Metal Detector Design Series Part I – Concept and Rough Sketch

Metal Detector Design Series Part I – Concept and Rough Sketch

In this series of articles, we’re going to design a new metal detector right here on D365.   Above is a rough “Napkin Sketch” of our design concept as it now stands.

Why Design a New Detector?
The major metal detector manufacturers have many excellent metal detectors on the market.  I am absolutely crazy about mine.    With all of the greatest respect to these manufacturers, this design is about continuous improvement.   I feel like the major detector designs are deficient in the following five areas and would like to address these specific issues with a new design:

1) Use of Latest Technology:  The major metal manufacturers excel in hardware design.  Search coil design,  detector durability, and ergonomics have come a long way over the last 20 years.  Remember the control boxes with the handles on top of them?  The design of the control boxes, however, leaves much to be desired.

Ask Yourself:  Which one of these does the control box on your detector more closely resemble?
– an oversized 1980s hand-held video game
– a device incorporating the latest technology, such as a digital camera, smartphone, or tablet computer?

2)  User Interface Design:  The user interface on many detectors is confusing and not very user-friendly.   Many of the interfaces actually  mimic the old analog needle – lower values on the left and higher values on the right.  Many of the interfaces are cluttered with unnecessary features and features that are rarely or never used.   Though we learn to live with it, many great detectors irritate their users with a non-intuitive interface.

3) Detector intelligence:  Today’s current detectors give you various information to help your brain interpret the signals from the search coil – such as display, sound, and repeatability.  However, other than perhaps providing a unique sound when a target is most likely a coin, the detectors have little or no ability to assist us in target determination.  They also have little or no ability to learn from your experiences.    For example, when you dig a tin can, the detector never is told that it was a tin can.   The detector is incapable of providing you with any additional information the next time it receives the same signals.  Also, I know of no detector that has a “Training” or “Demo” mode where the computer actually teaches you to use the detector.

4) Weight: The control box weight of many excellent metal detectors is excessive and surely unnecessary.

5) Software Adaptability:   Most good detectors have built-in and user-saved programs that set the detector up for different scenarios.  Coins, Relic, Field, Default and Jewelry are some typical built-in programs.   User programs might be saved for things like hunting in heavy iron, or correcting a built in program to allow for specific items that are rejected by that program.     Other than that, we have no ability to make a feature we do not use disappear, and no ability to add new features that do not exist to the machine.     Software developers have no Application Programming Interface (API) or other ability to modify or replace the software on the machine.

What do all of these issues have in common?    They all involve the Control Box.    The rest of the detector is great.   The search coil technology is strong.  The machines are durable.  The actual sending and receiving of signals is great.  The metal detector is great, but improvements can be made – chiefly with the control box.

So am I going to advocate building an expensive compact cutting edge computer to replace the control box?   No.  Instead I’m going to cheat, because chances are you already have such a computer on your person right now: your smartphone.

Replacing the Control Box
In our design, which we’ll codename the iMD, short for “Intelligent Metal Detector”, we are going to replace the control box with three components:
1)  Your smartphone
2)  A mount that securely holds and protects the smartphone.  We’ll call this mount the “Cradle”
3)  A small microprocessor connected to the search coil that send information to your smartphone, probably wirelessly via BlueTooth.  We’ll call this the “Node”.

Replacing the control box would allow the manufacturers to focus on what they do best – the hardware.   Just like Apple and other smartphone manufacturers.   They provide some default programs, but the greatest software available is all provided by third parties.

Though we’ll have to design the “Node”, using the smartphone will also hopefully help reduce the manufacturing cost of the iMD.   The smartphone has internet capability, which makes for some interesting and wild feature possibilities, such as remote monitoring, review, or analysis of your hunt by another detectorist.  The detector cannot rely on the internet to operate, however, as often we detect remotely in areas with no service.

The iMD design coincidentally also helps solve another issue I have while detecting – which is constantly having to check my phone.   I personally cannot just leave my phone off or in the truck.   I have already ruined one phone  from the constant dirt.    The detecting software might incorporate methods for dealing with phone calls and messages.

I’ve read where the phone can cause interference with your detector.   We did some preliminary testing that and I don’t seem to have this issue with our detectors.   Protecting the phone and possible interference are two things we will keep in mind though when we determine this design’s feasibility.

Open Source Software
The iMD would come with a software program that you would download via the AppStore or Android Store on your smartphone.    An application programming interface would be provided or licensed by the manufacturer providing programmers with a description of what information is provided by the “Node” to the smart phone, as well as how to connect to and process this information.   Third party developers, and even detectorists with programming skills, would be able to provide new and modified programs (henceforth “apps”). This will likely be the primary strength of this design.  Some of these programs would be free, and some at a reasonable charge.  Some benefits:

– Multiple Detector Apps for us to choose from.   For example, a software developer might provide a separate detector app designed specifically  for beach hunting,  Civil War hunting, or just gold nugget hunting.   We could have multiple detecting apps on our smartphone that we could use for different situations.

