Help: Making Project boxes

Why is that obvious? Tons of people put pcb's into metal boxes.

John

Obviously someone is missing something obvious.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Use more PCBs to make your boxes. Kinda like 'birds of a feather....'

Yeah metal is great! It shields, it conducts heat, it's strong...what else could a man want?

George H.

Horseradish.

John

Sounds like you just need some standoffs, so the bottom of the PCB doesn't touch the case. You can lay out the PCB to have a pad at each corner with a hole in it for a #6 machine screw (or whatever). If you want the circuit to be isolated from the case, then each pad should be isolated from the circuit. Or, if you want the case to be grounded, you connect one or more corner pads to ground. (I usually lay out boards so the ground is surrounding the central circuit area, where possible, so this is easy.)

If the PCB is really small (ie lightweight), you might be able to hang it between the connectors that are mounted on the outside of the case. If the connectors have ground tabs, you can make little "posts" out of stiff (cut-off component lead) wire that you solder to the PCB, then install the PCB by soldering the posts to the connector grounds.

I've used small plastic boxes as cases, but these were one-offs using boxes I just happened to have. Seems there aren't that many products that come in useful plastic boxes anymore, so I haven't done this in years. Maybe an old VHS case?

I've done plenty of cases from wood "back in the day". This was more for major projects like audio amps or benchtop equipment, with power supplies and a moderate amount of circuitry inside, so probably bigger than what you are looking for.

The basic approach I used was to make the case as

2 "C" units, sorta like the old metal "Bud" boxes. The top C (top and sides of the case) would be made out of wood that could be nicely finished. The bottom C would consist of a bottom upon which the circuit would be mounted, plus front and rear panels for switches and connectors. These latter could be made from sheet aluminum or thin Masonite, etc.

The front and rear panels could be screwed to the edges of the bottom board, or the bottom board could have a groove to hold them in place... usually with a matching groove on the top and sides of the case. Then big screws could attach the sides to the bottom, so the end result looked like a typical piece of stereo gear.

Best regards,

Bob Masta DAQARTA v5.00 Data AcQuisition And Real-Time Analysis

Scope, Spectrum, Spectrogram, Sound Level Meter Frequency Counter, FREE Signal Generator Pitch Track, Pitch-to-MIDI DaqMusic - FREE MUSIC, Forever! (Some assembly required) Science (and fun!) with your sound card!

As others have said, metal is a good choice because of shielding, and it is simple enough to use standoffs to isolate the board.

I have used plastic instrument cases available from Jameco for about $5-$15 that are well-made, rugged, and easy to make holes for controls, meters, etc.

If you are really strapped for cash, and really want plastic, you might find some plastic food containers that could be used for project boxes. Otherwise, you can often find things at flea markets, hamfests, or even in the trash that can be gutted and reused for projects.

And you can make boxes from plastic sheet material. You may have to use the right kind of glue, or use mechanical means to assemble them. You can find suitable material for free, such as old CD cases.

And for some projects, you can use PVC pipe, which is very durable and easily glued.

Good luck,

Paul

s

Hee Hee... big Grin. And I thought my job was to entertain you.

Way before chicken wings the essential 'bar food' in Buffalo was/is Beef-on-Weck. Which is slow cooked roast beef on a Kimmel wick roll (Hard roll with salt and caraway seeds) that you slather with horseradish. Notin' better for clearing out the sinuses in winter.

George H.

How to article for abs plastic from abs sheet:

I use wood for the stuff where size and sealing aren't critical. I have one of the cheap 10" Makita bench top table saws, it can't be beat for small projects - high precision with minimal effort.

An old tungsten carbide blade will cut aluminum with no problems too - a small vise to use as a bending brake, and you can make aluminum boxes, panels, mounting hardware, etc. Whitney Jensen/Roper hand punch is inexpensive and works well - plus the essential hand nibbler, and minor sheet metal projects are a snap.

I saw where other people had suggested you just use "offests'when usinig metal boxes, and your question came to my mind this morning when I finished off a box of cinnamon mints. Mybe this is a dopey idea,btmaybe not, so here goes:

Many mints come isvery sturdy boxes;, some are metal and some are plastic; the Walgreens cinnamon drops come in a really small tin that's roughly

1.5"X2.5" and roughly 5/8"high.

If you and/or friends/family like mints anyway, maybe some of the mint boxes would suit your purpose...? Also, if you don't need anything that's super- sturdy, there are plastic snap-boxes used for collectable/trading cards that might work out for you? Another idea is to check your local taples and Office Depot as well as Michael's or HobbyLobby or other craft shop nd see what sizes of wpre-made wood boxes they have.

Also, maybe these sites will help you out:

|Containers|CON-06/?x=25 &i=1&f=p

Well, hopefully one of those gives you some ideas...

|Containers|CON-06/?x=25&i=1&f=p

Another possibility is to use one of the new blue plastic electrical boxes. I've seen them as cheap as 20 cents each. They are certainly rugged enough, but rather ugly.

Paul

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s.

h,

Thanks everyone. I'll have to decide which option to go with.

But first. Where do i get those "new blue plastic electrical boxes"?

Thanks.

Darren Harris Staten Island, New York.

Any place that sells DIYer electrical goods? Gray and black are also common colors.

I've used sheet-metal, wood, and plastic to fabricate project boxes. basically whatever was on hand, also re-used existing vessels. (jars, cans, cases etc...)

For metal boxes just include an insulating spacer between the circuit and the case. wood, plastic, several layers of electricians tape, or part of the PCB itself. it may be advantageous to have the box connected the circuits internal ground node.

Pick a material which you are comfortable working with and can do work of acceptable quality in.

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?x=3D25&i=3D1&f=3Dp

s.

h,

Thanks everyone. All those links came in handy.

Darren Harris Staten Island, New York.

6/?x=3D25&i=3D1&f=3Dp

xes.

ugh,

Does anyone have any idea on how to secure 24 position straight header pins to one of these project boxes?

With normal PCBs it would be solder that secures the pins, but this obviously will not work with these plastic boxes. So after I find the correct size drill to make the holes in the box for the pins I have to use some sort of cement top keep the header in place.

|Containers|CON-06/663=

-321.html

Thanks a lot.

Darren Harris Staten Island, New York.

|Containers|CON-06/663-321.html

the type of cement that's best used depends on what sort of plastic it is.

can you solder the header to a PCB and then bolt the PCB to the case?

another option could be drilling undersize holes for each pin and forcing the pins in, but the website says that the case is conductive.

if you go this route expect in the ballpark of 1K resistance between adjacent pins.

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N-06/?x=3D25&i=3D1&f=3Dp

boxes.

enough,

663-321.html .

Do you know of a site that sells cements for this purpose?

I thought about that, since the already existing PCB will already be secured inside using stand-offs it makes this difficult.

cent pins.

I was just thinking. Since I'll be using stand-offs, perhaps I don't need a conductive box.(Even though PCBs with circuits etched in them are considered "static sensitive devices"). So I'm back to square one as far as finding a place to purchase these boxes. So far the distributors I've checked have huge minimum or they don't have the size I need.

Darren Harris Staten Island, New York.

boxes.

enough,

no, but plumbers do a lot of solvent welding of plastic, but first you need to know what type of plastic.

how about a longer than usual header to compensate for the stand-offs?

static sensitivity depends on the circuitry inside the case (I'm guessing EEPROMS, so it could be a proble)

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