Product Definition

[Carl-NC]

Tony the Tinkerer issues the following challenge:

A design challenge.

Currently there is increased interest in gold all over the world.
There are gold rushes happening at several places. The gold rushes I am most familiar with are in Guyana and Venezuela.
This region presents a special challenge for metal detectors.

• Heavy rains and mud during the wet season.
• Very hot and dusty during the dry season.
• Several hundred thousand gold diggers gold who can barely read and write and work in the most primitive and dangerous environment just to survive.

These gold diggers have to produce about 2 grams of gold per day just to survive. The gold is alluvial gold, scattered over thousands of square miles. Gold nuggets of the size of many pounds have been found, but the gold comes in all sizes from gold flower size to large nuggets unevenly distributed.
The total gold reserves of the entire region are immense, but have remained largely untapped until recently.
After drilling some 1700 test holes in just one claim, by a Canadian gold mining company, the claim has been declared as the second largest gold reserve in the world.

A metal detector suited for the special environment in this region would sell in many thousands per year if it was available.

My reply was:

Based on what I know of the African markets, what they want is GPX depth, Goldbug2 sensitivity, and Bounty Hunter Jr simplicity:

• No ground balance, should auto-track
• No gain/sens adjust, should be automatic
• No threshold, silent search
• No display
• Automatically covers fine shallow & big deep targets (multifrequency or multipulse)
• Automatically offsets frequency for minimum interference
• Loud speaker, pointed at the user
• On/off/volume might be the only control
• Easily replaceable batteries, easily rechargeable
• Replaceable coil
• Easily backpacks
• IP67 at a minimum
• Strong & rugged

The purpose of this thread is to nail down the fundamental definition of the product. We do not need to get into any circuit details of the design but should consider the following:

• The target market (I think that one is pretty well stated above)
• What they are looking for
• Under what conditions
• The best overall technology that will be successful (PI, VLF, MF, etc)
• The basics of the UI
• Power consumption / battery system
• Mechanical design (Note: it is not my intention to do a mechanical design, but it should be considered up front)
• Any other high-level considerations

I will also say that when I design a metal detector I like to look ahead at what spin-offs might be possible. I always try to maximize the return on my design efforts. In this case, the goal is to design a gold prospecting detector for 3rd world markets where ultra simplicity is critical. What would make this development attractive to the hobbyist prospector? Or to a relic hunter? Or to you?

[Tinkerer]

Hybrid Detector sounds like the go.

Electronic technology is not the problem. Any decent PI can do the job of finding the gold.
The big problem is the environment. The frequent rains feel like standing under the shower. Or if you leave a tool lying in the sun you burn your fingers when you pick it up. Yet the gold diggers work many hours every day just to get enough gold to survive.

The detector needs to be rugged enough to withstand the environment and working conditions for one year. The gold diggers try to use a plastic bag over the electronics. sometimes that works. More often than not steam condenses in the plastic bag and ruins the detector.

Therefore the detector needs to be waterproof and withstand the mud.
The electronics must withstand the high ambient temperature.
The operation of the detector must be ultra simple. Switch on and go. Maybe 3 mode settings chosen by one simple switch. Not 100 different settings, not even 10 different settings.

The detector should not cost more than one ounce of gold. Not a toy for somebody who can afford it.
It has to be real working tool that improves the amount of gold that is recovered.

[Tinkerer]

It is more than obvious that the esteemed members of this forum do not understand metal detectors at all !!! And because I woke up in a good mood , and I haven't taken my pills (they don't work for me anymore ) which somewhat cure me of my pathological obsession with grandeur- listen carefully people, because I won't repeat!!!
https://www.youtube.com/watch?v=eU2lwwth06k - watch and listen after 8 min 6 sec from this video…
I feel like in Hyde Park, London -https://en.wikipedia.org/wiki/Hyde_Park,_London … And so : the best metal detectors are those with more letters R in name . Here are examples :

1. Tractor - https://www.youtube.com/watch?app=desktop&v=ftAe90z8RLo
2. Bulldozer - here is an image -http://www.komatsu.co.id/page/96/d85ess-2
3. Fadroma - here is an image -https://www.alo.bg/6407759
4. Bager - here is an image - https://euromarket.bg/bg/product/hb2...-verijen-bager

