Mil spec engine harnesses


pdapaul said:
I only do electronics on £100k cars usually so we don't see much mil spec :)
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Fair point the last battery we bought for a satellite cost a good bit more than that, and it fit in your hand! If your only dealing with cheap motors..

Just kidding, its really nice to see someone raising the bar with wiring, its so often overlooked in builds, or lashed up and mummified in tesa tape!

Mil-spec is usually more about the exacting way the wire sits in the crimp (space rated stuff is a littke different as is uk and us specs) but it's like specifying the gap between the cut insulation and crimp as 0.2mm-0.5xd (d being wire diameter) and 0.2-0.3mm of wire beyond the end of the crimp etc. Its damn hard work to get right and the tooling cost is insane (£800 for a set of wire strippers, and they need recalibrating £50 when you set them to a diffferent size wire or every 6 months, so you often have a few sets).

Your looms do look really good though.
 
Oooooh, that makes more sense! When you said you wired satellites I though you meant you fitted sky dishes :)

I just presumed that that kind of thing now would be automated. Are most of the crimped connections done by hand?

Yes it's definitely overlooked, and the standard copper strand only has a finite life. Kseries looms are still all over 10 years old and a lot have been hacked, and swapped from vehicle to vehicle.

Don't suppose you have any teflon strippers going spare do you haha
 
Everything is done by hand, there is no automated system reliable enough yet. Most of my work is PCB population, and even that you get things like having to float the bigger surface mount resistors 0.2-0.3mm off the surface of the PCB to account for thermal cycling expansion of the chip vs the pcb in space. Every single solder join is done by hand and then checked by a QC person.
 
That's awesome!
I love the fact that when you need something doing to that degree it's still done by humans.
Do you have your own specific tasks that you do then pass the board on, or do you get to do a board in its entirety?
 
We do a board in its entirety, there are only 3 of us qualified to build here, so we all have to be able to do everything.

Yes, our stuff has to be guaranteed to survive about 10 mins of a 30G vibration launch then 20 years in space with no failures. The low orbit stuff we do is designed to be up there for about 80 years before it falls out somewhere.
 
Rest of the cable and some other parts have landed today. I will now be able to do the non mil cable engine looms in exact OEM coloured wire, which I think is a nice touch. There's 3.5km of cable there so should last a bit haha
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Looks like the rest of the OEM connectors will still be about 3 weeks unfortunately, but there's little I can do about it which is a shame.

I did have a little play with some of the pieces I've bought today , and I've made this if you can give me your thoughts.
It's a universal relayed 30amp switched output. The thick red runs straight to the battery, and then a single red(not shown) and the thin yellow/red need to be routed to a simple flick switch. The red & yellow/red will be loomed together so you just run them somewhere convenient and add a switch of your choice. Instant fused ignition feeds, capable of running an aftermarket pump, gauges etc. Use a self tapper or bolt to secure the earth and bracket and you're done. Easy, quick and foolproof (ish :)))


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That sounds like a handy idea

How come there are 3 fuses if this is only for 1 switched power supply?
 
Sorry, must have been the way I worded it. The relay has a max current of 30a, so you could pretty much run any configuration up to that (3x10's or 1x15 +1x10+1x5). I thought the 3 fuses would help to show the circuits you could run.
 
pdapaul said:
Sorry, must have been the way I worded it. The relay has a max current of 30a, so you could pretty much run any configuration up to that (3x10's or 1x15 +1x10+1x5). I thought the 3 fuses would help to show the circuits you could run.
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I'm still confused,

Does that mean that you can run 3 things off the 1 relay? As long as the current doesn't exceed 30amp?
 
Maybe a better picture now I've finished one.
So..thick red to battery, black to earth(bolt relay down), flick the switch and hey presto...up to 30amp switched feeds.

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I'm thinking a price of between £34.99-£39.99?
 
That looks good Paul.
Il prob get a engine loom of you too as well as the race spec interior one.
Will the engine one come with a power wire from starter , alternator?
My battery sits beside with a kill switch on the dash how will I work that?
Also need a fuse box for lights, brake light, rain light and wipers?
 
Good stuff :)
The engine looms will come with a wired starter trigger wire, as that's parts of the connector that plugs into the dash loom. I was going to offer a fresh charge harness, but could really do with knowing lengths, as I've found a good source for pre-made cables. If you can have a think of exactly what you want to run I can put together some ideas for a fuse box.
How does your battery currently connect to your cut out?
 
This is amazing glad to have people on here capable of doing things like this, all the best mate.
 
Sorry if this has been covered but if one was to go standalone ecu you could make up a fancy harness that makes it all plug and play?
 
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