Plastic project box....?

alexander.x · Post by **alexander.x** » 26 Jan 2012, 17:21

Hi all....noobie here.
I have a bunch of nice plastic cases I wish to use.
Do I need to modify them at all?
What do I need to watch for?
thanks

skylark44 · Post by **skylark44** » 27 Jan 2012, 01:34

First off...Welcome to the forums! Now for the fun stuff...what sizes are the cases? (that would help, to determine what (or how much) you could possibly fit in them, project-wise.

Nocentelli · Post by **Nocentelli** » 27 Jan 2012, 09:02

You will find that they hum when used as pedal enclosures, since a plastic case cannot act as a"Faraday cage" so affords no shielding from RF interference. One solution might be to cover the inside of the case with sticky-backed copper sheets and ground that if you want to make them into pedals. You would have to ensure that there is continuity from sheet-to-sheet, so this is potentially a fiddly (and possibly expensive) process.

On the other hand, if the pedals are for bedroom use only, and aren't massive gain effects, you might find you can live with amount of noise.

There are also power supply projects you could build with plastic boxes that don't need to be shielded, like a 9v-to-18 volt charge pump, or the "de-volt"/dying battery simulator (found at Beavis audio's website). You can also make instruments like simple one/two chip synths in unshielded boxes.

pedalgrinder · Post by **pedalgrinder** » 10 Feb 2012, 23:14

i've used lots of plastic boxes for audio purposes they can all be used what you need to do is go to the hardware store and purchase a roll of alluminium tape preferably the mesh one as you can bend and push it without tearing a hole through while pushing it into corners and stuff. as mentioned in the previous reply you have to make sure you maintain continuity. what i do is cut a small strip of tape and stick the 2 sticky side together so i have like a contact surface and a strip of aluminium down the middle to act a conductor so that all strips i have layed down connect. you then drill a hole and use a ring crimp lug and a screw and bolt for the earth as you can't solder onto it. I have this method the cheapest as it allows you to use all plastic boxes and i found the role of tape here in australia for $16 dollars and so far i've done like 10 boxes or more and still have plenty. It really isn't that hard if you want to save some money. if you have any questions feel free to ask me.

skylark44 · Post by **skylark44** » 13 Feb 2012, 00:56

That's a great idea

...I'll have to try that, on my next pedal build...thanx

.

alexander.x · Post by **alexander.x** » 22 Feb 2012, 12:44

thank you so much guys. I like that aluminum tape idea. I have some REAL metal tape used for sealing duct work, not "duck tape" which should work nicely. I have these plastic "cases" that I am going to use and when I finally get them completed...I will unveil them here first time on this site. Hopefully it will inspire somebody. It may take some time but it will happen.

Zipslack · Post by **Zipslack** » 22 Feb 2012, 18:11

If you want REALLY cheap, try using spray adhesive (3M makes some good varieties) and regular heavy-duty aluminum foil. Cut it to the approximate shape, spray the inside of the enclosure, press in the foil. Work quickly. Could also try this with fine-mesh screen (like for screen doors - make sure it's the metal and not plastic).

Don't forget to add a piece to the bottom plate (if plastic) and overlap the edges a little on the box so it makes connection with the bottom plate.

alexander.x · Post by **alexander.x** » 02 Mar 2012, 15:14

is there any effects that I can house in a plastic case that do NOT require shielding tape?
maybe something with less gain...?
I came across an acrylic case from the game "table topics" that I am going to try using.
It is super strong and I can use the top and bottom for two seperate projects. (found it at thrift store for $3)

pedalgrinder · Post by **pedalgrinder** » 03 Mar 2012, 01:25

because there is radio and tv that sends signals through the air a vast majority of the frequency spectrum is used. therefore all audio products if to work properly must be shielded. Unless your happy to hear noise. There is no choice.

alexander.x · Post by **alexander.x** » 03 Mar 2012, 03:35

is using shielded cable for ALL the connections an option?
or somehow cover the board more directly?
perhaps some old fashion experimenting is in order.
don't laugh at my noobiness...ok go ahead and laugh.

pedalgrinder · Post by **pedalgrinder** » 03 Mar 2012, 10:09

well i tried all the options your suggesting and i had to learn the hard way so take it from me shielded cable is ok if you have the room. But nothing beats proper metal case or decent shielding in the box. you can then run single wires as your connections points. And on the point of wiring. Make sure you use star grounding this and shielding are the two biggest tickets to making a successful good pedal. First i didn't shield my boxes all i got was hum then i used shielded wire i got hum but less. I then i had ground loops so i had to fix that. I've been through the pain. Make sure you use a shielded box and star grounding from the input or output socket. If you don't know what star grounding is then look it up online and educate yourself it will be the best thing you do to make a successful pedal. Trust me!!!

alexander.x · Post by **alexander.x** » 08 Mar 2012, 20:50

thanks for the info pedal grinder....I really want to use these plastic enclosures because of their sheer originality. I guess I have some work and research ahead of myself.
if I fail 100 times, then I will try 101 times...and so on.

pedalgrinder · Post by **pedalgrinder** » 09 Mar 2012, 21:19

i found when i was a beginner try simple circuits and get them hum free for a start you can experiment more with a simple one without such a headache once that formula is successful go bigger each time. The guys that build successful pedals on here know what there doing you can really learn a lot from them.