D.I.Y. F.F.S.

Binaural dummy-head microphone [Part 1] - Casting ears with alginate and plaster

2011-09-02T16:37:00.008+01:00

So, for my Binaural Microphone project I need a pair of ears.

There are 4 steps to creating the silicone ears:

1) Create a mould from the human model using alginate.
2) Create a positive cast using fine casting plaster.
3) Create a silicone mould from the plaster cast.
4) Create the final silicone positive from the silicone mould.

In this post I cover the first two steps. (I did a trial run on my own finger in this post.)

Get all your equipment together. Here you can see the alginate powder, fine casting plaster, a roll of cling-wrap, two cling-wrapped strips of cardboard and various mixing containers.

Read the instructions on the alginate and casting plaster before you begin work. You have to work very quickly so make sure you're prepared.

Roll the card around on itself to create a cylinder a few inches deep; make sure it's wide and deep enough to make a nice solid mould. This will be the dam around the ear into which you pour the alginate. Have your guinea pig stop their ear up with cotton-wool; if you're concerned about losing it in there tie some cotton around it so it can be pulled out. Also, make sure they coat their ear and hair in a thin layer of vaseline: the alginate won't stick to skin but it will grip hair. Place the dam on your pal and pour the alginate in.

Pour it out in as thin a stream as possible to avoid bubbles and make sure to get it in all the crevices etc. Start from the bottom up and flood the well, rather than just pouring it straight over the ears.

You'll see it change colour, and within a few minutes it will be ready to remove. Again, check the instructions on your alginate for timing. Mine was quick casting alginate, so I had about 30 seconds to mix, 30 to pour, and then 2 or 3 minutes before it was set.

Loosen it up by gently wiggling the mould, then pry it off from front to back. Be gentle with it and do it slowly, you don't want to tear the alginate.

Now you want to construct another dam around this new mould. Have your plaster ready to mix and pour as quickly as possible.

Pour it in a very thin stream into the mould. Fill it up enough so that you end up with a nice thick base of plaster.

Once it's in there gently tap the sides and wiggle it around to make sure the plaster fills the entire mould and to get any air bubbles out.

The plaster will set quite quickly. When it's ready, remove the cardboard.

Use a razor to score the alginate and slowly tear it away from the ear. Use tweezers and a needle to get the alginate out of the crevices, being careful not to scratch your plaster.

Piece of cake right?

Once you feel the plaster has fully cured, about 24 hours, you can finalise the cast.

Cut down the base if necessary so you'll use less silicone. 3 holes around the ear are drilled to attach the cast to the fibreglass head. The earhole is drilled to the width of the plastic tubing that will form the ear canal; the tubing has a 10mm outer diameter, with about a 7.5mm internal diameter which is roughly the average width of the human ear canal.

If you have any voids or bumps in the plaster cast, you can fill the former with a little fresh plaster and sort the latter with some sandpaper. You can sand the whole thing lightly with high-grit paper for a smoother finish. Brush away any dust left over on the cast and then spray several light coats of varnish to seal the porous plaster. Once the varnish is fully cured, you can move on to the next step: creating the silicone mould.

Moulding & casting with alginate and plaster (Finger - Trial run)

2011-08-26T08:53:00.007+01:00

In preparation for my Binaural Dummy Head Microphone project, in which I'll create silicone replicas of the human ear, I decided a trial run would be a good idea to try and avoid any unforeseen mishaps when it came to the real thing.

There are 4 steps to creating the silicone ears:

1) Create a mould from the human model using alginate.
2) Create a positive cast using fine casting plaster.
3) Create a silicone mould from the plaster cast.
4) Create the final silicone positive from the silicone mould.

The first two steps are vital because silicone can not be applied directly to the skin. Alginate is a non-toxic moulding agent that is perfectly safe, in fact dentists use it to take dental impressions. I found the best price for alginate was on eBay, and I bought the plaster from the 4D Model Shop in east London.

So here's my trial run of steps 1 and 2, using my finger as a model.

I made a tube out of cardboard covered in cling-film big enough that my finger wouldn't touch the sides. I mixed up the alginate according to the instructions: 1 part alginate to 1 part water. It sets completely in less than 3 minutes so you have to work really quickly. The alginate went into the tube, followed by my finger.

