Ravi,
Corrosive gases....YUP....that's definitely a more hostile environment than I have to design for. I imagine that makes for a critical material selection.
It is possible to make a "sealed" sheet metal enclosure....generally it involves 1)welding the enclosure seams to close them...
I try to always use zinc plated steel fasteners with zinc plated steel PEMs or nuts. There are times when I wind up using stainless screws (they are readily available with a nice black chrome finish) in which case I tend to throttle the torque back for the lower proof stress of the stainless...
Ravi,
Wow...that's a tough question to answer in generic terms. It depends so much upon:
Product volume (piece price versus tooling cost)
Shock/vibration
Thermal environment
Corrosion environment
EMI requirements
Aesthetic Considerations (industrial versus consumer)
For my industry (which is...
Mechwitch....thanks for the reply.
Yeah...this is a frustrating topic and I've resorted several times to doing torque testing as you suggest. Unfortunately, that always leaves me with the sinking feeling that perhaps the fasteners I used for the testing weren't of the lowest proof stress...
ARGGH!
For those of us buying "commercial steel" machine screws in the <0.25" major diameter...does anyone have a recommendation on the allowable proof stress for these "commercial steel" parts?
Background:
The SAE grade 2 spec doesn't apply to small machine screws as...
You could try
http://www.lmbheeger.com/products.asp?catid=61
http://www.elma.com/us/products/enclosures_and_components/Enclosures/
Other than that....we've always designed our own because we've never been happy with what's commercially available. You might also want to consider the danger...
im4cad.....BINGO!. That's precisely what I was looking for. The controls are a little clunky...or perhaps I need some practice driving that feature....It's not entirely clear how to get it to cut up to precisely a particular plane.
Nonetheless....that's what I was looking for.
Thanks
Hmmm...OK...that's better. Thanks for the tips.
However Pro doesn't actually remove the portion of the part up to the section plane...instead the section appears as lines that show through the shaded model. I was hoping there was an equivalent way to actually temporarily REMOVE from display...
In a former life I was a CoCreate user. SolidDesigner had the ability to create cutting planes (essentially a 3D version of a 2D drawing section view). It was terrific for being able to see relationships between parts that are inserted into other parts. Does this sort of capability exist in...
VonMises...how about:
Electronic Packaging and Design: "Designing electronics for high vibration and shock" by Howard Markstein.
If you're daring enough to post a Fax# I'll send you a copy of the article. It wades through some example applications of the formulas.
Ball bearings....if I remember what my college roommate told me (he iterned at the Timken plant in SC).....
It's all about surface tension. A blob (excuse the technical term) of molten metal is discharged from a nozzle into air. The surface tension of the material causes it to assume the shape...
Folks,
I'm looking for a product that is essentially an alignment pin that stakes into sheet metal (like the ubiquitous PEM). PEM makes a "TPS" product, but the diameter is too large for my application. Anyone know of a company that makes such a product with diameters in the...
Anyone have a rule of thumb for allowable BGA vibration in shock (before failure of solder joints?). We're hoping to find something more recent than the 30 year old Steinberg criteria. Any help?