I’d like to use ‘RIBBON CABLE’ in my next project.
Which connector or socket would be good for connecting rest of the electric component? (i,e. hotend block, RAMPS,.)
Should I use custom PCB board for connector of ribbon cable?
Wiring cable is always most difficult work for me. 
Can’t really pass that much current threw a ribbon cable I don’t think. You can group a couple lines together to carry the load but as far as I’ve heard, the load is small.
@Jon_Gordon Ribbon cable has AWG 22, I thought that is enough for most of 3d printer wiring except heated bed. Am I wrong?.
I don’t know actually, just saying what I heard. So you figure 30-40w at 12v (2.5-3.3A) and 22AWG has a max of 7 amps so that should be plenty with headroom. 23AWG and 24AWG you would run into limits though.
I use regular ribbon cable on two mendel 90, and it works very well. It has a surprisingly high current rating. Nophead have some math on this on his blog.
I didn’t use a custom board and don’t see the need if you are building a production machine. For experimentation and changing hotends a lot it is a bit troublesome if you solder the motor leads directly at the extruder. I did use a connector for the heatet and thermistor.
For the ramps side of things I bundle up a lot of cables and crimp them with a ferrule and a proper tool.
If you want some pictures I can shoot a few?
@DongWon_Han_DWONH You can use ribbon cable if you allow enough cores for the current requirement. Typical 0.05inch pitch ribbon cable can handle 1A per core. The quality of crimped IDC connections is also a factor. Give yourself adequate redundancy in the number of cores used for each power and return and you will be OK.
Your last bot you posted was an H-bot, so motion wasn’t an issue. However, if your upcoming project uses ribbon cable and it has to move continuously, be very aware of the bend radius or you will have premature fatigue issues. If you are going to terminate the cables yourself, use a bench vice or the hand tool to crimp and be careful not to crimp the cable at an angle, or you’ll end up with shorts.
Mark, that looks great! What you’re using looks more like FFC (flat flex cable), and not ribbon cable (typically terminates in IDC), but I could be wrong. This brings up a good point, though – @DongWon_Han_DWONH which are you actually talking about?
@Mark_Rehorst It is really great engineering!
I bookmarked the page, and will see more carefully. Thanks.
@Dave_M I don’t have preference over two.
But I guess FFC is somewhat small gauges?
You gave me a good point about bend radius. I’ll remember it.
If you don’t want to have screw terminals all over. (The Mendel uses a really dated and terrible board in my opinion) you may need to spin a board.
If u have a cable length of 2m ONEWAY at 12V and a 40W Heater at the hotend you need to use 5 single wires of the ribbon cable and 5 additional back to the board to get ±37,5W at the Heater. At 24 V this gets low to 2 cables to and 2 cables back from the hotend. I did the math already, cause I am to become a state certified electrical technician and worked on a similar project.
If you only want to use one single wire to the heater and back, you get roughly 15% voltagedrop over the wire and 28,9W at the heater. The missing 10Watts are heating your cable now 
not every printer is the same Imagine CoreXY with cable-management and electronics in the bottom and an overall dimension of 500x500x500
But for you, @Camerin_hahn here it is for 12V and 80cm oneway: at least 0,32mm^2 which is 4 wires to and 4 wires back.
You can calculate it for yourself, if you want to: https://lh3.googleusercontent.com/gNpozwXIHYamdR8nkLpxShk_lxnErQddvBL2Kys7YYfu2Ir4GvbplVGikKFWgyqHrB3D=s164
I believe it, 2 meters is way too far though.that is why i called it out.