plastic enclosure experiences

[aaronkessman]

I'd really like to use plastic enclosures because of lower price than aluminum and machinability. I'm aware of the drawbacks - shielding, durability. has anyone ever used plastic enclosures? can you recommend good ones to try out? Some of the ones ive seen at mouser have a cool angled control panel - i figure that'd be neat, huh?

thanks for opinions!

Aaron

[Arn C.]

I used a lot of different plastic and metal enclosures with equal results.
Plastic is a bit easier to work with and now that they have new paint for plastic "Krylon Fusion", life is now even easier.   I use shielded one end wire from both input and output jacks to the switch and I have no problems with noise.  One day I will put up a picture with most of my pedals, some plastic cases, some metal.  Happy building!!!

Peace!
Arn C.

[el duderino]

hey I used a plastic hammond box for a fuzz i built ,

i actually bought three boxes they are transparent and have different colours tinted. i thought that they would crack when i drilled them because they are made from perspex but they didnt, they have a cool look to them but i cant remenber the serial number........................  check out the hammond site in the electrical enclosures page.......
they are not to hard to get your hands on either/////

they also have those angled ones your talking about i think they are a bit more pricy though!!

it might be what your looking for... :wink:

[Mark Hammer]

I use plastic enclosures as well as Hammond aluminum ones.  The plastic ones are selected because a place near me has them cheap ($2@) and they're easy to machine and don't really need any finishing.

The boxes are made by PacTec, I believe.  They are extremely sturdy high-impact plastic, nicely sized, and are likely made for use in professional instrumentation rather than hobby use.  You can see a pedal made in one of these if you download the "woody.zip" file at my site (http://hammer.ampage.org).  The boxes are open ended, so I cut end-pieces out of copper-clad PC-board to fit in the slots provided.  The pictures show that I use a piece of copper shim for shielding.  I cut it out to size and put holes in it with a paper-punch.  The various pots and switches mounted on the chassis hold the shim in place.  The end-pieces have the copper facing the inside, so I simply run a lead from the end-piece to the shim to provide a continuous ground plane.  Shim stock is easily solderable, whether copper or brass.  

Many manufacturer over the years have used plastic enclosures (even MXR at one point, not to mention Ibanez Soundtank series and Danelectro) with acceptable results.  I understand the apprehension people have about the degree of shielding provided by plastic boxes.  In their defense, there is nothing that says you can't run shielded leads to the jacks and pot, and a great deal of EMI is going to come from above the pedal rather than below (which is why I just stick a sheet of shim to line the upper half of the box and leave it at that).  Besides, you may have more to fear from poor layout *inside* a box than from outside, so a cast aluminum box is no magic amulet that instantly eradicates noise.

The three things I would advise with respect to using plastic boxes, based on my own experience are to:

a) keep good manual control of your soldering iron - aluminum boxes don't melt!

b) place footswitches as close to the edge of the chassis as you comfortably can so that you stick them where the box is least flexible.

c) be careful when working with shim stock - it can be extremely sharp on the edges.