I don't have a photo of this, use your imagination.

A couple of minutes later I wiggled it free. Alginate breaks down quickly so I mixed up the plaster of paris immediately: 2 parts plaster to 1 part water. Pour that into the mould, above the level of the alginate so you have a base.

I left it for a couple of hours then carefully removed the cardboard.

Use a razor to cut into the alginate and start peeling it away. It comes away quite easily, so be gentle to protect the cast inside.

The cast came out pink....

...But faded to white overnight.

It's incredibly detailed, every single wrinkle, line and even my fingerprint is reproduced perfectly. It's really, really easy to do. Next stage: silicone moulding and casting.

DIY Talk Box

2011-08-17T11:20:00.009+01:00

Need to get the edge over the other Bon Jovi or Daft Punk tribute acts? I've got your back.

The point is to spend as little as possible so just see what you have laying about before you start spending money. This project cost me £6. I used:

- An old PC speaker
- 13mm (internal diameter) plastic tubing (Bought from ebay)
- A CD spindle case
- Old cds
- Mono plugs and sockets
- Socks
- A little plastic box

You just want the powered speaker with the circuitry, so throw away the spare. Open her up. You can see in this photos the 'tweeter' is just a little black circle of plastic. Cheeky fuckers.

Remove the speaker and the circuitry from the housing, being careful not to damage the wires or components on the circuit board.

You'll need to remove the plug to pull all the wires through the casing. So, open the plug, and if you don't know how to wire plugs I suggest you take a photo of the insides. Do a quick search online about wiring plugs too, I'm not responsible for any electrocutions that may take place.

I mounted my guts into a little plastic box I had laying about, you could get a cheap plastic project box off eBay for a couple of quid if you haven't got something suitable.

It's important to keep the circuitry encased safely, you don't want to be touching it by accident while it's plugged in or letting dust etc. in it. If you don't have something to mount the circuitry in, you can leave it in the speaker housing and just close it back up with just the speaker hanging free.

You need to house the speaker in something airtight so that the sound is forced up the length of the tube. I used a 50 stack CD case I had. A lunch box or something else might work, I've seen plungers and PVC end caps used. It should be reasonably sturdy though, a shopping bag ain't going to work. The CD spindle works really well because you can chop down the spindle and just plug the hose straight onto it.

Chop down the spindle, leave about 4 cm or so. Flip it over and you may need to trim any raised bits because we're going to mount the speaker here.

I used plenty of hot glue to attach a CD to either side of this base, just to strengthen it a bit and attempt to kill excess vibration/sound leakage. I'm not sure you need to do this but I figured it might help.

Now, centre your speaker over the hole, and hot glue it down. I guess duct-tape will work too, but hot glue is good for this sort of stuff and I had it handy. Cut a notch in the rim of the clear case top so you can run the wires out.

I intend to source some sound-proofing foam or styrofoam or something to fill the case, but for now it's got socks in it to try and limit sound leakage from the CD case. Once I've done that I'll ditch the duct tape and hot glue the whole thing together to ensure the case is airtight.

You can see there I've actually cut the speaker free from the circuitry, and added a plug and socket to the speaker and circuitry so I can disconnect the two parts.

So you can see the tube fits easily onto the speaker. The whole thing pulls apart into three components: tube, speaker and circuitry.

And here's a demo:

First Talk-Box test. by Nathan Gallardo

Contact Microphones / Hydrophones for sale: £15

2010-12-12T21:32:00.013Z

Hear samples at my Soundcloud

These are fully submersible, piezo-electric contact microphones.

Contact microphones are perfect for finding those 'invisible' sounds you'd never otherwise hear. They pick up the vibrations that travel through solid objects, as opposed to the air. They're brilliant for recording squeaking doors, pipes, cables, bridges, bubbling softdrink etc., it's all about experimenting.

Here's a few samples of the kind of sounds you can get including creaking exercise equipment, fence railings, spinning coins and London's Millenium Bridge :

Examples at my Soundcloud page

My microphones are entirely hand-built by me, and while all microphones are inherently somewhat fragile, mine are probably the toughest you'll find, having been reinforced and coated in a tough, waterproof plastic. They are completely waterproof (except for the plug obviously), mine has even been in the Thames.

