Zero effort cases?

[paulca]

So when hobbiests, like I, make PCBs they dont often have enclosures.

We can of course PCB design enclosures and get those printed too, or do CAD models and get those printed. etc. etc. etc.

But one thing you probably really DO need is at least a back plane to protect the board if you set it down on top of your tweasers, say. 

Well, usually fabs have a minimum order of 5 boards.  Use those! Add M2 or M3 mounting holes in the board corners.  Then when you get your first board soldered up and working, take hexspacers and add another blank as a back plate.  (this works with protoboard with mounting holes too).

Optional:  Those mounting holes make excellent places to clip scope grounds if you assign them (with an anular) to the GND net.  In this case insulated hex spacers to not ground your board to things it touches.

What are the minimal effort options for transparent top covers?  My "Toe deep" research suggested you have to recreate a different model in different software to get the right file format for a fab to laser cut your acrylic.  Is that be best option?

[jpanhalt]

I use little wooden pegs attached with small wood screws.  The pegs get reused for different projects.

I am not too worried about sitting on my tweezers, but something like this can hurt:

[paulca]

You know when I sat down at my workbench 2 minutes ago and my eyes fell on my needle point SMD tweazers....  Well, I found the mental image of sitting on them rather...unpleasant!  Thanks for htat.

[eugene]

A blank PCB with standoffs makes a good fixture for building prototypes or rework, especially if you have components on both sides.

An even lower effort solution for completed boards that are being used is self-adhesive rubber feet/bumpers. They can be purchased in any size and shape for cheap.

As for the acrylic cover, I haven't tried it, but you should be able to export the board outline and mounting holes to a pdf. Fab houses will usually accept a pdf for things like this provided the file is vector, not raster format.

[Doctorandus_P]

Not "zero effort", but definitely "low effort":

For the backside, I sometimes press the (soldered) PCB into corrugated cardboard, then deepen the dimles a bit with the backside of a for or tweezers so the majority of the PCB touches the still flat part of the cardboard. Then you can apply a bit of glue around the edges.

You can also make surprisingly good enclosures out of empty milk or juice cartons. These things are made of very high quality cardboard and the laminated plastic on both sides make it water and dirt resistant. You can cut it with scissors or a knife, and you can press folding ribs into it with a ballpoint.

Another method I use is:
1. Enter labels in a spreadsheet program
2. Adjust the line height to 2.54mm
3. Reduce font size so it's readably
4. Print it on paper.
5. Put transparent tape over it.
6. Glue it onto the PCB.

You can even "level out" an uneven PCB (for example containing SMT parts) with hot glue and then put the paper on top.

For prototypes you often wand some sort of feet to keep your PCB from shorting out form small metal pieces lying on your desk, while still keeping the backside accessible for soldering. You can put generous dots of hot glue in the corner, then hold it briefly under running water. This makes the outer layer of the glue hard and non-stick, while the inside is still soft. Then you can set the PCB on a flat surface. this will get the feet to the same height (because the still hot inside of the blob deforms) while the outside is cold enough so you can remove it easily. Doing this on a dusty or otherwise dirty surface also helps to prevent sticking.

I also have some projects in a very dirty environment, but also out of sight. For example behind the kitchen stove. An area that becomes sticky with grease if not often cleaned. Such projects I simply put in a plastic bag and then tie the opening shut. I have an extension cord so both the hot water kettle and the coffee maker share the same wall plug, and I had the RCD trip twice because of a few drops of water spilled on the extension cord. So I also put a plastic bag over the extension cord sockets and closed it. Only the power cords come out one end.

[ledtester]

Just a thought...

perhaps clear epoxy resin could be user to create a translucent cover.

Some people encase the entire project in clear epoxy resin, eg.:

5 Cool Gadgets made with Epoxy Resin -- Hacktuber
https://youtu.be/Eb-hAIb0OQs

[eugene]

I know you said no to 3D printed enclosures, but I've made lots of them. This is an enclosure for a small USB camera used in the lab. It about 36mm square and probably took me two hours to draw both parts, but I use FreeCAD infrequently enough that I need to figure some things out each time.

It would probably take a couple of hours to print both parts. Who doesn't have access to a 3D printer these days?

EDIT: the holes in the "bottom" of the enclosure would get heat set threaded inserts. Something like this: https://www.mcmaster.com/94459A774/ You set them with any soldering iron set to a fairly low temp. The tip never makes contact with the plastic and doesn't get damaged in any way.

[nctnico]

My boards always have mounting holes. From there it is easy to attach threaded hex spacers to lift a board from a surface. 10mm typically works well.

[asmi]

My boards always have mounting holes. From there it is easy to attach threaded hex spacers to lift a board from a surface. 10mm typically works well.

Yep, I also use 3.2 mm holes with 6 mm exposed metal ground pads to align the PCB in the soldering paste printer, and use M3x8 bolts + nuts to make stand off both to facilitate reflowing of the second side, and then to use them as support legs to ensure parts on the bottom side are not damaged. And in some cases I also design several boards to be "sandwitched" on top of each other and interconnected - with mounting holes aligned to provide mechanical stability.

[paulca]

You reminded me of that rabbit hole.

Upgrading your 3D printer to do solder paste 'printing' and pick and place.  It sounds simple.  I'm not convinced it is.