Build A Do It Yourself,
Home Made Metal Detector

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Making your own metal detector is definitely not an easy project, but there are those folks out there who possess the necessary aptitude, knowledge and skills. Hey, if you're an electrical engineer and you can look at those circuit diagrams and figure with ease what the voltage is on the other side of those two capacitors and that resistor, probably building that homemade metal detector will be no big problem for you. Maybe you will design the latest and greatest new metal detector and we will all want to get one one from you. A number of talented engineers have contributed significantly to the technology of metal detectors and there is always room for design  improvement. On the other hand, if you've never assembled even the simplest electronic project before, and don't know the difference between a resistor and a transistor, you have a huge learning curve to climb before you start and you're probably going to be in for a whole lot of big trouble and headaches.

The project has a lot of issues of practical versus impractical; experience and knowledge versus ignorance, etc. Can it be done?  Can you build your own metal detector?  There is no question, yes it can be done. If you are thinking of such a project, and would like to just learn more of the basics about how a metal detector works, take a look at this webpage: UNDERSTANDING THE PI METAL DETECTOR
While the title above names only pulse induction technology, it does address other types like induction balance (VLF) detectors and how they work as well. Its a well balanced all around discussion that is well worth reading for the person who wants to build a detector. Take a look at it so you can learn more about the basic concepts of how they really work - its a long article with lots of information. Perhaps the most important part of any metal detector that is designed to find gold nuggets is that detector's ability to handle heavily mineralized soils.

So lets consider the hard facts and get real: if you have no electronic skills and don’t regularly build this type of electronics project, will building a metal detector be practical?  The honest answer is: Probably not. It's basically a case where if you don't have any experience with electronics and you don't already know exactly what you're doing in soldering up electronics projects, then you'd probably be better off working at McDonald's on weekends because you would probably earn the money to purchase a commercially manufactured metal detector before you would get a homemade one built and working properly. I actually had an electrical engineering class in college - so I know a little something - but I freely admit I'm no electrical engineer and personally I would never seriously consider trying to build my own metal detector - but those are just my own thoughts. I'm not trying to discourage you; I'm just trying to be practical and reasonable about this project. Its better to face the facts at the front end before you start than after you've already invested hundreds of hours and lots of money for parts in trying to build your own metal detector project.

Recommended
Low Cost Metal Detector

If you are really serious, and have the requisite experience, tools and all the testing equipment necessary to build such a project, I am providing a website that will provide you the schematic circuit diagram plans and design you need. You can also purchase a pre-printed board for the project from the web site author. He also has loads of information on metal detectors in general. Will the finished metal detector be every bit as good as the best ones for sale in the metal detector shop? Probably not, but they definitely do work. I wish you the very best of luck in your efforts, and if you do take this path and succeed, send me an email. 

If on second thought, you think it may be a lot easier to purchase a low cost detector, I have provided a link to purchase a low cost nugget detector from Amazon on the right - take a look and see. If you are not truly a highly experienced electronics project guy, I do think the save up and purchase route will be the much easier and probably lower cost overall.

Here is the web site with the plans and design to build your own metal detector. There are both PI (Pulse Induction) and VLF (Induction balance) detectors described here:

 Metal Detector Design Schematics

I'd ignore the historic type detectors such as the BFO type units.

The more tools and fabricating skills you possess, the more likely it is that your home made metal detector project will be a success. You'll need a voltmeter, soldering gun and other tools that normally go with building electronic projects. I have done up a page on the non-electronic hand tools needed for this type of project, you can check it out at:  Mining Project Necessary Tools

Another common question along this same line concerns the possibility of building your own metal detector coils. That may be a much better idea than building a whole detector from scratch. Having your own set of coils in different diameters is important - small coils tend to find smaller, near surface targets, while large diameter coils will miss the smaller targets but see bigger targets deeper. I normally recommend that when you find a patch of nuggets to go over it with a number of different sized coils to get all you can out of the area. That's why having a number of coils in different sizes can be very profitable, and why building your own might be well worth considering. I know a number of folks who have made their own coils - a lot more than have built their own detectors. Coils are an expensive item and they are a lot less complex project than a metal detector. These hand made coils would not necessarily have to be used with a homemade metal detector, but could be used as accessory coils with any existing commercially made detector (of course the coil would have to be built to match the coil inductance specifications of that detector). After all, it seems like coils are such minimal items, just a little bit of wire wrapped in a circle, protected by some plastic. Well, in reality, coils are a lot more complex than just that, and there are a number of considerations for faraday shielding and other issues if you want to actually build your own coil. The following well-illustrated paper tells about how to design and build your own large mono coil for Minelab PI type detectors – it is in PDF format and you can download it here:

 Information on Building a Mono Coil for the Minelab PI detector

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