They come with a 50cm lead and 3.5mm mono jack as standard, but if you require a longer cable or a different jack just let me know.

They're only £15, so to order just email me at this address:

nathan(dot)gallardo(at)hotmail(dot)co(dot)uk

DIY Harmonica Microphone

2010-02-07T12:15:00.006Z

Here's how I made a harp mic without actually spending any money.

The casing is from an old security camera that didn't work anymore. I ripped the guts out of it, replaced the glass front with a bit of mesh from an old radio and cut some foam to fit in between the mesh and the mic. The microphone was the speaker from an old telephone, it's that orange thing in the photo.

Luckily the speaker fit into the casing with only a little convincing from my grinder. I bored out the hole where the power cable used to enter the camera and fit a 1/4'' mono socket in there. It's all wrapped up in electrical tape so it doesn't short against the casing. That's soldered directly to the speaker. Screw the back on and that's it.

You mightn't find an old security camera, but the whole point here is that you can build a harp mic for next to nothing. Find an old telephone and get a bit creative.

Here's a short demo of how it sounds. I've not done anything to the recording except for a touch of reverb.

Resonator Guitar [Part 13 – How to install the sound well, cone and bridge]

2009-07-08T20:40:00.001+01:00

I’ve had a few questions about how I installed the sound well, cone and bridge, so here’s a cross-section diagram.

The sound well is glued the the inside of the front of the guitar. I built this out of layers of MDF. The top layer is slightly wider to add more surface area to glue it to the front of the guitar. The bottom layer is made of plywood and is the same width as the other pieces, but the inside diameter is less, so it forms a ridge for the cone to sit on.

I cheated a little with the bridge. It is what’s known as a biscuit bridge. It is a circle of maple, with a channel cut across it, and another block of maple sits vertically in this. I had this laying around and couldn’t be arsed making my own so I used it. I drilled a hole in the middle of the resonator cone (read: frying pan) and screwed the bridge to the cone. There are ridges cut into the top of the bridge for the strings to rest in.

If you’re improvising a resonator cone, make sure you think about the height the strings will be at once the bridge is installed. The height of the cone will dictate the depth of the sound well.

Hope that clears it up!

Resonator Guitar [Video and Audio]

2009-07-04T18:01:00.001+01:00

So here’s a short video about how I made it.

You can also listen to a recording of it here. It’s the one entitled ‘First Homemade Resonator Test.’

Resonator Guitar [ FINISHED!! ]

2009-07-02T20:56:00.001+01:00

So it’s done. Finally! It’s taken nearly 2 months of working on it in my lunch hour but here it is. Click for even bigger pictures.

So it’s playable at last. There are some adjustments that need done though. The action is ridiculously high if I intend to finger beyond the 3rd fret, so I just need to shorted the bridge. There is also a rattle somewhere, but I think that’s easily sorted.

I’ll do a follow up post at some point.

Resonator Guitar [Part 12 – Nut and Frets]

2009-07-02T20:49:00.001+01:00

I can try a few different things for the nut as it doesn’t really need to be glued down straight away, so first I’m trying a steel one, inspired by a photo a mate showed me of Jeff Beck’s Stratocaster.

I found a bit of steel laying about so I cut it to length, cleaned it up with the grinder and used the original nut as a template to mark the cuts. I used hacksaws and files of varying sizes to cut the slots. The action at this point is really high, but I can lower that once I’ve strung it up.

Fret spacing is super important to get correct intonation, so I downloaded WFret from The Musical Instrument Makers Forum. It’s a brilliant little program, you just put in the scale length (length from nut to bridge) and it will print out as many frets as you like and give you the correct measurements.

So I printed out the template, cut it out and stuck it on and marked the positions. I scored the lines with a Stanley knife and used a thin hacksaw to cut the grooves.

That done, I cut the fret wire to the right lengths, and used the grinder to smooth the ends. I bashed them in using a hammer and a bit of wood to avoid dinting the frets. A proper luthier would shudder but it worked for me.

