Connector standards?

[Red Squirrel]

Right now I use terminal blocks to go between boards in projects. Downside of this is stuff like LCDs have a lot of wires and you pretty much have to open up the schematic just to reconnect it if you disconnect it. It's also harder to label individual small wires as the labels just fall off. Not enough surface area on a 20ish awg wire for it to stick properly to.

I want to start using proper interconnects between boards to make it easier to pull a board out to troubleshoot/modify then put it back.   There's tons of stuff out there so it's probably just the thing of picking something and sticking to it, but just curious what everyone uses, for sake of conversation.

I'm leaning towards PC pins for logic, like IDE cables use, perhaps buy sockets/headers for a few different sizes, like 20, 10 and 5 position.  I could either use ribbon cables to interconnect stuff, or setup a backplane system where everything plugs into a common board, depending on the project.   What kind of tools do I need if I want to make my own ribbon cables?

For power, I'm leaning towards molex, anything better, or can I use PC pins?  How many amps can I reliably put through a single pin?  I could simply use multiple pins for more power.   For molex what tools would I need to make my own cables?    Thinking it might be good to have and know how to use as it could come in handy for computer stuff.

Mostly just curious what everyone uses or recommends for this, or if it's really just a preference thing.   I'll be making a Digikey order soon so figure I'd order a bunch of various connectors/tools too.

[Cubdriver]

To make up ribbon cables with insulation displacement connectors, you'll want IDC crimping pliers or a small arbor press and some aluminum blocks to spread the pressure/cover the whole connector while making them up.  You can get by with slip joint pliers, but that increases the chances of bad connections that will make you nuts as you try to find them.

Molex 0.1 and 0.156 KK series connectors are good for interconnects; the 0.1" are good for 4A and the 0.156" for 7A. Ideally you'd want a proper crimper for those, too (big $ ), though you can probably get away with doing them one crimp at a time with a universal crimp tool.  If you can get your hands on the correct, terminal specific crimper, though, they are far easier to terminate.

Another option similar to the Molex KKs are Amp MTA connectors.  They too come in 0.1 and 0.156" pitches, and will mate to similar Molex headers.  The MTAs are insulation displacement types, and can be terminated using either a clunky manual t-handled tool or a ($$) pistol grip interchangeable head tool that takes a quick squeeze to set the wire.  I'd expect their current rating to be similar to the KKs.  As IDCs, they must be sized to match the wire gauge; the connector bodies are color coded to indicate their wire size.

Those are what I have experience with; hope this helps.

-Pat

[Red Squirrel]

For ribbon, could I mostly get away doing it by hand?  I was thinking line it up, then use a flat piece of wood to apply pressure.   Though I never worked with them so maybe it's easier said than done?

For the molex, is there also any way to crimp those with something like linemen plywers?  Though worse case I guess I can buy the crimper tools, but yeah some are $$$.

I never worked with molex before so want to make sure I'm looking at right parts, is this what I would need?

Header for circuit board:
http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=232698825&uq=636352419779864941

Plug:
http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=232698826&uq=636352419779874942

Pins that go on the wire which insert into the plug:
http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=232698827&uq=636352419779874942

I would use 18awg wire, as I already have a huge roll of that stuff, and it's a rather versatile size.   So basically circuit boards would get a header and cable would plug the same way at both ends.

For ribbon, these are the parts I'm thinking of getting:

Header:
http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=232698712&uq=636352419779864941

Plug:
http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=232698715&uq=636352419779864941

Card edge connector: (for situations where I may want to just plug a circuit board directly into another, ex: treat like a backplane)
http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=232698710&uq=636352419779854940

And of course the ribbon cable:
https://www.digikey.ca/product-detail/en/3m/8125-10-100/ML10G-10-ND/2658738

Should all that work together?  I may also pick a different size, just need to pick something that is versatile enough but also not too overkill.  Of course if I ever get into any major projects where I want to make a lot of something then I'd get the appropriate sizes at that particular time.  This is more for 1 ofs that I just want to have in stock.

[Cubdriver]

Unfortunately, your DK links are taking me to the overall search page rather than the individual connectors.  Could you post the connector part numbers?