And as I am very magnanimous - I will tell you the best :
Very beautiful and smart woman – ( many examples , as well as images on the web ). They are LRL ( long range locator for gold ) Beautiful and smart women ALWAYS marry rich men … which have many GOLD bars…
And so -if any of you can tell better technology than mine – please…
After this post is exhausted the raison for existence of this forum . But doubts gnaws me … I generously give you the opportunity for standing ovations and applause

https://youtu.be/jV6KYw-dDco
Here is a video of a visit to a medium scale (for local conditions) gold mining operation. The yield is about 30%. That means that about 70% of the gold is left in the ground.
The water velocity needed to lift a 2cm nugget off the ground needs to be 3 meter per second. You can see in the video that such a strong water flow is only present at the water jets.
When they have metal detectors they comb all the areas to recover the larger nuggets left behind.
Metal detectors also help locating the placers. It is all alluvial gold.

How long would your detector last?
How long would you last?

Many thousands of pounds of gold are recovered every year by such primitive means. https://www.youtube.com/watch?v=UadbNF5c3iA&t=50s

[Teleno]

It has to be real working tool that improves the amount of gold that is recovered.

Water is by far the most effective tool for recovering gold, I don't see a market for detectors in places with an abundance of water. In dry areas they definitely help, as long as you remove enough top soil to leave the bedrock within detection distance. It's not by chance that the biggest market for detectors is in Australia and for dredges/sluiceboxes in Canada.

My conclusion is that a water resistant detector for gold nuggets is overkill and it would make it unnecessarily expensive for the true users that won't need that feature.

[Teleno]

https://youtu.be/jV6KYw-dDco
Here is a video of a visit to a medium scale (for local conditions) gold mining operation. The yield is about 30%. That means that about 70% of the gold is left in the ground.
The water velocity needed to lift a 2cm nugget off the ground needs to be 3 meter per second. You can see in the video that such a strong water flow is only present at the water jets.
When they have metal detectors they comb all the areas to recover the larger nuggets left behind.
Metal detectors also help locating the placers. It is all alluvial gold.
?v=UadbNF5c3iA&t=50s[/url]

It doesn't work by lifting the heavy gold, but the opposite.

The water jets wash away the earth while the nuggets, being heavier and harder to move remain in place as a concentrate. The bottom of the washed out area is then scooped and washed in a sluice that further removes the remaining dirt leaving the nuggets isolated on a riffled mat.

The 30% yield consists of the larger nuggets, the 70% is lighter gold dust that gets washed away. Metal detecting doesn't help here at all.

[Tinkerer]

Suction is a different story. I was talking about the use of hoses in land. Gold mining deep underwater poses a different challenge. If metal detecting were an advantage there the demand would have long existed and be covered. It's not that underwater metal detectors haven't been available. Diving with pinpointers to snipe on underwater cracks is known but it's the realm of hobbysts. Imagine using a metal detector under a river with no visibility and a detecting range of 15 cm when the nuggets have sunk to the very bottom and sit on the bedrock under a layer of 1m or more of sandy and rocky deposits. It would take ages to gather the 3 grams needed to make the day. You just suction dredge it all up massively, and sluice it above water, any other way is not productive enough. I would suggest you try your idea and report to us.

I have heard of a guy paying US$ 25,000 in gold for a GPZ 7000 In Venezuela. This is of course a unique sale, although it is common to pay for any goods in gold and about 300% more expensive in the goldrush areas.
You are right with diving and detecting. This is not the way it is done professionally.
I am talking about people who make their living with small scale artisanal mining. Not amateurs and not "so called reality shows on TV".
The video I posted is real. It was made during an inspection by the owners or government officials (same thing) at a well funded medium scale mining site.
The way this works: Prospectors scout for possible placers of alluvial gold all over the region mostly during the dry season. Along river banks or anywhere where it is possible to cover some distance and ground "Wildcatting"
Any place that looks "interesting" (they have a good eye for it) there are telltale signs for gold, or diamonds or COLTAN or other minerals. By the way, does anybody know if COLTAN can be detected with a metal detector? When they find an interesting site, they pan for "the signs", color of gold, black sand (magnetite) "satellites" etc. Then return to "base" usually where the person is that gave them a "grubstake", with the news.
A small group of people then travel to the area and dig with pick and shovel trying to gather enough information to make it possible to decide how much to invest in the exploration.

