Supplies
You need your 18M to have the Cue Strips for Slat Adapters. They are available on the Cobra accessories page: 18M Cue Strip for Slat Adapter.
These have a 7 pin header on them for the normal Slat Adapter that I use to plug my cables into. The OLD original 18M cue strips did not have the extra header on them. I'm guessing they might all have them now?
The black female connector on the left is what the slat adapter would plug into. That's what we want to plug into.
Here's a pic of some of the other supplies I used:
The DB25 Straight or Right Angle adapters are available at http://www.technologicalarts.ca They are $4 each, but it will likely cost you $5-$8 for shipping from Canada to US.
I bought 100 of the 7pin dupont headers from ebay. Item description was "100 pcs 2.54mm Dupont Head 7P 1x7P Dupont Plastic Shell Pin Header". It was like $2.28 + $1 for shipping. (If you want them faster you can buy from US sellers at a higher cost.) The same headers are used for both male and female connectors. I used 9 of them as I used them connecting to the 18M, and for the interconnect in the middle. You could use them or individual or other headers to connect to the Right Angle DB25 thing. The DB25 thing has pins 1-13 on one row and 12 pins (14-25) on the other row. You'll have 3 COMMON wires coming from the 18M and like 7 COMMON wires on the DB25 thing. I just used 3 as all the COMMONs get tied together on the first slat. If you wanted to tie the 3 18M COMMONs to multiple wires on the DB25 thing you could.
The longer rainbow wires are from ebay "40pcs AWG22 1007 300mm DuPont Wire Cable Line". These are female to female. They were like $3.28 + $1.99 shipping. You use 7 of the 40 wires for each cue strip.
The shorter rainbow wires are male to female. I already have those floating around, so don't know exact cost. It should be similar to the above female to female.
Make sure your dupont wires are the thicker 22 AWG wires. If it doesn't say, it's likely 26 or 28 or worse. Many ribbon cables are very thin.
You can remove black shell from the dupont connectors and put the connectors into larger headers. The ribbon cables came with 1P headers, I removed them and put them into the 7P connectors. I used a little needle to release the little lock on the header. You can see in the picture I have one of the headers off. They just snap into the headers and lock in.
You'll need something to mount your DB25. They sell wall mount DB25 plates, but they usually stick out. I luckily had some extra ODA style DB25 mounting plates. I believe TRMPyro had some of these made at one time. They were also used by some other firing systems like the older Merlocks. These mounting plates look nice but are probably a bit more expensive. You can google "db25 wall plate" to see some cheaper alternatives.
The only thing that I couldn't buy that I had to alter was the right angle male to male.
The normal right angle headers look like this:
See how the one side is longer. We really want both sides that long. To get that, I just ordered one designed for 3 rows. It gave me some longer pins to choose from. The 1st row is too short. The 2nd and 3rd rows can be cut to the desired length.
>> See Update 1 - The 2x40 Pin 2.54mm Right Angle Double Row Pin Header works much better. <<
The pins can be pulled off the black thing. I just cut some down to make them about the same length of the longer ones in the normal right angle headers.
You can see one above the bag in the picture that has been cut down.
Be sure to cut them all the same length, or your connector won't fit as tight as it should.
I tried to order some right angle things like this, but the pins are too short. They are designed to be mounted to a PCB.
If anyone finds a longer version either male to male right angle or male to female with the longer pins, let me know.
If you wanted to permanently attach the cables (and not have the disconnect in the middle). Pololu sells some nice long 22AWG cables with the dupont connectors already on them. They didn't seem to have the shorter cables in 22AWG though.
The connectors don't look too hard to crimp if you have the time/tools to make your own. I found it cheaper to buy the rainbow cables and split them as needed.
They have a video on how to use the dupont cables also at https://www.pololu.com/category/71/wires-with-pre-crimped-terminals
2016/02/29 Update:
If you're looking for another possible mounting plate, I found this one online (this is NOT what I used) but it seems like it would work nicely:
I saw this online at http://www.vadcon.com/ap/patchpanel1ru.html for $4.99 (or less in quantity). You'd want to use a Straight DB2 connector instead of the Right angle as the Right angle cable would hit the inside of the case.
2021/09/27 Update:
I originally did my case slat adapters years before the 36M/72M came out. Now that they are out, you could buy a Cobra 36M or 72M case and just wire up one of the ports. That would provide a lot of the parts you would need.
Here's a picture of how a 72M case slat adapter is connected:
They also used normal ribbon cable. So I guess the smaller wire at that short of a distance isn't a problem.
There are also 3rd party folks out there like The Hobby Shop Fireworks that can help you.
They showed some case slat adapters on their facebook page.
Continue to Update 1