As far as the ribbon connectors go, I think you're at least going to need some sort of crimping tool - something like what's shown at this Amazon link, for instance:
https://www.amazon.com/Wovier-Crimping-Fixture-Attachment-Connectors/dp/B01DKLO1M8/ref=sr_1_2?ie=UTF8&qid=1499665808&sr=8-2&keywords=idc+connector+pliers
(if that doesn't work, search on IDC connector pliers)
Another option is a small arbor press and some metal blocks to spread the force out evenly, or perhaps a vise, but the biggest issue with a vise is the lack of feel - you could easily crush the connector accidentally.  You will need some sort of tooling, as they're harder to press together than you might think.


The Molex connectors I've used are (replace XX in part number with number of pins, 02 to 20):

22-11-2XX2 - 0.1" pitch vertical locking header
22-12-2XX4 - 0.1" pitch right angle locking header
22-01-3XX7 - 0.1" pitch housing; polarized with locking ramp (useable with either straight or right angle 0.1" headers)
16-02-1125 - Terminal, crimp, 0.1" Molex, #22-#30 AWG


26-61-4XX0 - 0.156" pitch vertical locking header
26-61-5XX0 - 0.156" pitch right angle header
09-50-7XX3 - 0.156" pitch housing; polarized with locking ramp (useable with either straight or right angle 0.156" headers)
08-65-0115 - Terminal, crimp, 0.156" Molex, #18-#22 AWG

As for crimping the Molex terminals, you probably won't be able to effectively crimp them with a pair of pliers - they're pretty small.  Ideally you'd do them with the manufacturer's 'official' crimper, which sets the wire depth and crimps both the contact and strain relief ears in one fell swoop, but they're like $300+.  Molex makes a cheaper version (~$55 US at DK), part number 063811-1000 that requires two operations to crimp each terminal, and is not a ratcheting tool.  As long as you're not doing a gazillion of them, that should work.  It's likely that with some searching you might find an even less expensive 'universal' type too, but I can't come up with a suggestion off the top of my head.

-Pat

[N2IXK]

I've had good results crimping IDC connectors onto ribbon cable using an ordinary bench vise.

The idea is that you compress the entire length of the connector simultaneously, which is hard to do with most types of pliers.

[mariush]

A crimping tool isn't that expensive. I have the Engineer PA-20 which can crimp almost anything between AWG28 and AWG18 : http://www.engineer.jp/en/products/pa09e.html
It cost me around 30$ on eBay .. considering it's something i'll use for years it's not that expensive.

There's also a PA-09 which is more "tuned" for smaller wires (let's say awg20 and lower)

Here's a chart : http://www.engineer.jp/en/products/pa09_20applicatn_chart.html

You should also look into some JST connectors. A lot of them are used with lithium batteries and with various hobby things (flying things, drones) so you'll find connectors and headers and even ready made cables on places like eBay for low prices (though I'd advise you to make your own cables since lots of those cheap ebay cables are really poor quality, or made with steel/aluminum wires instead of copper)

Molex in general is a bit more expensive, you'll find connectors from JST or Harwin or other brands may be much cheaper in quantity.

[Red Squirrel]

That's odd that the links don't work, I guess it must be cookie bound. This is the DK part numbers:

Ribbon cabling:
S9202-ND - "Card edge" connector if I want to plug a card directly
ED1543-ND - socket
ED10500-ND - cable plug
ML10G-10-ND - ribbon cable itself

May get multiple different sizes too, since crimper does not look that expensive then seems like a no brainner to get one.

Molex:  (this would be for actual power stuff, while ribbon would be for data)

WM1791-ND - PCB header
WM1785-ND - plug
WM13070CT-ND - crimp end that inserts into plug


Though I have also thought of looking into JST connectors instead of ribbon as they come in various pin counts too.  Definitely will want to use those if I do anything with battery packs, just to stick to the standard.  For big power (like 18awg) I'm open to other options too.  I may even just stick to the terminal blocks for those, as typically you will only have a few anyway so can label them.

[Red Squirrel]

Thanks for the ideas.  Yeah for external power I'd probably do USB or barrel jacks as it's universal.  For 5v low power stuff it makes sense to use USB for sure.  For 12v I'd perhaps even use a 12v car style plug.  I realized how handy that standard is when I setup my solar power pack for camping.  I put those ends on everything that takes 12v.  I can plop the solar power pack outside and run all the 12v stuff when camping or even during power outages.

