New procedure: first read, then think, finally order
As often happens, I tried adding a new item at the last minute to a recent Mouser order, a Davies Molding 220 box. These phenolic beauties have been around since the days of Knight-kit and they make for a nice, solid kit enclosure.
However, I didn't read the description, I had been ordering the Davies Molding 220A from my previous supplier. Mouser doesn't stock the 220A, they stock the 220. So I ordered the 220 without thinking. The 220A has four tapped holes for 4-40 hardware. But when I got the 220, I found out that the holes are tapped for 4-36 hardware. So it was close but no cigar, kind of like how M3 hardware is almost 4-40 but not really ! Luckily I only bought one.
Then I put in a subsequent order to Digi-Key and included some 4-36 screws - the idea was to make lemonade from the Mouser lemon.
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| Looks OK, right ? |
BZZZZT !
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| The four screws are torqued down all the way |
No, I forgot to do my reading, AGAIN. The 220 holes are only tapped .31" deep so a 5/16" screw will work. But I had ordered 1/2" screws from Digi-Key (that's all they had). So this doesn't work either. BTW, Mouser doesn't stock any 4-36 hardware. 4-36 hardware is available on ebay but they aren't cheap - apparently the 4-36 hardware was used by Lionel and Western Electric.
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| 35 cents per screw |
I think what I'll probably do is get out the old hacksaw and cut down 4 screws and use the box for my next prototype - but then in the future, while prepping a parts order:
1) READ
2) THINK
3) ORDER
We'll see how it works out !
Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm
