Making plug connections- what am I missing?

hokie71: Those are called "dupont" connectors. The females should break off clean. Try pointed pliers if you've got 'em.

You can buy wires with the same type of pins in groups of conductors like 40 that are attached together but are easily split apart. Try this eBay number or search for "dupont wire":

231708399395

The female headers are difficult to cut off cleanly. I've never gotten a perfect cut on one. I usually use an Exacto or utility knife to score them and then snap them off. Then I sometimes use 'liquid' electrical tape to patch up any exposed pin parts. It works ok, but you have to wait while it dries and then sometimes add a little more. I haven't tried a hobby or Exacto fine tooth saw, but that might be better than my method. 

For female headers, I have recently been trying to just buy them in the correct length I need. Digikey has them and I've seen some assortments kits on ebay (probably Amazon or other places as well) that are not too pricey. If I only needed a few different sizes I would probably just get them all at Digikey. I try to wait and get several items to order all at one time from Digikey to even out shipping costs.

You have described exactly the way I do the male pins, just solder the wire to the short pins. Then a little heat shrink tubing can be used to help prevent shorting things. I don't always use the heat shrink, but it will give you a much nicer looking end result. 

hokie71: As rtr12 has stated, you can get the female headers in proper multiples. I have done this myself to attach dupont wires to relay modules that include the pin headers on the circuit board.

Perhaps this is not what you are looking for. These work well with printed circuit boards (PCB) but are not generally used just to connect wires together. These are soldered to the PCB and then the dupont wires can make temporary (breadboard) connections for experimental circuits. Most Arduino microprocessors include connectors of this type.

Thanks Leo and rtr, very helpful information. I will hit the web today and chase down your suggestions.

When I'm using the .025 square posts and matching female headers, I just cut the female ones on the bandsaw.  You will lose one contact in the process, the price of using that style connectors.

I normally use Machine Pin Headers.

Search eBay for machine pin headers for the male pins and machine pin socket headers for the female pins.  When you use these, I solder the wire to the male ones on the thinner side pin, the thicker pin fits the female socket nice and tight for a good connection.

What they said!

Some additional comments.  There are female headers that have grooves or ridges that make it easier to cut (e.g., with a thin saw) without sacrificing a pin position.  I think the trick would be to look for the ones where the flat-part of the inserts are vertical instead of horizontal.  IMO if going thru the trouble of rolling your own, minds as well pay a few extra pennies per pin to get gold-plated contacts.  I show this above for both the female and male sides.  As the guys above say you can readily find 2-position or 3-position female housings rather than breaking/chopping up a longer strip.  As Leo says there are low-cost crimped contact housings so you don't need to solder.  They might even have male crimped insert housings in multi-positions but I can't recall seeing them.  In which case as shown you can simply use a male-to-male header to join 2 females (shown above with 3-position crimped females).

Sorry, I don't have any part numbers.  I just grabbed a bunch of connector stuff out of my 2.54mm square-pin header stash - bought a lifetime supply of this stuff in the last century.   

I'm like Stan, when I need some of these, I buy them in quantity so I'll have some for the next time (or three).  For the .025 square post females, I ended up with ones that didn't have any separation capability, the plastic between the pins was too thin to allow that.  So, I just slice them right through the pin to separate them.  Sure, I lose a pin for each unit, but the strips are dirt cheap, so I don't spend any time anguishing over the lost pins.

At least I did get gold pin and contacts.

I was referring to the long ones with the grooves as shown in Stan's picture above. I have a bunch of those in the vertical style.  

The dupont crimp kits would be good to eliminate soldering, I might just get one of those! I have several lengths of the pre-made 'dupont cables' in all combinations of male to female that I use quite a bit for bread boarding. I hadn't thought of getting one of the kits before for the other stuff I use the pin headers for? I'm a little slow, but I usually catch on after a while...

Those female machine pin headers GRJ shows look a lot better for separating than the ones I have. I didn't know what those were called until just now! Thank you GRJ! Just might have to get some of those too. Sacrificing a pin sounds good too. You can pull the pin where you want to cut making it easier, then I wouldn't  have to worry about salvaging it with the 'liquid' electrical tape.  

Another thing I have found pretty handy is a jumper with a male pin header on one end and an alligator clip on the other. Lots of other combinations of this type too.