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Topic: Looking for custom enclosure for my project (Read 3 times) previous topic - next topic

szangvil

I am looking for an enclosure that is about 2" by 2" by 0.75". I found many standard ones by Hammond or New Age Enclosures but the problem is that I need some holes cut out... one is for the Nano mini-USB connector, a hole for a LED and a hole for a small buzzer. I tried drilling the enclosure at home but it came out pretty ugly.

At this point, the enclosure is holding me back since I can't have my final PCB design before I have the dimensions of my enclosure.

I want a robust solution since I might have to make a bunch of these (hopefully over 100pcs)...

DVDdoug

For that quantity, one option would be to buy the boxes and find a "precision machine shop" to drill the holes.   The company I work for does that with quantities of about 100 per month.  (I don't know what they charge us.) 

A "precision sheet metal shop" could fabricate a custom box for you, but generally you'd have to design it and provide the drawings.

The shops that do that kind of thing should also have a contact for a silkscreening shop if you want something printed on the box.

Or, could try to make a jig or fixture to align the drill, but your jig has to be precise.


SirNickity


GoForSmoke

+1 on the 3D printing, if you don't require a metal enclosure. You might have an excuse to get your own Cupcake!

OTOH there are places you can send a design file and they will print the items... but what cost?

If the device won't make much heat or could be built on a heat sink then you could maybe pot it into a plastic brick.

If you want to cut sheet metal clean, use punch and die. For just making small holes in thin metal, a custom paper punch will do though you'd want some kind of positioning jig so the hole is in the right place. That would be for modifying a box like an Altoids tin and be prepared to sharpen the punch every so often. Another alternative would be to use hollow punches (Harbor Freight has them) or set up punch and die in a press.
Drills and saws for sheet metal work are for amateurs. They're slow and the cuts need too much dressing up.

I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

szangvil

3D printing is expensive... over $20 for a simple enclosure.

I do like the idea of potting it into a plastic brick. You you elaborate on that?

tigerbomb8

if you do go with the 3d printing it would be cheaper in the long run to buy a MakerBot (trust me you will use it ALOT) or you can get Ponoko or ShapeWays to make it

Inprogress


3D printing is expensive... over $20 for a simple enclosure.

I do like the idea of potting it into a plastic brick. You you elaborate on that?


Chirping in....yes do elaborate on "potting into a plastic brick." 
"The really amazing thing is how many people are successful with their Arduino projects considering the fact that so many of them do not have a technical background.  A lot of them seem to try, and succeed with, projects that no sane engineer would even attempt." - floresta commenting on the proper use of LCD displays

stealthtransam

I use potting compounds (Thermally transparent epoxy) all the time for weather proofing circuit boards for harsh environments.  One thing you have to take into account when potting a circuit board is thermal dissipation of the circuit and the thermal conductivity of the potting material you choose.  It is a more expensive route then a project box with some holes cut out of it and probably over kill for what your describing since you would have to mask off things like your USB connector to prevent the potting material from flowing into your connector.  In any case Potting compounds (thermal Epoxy) can be purchased from McMaster-Carr in small quantities for the hobbyist. 

xl97

have you tried to sketch up a few panels..and have them laser cut?  Im sure you could many panels/boxes from one sheet...

GoForSmoke

I've potted with hot glue. Yes, you need to mask off everything you don't want the potting mix to get in. Tape works well enough, give it a try. You'd need some kind of containment to flow the glue into but cardboard or card stock works just fine, you can print on that and cut it and glue however you wish or find something already made and punch your holes in that.

If you can put your circuit so that anything that makes heat (like a regulator or chip-top) is pressed against a piece of flat metal then set that on the bottom so that the glue wont get under it, you will have a heat sink that can be attached to a bigger heat sink if desired.
You don't have to fill to cover everything either. Do you want the led to be replaceable or not? Of course if it's potted to the base then it's not going to fall out either, it's your call.

The first potted circuits I saw were black blocks made of, IIRC, acrylic (same stuff those paperweights with an object inside are/were made of, Edmund Scientific sold a lot of it) with carbon black mixed in meant to keep what was inside a bit of a secret.
I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

Sacman

#10
Mar 29, 2012, 09:37 pm Last Edit: Mar 29, 2012, 09:42 pm by Sacman Reason: 1
Have you looked at the following:

http://www.okwenclosures.com/index.htm

http://www.polycase.com/

http://www.boxenclosures.com/

All three have a wide range of enclosures available and you might find something that you like better than a standard potting box or square enclosure. They have a lot of handheld options that come with battery compartments as well which is a huge plus.

All three of these sell low volume, even single units. I have enclosures from all three and I like OKW the best but they are all great. I thought the fabrication on the box enclosure one wasn't quite up to par with the other two.

They all provide customization services but I don't know the minimums. I actually just sent an email to OKW asking about screen printing minimums. I have access to a CNC to cut holes/openings. Yeah Me! More than likely there is a bulky setup charge regardless of qty. So if you want 1, you may have to pay a $500 setup plus $1.00 for the part. So if you do 100, is it worth an extra $5 each to have them cut perfect? I would say yes but I don't know their setup costs. I am basing this off of what seems to be common practice.

Look up your local machine shops. Most of them will work with plastic. Many people just assume that they only handle metal. Anyone with a CNC can set you straight and it won't be overly expensive. They can probably even set it up for you if you don't have access to the file type they need, probably solid works or autocad. If your project is really cool and you can get them interested, they might even do it cheaper.

Edit: Just realized you are in Israel. I was going to suggest that you ship them direct to me and I will cut them and forward them to you. A little challenging from here to there.

Luck,

Wade

szangvil

Hi Sacman

Thanks for the links they are all very useful!

Yes, I am in Israel, so the shipping cost is very dominant :(


szangvil

I have a surface mounted LED on the PCB inside the enclosure. I am looking for a plastic light guide that will "carry" the light from the LED up to the hole in the enclosure so the LED light will be visiable from the out side. I don't know what these light guide are called and how to look for one (I want to guide the 3 Arduino LEDs out of my enclosure so they will be visible from the outside).

Sacman

Luck,

Wade

szangvil

Actually, I want to avoid the soldering to make the assembly faster. I want to use the built-in Arduino LED. What would be the best light pipe for those?

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