rugged case with button and optional display

I used to make my own cases for electronics from plexiglass.

There was a "sign and display" shop in the city, where you could buy plexiglass cut to size on the buzz saw in the shop, and the friendly shop owner sold small bottles of chloroform that is used to "glue" the sides together (actually it is more like welding).

A good 5 minute epoxy may be a better choice of glue.

If there's any chance of that case getting wet or even covered in condensation, don't use a cyanoacrylate glue (aka 'superglue' by those who've only seen the anaemic consumer versions) without painting the case after it has been assembled. Cyanoacrylates are water-soluble, so anything assembled with them that is likely to get wet must be coated with a waterproof layer after assembly.

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martin@   | Martin Gregorie 
gregorie. | Essex, UK 
org       |

Cyanoacrylates are *not* water soluble, although they may well be hygroscopic.

The only tow things I have found that dissolve them are acetone and nitromethane.

There are a few other exotic compounds that do as well, but I dont have access to them.

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New Socialism consists essentially in being seen to have your heart in  
the right place whilst your head is in the clouds and your hand is in  
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After it has hardened fully even acetone only dissolves it slowly. I had a small amount on some polycarbonate and never could get it off even with soaking for hours.

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Rick

thanks not sure how i missed that on ebay ..... Just when I begin to think I have some reasonable ebay search skills ..alas...... :)

thanks again

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Wow, $8 sounds expensive for such a small piece of plexiglass. Is there something special about "Cell Cast"?

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Rick

I've used cya for years for model building - and have had bits fall off as a direct result of getting the model wet. The easiest cure in that environment is a coat coat of nitrocellulose dope of fue proofer.

Look at the history of the stuff: cya was developed for battlefield wound closure when analyses showed that the no 1 killer id wounded soldiers in tropical wars was infected dressings. First use was in Vietnam: don't use dressings - put the innards back inside, glue wound shut, onto chopper and back to the MASH without using dressings. Thats why cya is what it is: a water-catalysed, water-soluble glue. Water catalyses so it will set when applied to a wound, water soluble so it can be used in place of stitches and, after healing will dissolve without needing to be removed later.

The first brand available for general use was "Hot Stuff", sold by the Hunters, who owned Satellite City, an American supplier of materials/ tools/kitsets to model builders and a few years before the pathetic, diluted Superglue appeared on the general market. When the NFFS gave them a special award as part of the annual Models Of The Year list the description supplied by Bob Hunter made the origin and characteristics of the stuff quite clear.

Yes, the water solubility varies with the formulation, but all varieties are water soluble even the best brands. e.g. ZAP. Bear in mind too, that the purveyers of 'superglue' will be using the cheapest possible formulation regardless of setting speed, strength or durability of the bond.

And don't put nitromethane on your skin: like all organo-nitrates, it is easily absorbed through your skin and is very bad for your liver. THIS info is taught in every 1st year Organic Chemistry course.

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martin@   | Martin Gregorie 
gregorie. | Essex, UK 
org       |

On Wed, 10 Jun 2015 20:16:23 +0000 (UTC), Martin Gregorie declaimed the following:

Really...

My experience has been that they rely on atmospheric moisture to catalyze the hardening reaction.

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	Wulfraed                 Dennis Lee Bieber         AF6VN 
    wlfraed@ix.netcom.com    HTTP://wlfraed.home.netcom.com/

That includes shipping from China to your door, so pretty cheap really. Obviously if you have a local source it should be cheaper, but by the time you factor in the cost of driving there, and your time ...

International postage handling is based on reciprocal agreements where in each country the shipper pays the local tariff and the receiving country dispatches the mail and packages without extra charges.

I expect those agreements to end pretty quickly now massive small package shipments are made from China where the tariff is about $1, while they are sent to high-income countries where it normally costs around $10 to locally ship such a package.

When I receive a package from China it is transported and brought to my door by someone who gets more for that handling than the person in China has paid for the shipment. That is going to break sometime.

Uh, I've bought stuff from China for just $1 which included shipping. So I can't see how it would be the shipping cost that drives the price.

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Rick

As I said above, its was originally a medical glue: an ideal medical glue would have a water-catalysed setting reaction and then dissolve after the wound is healed so nothing needs to be removed.

Here's a good article:

and note that in the 'Aquaria' section it says "However, as a class of adhesives, traditional cyanoacrylates are classified as having "weak" resistance to both moisture and heat[5] although the inclusion of phthalic anhydride reportedly counteracts both of these characteristics."

Personal experience shows this to be true: I'd attached critical parts of a model aircraft's control system using cya and, after about a year of use outdoors, i.e. landing in damp grass, etc, the parts separated completely when I was caught out in a downpour while collecting the model from where it had landed. On this occasion I had not overpainted the cya joint with with a waterproof coat of nitrocellulose dope. About the same time a number of other cases occurred and since then we always put a coat of dope over any cya joints on models that are to be flown outdoors, which solves that problem.

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martin@   | Martin Gregorie 
gregorie. | Essex, UK 
org       |

Have a look at what Open Energy Monitor are doing. Looks like they sell the ir case which looks rugged, has a push button and a small screen. Maybe the y can sell it unbranded?

I don't see any indication this case is for outdoor use. "Rugged" looking is not sufficient. Also, the LCD needs to be visible outdoors and work in low temperatures. This can be found, but is not common.

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Rick

their case which looks rugged, has a push button and a small screen. Maybe they can sell it unbranded?

Rick, from the original posting

The case I linked to looks rugged because it is. It's an extruded aluminium box, far stronger than any plastic box.

Being placed in a warehouse is a semi protected environment. There is no re quirement for it to be waterproof. Inside a warehouse is inside, not outsid e.

Well that depends on what goes on in the warehouse.

--
New Socialism consists essentially in being seen to have your heart in 
the right place whilst your head is in the clouds and your hand is in 
someone else's pocket.

I know, but I have talked to him more and it needs more than just "rugged". You snipped the part about IP44. It is the "rugged" that he actually doesn't need. It will be mounted on a wall or post and if it is bumped by a pallet, even metal won't necessarily survive. A good plastic case should serve just fine. A real issue is temperature.

He asked for IP44 which provides protection against water and dust. A warehouse is not the same as an office environment. Maybe he doesn't need to submerge it in a tank, but there are requirements.

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Rick

Especially if it is in China!

---druck

Thanks for the suggestion. But as Rickman says - I think I need a bit more. A warehouse is sometimes clean a an office, but most likely not.

I had several uses in mind, which was not mentioned in the original posting.

A warehouse can be a distribution center, but it can also belong to a factory. In the latter case there is often an internal material flow, between buildings, that may be far apart.

Wlan may then become impractical.

The idea was that set up rpis at certain location, and a push on the button would generate a call to the wms-system. 'here is a pallet that needs moving'.

Now, after some discussion, those rpis may end up on the outside of the building wall, but most likely under a roof. So temperature becomes a factor, and also water proof or at least moist proof.

But the business case is put on hold, so I'll pick it up again when things starts moving again.

Rickman has been *very* helpful in this, and for that I thank him.

I really hope that we get to do this, as I see it as a fun project.