A few years back when I was still living in the region, a prospecting trip into French Guyana, crossing the border from Brazil, illegally, was quite common. A backpack with the tools including a metal detector, and food. High risk. Many went. Not all came back.
But the lucky ones measured their gold in pounds.
The manual work continues until funding for bigger equipment like a backhoe or small dozer is warranted. Ideally the ground is combed with the detector first. then the top layer is removed with the dozer. Again detected and so on, digging down to the sterile level "the pizzarra". Many times in the Guyanas region there are gold and diamonds in the same placer.

I cold go on and on, but we want to know about the detectors. The big problem with the detectors is that they are not rugged enough and often too complicated for the "prospectors" to use. The prospectors are usually people who are driven there out of desperation. They could not find a job anywhere else and are desperate enough to risk everything including their lives. Often they can not even read and write. Such people are the only ones who will face the incredible hardship.
Just in the Guyana region there are several hundreds of thousands of them.

In recent years there was a goldrush in SUDAN. the sand and scorching sun of the desert. Minelab made a killing selling detectors. Different environment. Same principle.
At present, around the world there over one million, some say over 2 million such desperate people searching for gold and minerals.

By the way, I have about 2000 rough diamonds from the Guyanas region. Mostly very small. Low quality. Real diamonds I would call "souvenir quality". For sale for little money. Or trade for work on a metal detector design for the "garimpeiros of the world"

[Carl-NC]

I've moved this conversation to a separate thread. While at White's I visited Indonesia (Sulawesi) because we thought there was an opportunity to sell detectors. I saw a variety of methods being used but no big hydraulic operation like in that video. In one area they were just hauling in hard rock material and running it through stamp mills and leach fields. The stuff was too fine to detect. In other areas people were digging and panning the mostly dry river beds that flood during the rainy season. The gold pans were hand-carved from wood. In another area they were working a creek that came down a mountain through the jungle, mostly sluicing.

Almost all the gold we saw was sub-grain, difficult with anything but a hot VLF. But the real problem was the shear amount of trash on the ground. These guys simply discarded everything they brought in. I remember seeing hundreds of gum wrappers scattered around, and drink cans everywhere. On one drive along the coast I saw miles of beaches that looked like a landfill, you would literally have to wade through garbage to get to the water. Otherwise the island was gorgeous, making it a very depressing thing to see.

In the end we decided that this was an unlikely market to pursue. The ground was hot enough to need a PI but the gold was too fine, and the trash too plentiful.

[Tinkerer]

I've moved this conversation to a separate thread. While at White's I visited Indonesia (Sulawesi) because we thought there was an opportunity to sell detectors. I saw a variety of methods being used but no big hydraulic operation like in that video. In one area they were just hauling in hard rock material and running it through stamp mills and leach fields. The stuff was too fine to detect. In other areas people were digging and panning the mostly dry river beds that flood during the rainy season. The gold pans were hand-carved from wood. In another area they were working a creek that came down a mountain through the jungle, mostly sluicing.

Almost all the gold we saw was sub-grain, difficult with anything but a hot VLF. But the real problem was the shear amount of trash on the ground. These guys simply discarded everything they brought in. I remember seeing hundreds of gum wrappers scattered around, and drink cans everywhere. On one drive along the coast I saw miles of beaches that looked like a landfill, you would literally have to wade through garbage to get to the water. Otherwise the island was gorgeous, making it a very depressing thing to see.

In the end we decided that this was an unlikely market to pursue. The ground was hot enough to need a PI but the gold was too fine, and the trash too plentiful.

The modern trash you describe, makes any detector use hopeless.

