Anyone Built a DIY metal detector?

[AtomRat]

:lol:

 

[petere]

Hi Guys
I am currently in the process of building a website with info on F1A4 mods i have done, and also a surf PI project which may be some help. Link below
Cheers

http://www.metaldetectors101.com

 

[Marauder]

Got a fair bit done on the Saturday morning.

Had the kids out "helping" and they got really keen on the cordless drill, so I can't pull that apart now but am still hoping to use the battery if i can find a donor drill body.

Anyway here's some photos.

Telescopic leg of a telescope

Attached a non metal extension(very gently )

Donor for arm cuff and handle (Snow board binding and electric drill handle)

Completed Unit (note the Nuggeteer coil, from Ebay)

So now i need a box for my electronics and a robust method of attaching the battery.

 

[AtomRat]

The old vlfs I have just have a rivited section of hollow pole which the shaft then slots into. Just 3 rivets holding it to the box thought I'd post this simple way in case you havnt seen it b4. How did the electronics go? Did the coil work with the circuut and you got a signal when waving metal?

 

[Marauder]

Haven't pluged the coil in cos i'm waiting for the 5 pin connectors from China. $3 for two but gonna be a couple of weeks.

So, The electronics might not even work! But I want to have it all ready to go before I switch it on.

The good thing about using the legs that I did is that they are square, so everything is easy to screw/ bolt on. Will mount the box below the handle.

 

[Marauder]

Well I got out on saturday and decided that i should make my own batery connector, since i've found my cordless drill to be so useful.

I must say that the renovator is a most excellent tool.

Electrical pickups are two halves of a razor blade

Battery connected and soldered connection work!

Now to find a suitable containers for the electronics, and still waiting on the aviator plugs!

 

[Marauder]

Those aviator plugs have got to be on the slowest boat from china!

 

[AtomRat]

China does takes ages... sometimes 2 months..

Charger looks the shiz mate, great idea! Do you have a Jaycar closeby?

 

[Marauder]

yeah and its kinda small and pokey, but they didn't have the right plugs. Thats why i went china. Also they were incredibly cheap. $1.80 per set(male/female) and free postage. I can't understand how anyone makes any money on that, but hey.

 

[SteelPat]

Try having a look at WES components. They have a good range of plugs. Otherwise Element 14 or RS components often have stuff that a bit out of the ordinary. I only ever get stuff direct from China as a last resort due to the shipping times and even then I pay extra for express shipping.

 

[AtomRat]

I missed your comment about desoldering issues above Marauder. I used to use a mates desoldering gun which was awesome, now im using the hand manual sucker to remove the mojority of solder or the copper mesh works very well for soaking up solder too. Since using these useful items..desolderings a bliss

 

[nicko61]

Hi Marauder, That looks like a good resto base hiding in garage, gotta love old Vals

 

[Marauder]

Yeah the charger is a long term project. Hopefully get it blasted next year.

 

[Marauder]

So I received the 5 pin connectors from China.

surprisingly they are the wrong size. they are far to small to fit the cable from the coil.

So will have to rewire the terminals on the Coil, to match a similar rated connector that i got off a mate.

But on a happier note i did find a suitable enclosure that i had bought many years ago from a different project.

So now i have all the bits, i've just got to assemble and test.

 

[AtomRat]

go mate go!! Haha..bloody issues...

 

[SCROUNGER]

I'm thinking some PVC pipe that i've got thats about the same diameter as the drill, and lots of tech screws...will give it a crack this weekend and have a rumage through the junk tonight to see what i can use.

also Its very likely to end up mission brown. Just a heads up to the fashion police.

No, please not mission brown!!!! That's so seventies Marauder :lol: :lol: :lol: Looking good apart from the future colour issues mate :lol: :lol:

 

[Marauder]

OK So i put it all together today, with mixed results.

First had the battery wires round the wrong way. Switched them over and we got some buzzing.

Second, I found that the op amp chip supplied was not an op amp. fortunately i bought two kits, so a spare op amp goes in. still buzzing, buzzing gets louder with sensitivity knob.

very frustrated.

 

[AtomRat]

Bugger man :/ all I'd say is check all polarity and that there's no shorting. Batteries the wrong way round could fry some ponents.. was it an LM386 amp or so?

 

[Marauder]

Hey atom. Yeah switched out the amp but no difference, had the speaker in backwards, so works better now, actually detects metal! It can detect a power drill from distances up to 3cm!

So the only thing I can think of is that the coil is wrong. Maybe inductance is too high or low?

 

[AtomRat]

Sounds like a possibility and I'm glad its now making a noise!! 3cm sounds a bit poor yeah, I'd check resistance and continuity or as you say inductance.