Let's made a PC-base metal detector with usb interface !!!

[WM6]

How about some photos, Aziz? I'm curious what it looks like, especially step-by-step.

I think Aziz approach can be in such way:

http://www.tb3.com/tesla/hugecoil/primary/primary.html

[Aziz]

Hi all,

yes, I will provide some photos of the Al strip making procedure and the final product. It will take some time so be patient please.

WM6,

yes, something like the Tesla coil making procedure is quite convenient. I want to use a polystyrene tape as it has the least dielectric constant and weight. I can make such a polystyrene tape by myself (for specific thickness).

Back to folding again..

Aziz

[Aziz]

Winding Spacer

Hi all,

I have a good winding spacer now after trying different materials. I did try thin anti-slip mat with holes, fibre glass tape, rope and so on.

The best material is still the polystyrene. This is a mass and cheap product, which can be obtained as big sheets. It must be cut into the desired width and thickness and all the stripes needs to be fixed together as a "polystyrene tape".

I am quite surprised about the easy and precise cutting procedure. One can cut it even into 1 mm thickness. I do not own a precision polystyrene cutter but this cutter can be made quite easy. All you need is a variable power supply, a piece of thin resistor wire, fixing tools and a table. One can cut many stripes in one cutting procedure.

Aziz

[WM6]

Hi all,

The best material is still the polystyrene.

Aziz

Hi Aziz what of polystyrene (Foil?) did you use?
Can you post some link on product site?

[Aziz]

Hi Aziz what of polystyrene (Foil?) did you use?
Can you post some link on product site?

Have a look at these sheets:
http://nbg-web01.opitec.com/img/800/747/800747-04-x.jpg

1 m length, 50cm width and different thickness (10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm and so on). Very cheap at DIY home market (Obi).

I will cut from a big thick sheet (40 mm) as many stripes as I need.

[WM6]

Have a look at these sheets:
http://nbg-web01.opitec.com/img/800/747/800747-04-x.jpg

1 m length, 50cm width and different thickness (10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm and so on). Very cheap at DIY home market (Obi).

I will cut from a big thick sheet (40 mm) as many stripes as I need.

Great Aziz, but is it not too fragile for winding?

[Aziz]

Great Aziz, but is it not too fragile for winding?

Hi WM6,

there exist different types of it. The standard type is more soft but there is also a very rigid and stable one available (costs more).

For the spiral type Al strip coil (as a winding spacer), the standard type is stable enough and can be bent without breaking.

It has a dielectric constant of 1.03 only. So a very good winding spacer.

I will buy the rigid ones next week and will try them too. It's also perfect for quick & dirty coil housings.

Aziz

[Aziz]

Hi WM6,

you were right. The standard polystyrene (foam) sheet was not stable enough (the one I had). It has quite big granulation and sometimes holes in it, that the final stripes were not perfect. Between the granulation boundaries, there isn't enough binding too. I could cut it but it was not stable enough for this purpose.

I have bought the rigid polystyrene sheet and it's really perfect (no granulation, seems to be amorph). I can cut it into even 0.5 mm thickness. Fortunately, the new sheet is also perfect for coil makings.

But I don't know, whether the new material is really polystyrene. Nevertheless, it contains almost air only.

Aziz

[Aziz]

Well ok,

I have found, that the new material is an extruded polystyrene foam also known as XPS foam. This material is well destined as a winding spacer with low dielectric constant, which can be cut with a hot thin wire into stripes of individual dimension. It is a mass product for home/building insulations and can be obtained everywhere for less bucks.

Indeed, I have cut many stripes till now and it is a funny process. The stripes are well stable.

Ok, the coil winding spacer is solved easy and cheap. I am going to fold another Al foil roll and will make pictures of the Al stripe and the DIY polystyrene foam cutter to show you how to do it.

Cheers,
Aziz

[WM6]

will make pictures of the Al stripe and the DIY polystyrene foam cutter to show you how to do it.

Cheers,
Aziz

Probably something like this?:

http://www.halloweenfear.com/FoamCutter.html

[Aziz]

My DIY XPS Cutter

See below the pictures of my DIY XPS Cutter

Much simpler, much more precise, reproduceable results
Powered with 12 V power supply (AC or DC).


Damn, I should run to the patent office with it..


Cheers,
Aziz

[WM6]

Damn, I should run to the patent office with it..


Cheers,
Aziz

I am sure you will get patent on this great titanium work.

What is inside Al-stripe wire? Is Alu stripe wound around polystyrene stripe core?

So you use polystyrene stripe twice: as body for Alu stripe Wire and as interwinding insulation spacer?

[Aziz]

I am sure you will get patent on this great titanium work.

What is inside Al-stripe wire? Is Alu stripe wound around polystyrene stripe core?

So you use polystyrene stripe twice: as body for Alu stripe Wire and as interwinding insulation spacer?

Hi WM6,

inside the Al-stripe is nothing. The Al-foil is folded always at the center. After folding it six times (!), you get a stripe of approx. 5 mm x 1 mm x 30 m. Imperfections in folding process increases the Litz-wire effect (more air between the Al-foil layers, 2^6 = 64 layers). The Al-stripe is then isolated with a simple and thin transparent Tesa tape. It's giving effectively two layers of Tesa tape isolation. The isolation will give the Al-stripe more mechanical stability.

The polystyrene tape is only for isolation between the Al-stripe layers to keep the interwire capacitance low.

Aziz

[Aziz]

Hi all,

I have been stopping the Al-stripe coil development last time due to bad back problems. So the coil is not finished yet. I'll continue it as soon as possible.

BTW, I have some project money now, which is waiting to be spent.


Aziz

[simonbaker]

See below the pictures of my DIY XPS Cutter

Much simpler, much more precise, reproduceable results
Powered with 12 V power supply (AC or DC).


Damn, I should run to the patent office with it..


Cheers,
Aziz

Excellent ingenuity Aziz -- always inspiring and useful...

-SB