Double D Coil, Shield?

[chemelec]

I Quickly made a double D Coil for testing on the Bandido and I think it Works much better than the Coplaner Coil.
Assembled, its 6 inches by 12 inches.

I didn't get the Inductance correct, so now I'm making a Final one. I have the new coils wound, No Problem.
Getting a Perfect Balance is Easy.

But I want to use a Spray Coating on the "Coil holder" for Shielding. Not Actually sprayed on the Coil.

I'm going to use a Conductive Nickel.

The Question is: Where do I put the Gap in this coating?

Between the Two Coils?
Or Where?

I Tried to find some articles or drawings on this and No Luck.

Take care....Gary

[Max]

I Quickly made a double D Coil for testing on the Bandido and I think it Works much better than the Coplaner Coil.
Assembled, its 6 inches by 12 inches.

I didn't get the Inductance correct, so now I'm making a Final one. I have the new coils wound, No Problem.
Getting a Perfect Balance is Easy.

But I want to use a Spray Coating on the "Coil holder" for Shielding. Not Actually sprayed on the Coil.

I'm going to use a Conductive Nickel.

The Question is: Where do I put the Gap in this coating?

Between the Two Coils?
Or Where?

I Tried to find some articles or drawings on this and No Luck.

Take care....Gary

Hi Gary,
I think depends on the shield used and also if it is on coils or on coil housing.
Example :
with foil you can shield coils then leave two gaps, one for each coil

Depend on the shield means that conductivity is important so with foil, nickel,
aluminium, litz etc that are great conductors you need always the gap to avoid a short turn around your magnetic field to close a current path.
If shield is not so conductive no need to have a gap: it happens e.g. with graphite...but one can also make a gap too to be sure not too much current flows in the shield if too thick and conductive --> generally speaking graphite doesn't require gap(s).

Other issue is shielding the housing then one can do when using nickel (as you want) like in Dave Emery's article on coplanar-concentric coils, so using small strips of adesive tape before shielding.

I think that for DD config a good gap in the nickel would be from center of former , parallel to "inner edges" of the two coils, untill end of the housing.
Of course all around the housing internal walls.

If you think to shield coils instead you can put two strips of adesive tape on them preventing shorting before appling the spray.

Best regards,
Max