The board doesn’t have a radius like a proper guitar would because I figured that might be too much trouble. I’m pretty damn pleased with that though.

I should also mention I used some yacht varnish on the board before installing the frets. I don’t recommend this as it doesn’t dry very hard.

Resonator Guitar [Part 11 – First Paint!]

2009-06-20T10:45:00.001+01:00

So we’re nearing the finish line now. I’m in for a nice surprise/major disappointment within a week or so!

I decided to paint the inside of the guitar black so that when you peer in the sound holes or take the cone out the ugly bracing and such is disguised.

The picture on the right looks a right mess. It is. But that’s cos I’ve only painted the bits you can actually see through the holes. I used a tin of black gloss I found.

I painted the edge of the sound holes now as well so that I’m not screwing around with the spray paint when I paint the body. The sound well will be painted as well at some point.

I’ve drilled a little hole in the sound well there that lines up with the hole I drilled for the jack socket. I’m not exactly sure what the best position is gonna be for the pickup; I’m going to try a few different options to see how I get the best sound. One option is to just mount it on that black brace directly under the bowl. It might turn out that it works best attached to the outside of the cone, so that’s why I’ve drilled that hole, so the wires can feed through.

So now finally the back is glued back on! I just used PVA, and loads and loads of masking tape to clamp the edges. I put tins of paint and a bucket of bolts (an actual bucket, not a rubbish car) on top to glue the back to the brace as I don’t want any rattling.

Resonator Guitar [Part 10 – Fingerboard etc.]

2009-06-17T20:47:00.001+01:00

Oh man I’ve been busy.

So, once the little kerfing blocks were attached around the top of the back side of the sides (got that?), I sanded them down flush so the back panel will attach nicely.

I decided the tailpiece still wasn’t quite right, so I used a countersink drill bit to countersink the holes the strings pass through on each side.

The ball ends of the strings will sit much nicer in there now and it actually sort of disguises the fact that the holes aren’t in a perfectly straight line.

The wood around the 'f’-holes was quite thin, and I was worried about two things. I don’t want the wood snapping off at the weak bits and also, it looked a bit shit.

I used some thing strips of wood to line the hole and glued them on.

That looks loads better now I reckon. The join is a bit uneven in places, so I’ll use some wood filler to build it up and sand it down smooth once it’s dry.

I’ve been looking for weeks for a bit of wood for the new fretboard. I was nearly at the point of buying some wood from the hardware store or even a proper ‘board off eBay! But then… SUCCESS!

Woah, I nearly spent some money there! It’s not hardwood, but then, it’s not £12 either. It’s quite a reasonably nice grain pattern on it, and I think some dark stain will make it look pretty good.

The wood was too thick, and a bit long. So I drilled a hole in either end, recessed it with a countersink, and then nailed it to my workbench. I used the electric plane from the second last photo to take it down to the right thickness. I was a little scared of the plane as there are a few doors around the place I’ve attempted to trim that are super uneven. I went for it though, and I’ve learnt the lesson is to set the plane to take off as little as possible and just go over and over it.

So, that done I needed to shape it up for the neck. The neck gets wider as it reaches the body, so I had to trim the sides slightly. I taped the wood to the neck, traced the outline onto it and put it in the vice.

I used a spokeshave, my favourite hand tool, to shave the sides down, checking it often so as not to take off too much. I finished it up with sandpaper.

It’s an experimental guitar, so I decided to do something a little flash with the fretboard.

I came up with this design by drawing straight onto the body to see how it would look. Satisfied, I drew it onto the fretboard and set to work with a coping saw, finished up the edges with a fine file and sandpaper.

I am seriously pleased with that!!

Stomp Box [Ultra Hi-tech]

2009-06-06T13:33:00.002+01:00

[Note] This doesn't actually work anywhere near as well as I'd hoped. But I'm working on it.

This simple project is a stomp box. Basically, it’s a box you stomp on to keep beat. It’s got a speaker from an old radio inside, wired to a 1/4” mono socket.

The speaker works as a microphone, picking up low frequencies. I sat it on top of some rubber washers before screwing it down so there’s no rattle.

I recessed the jack, ‘cos I’m a bit fancy.

