ken555
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| posted on 23/7/15 at 09:09 PM |
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It's not rocket science
Nasa documents for electrical connection etc. Always worth a read. Page 80 is great for joining cables.
http://www.hq.nasa.gov/office/codeq/doctree/87394.pdf
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bi22le
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| posted on 23/7/15 at 09:38 PM |
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Page 46 mentions cable ties and spiral wrap.
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
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coyoteboy
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| posted on 23/7/15 at 10:03 PM |
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It's a part of my day job. ESA have similar docs. I keep copies of both on my desk for reference!
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scootz
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| posted on 23/7/15 at 10:06 PM |
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I guess these standards explain why NASA can land craft on comets gazillions of miles away, yet I can barely make an lighting connection last a
winter! 
It's Evolution Baby!
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ste
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| posted on 23/7/15 at 10:26 PM |
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Very outdated stuff on there. I work on Eurofighters and most joints are crimped as they are more reliable.
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coyoteboy
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| posted on 24/7/15 at 01:08 AM |
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Not out of date, you may just have missed the fact that crimps are used but that there are significantly more constraining design drivers in space
hardware. There is a general reluctance to use new kit if old kit/methods are proven to work flawlessly though I give you that. But that's
generally because space builds are one-off, mentally high value and there's no one rushing you to find a faster, cheaper way of producing
something that has to work flawlessly in the vacuum of space, swinging between -200 and +200 many times a day and can never be inspected, replaced,
bypassed etc. NASA/ESA test things like this as they come available in projects and update as soon as a better solution or method is available and
qualified.
The vibration requirements for MIL/plane hardware is pretty harsh, duration-wise, our vibration is limited to a few minutes, after that loadings are
largely thermal induced or self generated.
What crimps are used on the Eurofighter and in what sort of locations?
Check out the ESA crimping
standards for more fun reading.
[Edited on 24/7/15 by coyoteboy]
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lsdweb
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| posted on 24/7/15 at 07:18 AM |
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Very interesting - thanks for posting the link!
I wouldn't get past page 25 unfortunately (colour vision test!)
Wyn
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Irony
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| posted on 24/7/15 at 07:48 AM |
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This is a great thread. It should be stickied at the top of the electrical section. It is great to have some sort of a official document regarding
this much argued over topic. Thanks guys.
P.S I'm a crimper by the way.
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ste
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| posted on 27/7/15 at 12:00 AM |
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quote:
Originally posted by coyoteboy
What crimps are used on the Eurofighter and in what sort of locations?
[Edited on 24/7/15 by coyoteboy]
Technical drawings I can't post as they are covered under the official secrets act.
Some off the internet here
http://www.peigenesis.com/en/amphenol-connectors/amphenol-sjt-series-mil-dtl-38999-type-1-5.html#contact-crimping
I fully understand why the methods are used for space, it takes a lot to qualify parts and techniques for aerospace
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coyoteboy
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| posted on 29/7/15 at 08:00 PM |
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Yep, good old amphenols - fairly commonly used but massively over-sized for the bulk of our work! (we do mainly subsystems, not harnessing) Customers
generally specify D-sub connectors, often Positronic, but usually crimp terms - we just provide the black boxes and/or harnesses to suit. I'd
still say 50% of the larger connectors we use are solder-bucket types, and wicking is controlled, plus additional strain relief in the form of heat
shrink or separate support struts used. Plus it's normal for us to tie down at ~50mm intervals on large harnesses.
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coyoteboy
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| posted on 29/7/15 at 08:00 PM |
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[Edited on 29/7/15 by coyoteboy]
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DaveFJ
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| posted on 31/7/15 at 11:57 AM |
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Interesting that they specify that ty-wraps should always have the 'ribbed' side touching the wires.
When I was working on military helicopters we had to use 'special' ty-wraps with an external ratchet so that the ribs did not fret the
wires......
Dave
"In Support of Help the Heroes" - Always
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