I know this has been covered somewhere, but can't find exactly what I am looking for. I am a newbie maker. I am currently making a 4-string CBG from a Tabak wooden box. I am doing a neck-thru and wanting to mix a piezo buzzer with a homemade pickup I made.
The pickup I made is basically two very strong hard-drive magnets wrapped in copper wire (about 600 wraps or so), then placed into a steel Altoids tin I modified to look like a mini-humbucker (will take a pic and post as soon as I can if needed). I don't have any pole pieces in that I was looking for the top of the Altoids tin (bottom depending on your perspective) to be magnetized and act as one flat "pole piece".
I wired it to an input jack, plugged it in to a small Crate amp, and hung it inside an acoustic guitar to try seeing what it would pickup on. It didn't seem to work. So I am wondering if I HAVE to have pole pieces and if I need to redesign my pickup?
My biggest fear is cutting a slot for the pickup in my lid, wiring it up, and then it not work. I'd have to scrap the box then since my single-coil "mini-bucker" and an actual pickup I have from an old Fender are totally different sizes.
Any help would be much appreciated!
hanging a magnetic pickup inside an accoustic guitar wont give you any sound, it nees to be close to a steel string as its the steel moving that moves the magnetic field in the pickup making the current to be amplified, try holding it above the strings of an electric guitar first.
Hey Brian - I have been fiddling with various pickups myself, winding some, using existing windings, wall warts, cordless drill charging units etc.
It would be nice if there was a "sticky" at the top on this topic, just for use newbs.
I have made a simple one string dealy with about a 3" hole and a jack mounted with little alligator clips just to try different pickup before I commit to installing them. I aim for about 1/4" below the strings for my tests, you may not be close enough.
What OFG said....make sure you are not trying to test using bronze strings.
No sound at all... I had a buddy help me with a multimeter and it seems the coil, and/or soldered connections, may have been grounding on the tin box. I have now insulated the box with some thin rubber and going to try it out again (multimeter first and then amp tonight maybe). These magnets are super strong and should still keep the outside tin magnetized, even through the rubber.
So it sounds like my theory is solid, and I don't need pole pieces, just need to keep fiddling with it. Please correct me if I am wrong with that thinking.
you shouldn't need pole pieces, I've made a couple just out of ring magnets and they worked fine. what I was saying is it needs to be close to the strings, don't just dangle it inside the guitar as that won't work. I've never tried one with only 600 turns though, might not get much out of that (usually at least 2000) Also although the pickup needs to be close to the strings a neodymium magnet has a huge magnetic field and will dampen the strings vibrations if put too close. Might have to do a bit of huntin to find the sweet spot.
you may have figured all of this out all ready, but sometimes when winding your own stuff, you need magnetic wire, the wax coated wire used for coils and pick ups. If you are winding it around steel or something, and it that wax coating gets cut and is touching something metal, or the coil is touching two bares wires inside the coil, then it will be a dead pick up. Just to be on the safe side. I am experienting with some stuff here latley, and I cut a piece of metal for a flat style pup and the edges are really sharp. It's a good idea to keep in mind when winding stuff.
Here's a pic of what I did. If you have ever seen a hard drive magnet inside a hard drive then you recognize the shape of the back-plate. I left one magnet attached to it, removed the plate from the other magnet and just snapped it ontop of the other. I then wrapped it up with 30 gauge copper wire. The steel case is part of an Altoids box and is insulated with part of a rubber glove.
I got some connectivity tonight, but only along the bottom side of the box, not the top. I pulled it out of the box only to realize that the corners (right next to where it is wired to the input jack) are the only spots I get a signal. It's not doing ANYTHING anywhere else. Those points touch the bottom of the box when seated so it gets a signal (in that I can tap on it with my fingers or a piece of metal). There is still NO sound. :-(
The magnet needs to be in contact with the strings on this one. The magnets need to be bare. So the wire needs to be around the magnet. Like a typical pickup. And I am not sure what wire you are using there, but it needs to be coating. Just old copper wire will not work. Hope this helps. One of the best and easiest pickups you can build with is a sewing bobbin pickup. Wind up a bobbin with wire and use a bolt through it and add a magnet to the bottom. Perfect for one string builds.
You pickup design sounds like a Lipstick Tube style pickup. My guesses are: 1-you could have a break in the coil winding. 2-your coil is shorting out inside the case. 3-your coil isn't strong enough and needs more windings.
It's possible the wire is wound around the coil the wrong way for it to work lengthwise.
Here is somebody who made a working hard drive magnet pickup: http://www.joebrown.org.uk/wp/?p=1476
This is the same direction/orientation the lipstick tube coil was wound.
The question is, was a lipstick tube magnet oriented through the width or the length? I always assumed it was through the width. Whereas the hard drive magnet appears to be oriented through the length, like a science bar magnet.
You may be able to take your pickup as is, and turn it on end and have it work. So it would be like one giant polepiece from a Strat pickup.
On the other hand, it could be that those "rules" about magnet orientation are for weaker alnico and ceramic magnets and it wouldn't matter which way you oriented a hard drive magnet. I don't have any here to play with, so I can't say for sure.
In general, I suggest getting the pickup working without the cover first, then add the cover and see what happens. You can quickly test the pickup by holding it closely over the strings and plucking the strings.