Boxes, revisited

[AndrewH]

Right, so now I have already asked what types of boxes you guys use, and received very helpful replies...I can find that thread, so now I start this one

I was told that metallic boxes help in shielding? also that some folks use plastic boxes with some aluminum foil strapped on the inside?
Now, the difference in price between a hammond aluminium box and a plastic box is huge, so I was wondering, could a similar (or somewhat similar results be obtained by using plastic boxes and coating the inside with conductive spray? ( you know the stuff? comes in cans similar to spray paint cans?)

Is that a viable alternative?

[Ripthorn]

There is a good article regarding this at GEOFEX.  The short answer is that a plastic box with foil or conductive paint will work just fine.

[AndrewH]

thanks alot Rip...

[DougH]

This might help you as well: http://www.diystompboxes.com/wiki/index.php?title=Main_Page

There is a lot of good info about enclosures, alternatives, finishing and other assorted tips as well.

[Nitefly182]

Plastic boxes are indeed cheaper but is the difference really that huge in the grand scheme of a build. Last time I checked a small plastic box was about $3 and a small hammond box was about $5.

[jefe]

Plastic boxes are indeed cheaper but is the difference really that huge in the grand scheme of a build. Last time I checked a small plastic box was about $3 and a small hammond box was about $5.

True... and conductive paint isn't exactly cheap either

[DougH]

Plastic boxes are indeed cheaper but is the difference really that huge in the grand scheme of a build. Last time I checked a small plastic box was about $3 and a small hammond box was about $5.

I did this for $2 or so just to see if it would work: http://www.aronnelson.com/gallery/main.php/v/DougH/fuzz/AstroTone/

It did. Was it worth the price savings? It depends- gluing in the foil was more work but probably not any worse than powdercoating an aluminum box. I prefer the look of powdercoated die cast, there are more box sizes available, and it is sturdier. But if you need to save pennies, it is do-able and I prefer working with plastic/pvc over the RACO boxes I used to use for the looks and the ease of working with it. Still, I prefer aluminum overall.

[Ronsonic]

If you're doing a proper job of shopping the metal boxes, the price difference isn't worth the trouble of messing with plastic. Conductive paint isn't cheap. If you're in the US, try pedalpartsplus.com or effectsconnection.com or small bear and you'll see the diecast stuff is too inexpensive to justify mucking with plastic.

[ItZaLLgOOd]

I use 4" PVC pipe with SS tops and bottoms for my stuff.  If somebody wants me to make a pedal for them I'll usually get them an aluminum enclosure when I order the rest of the stuff.  It's harder to get good results consistantly with the PVC and is more work but cheaper for me.

[MR COFFEE]

Hi John,
Would you post a picture of what you are doing? Sounds interesting.

mr coffee

[ItZaLLgOOd]

Yeah, I'll take some pictures tonight.  I have one about 1/2 way done.

[AndrewH]

well here (in South Africa ) it is quite a difference, a plastic box costs about 20 rand (roughlt 2 USD) while a comparable Hammond box will sell for about R130 (close to 13USD) so it's worth investigating.

That said, I've now got a mate making my boxes, so what would be the ideal material? would something with a better conductivity be better for shielding? or are we looking for a better permitivity? would a copper casing be a good idea?

[jefe]

well here (in South Africa ) it is quite a difference, a plastic box costs about 20 rand (roughlt 2 USD) while a comparable Hammond box will sell for about R130 (close to 13USD) so it's worth investigating.

Sure, it's worth investigating... just remember to consider the extra costs of shielding the plastic box, and remember that plastic is not as strong as metal... you will be stepping on these, after all...

That said, I've now got a mate making my boxes, so what would be the ideal material? would something with a better conductivity be better for shielding? or are we looking for a better permitivity? would a copper casing be a good idea?

Watch out here... you could potentially end up going way over 13USD per box making your own. Or you could potentially save some money. Either way, we need to know how your mate is making them before giving you a good answer here. Is he bending sheet metal & welding the corners? I'd go with aluminum... but steel is cheaper. Copper is probably too soft, unless you go with a thicker material... which adds alot to the the cost. See what I mean here? Making your own may or may not save you money.

[Mark Hammer]

I bought a bunch of nice plastic boxes for $2@ a while back, and picked up some sheets fo copper shim at the same time.  If you look at some of the pix in this zipfile - http://hammer.ampage.org/files/Woody.zip - you'll see how I use the shim to shield things.  Since all pots and switches are going to be mounted on the top of the box, I use them to hold the metal sheet to the box.  I figure the biggest sources of EMI are going to come from above anyway, so if the top surface is shielded and the connecting wires are short, I'm in pretty good shape.

[ralley]

well here (in South Africa ) it is quite a difference, a plastic box costs about 20 rand (roughlt 2 USD) while a comparable Hammond box will sell for about R130 (close to 13USD) so it's worth investigating.

Hi Andrew, where were you buying that you paid that much?  I used to buy Eddystone boxes from Yebo Electronics and the 1590B style boxes were only R60.

Ouch, I actually just checked and they are now R97.  The link is: http://www.fort777.co.za/index.php?main_page=product_info&cPath=715_730_732&products_id=4030

Rob.

[ItZaLLgOOd]

Here are the basics of what I do for my enclosures.




I have access to a CNC plasma cutter to make perfectly round tops and bottoms out of stainless steel.  I go to the
metal place and get drop off's from their big sheer so it doesn't cost to much.
My Dad used to be a plumber and my grandfather still is so there is usually some scrap 4" PVC laying around somewhere.
When I get better with my wiring I will try some 3".

This is a crumby pic but it is a finished pedal.

 

[AndrewH]

[/quote]

Hi Andrew, where were you buying that you paid that much?  I used to buy Eddystone boxes from Yebo Electronics and the 1590B style boxes were only R60.

[/quote]

Hey Rob, thanks man. I was buying at Communica, Yebo electronics is now only in pretoria, but for a thirty/forty rand saving per box, certainly worth the drive. thanks

[frank_p]

Some ideas (?)

Old car metal gaz tank caps


Aluminium fence caps:




Plugged aluminium square extrusions


For multi-fx




Or scrap aluminium valves motor cap

[frank_p]

I went to see the fence caps at Renodepot (Rona).  There are some pyramid shaped fence caps made from stamped steel big enough to put electronics in there.  They are made to be screwed to a wooden beam.  About 2,50$ each.  Already painted.  Might be a good solution.  They are robust but there is no metallic bottoms of course...  Not sure if a 3pdt stompSW might fit in.

[frank_p]

Went dump diving and I found this:
If you spot a refrigerator, go see if the drawers are made from stamped steel.  Those can make big enclosures for a multi-effect or a chassis for an amp.  Rugged, big, pre painted and free !