– “Best of Breed” programs. Many apps will be available, but some will rise to the top as the best and favorite of  iMD users.

– New Innovation:  The greatest thing about open-source software is that new and innovative features outside of our current paradigms are possible.

– Upgrades:  Upgrading the iMD might be as simple as getting the latest phone.  As new technology is released in new phones, the programmers can incorporate those into the detecting experience.  For example, your iMD might be secured by the latest fingerprint technology in the latest iPhone.

Final Thoughts
In this article, we outlined the problems to be addressed by the design, and roughly outlined the  iMD design concept.  In Part II, we’ll design a basic interface.  In part III we’ll talk about the “brains that really differentiate the iMD concept from anything out there.


Hopefully the iMD concept will, at a minimum, aid in the discussion of the next generation of metal detectors.

Questions, Comments
We’d like your input.  Please feel free to share your comments and ideas by Contacting D365 or in the comments box below this article.   Feel free to punch holes in this design and point out additional ideas or challenges.  We are going to include feasibility studies on this design later in the series.  Keep in mind that a good design is a process.  If we hit roadblocks, we will determine solutions and re-design elements as necessary.   To design something radically new, you have to start with the assertion that anything is possible.  If every radical redesign was interrupted by assumptions that the implementation is impossible, nothing innovative would ever be created.

The design information in this article is the property of Detecting365.  All rights reserved.     This article is intended as a discussion to facilitate improvement of existing consumer products.  No infringement on any current patent, trademark or license is planned or intended.

Photo Credits
Napkin sketch property of D365.  Use it freely, but please link it back to

There are 16 comments for this article
  1. wight Hiatt at 12:49 pm

    I have owned @least 4 different detectors and 3 different Brands,now I would just love 1 all Coverage Unit to be able to find and pick-up on all things of possible value for digging.I want 1 Detector good for all metals including Depth more than most seem to penetrate when locating smaller items like coins,jewelry,and antiquities!!! Hope you can build something that is complete with the vast area of coverage because I do not get to hunt a lot after having several Back Surgeries but I do as often as possible since they declared me Disabled and yet i’m still young @ 53 years old !!!!! Thanks for trying to benefit the Detecting Society with some better Equipment !!!!

  2. Dirt Scanner at 12:51 pm

    I like the idea and the discussion, I have often thought that there had to be a way to incorporate smartphone/computer technology into a metal detector. I know there are detectors that are getting close and it will happen sooner or later. I believe that those of us that actually detect need to be the driving force in getting the discussion going and bring design improvements into reality.

    • Clark Rickman at 2:28 pm

      Hey! haha Yep there are several of those things on the app store. That is basically a gimmic electromagnetic detector. Useful only for amusing friends with your phone like you are airport security. The “Detector” in the photo is photoshopped. Doesn’t exist. What we are talking about is replacing the display and brains of the detector with a smartphone, but leaving the rest of the detector working as is.

      BTW Wow. I LOVE the KClectic detector light. I have to get one of those!

  3. Billy Dwight Hiatt at 1:33 pm

    People are ignorant enough to need a cup holder or a place for their cell phone should not own a Metal Detector in the 1st place.They are designed to use locating coins,jewelry,and items from Wars fought around the world and also locating antiquities from long ago,they are not used while sitting in your recliner in the air conditioning and catching a nap !!! LMAO !!!

  4. ken ward at 4:36 pm

    I have used all them high dollar detectors. The ones I enjoy the most is the Tesoro brand. I like the light weight. One battery. Life time warranty. If only they made a light wader model. Just for shallow water hunting. I would be a very happy camper… KEN

  5. Michael Wors at 11:59 pm

    I’m still learning from you, as I’m making my way to the top as well. I definitely love reading everything that is written on your blog.Keep the stories coming. I liked it!

  6. Rock at 12:59 am

    This is a great idea , I have been working on using a 8″ tablet for the detector control . Also we have been working on a new design for the coils . Like you said using a bluetooth for the connection . But a coil that can be retuned and shifted to another size or shape . This way you can have more that one coil to use with just one coil on the machine !

    It seems to me that it is time for the coils to make a leap in technology over what is used now.
    Don’t get me wrong there are fantastic coils on the market and many are made be the company’s their selves that make the detectors . And now we have a few good aftermarket Coil makers .

    With the processing power that is in a Tablet computer that is made today one should be able to make a detector that can do about anything one could think of. And with software written as you have stated the possibilities should be almost endless what one can do with a detector of this style .
    Anyway that is what we have been up to but at this time we are just working on the coil design .

    By the way I really do love your site here and your write ups . It is fantastic .
    Also I have learned quite a lot from reading your post on all to do about detecting . Keep it up as you are helping a lot of new people getting into the hobby . I send most everyone here that I meet that are learning to detect and have asked for help . If there is one thing I have learned is that no matter how old you are or how long you have been detecting you can and will learn from other detectorist and how they do things and how they tune there machines and what and how they use there equipment to detect ! So when I see someone teaching I stop and pay attention to what they have to say ! Your one of the ones I stop and listen too .

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