That’s a carpet tile on top so it’s more boomy. I’ve left the bottom uncovered (ooh er) so I can experiment with putting different stuff in there to change the sound, ie. rags, foam, paper.

Also, I might have wired it back to front.

Resonator Guitar [Part 9 – Removing the fingerboard]

2009-06-06T13:19:00.001+01:00

I really want to put steel strings on when it’s ready, but the guitar is originally a classical and they’re not designed to take the strain of steel strings. So I decided to remove the fingerboard and see if there was some way to put a metal rod inside it for strength. Out comes the mallet and scraper thing.

The fingerboard came off quite easily, probably ‘cos it was glued on with the same shit the rest of the thing was put together with.

There was already a metal bar in there!! This is a real coup. I’m going to sand down the neck now and get it ready to attach a new fingerboard. I considered sticking the old one back on but its just a crappy laminate, so I’m going to splash out on some rosewood and do a proper fret job.

I also finished re-gluing the front and attaching ghetto kerfing.

I used pegs to keep pressure on the little wooden blocks while the glue dries. The blocks will just provide more surface area when it comes time to reattach the back panel.

Resonator Guitar [Part 8 - Tailpiece]

2009-06-02T21:31:00.001+01:00

I thought of a few different designs for the tailpiece to anchor the strings. I was going to use a T hinge but as I couldn’t find one that I was happy with, I decided to carve it from wood.

I found a block of solid wood that I thought would take the strain of the strings. I think it was part of an old plaque or something as it had a fancy routed edge on it. I cut it to shape and then, as I wanted it angled, drew on guide lines.

I sawed several cuts into it and then removed the excess with a chisel.

I used the spacing from the bridge I originally removed and marked the points with a bradawl and drilled the holes. Somehow they came out slightly uneven on one side, but what’re you gonna do. After sanding down I’m pretty happy with how it turned out.

And here it is glued and clamped.

Today I also did some work with the wood filler to fill holes, repair chips and smooth out saw marks.

Resonator Guitar [Part 7]

2009-05-30T13:28:00.004+01:00

So with the sound well glued together, I decided to smooth down the inside edge. The cover plate will mostly hide it, but I might as well sort it while I’ve got the chance. Sanding it by hand would have taken ages, so I rigged this up:

It’s a short section of broom handle. I put a fat screw in one end and chopped off the screw head once it was secure, leaving about an inch of shaft exposed. Then I wrapped it in sandpaper and secured it with cable ties. I attached it to the drill press and it works like a charm! I hung the vacuum from the drill to catch all the dust, as particleboard (aka, MDF) dust is nasty stuff and no fun to clean up.

That done, I glued it into the body. I also glued in a short section of wood to brace the front of the guitar against the strain of the strings. I applied pressure with some high tech pressure applying devices and left it over night.

The next day I smoothed the edges around the big open hole on the front with a Stanley knife and sandpaper. I put a very long screw into the neck heel, perpendicular to the finger board, to strengthen it, and then 2 more shorter screws into the heel from inside the guitar so it doesn’t pull away from the guitar once strung up. I don’t know if it’s really necessary to do all that but I’m not taking any chances.

I also used wood filler to fill any gaps in the front of the guitar, and to repair some chips on the headstock that happened when I reshaped it.

That done, I put in the back brace. I glued it in and used masking tape to apply pressure. I’ll screw it in from each end once the glue is dry.

[Edit: On completion of the guitar, the neck was at a slight angle to the body, meaning the action is very high. I suspect this may be where it happened. The back brace may have been slightly too long, pushing out the neck heel, and raising the neck. So be very careful to check the neck is dead parallel to the body if you do this.]

I left that to dry over the weekend.

Resonator Guitar [Part 6]

2009-05-27T22:11:00.001+01:00

Today work started in earnest on the sound well. This is the bit the cone sits in. The plan was to cut rings out of plywood and stick them all together to build the well. I found some manky old plywood laying about and tried gluing it together before cutting it.

I glued and clamped it overnight but in the morning I realised it was just a bit too manky, so I ditched that and tried again using particleboard.

In this picture you can see the compass I made from a strip of wood because I am too cheap to buy a real compass.

Cake anyone?

