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Wire harness design software

Kiwi.Paul

I'm New Here
Hi guys
Can anyone recommend some sort of wire harness design software. I have all of the schematics for my individual components but want to map out exactly what each pin on each connector is for and where it goes.
Hopefully have the entire aircraft electrical system in one place on one document.
Your thoughts appreciated
Paul
 
There is CAD computer aid design software, some free some for fee. The commercial stuff is expensive and has steep learning curve.

Do you have CAD experience? It is not hard to learn. Also building a plane is about learning and getting new skills. However if all you want to do is draw out wiring it will take time and effort depending on your experience. You can research it. Price of CAD is zero to thousands. Often the top ones are licensed and have to pay fees ongoing. If all you are doing is wiring diagrams there are other options.

ON THE LOW tech end is simple graphic programs that draw lines and shapes. I use Paint.net and Outlook Power Point. Paint.net is free and PP is part of Microsoft office. Neither is CAD but can do drawings. I use them all the time to make simple 2D pictures or diagrams.

The other is get a big old piece of construction or poster board out, pencil, straight edge and eraser and go at it. It can be a working wiring diagram. Once you have it all sorted out you can move it to some digital medium. The nice thing is if you have ROOM, really big drawing size, make a scale drawing that you can estimate wire lengths. You can do that with CAD as well.
 
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I use Autodesk Eagle, free edition

I use Autodesk Eagle, free edition. PDF examples in my files linked in my signature.
 
I just added the information into the schematic as notes. Not exactly what you were talking about, but it accomplishes the same thing in a more basic fashion. You could be more specific if you wanted to add some nomenclature like J1-35 to denote connector and pin. I also added the wire size and color under each signal. See my example.

I have a lot of supplemental info added into my schematics. For example connector part numbers even for Faston terminals. I even added torque specs that I had to look up for terminal blocks. For me the schematic is my reference and I'm trying to make everything that I might need to remember in the future be on the schematic so I don't have to look it up again or track down a part number later on.

I know some people like to use wire numbers, but I just use the signal names for identifying the wires. I use a heatshrink labeler to add those names onto the wires.
 

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I used a free schematic program called ExpressSch from Express PCB
https://forum.expresspcb.com/expresssch-forum/express-schematic-7-0-2/
They provide it for creating PCB layouts but it has a lot of flexibility and comes with a library of components like switches, CBs, fuses, etc. You can also create your own components. I used it for just my electrical but you could use it for the signal wiring as well.
 

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I’m using diagrams.net. It’s specially for drawings so it’s less complex than cad, and if you move stuff around the wire lines stay connected.
 
I’m using diagrams.net. It’s specially for drawings so it’s less complex than cad, and if you move stuff around the wire lines stay connected.

Same here, but I didn't diagram every pin on every wire. I just kept the images of the vendor documentation which has the detailed pinouts for each device.
 
Electrical documentation

I'm using Microsoft Excel for all of the detail level connections for the avionics. There is one tab in the spreadsheet for each equipment connector i.e. DB25, DB37 etc as well as all the switches, plugs, lamps. Sample screen shot attached.

For the main power schematic, I'm using TurboCAD which I already had previously purchased to draft up some home renovation drawings. TurboCAD is able to import and work with free DWG files from Bob Nuckolls "Aeroelectric Connection" as a convenient starting point that saved some time.

For the high level avionics diagram I used Microsoft Visio. Powerpoint would also be fine for doing this.

Note I decided to not attempt to try and draw one combined diagram with every single line and connection because it would be very time consuming and not much gain (for me) over using Excel. (The important thing is what each pin connects to, and there is no real need to draw/follow a line on a diagram to be able to capture that data.)
 

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ExpressSch from Express PCB

I second an earlier recommendation by gyoung for ExpressSch Plus. Tried SOLIDWORKS and found it very powerful but far too complicated for me. ExpressSch is easy to learn, use and free. Making the wiring diagrams is time consuming but I expect the effort will pay off during installation and troubleshooting. Attached is an example of what you can do with ExpressSch.
 

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Free software

Free softwarr
I like DigiKey SchemeIT for electronics
LibreCAD for cad drawings
InkScape for Vector Graphics however, eventually Adobe Illustrator has to be used to create an actual AI file. Most printers want an Adobe Illustrator file.
 