But there are many many places in the world where there are gold rushes at present.
New gold rushes are always kept secret, but eventually all secrets leak out. The gold rush in Guyana became known about 10 years ago, when large quantities of gold were being smuggled out of the country. The gold is spread over Venezuela, Brazil, Colombia, French Guyana, Surinam, (Former British) Guyana. Guyana is the only English speaking country in South America and would therefore represent a certain marketing advantage.
Like everywhere, the further the gold travels, the finer it gets. In the upper parts of the river, where the river is not navigable anymore, the gold is coarser. Nuggets of several pounds have been found.
There is the famous legend of Jimmie Angel, the Angel Falls are named after him. In 1933, an American paid him a lot of money to fly him to the top of one of the TEPUYS, the flat topped mountains of the Guyana massif. They picked up some 45 pounds of gold there. However, these mountain tops are most of the time hidden in the clouds and of very difficult access. Trying to land again on the top in 1937 Jimmie crashed his plane.
Jimmie Angel's name again turns up in 1964 in connection with the owner of "LAS CRISTINAS" mining concession. The Las Cristinas has been in litigation for some 30 odd years and only recently a settlement has been reached. Who Owns Las Cristinas Gold_.pdf

[Tinkerer]

https://youtu.be/apvq8VBrwYE
A smaller gold digging operation, again in Guyana. Why do we always see them working in the mud? This is because during the dry season there is no water for the pumps to work.
I wonder how much lost gold one would find around this camp with a metal detector during the dry season?

[ivconic]

Based on what I know of the African markets, what they want is GPX depth, Goldbug2 sensitivity, and Bounty Hunter Jr simplicity:

• No ground balance, should auto-track
• No gain/sens adjust, should be automatic
• No threshold, silent search
• No display
• Automatically covers fine shallow & big deep targets (multifrequency or multipulse)
• Automatically offsets frequency for minimum interference
• Loud speaker, pointed at the user
• On/off/volume might be the only control
• Easily replaceable batteries, easily rechargeable
• Replaceable coil
• Easily backpacks
• IP67 at a minimum
• Strong & rugged

My wish list will look different:
Yes ground balance, manual and auto-track, by choice.
Yes gain/sens adjust, automatic as option by choice
Yes threshold, adjustable by the user.
Yes display, displaying all the parameters and the received signal too, numbers and simple graphs.
No, no need for any "automatic covering all the targets". "Automatic" = lot of mistakes and inaccuracy.
Automatically offsets frequency for minimum interference, maybe as an option by choice. Manually adjustable by operator; YES.
Loud speaker, yes, mandatory. Maybe two; one for the filtered signal and one for the soil signal.
On/Off/volume, Yes, not only control.
Batt. Yes. Don't mind.
Coil repl. Yes, why not. Simple universal DIN connector, so to diyers can make custom coils too.
Backpacks... don't mind at all.
IP67??? WTF is that? Waterproof? Don't mind at all.
Strong&Rugged, don't mind. I always take extra care on my toys. Lightweight though; YES.
...
Tony I do recall 10-12 years back your story. It is interesting story.
Nevertheless... what developing platform you are talking about?
Is it the one from last attempt? The one expensive and not so easy to obtain?
Why don't you offer slightly easier one, cheaper and easy to obtain.
STM32 based cheap dev boards, plenty of those. Additional ADC if needed. Variety, so each one of us can pick one available in locally.
You see... Tony; no matter how splendid your final result may turn out to be; it will die fast in case nobody (or just a few) is able to reproduce it in own workshop.
It will end up as an attempt done by few. Not something for wide public.
...
Guys let's talk seriously now.
If you want wide public attention and project to live long; be carefully when picking dev systems/boards, delicate components and ease of achievement.
250 people can contribute much more to project than... 2 or 3 dudes only.
Ain't exactly this Geotech forum the place to prove that?
There have been a few simpler projects in the past that have turned into an avalanche... and all it took was rolling a small ball of snow down the hill.
TGSL, IDX, IGSL, Delta Pulse, FelezJoo, SMW, Wave, Hammerhead... many others too.
When you have an army of hundreds on your side; project will live loooong and evolve faster into much better.
I hope you understand what I mean?
Picking "XYZ123"#&#"$&#&uwrtbbfBBB223" development system with the price of $xxx and PhD ease of using it...
Not a pick of a year, trust me.
I am in the mood for this. Let's push this for real. C'mon Tony! But give some "human" approach.
Cheers!

