How to make a square coil?

[1843]

Hi all,
Does anyone know how to make a square coil?(about winding,water pipe,etc)

Regards

[Carl-NC]

You can build a PVC frame, and just tape the windings directly to it. Number of turns depends on the circuit and coil size.

- Carl

[1843]

My square coil

Hi Carl,

I made a gap along the PVC frame then I did wind the wires between the gap.
Its detection is very poor with any PI machine.
Does my winding have problem?

[chemelec]

Hi Carl,

I made a gap along the PVC frame then I did wind the wires between the gap.
Its detection is very poor with any PI machine.
Does my winding have problem?

What Dimensions is it?
How many Turns?
What gauge of Wire?

[1843]

What Dimensions is it?
How many Turns?
What gauge of Wire?

70cm x 70cm
12turns
0.4mm wire

[chemelec]

70cm x 70cm
12turns
0.4mm wire

That .4 mm appears to be a 26 AWG Wire.

I would try a larger wire, about a 20 AWG (.8 mm) and maybe a few more turns. (Possibly 15)

[1843]

Can I add few turns wire to my coil by soldering? Or I must use a new wire?

[bbsailor]

1843

Yes, you can splice the coil wire.

Do it like this.

Cut 3 cm of heat-shrink tubing and slip over wire.
Strip 1 cm from each wire end.
Overlap to form a 1 cm long twisted joint.
Solder twisted wires together.
Slip heat-shrink over the soldered joint.
Heat the heat-shrink tubing.

This should work and save you from rewinding the coil.

bbsailor

[1843]

Thank you Carl, bbsailor and Gary.
Best Regards

[chemelec]

Can I add few turns wire to my coil by soldering? Or I must use a new wire?

As "Bbsailor" Said: You Can just Join to it IF you just want to Add a Few Turns, But I still feel your wire size is Too Small.

Using that .4mm wire results in a fairly high resistance, thus reducing the pulse current and depth of detection.

What are you trying to find with this Square coil?
Hopefully only Large Objects. These large square coils do not detect Small objects very good.

I would still recommend you totally Re-Wind it with a .7mm or .8mm wire.

[jwms]

Have not done this but should work and look great at the same time.
1. Wind the coil on a form to get the wire length. Mark the form at the start point and make the wire with paint, finger nail polish, etc. Make sure you get each wire in the bundle.
2. Form a loop in the tubing you plan to use. Use dry sand as a filler to keep the tube from flattening while heating and forming it.
3. Spread the loop after it has set and attach a T coupler used to join sections together. Glue only one end!! Set the angle to match
your shaft angle. This will form the ears of the coil mount.
4. Feed your wire from the form into the open end of the tube.
5. Continue until the wire shows on the other end of the tube.
6. Feed enough of the leader into the tube again until you reach the paint mark.
7. Align your second paint mark (which should be near the gap) with the first mark now in the tube.
8. Bind the wires together with something like a regular pipe cleaner. (Pipe smokers know what these are.)
9. Continue feeding the wire around until you reach the marks. Add the next wire to the bundle and bind.
10. When done, start winding the bundle with tape, shielding tape, finish tape if used.
11. Bring the ends out of the loop through the T.
12. Glue the end of the loop to the other end of the T.
13. Attach your lead-in cable wire.
14. Use a can of spray foam and some tubing to get the foam down into the loop.
15. As you inject the foam, pull the tube out to keep room for the foam to expand.
16. Use flexible sealant to close up the hole and paint coil to suit.
17. Only good for single coils but can be made to any size.

Any comments welcome. As I said, have not tried this but sounds solid.

[RING-N-THINGS]

I'm looking to build my first square coil also What pi Md should be good/easy ?. 'White's Surf master','Tesoro Sand Shark','Garrett Mark II', any suggestion.BTY I' am new to this ..TY