Help: Coil Housing Dimensions..

[Aziz]

Now the stem mounting is finished. See below the basic assembly. The stem can be layed down for convenient search operation. It is very basic but working well.

Aziz

[simonbaker]

Love it Aziz -- very interesting everyone's homebrew manufacturing, looks excellent! Hope the stem supports are strong enough, I was wondering if they were a little thin from the beginning, but looks like you thickened the bases nicely. Fiberglass is tough stuff I guess. Should be a really good coil, looking forward to hearing results.

Cheers,

-SB

[Mrand]

Very beautiful coil! I found in the net very interesting mechanical design. It is very adequate for your coil.
Sorry Aziz, it only jokes. I wasn't able to refrain. I'm very admiring your work and I am congratulating.
Mrand

[Götz von Berlichingen]

Very beautiful coil! I found in the net very interesting mechanical design. It is very adequate for your coil.
Sorry Aziz, it only jokes. I wasn't able to refrain. I'm very admiring your work and I am congratulating.
Mrand

Well, this one looks quite ugly, but must be easy to disassemble and carry.
I have been searching for cheap and easy to use Hardware Parts.
A plastic Flowerpot Saucer or Frisbee should be a good Coil Housing.
The long "Crutch" Part is still a Problem, i want it in 3 Parts or
a Telescope thing, like a Nordic Walking Pole or Paintroller Handle.
Too bad, all Telescope things that i found are made from Aluminum
or expensive Carbon Fiber.
I'm always looking for suggestions about Hardware.

[Max]

Well, this one looks quite ugly, but must be easy to disassemble and carry.
I have been searching for cheap and easy to use Hardware Parts.
A plastic Flowerpot Saucer or Frisbee should be a good Coil Housing.
The long "Crutch" Part is still a Problem, i want it in 3 Parts or
a Telescope thing, like a Nordic Walking Pole or Paintroller Handle.
Too bad, all Telescope things that i found are made from Aluminum
or expensive Carbon Fiber.
I'm always looking for suggestions about Hardware.

Hi,
it's an interesting topic... cause sometimes it's not easy arrive to such places e.g. over hills with all MD stuff mounted... better disassemble and pack in a bag or something and then mounting again on top of the hills...

But the most relevant part in that is the pole: telescopic pole is needed to save time and do it easy.

I have two ideas for you:

1. telescopic brooms: some have plastic telescopic pole... not aluminium or metal... are light

2. photographic one leg tripod (monopod) : light and cheap ones are plastic made too

Kind regards,
Max

[Noemio]

What about using part of a cheap fiberglass fishing rod?

[Max]

What about using part of a cheap fiberglass fishing rod?

Hi,
that's another idea: I used that many years ago... and other fiberglass too.

But there's a big drawback: fiberglass for fishing rods is made flexible most of the times... really strong ones are rare and where you need more roughness in fishing... like e.g. for barracuda stuff... you'll use very strong rod... but that have additional weight too, unless you use carbonium stuff.

From my experience the rod must be strong as possible and very rigid in MDs.

If you use a very light coil setup this is not an issue: any fishing rod stuff will be fine... if the coil weights e.g. 0.200Kg or less but what if the coil is 0.4Kg or more... ? I saw 700gr coils... not that easy sweeping them.

You'll get much oscillations, that's what happens, you'll get really difficault pinpointing on motion detectors... and your sweeping action will lead to more and more false signals...(cause you can't control the end/reverse of sweeping very good with a flexible rod).

Using thick fiberglass solve the issue of oscillations... but it's more weight.

So I think fiberglass is better avoided for pole stuff... better use simple plastic pipes or e.g. aluminium alloy. Wood could be another actractive alternative... but weight issues need you use a kind of wood "pipe" too...

Kind regards,
Max

[simonbaker]

Should be a competition, how to make MD from every day stuff -- great fun . I want to check bamboo for pole. I always scan discount stores for possibilities. Same as Max, many brooms, dusters have very interesting poles these days. Coil housing: have not quite found -- some plastic paint can lids look tempting but not quite right. Saw a round plastic "parts tray" with convenient grooves, might work -- the plastic toilet seat screws, bolts most useful so far. Keep looking!

Cheers,

-SB

[Aziz]

I have filled the plastic pipe with PU foam. It seams, this is not tight enough. The stem is bending over and swinging. Telescope stems are quite tough but not metal free. I have searched and searched but nothing convenient found yet. Bamboo would be good - but I haven't found yet.

If I find not an appropreate stem, I will tighten the stem with one layer fibre glass + resin. Also the whole stem will be stickable to put this in a luggage. I am planning to take my first prototype with me around the world.

Aziz

[Qiaozhi]

You could also make a wooden stem, like the earlier Nexus detectors. It folds in the middle, instead of being telescopic.
You can just about see it here:

[simonbaker]

You could also make a wooden stem, like the earlier Nexus detectors. It folds in the middle, instead of being telescopic.
You can just about see it here:

Maybe not sleek but perfectly practical -- will probably use with my bamboo.

Here is another idea. In plumbing hardware, take pieces of PVC pipe. You can fit a PVC at bottom and aluminum at top (my tesoro has plastic bottom, aluminum top). Or just PVC, a little heavy, but... There are all kinds of sleeves, etc to combine pipes. You can also use plastic sleeve to combine two wooden dowels, need some way to lock though. Then just pull apart to pack it. I would look at PVC.

Cheers,

-SB

[Aziz]

I have started to tighten the coil stem with fibre glass and resin. Even one layer is not tough enough. So I have to do at least two layers. On the bound part, where the stem is be held even three layers. This makes the stem heavy but very tight. It looks aweful. But I want a good working detector - not a good looking one. I will paint the coil and the stem with white paint, when the coil is finished.

Aziz

[Aziz]

I am now satisfied with the mechanical stability of my coil stem despite of its weight. See enclosed images. It consists of two parts which are sticked together. It has to dry at least one day before grinding and painting them.

Aziz

[Aziz]

ups.. the pics now.

[Aziz]

Next step: cabling and connectors...

I am going to use the following connectors (see below). There are high quality 5 pin audio connectors with gold plated pins. Also two 3.5 mm stereo connectors for the sound-card input and output. I will not use the shown left one (low quality). I haven't found the right cable so I will use three RG174 coax cables which are bound together with tape.

Aziz