EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: cellularmitosis on July 31, 2017, 05:27:49 am
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There are lots of very inexpensive extruded aluminum project enclosures on ebay.
Unfortunately, almost none of the sellers seem to include some of the most important dimensions, leaving the question of "How wide does my board need to be?" unanswered.
I thought I'd start a thread which could serve as a central point of knowledge around these cheap extruded enclosures.
I'll kick us off with a few which I've purchased and measured with some digital calipers.
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First up, the "50*58*24mm" enclosure.
All of these enclosure listings seem to follow this X*Y*Zmm keyword format, so just search ebay for "50*58*24mm" and lots of listings will pop up.
"board width max" is the width of the board slot. "board width min" is the distance between the ends of the board slot "fingers".
Your board needs to be at least as wide as the average of those two, otherwise it could fall out of the slot if you slid it all the way to one side. Let's call it 50.6 max, 48.6 min, which means your board needs to be between 49.6 and 50.6. Splitting the difference and going with 50.2mm would be a good bet, 50.0mm would also work well.
"space above board" is calculated by measuring from the bottom of the board slot to the ceiling of the case, and then subtracting out the board slot height. "space under board" is calculated similarly.
"screws center to center" is calculated by partially inserting the screws, then measuring from the outsides of the threads from one screw to another, then doing the same for the "inside" dimension, then splitting the difference to derive the "center to center" measurement.
There are a lot of board houses who's first pricing bracket allows sizes up to 50x50mm. This case is a great match for that board size price point.
More to come tomorrow!
Edit: updated dimensions screenshot to fix a calculation error in "space above board".
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The "100*99.6*43.8" enclosure. (The ebay listings don't seem to include the trailing "mm" for this enclosure).
Strangely, the enclosure I received did not exactly match the photos in any of the ebay listings (https://www.ebay.com/sch/i.html?_nkw=100*99.6*43.8&_sacat=0). They all seem to list a split enclosure where the bottom half is larger than the bottom half. The top and bottom of the enclosure I received are identical parts.
This enclosure is a good match for board houses which have a price point for 100x100mm boards.
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Good, I like the idea of this and will add to it as I get time. there are sometimes drawings available if you look, but even then they typically miss some critical dimension, such as clearance above or below the PCB slots
Just one other thought, add any case nomenclature, as there does seem to be some unofficial (or official, and I just don't know about it) naming convention, such as 1104 (which seems to be 11ish cm wide, by 4 cm high*) and 1304 (which is about 13 cm wide, by 4 cm high*), while a 1306 is roughly 13 cm wide by 5.5cm (6?) high.
* not exactly, but there does seem to be some scheme involved, maybe?