need more stuff to be able to have more on the list of stuff to build is more envelope generators as well as more repeats of simple things like oscillators and logic gate stuff; NOR NAND XOR etc. Here's a picture of me testing it playing along with some stuff I'd tracked in Sunvox on my Jornada 720.

I've also done a very silly job that I've been meaning to do for ages. All the pot's on BLARP are these small trimpots that you can adjust using a small flathead screwdriver....this means every blarp session for me start with me rummaging around trying to find a small screwdriver. I had a couple of tiny 2" long ones and they were really good as you could leave them propped into a trimpot meaning you could move your hand away but quickly move it back to make changes.....anyway I finally cracked and in 10 minutes made half a dozen mini screwdrivers out of some bits of spring steel (salvaged from the inserts in old windscreen wiper blades!!!..good for making Kalimba prongs too!) and some polymorph. Polymorph is a great plastic that melts when you place it in just about boiling water but is reaaly solid and strong when cooled.

I hope after a bit more building I'll put a video together of a BLARP live jam!

Thursday, 10 May 2012

New Minimalist ditty, One Chord and a Circular Saw Blade

Just posted this up to soundcloud. It's a quick composition thats made from (yep you've guessed it!) one guitar chord and recordings of a circular saw blade. I'm finally finding bits of time to play around with ideas again as I'd love to do another release later this year. It's very underproduced and needs headphone or a pair of speakers to even hear the thing!

Jornada 720 online (finally)

Ages ago when I first picked up my beloved jornada 720 I looked into getting it online...the jornada came with an inbuilt dialup modem but had no built in wireless connection or bluetooth. I picked up a compatible PCMCIA wireless card from ebay. The card is a Cisco Aironet 340 and has the ability to throw data about at a mindblowing 11mbps! Anyway I realised as soon as I tried it that it couldn't cope with "modern" wifi encryption like WPA or I never really did any more. I came across this card at the back of a draw and thought I'd have a play as I realised if I set my HTC phone as a wifi hotspot it uses no encryption/security. It worked really fact all I did was turn the htc hotspot on and put the PCMCIA card in the slot and when I launched internet explorer on the jornada it had already connected!

Now I can't say I'm going to do extensive browsing on the jornada but it's very handy to be able to email stuff of the jornada to sunvox project files for example. Who knows I might get into retro wardriving mid nineties style!

Wednesday, 9 May 2012

My DIY mount anywhere Shockmount

So I had some time today and decided to build a shockmount. I wanted it to be adaptable and useful and as I record all kinds of things in all kinds of places I wanted it to be easy to mount in lots of different ways.

So heres what I did;

I took some PVC gas main type piping I pulled from a skip a while ago...its about 80mm in diameter and the walls are about 10mm thick...I cut a length that's, I guess, around 12cm long (just done by eye no measurements!)

One of the ways I wanted this to mount was to be able to go onto camera tripod style mounts. This means it could be used with my favourite camera clamp (more on that later) but could also use those mini camera tripods, real tripods or even (although I don't currently own one) one of those gorillapods. So I drilled a pilot hole and taped a thread into the PVC..

I also wanted an alternate mounting point, so on the opposite side to the camera mount, I drilled and mounted a small angled plate/bracket of meccano origin! I did this as the holes in the sides of the plate could be useful if I need to string up/hang the shockmount from cordage but also the whole plate could be grabbed by my microphone stand clips (I use the squeeze clip, one size fits all type mic stand adaptors see pic later)

I then cut some grooves at either ends of the tube to hold the elastic bands in place (I ended up using some hair bands). I also cut more than one set of grooves as I found I needed different tensions across the face of the mount when I placed a mic in it. This is as mic's can be heavier at one end so the ability to tighten the bands by shrinking the hole that the bands create allows the mic to be gripped well at each end regardless of its weight and shape. This is important if you want to mount this tilting downwards so the mic doesn't fall out.

So here are some pics of it finished. These first ones show the mount on my favourite adjustable camera clamp I found in a charity shop a while ago for a pound!

And this one shows it more traditionally on a mic stand using the clamp onto the bracket.

BTW the mic in these shots has become my favourite over the years (I have a small collection of cheap mic's!) its an Audio Technica MB4000c I bought second hand for next to nothing. I love it, it's a small diagpram condensor cardiod and is really clear and has low noise...I've never heard anyone else say they use one but I think it's a gem!