And here is the final product just before I glued it together. There are 4 layers here. The top ring is slightly wider than the others so that it has maximum contact with the inside of the guitar. The bottom layer is cut from thin plywood (not manky) and is also wider, but this time protrudes into the middle so as to provide a rim for the cone to sit on.

This will all be glued together and then glued to the inside of the guitar. This is a major milestone!

I am yet to spend a penny on this project!

Resonator Guitar [Part 5]

2009-05-23T12:59:00.002+01:00

I really wanted to finish the sound holes with a metal edge, so first I tried using metal strips salvaged from the bottom edge of ring binders.

I quite liked how that turned out, but it was pretty much impossible to make a good job of the corners and the very short edges, so I tried something else. I cut open a softdrink can, traced the bolt onto it, then cut them out about 1cm bigger than the original. I then scored the tin from the back along the actual lines of the bolt, and cut the inside of it into tabs. It's kind of hard to explain, so look at this picture.

I placed it on and bent the tabs round the edge of the hole.

I really like how that turned out. Once the whole thing is painted I'll glue them on properly. If it looks like it won't turn out I think I'll just use a stencil and paint a border around the holes. We'll see.

Resonator Guitar [Part 4]

2009-05-23T12:43:00.009+01:00

I needed to block off the old sound hole in the guitar as I wanted to cut some new ones. So I traced the hole onto the bit of wood I'd removed for the sound well and cut out two circles, one slightly larger than the other. Once the new sound holes were cut, I glued the bigger circle onto the inside of the guitar for support, then the smaller one into the old soundhole.

I clamped it and left it over night.

Now the thing was really started to look like what I'd imagined!

Resonator Guitar [Part 3]

2009-05-23T11:06:00.003+01:00

So it’s time to start modifying the body.

First up was the big hole that the cone will sit in. I used a stanley knife and pliers to remove all the bracing inside the guitar. Then, using the frying pan as a template, I traced a circle onto the front of the guitar, making sure that the centre point was exactly where the old bridge was, so that the intonation of the frets stays the same. I was going to cut out the circle with a coping saw as the last time I used a jigsaw I was totally rubbish. But when I realised that would take forever I faced my fears and jigsawed it after all.

It was actually a hell of a lot easier than I thought it would be. I first drilled a hole to fit the jigsaw blade in. I made sure to cut well inside the line and then finished it off with a file and sandpaper.

The next thing I decided to tackle was the sound holes. Because 'f' shaped sound holes on guitars are like, so passé, mine are shaped like lightning bolts because lightning bolts are rock'n'roll, just ask AC/DC, Metallica or Queen. So, using an advanced piece of graphic design software (MS Paint) I drew some lightning bolts and printed them out to the right size. I positioned them on the guitar with some blue tack and stood back to check the positioning.

Pleased with that, I traced them onto the wood and jigsawed them out, again cutting well inside the line as it's a lot easier to remove wood than replace it.

I finished it off with files and sandpaper.

How resonator guitars work

2009-05-21T20:45:00.010+01:00

As promised, a little basic information about resonator guitars.

Resonator guitars work on the same basic principle as standard acoustic guitars, but the mechanics are slightly different. I'm not an expert on this so I'll keep it simple. On an acoustic guitar the strings are anchored at the head at one end, and at the bridge at the other. When you pluck a string it vibrates, and the vibration travels through the bridge and vibrates the whole front of the guitar, aka the soundboard. This vibrates the air inside and around the guitar, which in turn vibrates your ear drum.

Resonators guitars have a huge hole, about the size of a frisbee, cut in the front of them. Inside this hole sits the cone. There are a few variations on the same principle, so I'll just talk about the ones most similar to what I'm building. The cone has the concave side opening into the guitar (although some face outwards) and in proper resonator guitars is made out of very thin aluminium, about a 0.25mm thick. This rests inside the sound well. The bridge is generally made of a hardwood such as maple and sits on the top of the cone. So when the vibrations from a plucked string travel through the bridge, they vibrate the cone. The sound then bounces around inside the body and shoots out the f holes and the fron of the guitar.

It's a lot more complicated than that, but thats the basics as I understand them. A google search will reveal loads more information from people who actually know what they're talking about.

