I saw the Project14 monthly topic of Electromagnetism and thought about it for a bit and couldn't think of anything that I could do - there didn't seem anyway of involving mobile robots in this, so I had decided not to participate. Some time later it occurred to me that maybe I could make some sort of electric guitar. I am no musician but I can just about plink out Doh-a-deer, a female deer on the piano with one finger. I can just about do the same on a guitar so I thought maybe I could make a one stringed electric guitar. After all, it is mostly just a magnetic pickup.
Amazingly, you can actually get one string guitar music ( https://1-string.com/abba-mamma-mia/ ) - I thought I might just about be able to play Mama Mia on one string.
I already had some magnets that I thought might be suitable as they are cylindrical. Also amazingly, Farnell still sell them, which surprised me as I purchased them many years ago. I'm not sure what sort of magnetic strength you need for electric guitar pickups (or - to be honest - whether they actually use magnets or electromagnets) so hopefully these will be OK.
As this project is not that complicated (hopefully) I thought I might try and make some sort of finished product, so a shaped and painted guitar shaped thing. As I don't want to spend any money unless I have to I will try and use whatever wood I have. I do have some pieces of pallet but I'm not sure they are long enough or strong. How long should a guitar be? I do have some other pine planks so I might glue two of those together. I'm not aiming for a long life so I'm not going to worry about the wood bending under the strain of the string. If I can get hold of a proper guitar string winding thingy I might use it, otherwise I'll just use some sort of screw hook. I might try it fretless to start with as I know that you can get fretless guitars - bass guitars anyway, but if frets seem to be needed I might try wire cost hangers cut to size. After all, it is only one string. Fret wire doesn't seem to be expensive but why pay if it can be avoided. Guitarists always seem to be breaking strings so hopefully I can get an old one from somewhere. I wonder if a particular thickness might give a better result - if only I knew what that might be?
I think a 3D printed coil holder with a centre hole the same diameter as the magnet should be easy to create which will then only need a hole drilled through the body of the guitar so it will fit into it. I'll have to think about how to wind a good coil so I might need to make a coil winder of some type, or maybe just do it very carefully by hand. I'll also have to decide what thickness of wire to use as I probably will have to purchase that. I wonder how many turns are needed?
I do not have a guitar amplifier, although I know where I can borrow one, so I might try that approach, but I do have a left over amplifier box for plugging an old iPhone into (now defunct) which has an Aux input and I use this for boosting my laptop sound for playing music when working in the garage. So if I get the guitar working I might then think about putting a pre-amplifier inside the body of the guitar and just plugging it straight into the Aux input of the music amplifier. All I know about a guitar pre-amp is that the input impedance is very low as it is just a coil on the input so it is more of an impedance transformer than a signal amplifier - or maybe it is more than this. I tried Googling guitar pre-amplifiers but all that comes up is a foot pedal - no actual circuits. I even tried looking for guitar pre-amplifier kits and couldn't find any of those either.