I'm also mostly into through hole at this point so I don't mind the larger connectors like 2.54mm pitch for data and probably won't touch the really small flat flex for a while, but I did think of that as an option too.  I kinda have a love for older school style, like I use through hole resistors and stuff in my projects.  I do want to do some SMD eventually because so much stuff only comes in SMD now.  Easier to work with when you have a proper PCB made though, I've only done perf board projects so far.  What I will probably end up doing is making break out boards for the SMD parts that I buy and then they will plug into perf boards.   I kinda like the idea of trying to make my stuff as modular as possible especially since I'm still in learning mode. 

I have used ethernet cabling for some projects but then I just used terminal blocks and used the standard ethernet color scheme just for sake of consistency.  Worked out nicely for an LCD that happened to use exactly 8 connections.  Though come to think of it, never really considered using actual jacks and basically patch cords for interconnects, that could actually work decently as for situations I need more than 8 I can just have more than one connector.  I'm actually wondering if that would be better than the ribbon cables.  Not exactly conventional though but think it would work.

So for data, I basically have ethernet, or IDC ribbon, which I'm kinda leaning towards, but nice to hear the other options too. 

For internal board to board power the more I think of it, I may just stick with terminal blocks.  I kinda like the idea of the molex connectors too though but it sounds like the crimper is rather specialized and expensive.  So probably not something I'd want to invest in unless I plan to roll a huge batch of things that I want a better connector for.

Those pluggable terminal blocks may be interesting too.  More I think about it, I think I may stick to those rather than the molex connectors.  If I want the individual wire connections to be more "permanent" I can always put a bunch of hot snot.  

[abraxa]

I like to associate pictures with names, so one of my personal go-to references is http://dangerousprototypes.com/blog/2017/06/22/dirty-cables-whats-in-that-pile/ - maybe it helps you.

[Red Squirrel]

Ok so think I made my decision, I'll go with the IDC ribbon cables and buy the crimper for data stuff, I like that they use the 2.54mm pitch standard which works with protoboards and they look fairly straight forward to work with. 

For power, I'll go with the Mini-fit Jr and get the cheaper crimper.   I'll go with 6 pin for now as that is rather versatile. I can have multiple voltages, or double up on conductors, etc as required for any specific project.  Can always get different size connectors too and use same pins.  I'll most likely use 18awg wire all the time since I have a big roll of it. The connectors are also big enough that they are easy to label, so I'll be fine sticking to one size for most projects. 

I just want to make sure I'm on the right track for the Molex connectors as I've never worked with them before, will these connectors/pins work with each other?

(hopefully these links worked, tested in a separate browser to ensure it's not based on cookies)

Male connector:
https://www.digikey.ca/products/en?keywords=WM1031-ND
with these pins:
https://www.digikey.ca/products/en?keywords=WM2500CT-ND

Female connector:
https://www.digikey.ca/products/en?keywords=WM3702-ND
With these pins:
https://www.digikey.ca/products/en?keywords=WM2501CT-ND

Crimper for molex:
https://www.digikey.ca/products/en?keywords=WM9999-ND

I mostly just followed the "For use with" etc parts from Digikey to get to these parts.

Am I on the right track?  I think I might pull the trigger on this order so I can start playing with these.  Though, I may also drop one gender, and instead go with PCB sockets and use same gender on both ends, but think for now I'll just solder wires directly to boards with the plug of appropriate gender on the other end, as these don't use a standard protoboard pitch. For a more official project I'd get PCBs made then use sockets. 

[rdl]

The crimp on "pins" I have used are made from folded metal (same as the sockets), and are pretty flimsy in my opinion. I won't even use them unless there's no other option. I've had the best results using (solid metal) header pins on the boards and crimp sockets on the cables. To be fair, I've only used the Molex SL type, maybe there are others that are better.

[Red Squirrel]

The ones I linked to are similar to what is inside computers (I think - someone correct me if I'm wrong) so they are decently robust.

[rdl]

The photo in the Digi-key link looks like folded metal, but maybe it's more heavy duty than what I've used. Anyway, male/female connections are usually only used for wire to wire and that can be avoided in favor of wire to board most of the time.

[Red Squirrel]

Yeah I'm kinda rethinking having both genders and just stick with one, then do board to board.  The pitch won't match protoboards, but I really do want to get into making PCBs soon anyway.  The last protoboard project I made, half way through I wished I had just gotten a PCB made because it was tedius. Just need to sit down when I have lot of time and learn kicad properly and gerber file process etc and go at it.

As for the pins, are there different versions of those that will fit the same connectors or will those particular ones even fit?  Maybe I'm not looking at the right type.