P.S.
Carl why does comic sans serif text look so "fat" and "greasy" ??? You messed around with that font on purpose!?

[Tinkerer]

Thank you, Carl, ivconic, Idefix, for the help and feedback. All good points.

Somebody has to take the lead:
I prefer it not to be me. How about waiting a few days, to give other interested forum members a chance to join and then chose the leader?

Companies with a commercial purpose:
I have been waiting for many years for a company to produce such a machine. It never happened. Yet there is a very big market for such a product. In the Western World we live in a cocoon of comfort and forget about the third world where people struggle to survive.
https://youtu.be/Z0V4BJYcLJs This documentary shows the struggle of a gold digger in the South American country SURINAM to reach the gold patch where he is going to spend the next 3 months (the yearly season) digging for gold. This is the environment where a nugget detector is going to be used. As I said somewhere: "been there, done that" in my foolish days 50 years ago to the day. Similar conditions are met in Africa and South East Asia.

Maybe if we show the commercial companies how to do it, we can shame them into bringing such a machine to the market.

The forum is a way to share a passion, and to exchange points of view and is an excellent source of information, for everybody, including companies.

On the other hand, if this enterprise continues, it will be rich in lessons. I agree 200% with Ivconic, for the use of a platform like the blue pill, and easily programmable with an IDE accessible to all, like the Arduino IDE. and I will add with a software sources share on Github. I fully agree with that.

Carl, maybe it would be a good idea to make a "sticky" section, starting with post #14 as the design goal. Then add any "milestones" we reach to that section.

Discussion is good. As everyone brings up his points, it increases the general knowledge and often sheds light on new angles of a problem and new ways to look for solutions. But, like separating the gold from the black sand, it is necessary to condense the most useful parts of the discussion from the frivolous, to make it easier to follow the thread.

[Tinkerer]

https://youtu.be/mptUhtsHCG8 gold mining in SUDAN, AFRICA

[nickel_n]

I wish i could contribute but not able.
I can only read the topic with great interest
Definitely a metal detector user of 30 plus years and that's it.
i do most of my detecting at the beach on the water's edge or in the water
to 2-3 meters dip with high mineralised sand and allot of iron rubbish.
Could you PLEASE consider a water proof version that can be used in SALT water.??
THANK YOU

[Tinkerer]

I wish i could contribute but not able.
I can only read the topic with great interest
Definitely a metal detector user of 30 plus years and that's it.
i do most of my detecting at the beach on the water's edge or in the water
to 2-3 meters dip with high mineralised sand and allot of iron rubbish.
Could you PLEASE consider a water proof version that can be used in SALT water.??
THANK YOU

nickel_n,
Yes, you can contribute in a very useful way.
Many of us live far from the ocean and do not know what the specific problems that you encounter are.
It seems to be a small difference if a detector should work in streaming rain or in 10feet of salt water. In fact the saltwater detector design has to address many more design challenges.
If there are enough people chiming in with an interest in a salt water detector, I am sure a sub group team with similar interests will form.

Which detector are you using at present?
Why do want another detector?
What specifically are the problems you face?
Do you have any suggestions of how to solve these problems?

I know of people who recover 2 pounds of gold, mostly gold rings and gold chains from the beaches every year.

[Orbit]

And it will be the best detector on the market so far if I understand ? Every market is different, they are looking for a nugget somewhere they are looking for coins somewhere recently they are looking for a buried bag of 400 pieces and more coins all those very expensive branded and touted devices are out of the game! I would like to see concretely something better, I'm afraid it will be similar to any device.. So I'll be a fan and nothing more!This is already 5 pages where something is being prepared, I mostly work on pulse devices and in my opinion I have reached the end, I have done everything that I think is good. So I will watch with pleasure how the project goes!