Help: Coil Housing Dimensions..

[Aziz]

Hello friends,

I need for standard search coils three dimensions:
W: inner width for mounting the stick
H: height for the mounting hole (center position of the hole).
Also the H hole diameter in mm.

Thanks for any help. I want to build the search coil housing for my laptop MD search coil.

Aziz

[Qiaozhi]

Hello friends,

I need for standard search coils three dimensions:
W: inner width for mounting the stick
H: height for the mounting hole (center position of the hole).
Also the H hole diameter in mm.

Thanks for any help. I want to build the search coil housing for my laptop MD search coil.

Aziz

It depends on what stem you're planning to use. They are not all the same.
The Tesoro 9x8 web coil has w=19mm and h=15mm.
But the critical dimension is the width. Different stem, different width.

[Aziz]

Hi Qiaozhi,

thanks for your effort.

I would like to have other dimensions from other contributors here. Please help me on finding a best compatible search coil design.

Aziz

[Qiaozhi]

Hi Qiaozhi,

thanks for your effort.

I would like to have other dimensions from other contributors here. Please help me on finding a best compatible search coil design.

Aziz

Fisher is the same as the Tesoro, but Garrett is w=20mm, h=20mm.

[Aziz]

Hi Qiaozhi,

thanks again for your effort. I am going to build the search coil housing now. The positive form is finished and I can start with the fibre glas resin layers tomorrow.

The stem is made of plastic (tube) and I will fill this with PU foam to get it tighter. I also have bought plastic screws to mount the stem to the search coil.

Thanks,
Aziz

[Aziz]

Here is the coil housing form:

[simonbaker]

Here is the coil housing form:

It looks very good . I am interested in wood too. I want to make a "classic" design with wood and bamboo, just for fun, and hardware like old WWII radios.

-SB

[Qiaozhi]

It looks very good . I am interested in wood too. I want to make a "classic" design with wood and bamboo, just for fun, and hardware like old WWII radios.

-SB

Bamboo would be good. Very strong and light.
Please post photos.

[Aziz]

First fibre glas and resin layer applied.

The wood form is glued on a wood board. Then it is fully brushed with fat to avoid the resin glueing on the wood (except the plastic stem holder, this will be part of the search coil). The fibre glass is placed to cover all regions of the coil housing. The resin is brushed over the form. The fibre glas gets transparent with resin. Needs now drying before next layer is made.

Aziz

[Aziz]

Now second layer is done.

The graphite shielding of the inner side is the next step.

The bottom side of the search coil will be done after the coils are placed, balanced and fixed.

[Aziz]

Ok, the coil housing is dried and the graphite shielding is made:
(see below). There is a drain wire built-in in the shielding. The graphite shielding has some spacer to avoid conductive loops.

Next step: cabling and stem mounting.

Aziz

[Max]

Ok, the coil housing is dried and the graphite shielding is made:
(see below). There is a drain wire built-in in the shielding. The graphite shielding has some spacer to avoid conductive loops.

Next step: cabling and stem mounting.

Aziz

Hi,
that's interesting Aziz! You've done good work on it.

What about weight ?

I think will be really resistant... more than ABS. But weight is an issue.

Kind regards,
Max

[Aziz]

Hi Max,

Hi,
that's interesting Aziz! You've done good work on it.

What about weight ?

I think will be really resistant... more than ABS. But weight is an issue.

Kind regards,
Max

Thanks. Indeed, weight is a big issue. The coil housing is roughly 2-3 mm thick. It will be filled with PU foam later. After the bottom side, the coil holes will be cut and grinded. So this will make a bit lighter.
But a high mechanical stability is more important than the weight. Lock-in amplifier is too much sensitive and therefore the coil housing and cabling is very important. Also the shielding.

regards,
Aziz

[aft_72005]

Hi Aziz
Very Interesting ,because I decided building former for coil seem as your former at the past.
But I am busy and cannot found more time for this work yet.
Please show more pictures and more inform us .
Best regards.

[Aziz]

I regret not buying the good quality and expensive cable connectors. In the high fidelity audio applications, there are very good connectors available and I saw some of them in the shop. I will buy them next week to continue the search coil assembly.
Cabling the coil must be done before balancing the search coil due to effects of the cables itself.

Keep at it. I will post further pictures.

Aziz