21 replies to this topic

[Deejayry]

So I said I'd post back when I have made some more progress... so here we go!

 

I've had a busy couple of years playing with minis, but not found much time for working on my own but recently I've been able to spend some time finalizing the design of my wiring harness. I decided to bite the bullet and pay for some proper harness design software and spent the last two months drawing up the layout, logical connections planning the concentric twisting and pinouts for the inter-harness connections then finally specifying the components to be used. I've also spent some time in Fusion 360 drawing up CAD models of the dashboard & centre console / PJB layout. 

 

Yesterday I finally got full documentation of the wiring and a complete bill of materials for the entire project. I have placed the first of several orders of parts at the moment the cost is somewhere near £3000 not including tooling which I expect to be in the region of a further £1000-£1500. No expenses are spared here on the parts and on the tooling this harness has to be right first time.

 

For now I thought I'd share some of my cad renderings and harness drawings with you guys, the images are the latest renderings but i have changed a few small details since, firstly i have fixed the dodgy spacing between the rows of switches and circuit breakers also increased the spacing between the top two rows of switches, they just fitted at the 30mm spacing when using generic switches as placeholders but when i got round to importing the cad models of the actual toggle switches i am using i found that they were slightly larger so i have increased the spacing from 30mm to 40mm for the top row.

 

The harness drawings are an example of the level of documentation required when building a harness of this standard and also when performing any maintenance in the future. the harness sections shown are the Engine Power Harness (EPH) with around 40 logical connections and the Engine Management Harness (EMH) with in the region of 150 logical connections. The Main Chassis Harness (MCH) has over 250 logical connections, its a big job keeping tabs on all of them especially when picking up after a few days! I've not included the planning of the concentric twisting as most of it is just calculations scribbled on paper, this will be digitized and saved with the rest of the documentation upon completion of the entire system, the level of planning required to work this all out is huge and I'm expecting that I may have to change the inter-harness connector pinouts slightly to work neatly with the concentric twisting. 

 

once parts start turning up there will be more updates.

 

 

Attached Files

•  EMH-001.pdf   612.2K   32 downloads
•  ESH-001.pdf   568.35K   19 downloads
•  RWP_ASSY_001.pdf   167.97K   24 downloads
•  Centre_Console_2018-Dec-01_04-39-37PM-000_CustomizedView22410052642.jpg   32.23K   5 downloads
•  Dash_Assembly_2018-Dec-02_01-15-53AM-000_CustomizedView4283195974-1024x768.jpg   41.16K   4 downloads
•  Dash_Assembly_2018-Dec-02_12-20-17PM-000_CustomizedView35276210747-1024x768.jpg   76.5K   4 downloads
•  Instrument Pod.jpg   33.21K   3 downloads

[Magneto]

Wow, I had no idea of the full scope of this project, my hat's off to you!

[nicklouse]

there is so much i like about this but also so much i dont like.

 

i guess you will be making up some spares.

[Deejayry]

there is so much i like about this but also so much i dont like.

 

i guess you will be making up some spares.

 

Thanks... I think I'd be interested to know what In particular you like and don't like about this project? I'm open to discussion my layout is designed mostly for function, for example adding the fascia panel around the switches was an afterthought but I feel it brings a lot to the design. 

 

Spareswise I won't be doing much in the way of spare electrical parts, I will have a few bits left over due to minimum order qty and will keep spare contacts to perform repair if needed.

 

All the dash parts will be prepreg carbon fibre oven cured in a mould. So far the mould for the centre console is complete and in a month or two I'll crack on with making patterns and moulds for the instrument pod and main dash panel. Once the moulds are all done I'll buy in a load of prepreg  and get the parts all laid up and cured. I'm happy to sell a few of these carbon dash parts once I've finished doing what I need to on my mini. Price will be for materials plus a little extra to help offset the thousand or so spent on patterns moulds oven, freezer... The list goes on!

[nicklouse]

ok. what i love is the connectors the kit etc what i dont like is the main wiring. (engine managment and sensor wiring is great)

 

i may have missed them but i see only 3 relays?

 

presuming this i see a lot of small wires carrying possible peak high currents yes i see lots of fuses (or are they pop out breakers) but no indicators. So if something fails you change the fusethat has gone and it goes again as there is another that has also gone. if they are pop outs ok you will see all that have gone. but the wiring could have gone and needs replacing. (hence my question about spares).

 

i love the wiring as a set of control wires to opperate relays to work the parts.

 

lack of relays then i like loose wrapped wires so it is easy to pull them and change damaged wires.

 

But i am sure you have everything covered.

[Deejayry]

ok. what i love is the connectors the kit etc what i dont like is the main wiring. (engine managment and sensor wiring is great)

 

i may have missed them but i see only 3 relays?

 

presuming this i see a lot of small wires carrying possible peak high currents yes i see lots of fuses (or are they pop out breakers) but no indicators. So if something fails you change the fusethat has gone and it goes again as there is another that has also gone. if they are pop outs ok you will see all that have gone. but the wiring could have gone and needs replacing. (hence my question about spares).

 

i love the wiring as a set of control wires to opperate relays to work the parts.

 

lack of relays then i like loose wrapped wires so it is easy to pull them and change damaged wires.

 

But i am sure you have everything covered.

There are actually 10 relays in total, what you see are 3 relay / flasher housings, it made more sense to me to class each housing as a separate connector. There is one housing to take 2 flasher relays for indicators & hazards, one relay housing takes 6 micro relays for the engine management specific circuits and the other relay housing will have 4 relays for main power, enable power, dip and full beam.

 

Each circuit is on its own breaker which is a push /pull type 

 

All of the wiring is spec 55 tefzel insulation capable of considerably higher temperature than pvc / txl / gxl, and all the high current circuits are rated for voltage 5% drop over their length.

 

I don't see how relays would affect your confidence in the wiring and choice of covering, the protection provided by fuse or breaker would do the same job regardless of the presence of a relay. 

 

I have chosen to concentric twist and heatshrink all of the harness runs that run around the car, the wiring behind the centre console will be bundled together neatly but I will not use heatshrink to cover it, there is too much complexity in this area and no technical benefit to using heatshrink in this area.

Edited by Deejayry, 07 December 2018 - 09:30 AM.

[PoolGuy]

It’s about time for an update on this?