If I've got any of that wrong, please let me know.

Resonator Guitar [Part 2]

2009-05-20T20:48:00.004+01:00

Right, so today I removed the rest of the bracing from inside of the guitar and made a start on reinforcing the structure of the body.

There wasn't any real kerfing to attach the front and back to the sides, and the old glue isn't holding it, so I've started glueing it down, using some little wooden blocks (cut from the old braces) to add some more strength. As I've only got two clamps I can only do this on a short section at a time!

Today I found an aluminium pan I intend to use as the resonator cone. It's really light and makes a surprisingly loud noise when you DING it, so I reckon that might do the trick. Obviously I'll remove the handle before installing it!

Because I don't particularly like ornate headstocks I decided to alter the original design on the guitar. I really like guitars with straight-topped or slightly curved headstocks, so I went ahead and rounded it off with a saw, a file and sandpaper. I used a sauce pan lid as a template for the curve.

In the next picture you can see some sketches I've done to try and figure out what the hell I'm doing, a bath drain cover-plate I thought about using for sound holes but have since thought better of using, and some metal strips. The strips are the edges off ring binders that stop the bottom edge of the binder wearing away. They're sort of U-shaped so I'm thinking of using them along the edges of the F-Holes, which will actually be lightning bolt shaped.

The next stage is the 'sound well' that the resonator cone will sit in. If you're not sure what that is, fret not (boom tish), the next post will be all about resonator guitars, their parts and how they work. Not that I'm any sort of authority on the matter!

Resonator Guitar [Part 1]

2009-05-18T22:06:00.000+01:00

Right, this is my most ambitious project so far. Except for the jet aircraft I started designing when I was 9, but this one might actually become a reality.

I found this broken down old, 3/4 size guitar the other day. It had (dangerously rusty) steel strings on it, which I'm pretty sure it wasn't designed to handle, and as such the bridge had pulled nearly right off the body.

I wasn't sure what to do with it until I hit upon an idea today. I'm going to attempt to convert it into a resonator, like the ones below:

The sensible thing to do would have been to find out how these things actually work before I did anything else.

Luckily for me though, I'm not terribly sensible, so I ploughed straight on and tore the poor little axe apart.

Miraculously, I managed to remove the rusty strings without contracting lockjaw. The whole thing is put together pretty poorly, so the back panel came off real nice like once I got my pal Stanley K. Nife involved. Inside you can observe the piss poor bracing and lack of kerfing (a word I learnt today,) and general lack of craftmanship involved in the production of the instrument. While I had a sharp knife at hand I took the opportunity to remove the bridge, on account of it was warped and buggered.

With that done, I spent the evening researching how resonator guitars work, did a series of sketches, had a cup of tea, and then started this blog.

First Cigar Box Guitar

2009-05-18T21:48:00.001+01:00

I'd been meaning to make a cigar box guitar ever since Plankenstein, so when I found an old cigar box for 50 pence in a charity last year, I had no excuse for putting it off any longer.

The only things I purchased for this project were the box, and the piezo-speaker and jack. All in all it came to a couple of quid. The 'found items' philosophy extended to the strings, which are in fact bits of wire.

The nut is a big fat bolt I found. I cut the end off, and filed down one side flat so it would sit flush on the neck. The neck is a bit of wood I found in the shed and sanded down with nothin' but good ol' elbow grease. And sandpaper.

The mint tin acts as the bridge and the pickup. The pickup is just a piezo transducer wired directly to a quarter inch jack. I got them both from Maplin. The strings are anchored in a converted door bolt housing. I broke two drill bits drilling the fucking thing but it works like a charm. The neck runs right through the body for MAXIMUM SUSTAIN.

The tuners are carved from wood, and do actually work, but the wire is so stiff thats its really difficult to actually tune. That said, you can hear a sample of it here, entitled Cigar Box Guitar Test 1.

First Project: Two-stringed Diddley Bow

2009-05-18T21:38:00.000+01:00

Inspired by Seasick Steve, I built this diddley bow last year. It's made from a bit of wood, bolts, it's got two strings, and uses a hand made piezo electric pickup made from a mints tin. I dubbed it Plankenstein.