Free Schematic Program

Another free option (albeit with one of the steeper learning curves) is KiCad.

It's a full-featured schematic editor and PCB layout tool (like Eagle), but open source and free. You can find a lot of component libraries, but I haven't come across any for any glass panel manufacturers.

I'm just getting started on any planning of that sort (it will be a little while before the 10 is ready for those), but I plan to give it a try.
 
been drawing my schematics with Qelectrotech for a few years now... available for Windows, Mac OS and Linux.
Free, doesn't take too much to learn, and light on your computer and HD. Loads of usable or modifiable industry symbols, auto-tie function, grids, etc. And most of the bugs have been ironed out over the years :cool:

https://qelectrotech.org/
 
Smartdraw

I used SmartDraw. It's a very versatile, powerful program. It does much more than just electrical diagrams, but that's the feature I linked you to here:

https://www.smartdraw.com

(Edit: It used to be a one-time purchase, but it appears it might now require a small monthly fee instead, which is either a shame or a benefit, depending on how you look at it.)
 
CAD software

Another plug for Express SCH. Easy to learn and does everything I need for my system drawings.
 
When time comes to understand how things work, or to debug, you may well find that a wiring diagram, pin to pin, doesn't tell you all really want to know. For example, where does serial port 1 on the left screen go?

I've found that having a list of serial port connections is useful, especially when time comes to program each port. Similarly, to understand potential failure modes, I have a list of everything on the CANbus -- and I also have listed which serial ports provide backup connectivity. Same for ARINC429.

It's forest and trees. Each will tell you something different, but I don't have a pin by pin wiring diagram for my avionics and I've never missed it.
 
....Hopefully have the entire aircraft electrical system in one place on one document....

Paul, I chose to make wiring schematics for each system. This list of my schematics will give you an idea how I decided what goes where.

Miscellaneous equipment
P-Mags
Transponder
Audio devices
Lights
Power and starter

The last one includes the main buss. The others show a representative portion of the main buss and how they connect to it.

These all are clear and legible on 8.5 x 11 paper, which I keep in a notebook. Since they are easy to print out, I use one set to show my verification: when I complete a wire, I highlight it in yellow. When I verify it and test its continuity, I highlight it in green. I can see in a glance what's been done.

As you've seen, there are any number of drawing programs you can use for this. That's entirely up to you. My only recommendation is to find one that has a relatively short learning curve. Don't worry about whether it has the symbols or not since it's easy enough to draw those. I keep an additional schematic just for symbols, so that I can copy and paste once they are drawn.

Dave
 
+1 for Kicad

I used Kicad to build hierarchical schematics covering all of my subsystems. I found it reasonably easy to make custom symbols as well. If I can remember I will post a pdf of my schematics tomorrow. I work on Linux and it works well for me and is free. I also created a schematic and PCB layout for a non-airplane project. It has an OK library of parts for a free app.
 
I used a free schematic program called ExpressSch from Express PCB
https://forum.expresspcb.com/expresssch-forum/express-schematic-7-0-2/
They provide it for creating PCB layouts but it has a lot of flexibility and comes with a library of components like switches, CBs, fuses, etc. You can also create your own components. I used it for just my electrical but you could use it for the signal wiring as well.

I've been using expressch since 2003 to design aircraft electrical systems. Here is an example of a complete aircraft wiring design: http://www.vx-aviation.com/sprocket/photos/panel_elec/schematics-2/

Simple to use, very stable software.

Doesn't really matter what documentation package you use, but I think it's essential to document every wire in your aircraft for maintenance and resale value.

VV
 
just getting started trying out Express SCH. Anyone know best way to get a default set of components and symbols. Where are a library of existing diagrams I might be able to start with? RV10 planning on G3X, G500 autopilot, VPX, GTN750.
 
Hi guys
Can anyone recommend some sort of wire harness design software. ....
Hopefully have the entire aircraft electrical system in one place on one document.
Your thoughts appreciated
Paul

What I did was to make several system schematics instead of a single airplane one. This let me print them on normal letter-size paper and have it be easily readable. The systems are:

Power and starter,
Lights,
Miscellaneous equipment,
P-mags,
Switch panel,
Transponder,
Com and audio,
Warning lights,
Wing root connectors.

Since they are very easy to print and store, I was able to make an installation copy of each and go over it with a highlighter as I built and tested the harnesses.

Dave
 
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