Plastic enclosures

[lucifer]

Hi all,
Where do you get enclosures from for your DIY metal detector projects?
Please share any sources of nice plastic boxes.

Thx

[SVEN1]

I don't use plastic enclosures anymore. Finding metal enclosures help combating 98% EMI issues. Especially when building PI's.
You can find lots of enclosures on ebay http://www.ebay.com/sch/i.html?_nkw=aluminum+enclosures

[lucifer]

Thanks for the input, Sven1. Never thought about aluminium enclosures. I've been using my PI detector (in a plastic box) for a few years already and haven't had any serious EMI issues so far. Do you have the enclosure grounded to the battery negative terminal?

[Davor]

Aha!

Grounding point is a non-trivial thing with metal enclosures. Poor choice will create far more problems than it solves.

[SVEN1]

Thanks for the input, Sven1. Never thought about aluminium enclosures. I've been using my PI detector (in a plastic box) for a few years already and haven't had any serious EMI issues so far. Do you have the enclosure grounded to the battery negative terminal?

PCB is grounded to the case. Positive is the ground on my PI.
I have an external frequency control that can be adjusted to knock out most EMI that I encounter. Before the metal enclosure, EMI was an issue, constantly had to adjust for different EMI transmissions. Now it's really no longer an issue.




Here's what I did for my water unit:

Lined the inside with copper foil tape with conductive adhesive and coated it with epoxy, left two spots uncoated, box side and lid and grounded to PCB.
It works for me.

[lucifer]

Thanks, I might try this on my PI machine to see if there's any improvement.

[johnl]

Plastic enclosure

Hi all,
Where do you get enclosures from for your DIY metal detector projects?
Please share any sources of nice plastic boxes.

Thx

Here is link for Ikelite clear molded polycarbonate housing 5710 it is the best I think, the less expensive enclosures leak
http://www.shootingunderwater.com/ik...sing-5710.html
http://www.apmhexseal.com/

[SVEN1]

THE Ikelites are the best and waterproof to extreme depths. Had Ikelite housings for my underwater cameras and strobes back in the 1980's.
The only thing is they are very expensive and if just shallow water hunting, no need to go to that expense. Now and then you'll find the Ikelites on ebay.

[johnl]

Hi all,
Where do you get enclosures from for your DIY metal detector projects?
Please share any sources of nice plastic boxes.

Thx

I found polycarbonate enclosure at sealcon for only $5 closeout sale

http://www.sealconusa.com/applicatio...-products.html

[multieagle]

Aha!

Grounding point is a non-trivial thing with metal enclosures. Poor choice will create far more problems than it solves.

If I use a plastic box that has been painted with aluminum paint (Dynamic Non-Smudge Aluminum, Cast Aluminum - aluminum flakes in a chemical emulsion), would it work if painted on the outside of the control box? If so, must the board be grounded to the outside?

[Davor]

The safest thing is to decide what point on your PCB is the most neutral of all and exalt that specific point to a common ground. It is a signal ground. Everything else's grounds should emanate from there in ray-like fashion. You may allow things to go in series, but you never connect them to go in loops.
That said, mst probably you have a connector that is tightly fastened to the box that may serve as a grounding point. Use it and your box is properly grounded in a single point. In that case you must make sure nothing else is connected in a same fashion to avoid loops.

[multieagle]

Thanks Davor.